vyEPA
United States
Environmental Protection
Agency
Policy, Planning,
And Evaluation
(PM-221)
EPA-230-05-89-058
June 1989
The Potential Effects
Of Global Climate Change
On The United States
Appendix H
Infrastructure
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THE POTENTIAL EFFECTS OF GLOBAL CLIMATE CHANGE
>x ON THE UNITED STATES:
APPENDIX H - INFRASTRUCTURE
Editors: Joel B. Smith and Dennis A. Tirpak
OFFICE OF POLICY, PLANNING AND EVALUATION
US. ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, DC 20460
, MAY 1989
Tut Priititd on Ricycltd Paper
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TABLE OF CONTENTS
APPENDIX H: INFRASTRUCTURE
PREFACE iii
THE POTENTIAL EFFECTS OF CLIMATE CHANGE ON REGIONAL AND NATIONAL
DEMANDS FOR ELECTRICITY 1-1
Kenneth P. Linder and Mark R. Inglis
IMPACT OF GLOBAL CLIMATE CHANGE ON URBAN INFRASTRUCTURE 2-1
J. Christopher Walker, Ted R. Miller, G. Thomas Kingsley,
and William A. Hyman
IMPACTS OF EXTREMES IN LAKE MICHIGAN LEVELS ALONG
ILLINOIS SHORELINE: LOW LEVELS 3-1
Stanley A. Changnon, Jr., Steven Leffler, and Robin Shealy
EFFECT OF CLIMATE CHANGE ON SHIPPING WITHIN LAKE SUPERIOR
AND LAKE ERIE 4-1
Virgil F. Keith, J. Carlos De Avila, and Richard M. Willis
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PREFACE
The ecological and economic implications of the greenhouse effect have been the subject of discussion within
the scientific community for the past three decades. In recent years, members of Congress have held hearings
on the greenhouse effect and have begun to examine its implications for public policy. This interest was
accentuated during a series of hearings held in June 1986 by the Subcommittee on Pollution of the Senate
Environment and Public Works Committee. Following the hearings, committee members sent a formal request
to the EPA Administrator, asking the Agency to undertake two studies on climate change due to the greenhouse
effect.
One of the studies we are requesting should examine the potential health and environmental
effects of climate change. This study should include, but not be limited to, the potential impacts
on agriculture, forests, wetlands, human health, rivers, lakes, and estuaries, as well as other
ecosystems and societal impacts. This study should be designed to include original analyses, to
identify and fill in where important research gaps exist, and to solicit the opinions of
knowledgeable people throughout the country through a process of public hearings and
meetings.
To meet this request, EPA produced the report entitled The Potential Effects of Global Climate Change on the
United States. For that report, EPA commissioned fifty-five studies by academic and government scientists on
the potential effects of global climate change. Each study was reviewed by at least two peer reviewers. The
Effects Report summarizes the results of all of those studies. The complete results of each study are contained
in Appendices A through J.
Appendix Subject
A Water Resources
B Sea Level Rise
C Agriculture
D Forests
E Aquatic Resources
F Air Quality
G Health
H Infrastructure
I Variability
J Policy
GOAL
The goal of the Effects Report was to try to give a sense of the possible direction of changes from a global
warming as well as a sense of the magnitude. Specifically, we examined the following issues:
o sensitivities of systems to changes in climate (since we cannot predict regional climate change, we
can only identify sensitivities to changes in climate factors)
o the range of effects under different warming scenarios
o regional differences among effects
o interactions among effects on a regional level
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o national effects
o uncertainties
o policy implications
o research needs
The four regions chosen for the studies were California, the Great Lakes, the Southeast, and the Great Plains.
Many studies focused on impacts in a single region, while others examined potential impacts on a national scale.
SCENARIOS USED FOR THE EFFECTS REPORT STUDIES
The Effects Report studies used several scenarios to examine the sensitivities of various systems to changes in
climate. The scenarios used are plausible sets of circumstances although none of them should be considered to
be predictions of regional climate change. The most common scenario used was the doubled CO2 scenario
(2XCO2), which examined the effects of climate under a doubling of atmospheric carbon dioxide concentrations.
This doubling is estimated to raise average global temperatures by 1-5 to 45°C by the latter half of the 21st
century. Transient scenarios, which estimate how climate may change over time in response to a steady increase
in greenhouse gases, were also used. In addition, analog scenarios of past warm periods, such as the 1930s, were
used.
The scenarios combined average monthly climate change estimates for regional grid boxes from General
Circulation Models (GCMs) with 1951-80 climate observations from sites in the respective grid boxes. GCMs
are dynamic models that simulate the physical processes of the atmosphere and oceans to estimate global climate
under different conditions, such as increasing concentrations of greenhouse gases (e.g., 2XCO2).
The scenarios and GCMs used in the studies have certain limitations. The scenarios used for the studies assume
that temporal and spatial variability do not change from current conditions. The first of two major limitations
related to the GCMs is their low spatial resolution. GCMs use rather large grid boxes where climate is averaged
for the whole grid box, while in fact climate may be quite variable within a grid box. The second limitation is
the simplified way that GCMs treat physical factors such as clouds, oceans, albedo, and land surface hydrology.
Because of these limitations, GCMs often disagree with each other on estimates of regional climate change (as
well as the magnitude of global changes) and should not be considered to be predictions.
To obtain a range of scenarios, EPA asked the researchers to use output from the following GCMs:
o Goddard Institute for Space Studies (GISS)
o Geophysical Fluid Dynamics Laboratory (GFDL)
o Oregon State University (OSU)
Figure 1 shows the temperature change from current climate to a climate with a doubling of CO2 levels, as
modeled by the three GCMs. The figure includes the GCM estimates for the four regions. Precipitation
changes are shown in Figure 2. Note the disagreement in the GCM estimates concerning the direction of
change of regional and seasonal precipitation and the agreement concerning increasing temperatures.
Two transient scenarios from the GISS model were also used, and the average decadal temperature changes
are shown in Figure 3.
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FIGURE 1. TEMPERATURE SCENARIOS
GCM Estimated Change in Temperature from 1xCO2 to 2xCO2
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Great Southeast Great California United
Lakes Plains States'
Great Southeast Great California United
Lakes Plains States*
Great Southeast Great California
Lakes
Plains
United
States*
GISS
GFDL
OSU
* Lower 48 States
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FIGURE 2. PRECIPITATION SCENARIOS
GCM Estimated Change in Precipitation from 1xCOa to 2xCO2
>
o
UJ
Great Southeast Great California United
Lakes Plains States'
WINTER
I
Great Southeast Great California United
Lakes Plains States*
1.0
0.8
0.6
0.4
0.2
0.0
-0.2
-0.4
-0.6
No
Change
SUMMER
Great Southeast Great California United
Lakes Plains States'
GISS
GFDL
OSU
* Lower 48 States
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1980s 1990s 2000* 2010s 2020s 2030s 2040s 2050s
TRANSIENT SCENARIO A
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TRANSIENT SCENARIO B
FIGURE 3.
GISS TRANSIENTS "A" AND "B" AVERAGE
TEMPERATURE CHANGE FOR LOWER 48 STATES
GRID POINTS.
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EPA specified that researchers were to use three doubled CO, scenarios, two transient scenarios, and an analog
scenario in their studies. Many researchers, however, did not nave sufficient time or resources to use all of the
scenarios. EPA asked the researchers to run the scenarios in the following order, going as far through the list
as time and resources allowed:
1. GISS doubled CO2
2. GFDL doubled CO2
3. GISS transient A
4. OSU doubled CO2
5. Analog (1930 to 1939)
6. GISS transient B
ABOUT THESE APPENDICES
The studies contained hi these appendices appear in the form that the researchers submitted them to EPA.
These reports do not necessarily reflect the official position of the U.S. Environmental Protection Agency.
Mention of trade names does not constitute an endorsement.
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THE POTENTIAL EFFECTS OF CLIMATE CHANGE ON
REGIONAL AND NATIONAL DEMANDS FOR ELECTRICITY
by
Kenneth P. Linder
Mark R. Inglis
ICF Incorporated
9300 Lee Highway
Fairfax, VA 22031
Contract No. 68-01-7033
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CONTENTS
FINDINGS 1-1
CHAPTER 1: INTRODUCTION 1-6
CHAPTER 2: METHODOLOGY 1-8
OVERVIEW OF ANALYTIC APPROACH 1-8
CLIMATE CHANGE SCENARIOS 1-10
WEATHER-SENSITIVITY OF DEMAND 1-13
UTILITY PLANNING MODEL 1-18
SUMMARY OF KEY UNCERTAJNTIES AND LIMITATIONS 1-23
CHAPTER 3: RESULTS 1-27
GREAT LAKES REGION 1-27
' SOUTHEAST REGION 1-29
SOUTHERN GREAT PLAINS 1-31
CALIFORNIA 1-33
UNITED STATES 1-33
CHAPTER 4: IMPLICATIONS OF RESULTS 1-37
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FINDINGS1
Global warming in response to increased atmospheric concentrations of "greenhouse gases" could affect
electric utilities through several different pathways. One of the most critical impact pathways is likely to be the
demand for electricity because of the importance of weather-sensitive demands in determining (1) the amount
of generating capacity a utility must build and maintain to meet its customers' demands reliably and (2) the most
efficient ways of utilizing the utility's resources. These determinations are important to the utility industry
because of its capital-intensivity and its long planning horizon; uncertainty in future demands associated with
potential changes in climate may pose substantial economic risks to the industry.
A study was conducted to estimate the potential impacts of greenhouse gas-induced temperature changes
on U.S. regional and national demands for electricity, and the implications of these changes in demands for utility
planning and operations. The study is an extension of an earlier analysis of two case study utility systems
performed by ICF Incorporated. In the current study, climate change impacts are estimated for aggregations
of utility systems in the Great Lakes, the Southeast, the Southern Great Plains, California, and the United States
as a whole. Impacts are measured in terms of changes in utility peak demands and annual energy requirements,
generating capacity requirements, electricity generation and fuel use, and capital and operating costs.
The steps in the analysis can be summarized as follows. First, two alternative climate change scenarios
were developed for 47 state and sub-state utility regions. The climate change scenarios are based upon the
results of two "transient experiments" developed by the Goddard Institute of Space Sciences (GISS) using a
general circulation model of the Earth's atmosphere. The experiments differ primarily in the assumed
atmospheric concentrations of greenhouse gases and the degree of volcanic activity. They are designated as
"GISS A" and "GISS B." For purposes of this analysis, only changes in monthly mean temperatures from GISS
A and GISS B were used to characterize future climate changes. Climate change scenarios were developed
using both GISS A and GISS B for 2010, and using only GISS A for 2055.
Second, the weather-sensitivities of demands for electricity were estimated based upon findings of the
case studies and analyses of historic temperature and demand data performed by individual utilities. Estimated
parameters relating changes in temperature to changes in peak demand and annual energy requirements were
developed from these sources. It was assumed that these relationships based upon analysis of historic data would
continue into the future and would be valid over the range of temperature changes estimated in the GISS
transient experiments (3.4-5.0 degrees C average annual increases in GISS A by the 2050s). Because of several
uncertainties associated with the estimation of the weather-sensitivity parameters, an alternative set of values also
was used in the analysis. The alternative increased the estimated weather-sensitivities by 50%.
Third, the results of these steps were combined to estimate changes in demands for electricity in 2010
and 2055 under the alternative climate change and weather-sensitivity assumptions. Estimated increases in peak
demand on a national basis ranged from 2 to 6% in 2010, with substantial variation around these results on a
regional basis. Changes in national annual energy requirements in 2010 were more modest, ranging from 1 to
2%. In 2055, peak demands nationally were estimated to increase by 13 - 20% and annual energy requirements
by 4 - 6%.
Then, these results and a set of utility planning assumptions were used as inputs to a model that
simulates utility resource planning and operations. The model was used to evaluate the implications of the
changes in demand induced by climate change for generating capacity requirements, generation and fuel use, and
electricity production costs. Climate change impacts were estimated by comparing (1) the planning model
'Although the information in this report has been funded wholly by the VS. Environmental Protection
Agency under Contract No. 68-01-7033, Work Assignment No. 225, it does not necessarily reflect the Agency's
views, and no official endorsement should be inferred from it.
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Linder
outputs assuming climate change occurs with (2) "base case" outputs assuming no climate change occurs. In
addition to uncertainty being represented by alternative climate change scenarios and alternative weather-
sensitivity parameter estimates, the rate of growth in base case electricity demands was varied, corresponding to
alternative GNP growth rate assumptions.
Some of the results of the analysis are summarized in Figure S-l and Figure S-2. Figure S-l presents
the estimated national impacts of change : electricity demand induced by long-term temperature change on
new generating capacity requirements (in gigawatts) and on electricity generation (in billions of kilowatt-hours).
In 2010, new capacity requirements induced by climate change increase by 9-19%, or about 25 to 55 GW. The
majority of the capacity increase is for peaking capacity as opposed to baseload capacity. This is a significant
finding, representing an average increase of up to 1 GW per state. The investment associated with these
capacity increases is several billion dollars (in constant 1986 $). By 2055, the change in new capacity
requirements increases in percentage terms and represents several hundred gigawatts. Under high GNP growth
and high weather-sensitivity assumptions, the estimated increase due to climate change is almost 400 GW.
Annual generation increases are not quite as large in percentage terms, but nonetheless account for
several hundred billion kilowatt-hours by 2055. Annual fuel and O&M costs associated with these increases in
generation are hundreds of millions of dollars in 2010 and billions of dollars by 2055.
Figure S-2 presents some of the regional results. The figure indicates new capacity requirements in 2055
under (higher growth) base case conditions and under the higher weather-sensitivity climate change assumptions.
The impacts range from an increase of about 20 GW in California to over 100 GW in the Southeast. As a
percentage of base case demand, the results are particularly significant for the Southeast and the Southern Great
Plains. In fact, the potential climate change impacts estimated for these two regions are similar in magnitude
to the range of base case demand growth uncertainty represented by the alternative GNP assumptions.
There are several important uncertainties and limitations to the analysis that should be kept in mind
when interpreting these results. Because of these uncertainties and limitations, the cases analyzed have been
referred to as "scenarios," and the results should not be considered as "projections" or "forecasts." Among the
key uncertainties and limitations are:
o A narrow focus on impact pathways, considering only the potential effects of temperature change on
changes in electricity demand. Greenhouse gas-induced changes in temperature and other climate
variables could affect many other aspects of utility planning and operations.
o Limited availability of climate change information (e.g., variations in temperature changes and
occurrence of extreme events) important for utility planning.
o Uncertainties associated with the development and characterization of climate change scenarios for
utility areas from global "grid square" data.
o Use of a single source of climate change information, although the use of the GISS transient experiment
results for 2010 and 2055 indicates relative sensitivities to small and large temperature changes.
o Uncertainties regarding the concept, methods, and assumptions in developing and applying the estimates
of parameters representing the weather-sensitivity of demand.
2 To provide some perspective, the generating capacity of a large nuclear or coal-fired baseload powerplant
typically ranges from 0.6 to 1.0 GW. Natural gas or oil-fired peaking plants are much smaller.
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2200
2000
New Capacity Requirements
1*00
1*00
1200
10OO
200
2010 2066 2066
Lower Higher
GNP QNP
Assumption Assumption
2010 2066 2066
Lower Higher
GNP GNP
Assumption Assumption
Additional Climate Change Impacts: Higher Sensitivity
Climate Change Impacts: Base Sensitivity
Base Case (No Climate Change)
Figure S-l. Potential impacts of climate change on electric utilities in the United States.
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Under
(2055)
M
«<
«•
i
a
(9
California Southern Southeast Great Lakes
Great Plains
Climate Change Impacts: Higher Sensitivity
Base Case (No Climate Change)
Figure S-2. Potential impacts of climate change on electric generation capacity requirements.
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Under
o Uncertainties regarding market, regulatory, technological, and other conditions that will be facing the
utility industry in the future independent of climate change.
The analysis was structured to develop reasonable estimates of potential temperature changes on
electricity demand, and to assess the implications of these changes in demand for utility planning and operations.
Recognizing the points made above, the impact estimates are uncertain and are sensitive to particular
assumptions that have been made. However, our findings indicate that utility planners and policy makers should
begin now to address more fully and to consider climate change as a factor — along with other uncertainties and
issues -- affecting their planning analyses and decisions. Specific implications of the findings include:
o Estimated regional impacts differ substantially. The largest changes are anticipated in the Southeast and
the Southwest, where air conditioning is a particularly important use of electricity.
o The regional analyses suggest that there may be important, new opportunities as a result of climate
change for future bulk power exchanges or capacity sales.
o To the extent that the majority of new capacity requirements induced by climate change is for peaking
capacity, this implies a new technological and market focus on these types of generating plants.
o A greater focus on short lead-time peaking capacity at the margin affords utilities more planning
flexibility to respond to short-term changes in climate or other uncertain conditions.
o Increased electricity demands could increase the difficulty of achieving energy conservation goals that
represent one policy option to contribute to atmospheric stabilization.
o Because of the nature and patterns of weather-sensitive demands, climate change could result in
different overall fuel mixes for electricity generation than would be expected under base case conditions.
o The impacts of uncertain climate conditions in the long-term potentially poses significant planning and
economic risks to the utility industry.
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CHAPTER 1
INTRODUCTION
This report examines the potential effects of greenhouse gas-induced climate change on regional and
national demands for electricity and the implications of these changes in demands for utility planning and
operations. Climate change could affect electric utilities through several pathways. These pathways include the
availability of electricity supply resources (e.g., availability of stream flow for hydropower generation; availability
of solar, wind, and other renewable generating resources) and conditions influencing facility and system design
(e.g., design of power plant cooling systems, siting of power plants and transmission corridors).
Electricity demands, however, are likely to be a critical impact pathway because of the importance of
weather-sensitive customer demands in determining (1) the amount of generating capacity a utility must build
and maintain and (2) its operating plans (e.g., fuel procurement, generating unit dispatch) to satisfy daily,
seasonal, and annual patterns of electric energy consumption. In addition, the industry is very capital-intensive
and has a long planning horizon; uncertainty in future demands associated with potential changes in climate
may pose substantial economic risks.
ICF Incorporated recently completed a detailed analysis of the potential impacts of temperature change
on case study utility systems over the period 1986 to 2015.3 The case studies were located in Florida and New
York. In this report, our analytic approach is extended and our findings from the case studies serve as inputs
to develop estimates of climate change impacts for selected geographic regions and for the VS. as a whole to
the year 2055. The geographic regions correspond to areas subject to other analyses contained in the U.S.
Environmental Protection Agency (EPA) report to Congress on climate change impacts, namely the Great Lakes,
the Southeastern US., the Southern Great Plains, and California.4 It should be emphasized that sufficient
resources were not available to study these regions in the same level of detail as the individual utility system case
studies. Therefore, the analyses and results reported here should be considered as preliminary.
Two alternate climate change scenarios were used in the development of the impact estimates. These
are "transient experiments" developed by the Goddard Institute of Space Sciences (GISS) for use in the EPA
report to Congress. They are designated as "GISS A" and "GISS B." In comparison with GISS A, the GISS B
experiment assumes lower atmospheric concentrations of greenhouse gases and more volcanic activity in the
future. These climate change scenarios were preferred to outputs representing equilibrium conditions (e.g.,
conditions associated with a doubling of the atmospheric concentration of carbon dioxide) from other general
circulation models (GCM*s), because the transient scenarios provide estimates of rates of climate change as well
as levels of change. For purposes of this analysis, only changes in monthly mean temperatures were used to
characterize future climate changes. More specifically, decadal average monthly temperatures were used to
estimate changes in electricity demands in the years 2010 and 2055. In turn, these changes in electricity demands
were used to estimate changes in utility generating capacity requirements, annual generation and fuel utilization,
and electricity production costs for the two future years.
3 "The Potential Impacts of Climate Change on Electric Utilities," published by the New York State Energy
Research and Development Authority (NYSERDA), Report 88-2, December 1988, and soon to be published by
the Electric Power Research Institute (EPRI). Study sponsors in addition to NYSERDA and EPRI were the
Edison Electric Institute and the US. Environmental Protection Agency.
4 As will be described in Chapter 2, the utility planning model used in this analysis requires the definition
of geographic regions in terms of aggregations of specific state sub-regions. Thus, the boundaries of the Great
Lakes, Southeast, Southern Great Plains, and Northern California contained in this report may not be identical
to regional definitions in other impact reports.
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Sensitivity analyses were conducted to estimate the utility impacts of uncertainties in other future
conditions which may interact with climate change to affect utility planning and operations. The sensitivity
analyses address uncertainties in future levels of GNP growth (and, therefore, growth in "base case" electricity
demand) and in the estimated response rate of customer electricity demands to given temperature changes.
The remainder of this report is organized as follows. Chapter 2 documents the methods used to
estimate the temperature-sensitivity of electricity demand and the impacts of these changes on utility plans and
operations. The chapter also describes the methods used to apply the GISS transient climate change scenarios
and the design of the sensitivity analyses. Chapter 3 reports the results of the analyses. Finally, Chapter 4
discusses the implications of the results.
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CHAPTER 2
METHODOLOGY
OVERVIEW OF ANALYTIC APPROACH
The analytic approach is summarized in Figure 1. The initial steps in the analysis are (Step 1) to use
the GISS climate change scenarios to develop alternative temperature change scenarios for state and sub-state
utility regions and (Step 2) to estimate the sensitivity of electricity demand to temperature changes in these
regions. This information is used to evaluate the potential implications of climate change for future electricity
demand.
The results of these steps are used with (Step 3) a set of utility planning assumptions as inputs to a
model which simulates utility capacity planning and operations. The model is used (Step 4) to evaluate the
implications of climate change for generating capacity requirements, generation and fuel utilization, electricity
production costs, and other utility planning factors. Climate change impacts are estimated (Step 5) by comparing
these planning model outputs with "base case" outputs (i.e., outputs assuming continuation of current climate
conditions).
Key assumptions also were varied to evaluate some of the uncertainties which will affect utility planning
in the future. In particular, the rate of growth in base case electricity demands was varied - corresponding to
alternative GNP growth rate assumptions — as was the estimated sensitivity of electricity demand to future
temperature changes. The alternative assumptions were input to the utility planning model to estimate the
sensitivity of the model outputs to the assumptions.
As noted in Chapter 1, the analytic approach basically is the same as that used in ICFs analysis of
potential climate change impacts on individual case study utility systems.5 In this study, the approach has been
extended to address state and sub-state areas as the unit of analysis. These areas represent aggregations of
individual utility systems determined by the utility data base and planning model employed. In all, the 48
contiguous states are divided into 47 utility areas. Resources did not permit a detailed, quantitative examinatiion
of weather-sensitivity of demand in each of the areas. Rather, a more qualitative approach was used based upon
comparisons of historical electricity demands and climatic conditions in the areas, the results of the case study
analyses, and weather-sensitivity studies conducted by several utilities.
Because of this limitation, the findings of the analysis should be considered as preliminary, and results
for any individual area or region are subject to more detailed analysis and refinement. Our judgment, however,
is that overall the analysis provides reasonable estimates of the direction and order of magnitude of possible
climate change impacts on the demand for electricity.
The remaining sections of this chapter describe the methods, data, and assumptions used in undertaking
each of the steps illustrated in Figure 1.
5 Time and resource limitations for the present study prevented us from addressing the weather-sensitivity
of supply - particularly the effects of climate change on stream flow as a source of hydropower - as was done
in the case study analysis of New York. The earlier study concluded that climate change may have significant
impacts on hydropower availability for some utility systems. One other difference is that the present study does
not examine the different economic consequences of utilities responding to climate change with short-term
coping strategies vs. including the anticipation of climate change in their long-term plans. The implicit
assumption here is that utilities are able to anticipate climate change correctly and include these changes in
determining their most economic planning strategies.
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Climate Change
Scenarios
Weather-Sensitivity
of Electricity
Demand
Utility Planning
Assumptions
Utility
Planning Model
— ^
Impacts on Utility
Investments.
Operations. Costs
Figure 1. Analytic approach.
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CLIMATE CHANGE SCENARIOS
The demand for electricity can be affected by many different climate parameters, including temperature,
humidity, and wind direction and speed. Seasonal and annual electricity sales are related to climate principally
through customer demands for weather-sensitive energy services such as space heating, air conditioning, water
heating, and - for some utilities — irrigation pumping. The demand for these services as a proportion of total
electricity demands varies substantially across regions and utility systems. Weather-sensitive electricity demand
can account for up to a quarter or more of a utility's total, annual energy requirements depending upon the mix
of electricity sales among various types of customers (residential, commercial, and industrial), customer
equipment stocks, electricity prices, and climate.
Further, annual and seasonal peak demands for electricity are highly correlated with the occurrence of
extreme temperatures and other conditions associated with events such as summer heat waves and winter storms.
The occurrence of these events and customer responses to them are particularly important to utility planners.
Because electricity cannot be stored efficiently and must be produced at the same tune that it is consumed, the
utility must plan to build and maintain enough generating capacity to meet its peak demands with a high degree
of reliability.
A trend toward increasing temperatures associated with global warming would tend to increase annual
energy requirements and generating capacity requirements for utilities with relatively high air conditioning,
irrigation pumping, and other summer seasonal loads. On the other hand, utilities with relatively high space
heating and other winter seasonal loads could see their annual energy and generating capacity requirements fall.
Some utilities have a fairly even distribution of summer and winter loads, and depending upon the seasonal
distribution of temperature changes and customer responses to these changes, the increases and decreases in
summer and winter energy requirements could be largely offsetting. For these latter utilities, however, the effects
of global warming on seasonal demands and (in particular) extreme events could result in significant impacts on
peak demands and generating capacity requirements, even though annual energy requirements would not be
affected substantially.
Our challenge in this study was to use available climate model outputs to develop climate change
scenarios appropriate from a utility planning and operating context for each of the 47 utility areas. Resource
limitations required that the scenario development method be simple and that the calculations be subject to
mechanization.
The first decision was to use the outputs of the GISS transient experiments as the source for the climate
change scenarios. This decision was made for two principal reasons. First, utilities plan for future years based
upon projections of demand growth and other conditions expected to occur in those future years. A utility's
obligation to serve requires that it plan for sufficient resources to be available to meet demands of its firm-
service customers; on the other hand, there are severe financial and rate penalties associated with building more
capacity than needed. The utility planning model used in this study simulates these trade-offs by "optimizing"
planning decisions (in an economic sense). However, operation of the utility planning model and estimation of
climate change impacts using the model required that utility base cases and climate change-modified cases be
developed for specific years. The GISS transient experiments - as opposed to GCM results characterizing
equilibrium conditions (e.g., at 2xCO2) at some unspecified future time — provide this kind of climate change
data and are ideal for our purposes.
The second reason is that outputs from earlier GISS transient experiments were used successfully in the
individual case study analyses, and thus, these types of experiments have proven to be a useful source of climate
change information. Temperature change estimates are reported directly (i.e., measured in degrees rather than
as ratios or as estimating relationships) by GISS, and very little additional processing of the data was required
to develop inputs for the analysis.
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Utility impacts were estimated for two future years ~ 2010 and 2055. The first of these years was
selected because it is within the current 20-30 year horizon typical of many utility long-term planning analyses.
The second year was selected because temperature changes induced by greenhouse gas emissions are expected
to follow an increasing trend over time, and a more distant future year would provide estimates of utility impacts
under larger temperature changes. The GISS transient experiment results for 2055 approach the magnitude of
temperature change impacts that could be expected from a doubling of atmospheric concentrations of CO2-
In addition, a practical reason for selecting 2055 is that it represents the modeling horizon for one of
the GISS transient experiments. GISS B runs to 2029, but GISS A was extended to 2059. Results from the
experiments were provided by GISS for analysis as decadal averages of the monthly changes. Therefore, 2055
is the midpoint of the GISS A 2050-2059 decade, and the results of this experiment as provided by GISS could
be used directly.
Both GISS A and GISS B results were used in developing alternative temperature change scenarios for
the 2010 analyses. Decadal averages of monthly temperature changes for 2000-2009 and 2010-2019 from the Giss
A experiment were averaged to provide one set of temperature change data needed to develop utility impacts
for 2010. A second set was developed similarly by using decadal averages from the GISS B experiment.
The GISS transient experiment results were provided for geographic regions based upon global "grid
squares." Our next task, therefore, was to map the grid square results to the 47 individual utility areas
represented in the utility planning model. Figure 2 illustrates the utility areas with an overlay of the GISS grid
squares. As can be seen, some utility areas fail unambiguously within a single grid square, and the GISS results
for that grid square were used directly. Other utility areas cross boundary lines between grid squares.
For the latter areas, a simple algorithm was used to calculate future temperature change estimates from
the grid square data. Maps were consulted which indicated large population centers and, therefore, centers of
weather-sensitive electricity demand. If the population centers for a particular utility area were contained largely
within one grid square, the area was assigned to that grid square, and the temperature change estimates only for
that grid square were used. If the area's population centers were distributed roughly equally between two grid
squares, the temperature changes for the two grid squares were averaged Finally, if a large majority of the
population in an area was located in one grid square and a smaller (but substantial) amount in an adjacent grid
square, the temperature changes representative of the area were calculated as a weighted average with the grid
square weights assigned as two-thirds and one-third, respectively.
The final step in establishing the temperature change scenarios was to determine how the monthly
temperature change data would be used to estimate the key impacts on peak demand and energy requirements.
Project resources and available utility data and studies on the weather-sensitivity of demand were limited. As
a result, detailed weather-sensitivity analyses could not be conducted for each of the utility areas as was done
in the system-specific case study analyses. The next section describes how the results of those case study analyses
and the limited, available utility studies were used to develop ranges of estimated weather-sensitivity parameters
for peak demand and annual energy requirements. The peak demand weather-sensitivity parameter is
represented as the percent change in peak demand per degree C temperature change at the time of peak. The
annual energy weather-sensitivity parameter is represented as the percent change in annual energy requirements
per degree C average annual temperature change.
Therefore, to apply these parameters, estimates of average annual temperature changes and temperature
changes at the time of utility area peak demand are needed The average annual temperature change estimates
were calculated from the GISS decadal monthly averages as a simple average of the monthly values. Estimates
of temperature changes at the time of utility are a peak demand are more problematic. The discussion above
indicated that periods of utility peak demand typically are associated with abnormal or extreme weather
conditions. The GISS data do not provide information on the potential effects of global climate change on daily
weather patterns and extreme events. Climate change could either exacerbate or smooth the patterns.
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Pacific
Weil Soulh Cenlral
0 M IM MO 100
Demand region
Alaska (AK) not shown.
Figure 2. CEUM demand regions and GISS grid squares.
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Under
In the absence of additional information, our approach for estimating temperature changes at the time
of peak demand was to average three summer monthly temperature changes from the GISS data for summer-
peaking utilities, and three winter monthly temperature changes for winter-peaking utilities. The three monthly
temperatures were averaged to provide a sense of the seasonal temperature changes implied by the GISS
transient experiments. We did not select the largest monthly change, because the largest change is not
necessarily correlated with the highest temperature values or other non-temperature-related variables that may
contribute to a utility's peak.
Table 1 presents our estimates of the average annual change in temperature and the average change in
temperature during the season of utility area peak for 2010 and 2055. The average annual temperature changes
range from 0.9 to 15 degrees C in 2010 for the GISS A transient experiment and from 0.6 to 1.6 degrees C for
the GISS B transient experiment. The changes at time of peak are more variable, ranging from 0.6 to 1.8
degrees C in 2010 for GISS A and from -1.0 to 2.1 for GISS B. (Recall that the GISS B experiment assumes
lower atmospheric concentrations of greenhouse gases and more volcanic activity.) For 2055, the changes in
annual average temperature range from 3.4 to 5.0 degrees C, and the average temperature changes in the seasons
of utility peak range from 3.1 to 53 degrees C. Based upon our case study analyses where the temperature
change scenarios varied from approximately 0.5 to 1.0 degrees C (in 2015), we would expect that the potential
impacts on electricity demand of the temperature changes presented in Table 1 would be significant.
WEATHER-SENSITIVITY OF DEMAND
This section describes the development of estimates of the sensitivity of customer demands for electricity
to changes in temperatures. In our case study analyses, statistical as well as structural techniques and historical
data bases were used to relate changes in demands for electricity to changes in temperature. It was not feasible
to duplicate this approach for all of the utility systems in the United States, or even for a subset of
"representative" systems. Rather, we relied upon the results of the case study analyses and independent analyses
conducted by selected utility systems across the United States to develop a limited set of parameterized weather-
sensitivity values. These values differ as a function of utility service area and customer characteristics. Based
upon these characteristics, the 47 utility areas were classified according to the expected direction and magnitude
of customer responses to temperature changes, and the appropriate weather-sensitivity values were assigned.
Our approach for developing weather-sensitivity values employs several assumptions and simplifications.
This implies a wide range of uncertainty surrounding the estimates. Key uncertainties relate to:
o Concept. In our case study work in New York and Florida, equations which related hour-to-hour (or
tri-hourly) changes in load to hour-to-hour (or tri-hourly) changes in temperature were developed to
produce estimates of the weather-sensitivity of electricity demand. Application of this analytic approach
requires interpretation, since the approach assumes that utility customers will respond to changes in the
level of average temperatures over the long-term as they do to cope with short-term variations in
temperatures. The short-term measures variation in the utilization of weather-sensitive equipment due
(principally) to changes in behavior, whereas the long-term must also account for variation in the stock
(market saturation and energy-related characteristics) of weather-sensitive equipment.
o Methods. In addition to applying statistical techniques to historical demand and temperature data in
the New York case study, we also used a structural model which explicitly accounted for possible
increases in the market saturation of weather-sensitive equipment - air conditioning, in particular. Very
different results were obtained using the alternate methods, with the structural approach producing
higher estimates of weather-sensitivity. These differences have not been reconciled completely.
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TABLE 1
Climate Change Scenarios:
Average Annual Temperature Change and
Average Tenperature Change in Season of
Utility Area Peak
(degrees C)
2010 2055
GISS A GISS B GISS A
Utility Area Ann^ Peak Ann Peak Ann. Peak
Maine/Vermont/NH 1.07 0.85 0.99 1.09 4.43 4.44
Mass./Conn./RI 1.07 1.29 0.99 0.94 4.43 4.10
New York, Upstate 1.12 0.81 0.83 0.22 4.70 4.14
New York, Downstate 1.07 1.29 0.99 0.94 4.43 4.10
Pennsylvania 1.12 0.81 0.83 0.22 4.70 4.14
New Jersey 1.07 1.29 0.99 0.94 4.43 4.10
Maryland/Delaware/DC 1.14 1.08 0.91 0.33 4.54 4.34
Virginia . 1.15 1.35 0.99 0.44 4.38 4.53
West Virginia 1.14 1.08 0.91 0.33 4.54 4.34
N. & S. Carolina 1.15 1.35 0.99 0.44 4.38 4.53
Georgia 1.15 1.35 0.99 0.44 4.38 4.53
Florida 0.99 0.92 1.00 0.67 3.43 3.71
Ohio, North 1.12 0.81 0.83 0.22 4.70 4.14
Ohio, South 1.12 0.81 0.83 0.22 4.70 4.14
Michigan 1.05 0.76 0.81 0.19 4.57 3.80
Illinois 1.07 0.90 1.06 0.80 4.55 3.74
Indiana 0.90 0.65 0.78 0.14 4.30 3.12
Wisconsin 0.90 0.65 0.78 0.14 4.30 3.12
Kentucky, East 1.15 1.35 0.99 0.44 4.38 4.53
Kentucky, West 1.41 1.40 1.62 2.12 5.03 4.98
Tennessee, East 1.15 1.35 0.99 0.44 4.38 4.53
Tennessee, West 1.41 1.40 1.62 2.12 5.03 4.98
Alabama 1.41 1.40 1.62 2.12 5.03 4.98
Mississippi 1.41 1.40 1.62 2.12 5.03 4.98
Minnesota 1.12 0.96 0.89 0.42 4,39 3.14
N. & S. Dakota 1.25 1.05 0.86 0.77 4.19 3.44
Iowa 1.04 0.79 0.83 0.33 4.28 3.25
Missouri 1.24 1.15 1.34 1.46 4.79 4.36
Kansas/Nebraska 1.23 1.26 0.98 0.96 4.20 4.09
Arkansas 1.41 1.40 1.62 2.12 5.03 4.98
Oklahoma 1.14 1.45 1.02 1.22 4.18 4.69
Louisiana 1.09 1.41 1.01 1.48 3.78 4.33
Texas, East 1.14 1.45 1.02 1.22 4.18 4.69
Texas, South 1.21 1.85 0.62 0.94 3.93 • 4.56
Texas, West 1.16 1.59 0.89 1.13 4.10 4^65
Montana 1.35 1.30 1.03 1.38 4.29 4.19
Wyoming 1.48 1.04 1,09 1.24 4.48 3.76
Idaho 1.17 1.08 1.05 0.89 4.12 4.08
Colorado 1.40 1.25 1.08 0.84 4.35 4.19
New Mexico 1.10 0.59 0.66 -1.05 4.63 5.29
Utah 1.36 1.15 0.94 0.30 4.53 5.02
Arizona 1.10 0.59 0.66 -1.05 4.63 5.29
Nevada, North 1.21 0.71 1.07 0.56 4.06 3.48
Nevada, South 1.15 1.27 0.96 1.12 3.54 4.14
Washington/Oregon 1.18 . 1.11 1.02 1.19 3.92 3.40
California, North 1.17 1.09 0.99 0.89 3.71 3.83
California, South 1.15 1.27 0.96 1.12 3.54 4.14
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Under
o Assumptions. Other explicit or implicit assumptions underlying the estimates also are a source of
uncertainty. For example, the statistical approach assumes implicitly that the energy-efficiency of
weather-sensitive equipment is not changing or is changing at the same rate as in the recent past.
Is this a reasonable assumption, or will climate change induce a greater rate of technological change
in the future?
The utility studies we relied upon in developing our weather-sensitivity estimates for this analysis all were
statistical. While some of the uncertainties described above would tend to be offsetting, our judgment is that the
response of electric utility customers to greenhouse gas-induced temperature changes could be greater than the
estimates developed from these studies. That is, estimates of changes in electricity demand per degree change
in temperature have been used to develop linear weather-sensitivity relationships, but it is quite possible that
behavioral responses per degree temperature change will increase as temperatures increase. To address this
possibility, we have designed a sensitivity case (described below) which increases the estimated weather-sensitivity
parameters by 50%.
Table 2 indicates the utility systems which provided data or in-house studies relating the demand for
electricity to changes in temperature and other weather variables. In addition to being geographically dispersed,
the utility systems vary across a number of key characteristics such as season of peak demand (summer or
winter), mix of customers (by sector), market saturation of weather-sensitive equipment powered by electricity,
and annual requirements for weather-related energy services (e.g., heating and cooling). The utilities also
differed in terms of characteristics of the data and studies that were available. Differences included:
o Purposes and time periods of the studies,
o Analytic approaches and levels of sophistication,
o Focus on weather impacts on peak demands vs. seasonal or annual sales,
o Definitions of and data sources for weather variables,
o Functional forms and estimation techniques, and
o Levels of disaggregation (e.g., sectoral vs. system).
Despite these differences, the data and studies yielded estimates of temperature-sensitivity that were of
a similar order of magnitude, but with variations that could be explained based upon differences in utility
characteristics. For example, the estimates from the Florida utility indicated a greater sensitivity of summer peak
demand to a given temperature change than was the case for utilities in the North. Further, utilities with high
summer loads and service areas concentrated in urban areas showed a strong tendency for annual demands to
be positively correlated with temperature changes, while utilities with relatively larger winter loads and rural
populations indicated the potential for reductions in annual demands associated with temperature increases. For
most of the utilities, winter demands were significantly less sensitive to temperature changes than summer
demands, indicating the relatively lower market saturations and utilization of electric heating equipment as
compared with air conditioning equipment.6
6 The exception was the Bonneville Power Administration which markets power to utilities in the Pacific
Northwest. This region is characterized by a high market saturation of electric heat and low summer cooling
f*A/111 WAV** A«**M
requirements.
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Linder
Table 2. Sources of Weather-Sensitivity of Demand Data and Studies
Case Study Utilities
• Upstate New York
New York Power Authority - Upper New York
New York State Electric and Gas
Niagara Mohawk Power Company
Rochester Electric and Gas
Downstate New York
Central Hudson Gas and Electric
Consolidated Edison
Long Island Lighting
New York Power Authority -- Southeastern New York
Orange and Rockland
A Major Utility in Florida
Other Utilities
• Bonneville Power Administration (Pacific Northwest)
• Boston Edison
• Philadelphia Electric Company
• Southern California Edison
• Tennessee Valley Authority
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Under
The studies indicated a range of peak demand sensitivity on the order of 1% to over 6% change in utility
system peak demand per degree C. The percent change in annual energy demands for utilities with high summer
loads ranged from about 03 to 3% per degree C, while comparable values for utilities with high winter loads
were a decline of 0.25 to more than 0.50% in annual energy demands per degree C increase in temperature.
Based upon these findings, we established parameterized values for "low, medium, and high" temperature-
sensitivity for assignment to each of the 47 individual utility areas. The values are as follows:
Peak Demand Sensitivity
(% change in system peak demand per *C)
Low Medium High
Summer-peaking areas 1.35 2.70 5.40
Winter-peaking areas -1.35
Annual Demand Sensitivity
(% change in system annual demand per °C)
Low Medium High
High summer load areas 0.45 1.35 2.70
High winter load areas -0.27 -0.54
Note that the range of sensitivities for winter-peaking utility areas and high winter load areas is limited.
This is because of the relatively small number of areas which fall into these categories and the similarity of area
characteristics. These areas are concentrated in the Northeast, Mountain States, and Northwest.
The next step was to assign a weather-sensitivity value to each utility area Information was gathered
describing a number of factors which would be correlated with the likely direction and order of magnitude of
an area's response to changes in temperature. These factors included:
o Average electricity use (in kwh) per residential customer. This is a surrogate for holdings and utilization
of weather-sensitive electric appliances and equipment
o Electricity sales to industrial customers as a percent of total sales. Weather-sensitivity is inversely related
to this factor because of the relatively low proportion of electricity use in the industrial sector attributed
to space conditioning and other weather-sensitive end-uses.
o Estimated annual load factor. Load factor relates peak demand to total electric generation; a low load
factor is associated with a relatively high peak demand and high peak weather-sensitivity.
o Summer-winter peak demand ratio. This ratio indicates the extent to which a utility's peak and seasonal
demands tend to be concentrated in a particular season or are distributed more evenly across the
seasons.
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Under
o Heating degree days and cooling degree days. These temperature data also provide information on the
likely seasonal distribution of electricity demands and the relative utilization of weather-sensitive
equipment.
Judgmental consideration of each of these factors led to the classification of each utility area in terms
of (1) the direction of change in peak demand and annual energy requirements associated with a given change
in temperatures and (2) whether the magnitude of change in demand would likely be low, medium, or high. The
results of this process are indicated in Table 3. While not precise for any individual area, our assessment is that
the process yielded relative results that are reasonable across all areas.
Note that for several areas the direction and/or magnitude of the peak sensitivity value differs from that
for annual energy. These cases all are explainable. For example, the entries for Upstate New York indicate a
direct relationship between temperature change and peak demand, but an inverse relationship between
temperature change and annual energy. For this area (confirmed by our case study analysis), summer peak is
more sensitive than winter peak to temperature change, yet the predominance of seasonal heating loads as
compared with seasonal cooling loads leads to annual energy falling by a small amount for every degree increase
in average annual temperature.
The estimates of changes in peak demand and annual energy demand induced by climate change are
calculated by multiplying the peak season and average annual temperature changes for each utility area (from
Table 1) by that area's estimated temperature-sensitivity of demand (from Table 3). The results of these
calculations — as percent changes — are presented in Table 4. As discussed earlier, there are a number of factors
(e.g., technological change, changes in behavioral response) which could change the linear relationships implied
by our calculations. Based upon our current state of knowledge and understanding, however, these relationships
are considered to be reasonable.
Note from Table 4 that in all areas the absolute value of the change in peak demand is greater than the
absolute value of the change in annual energy. This result was expected given the nature of seasonal, weather-
sensitive energy services. The table indicates increases in peak demand of 10% or more in some areas in 2010,
and 25% or more in 2055. Annual energy changes are more modest, ranging up to about 4% in 2010 and 13%
in 2055. These are very substantial changes and, as described in the next chapter, lead to significant impacts on
utility planning factors.
UTILITY PLANNING MODEL
Given (1) characteristics of current generating capacity and operating costs as well as (2) performance
and cost characteristics of future investment options and operating strategies, a principal objective of utility
planning is to meet future generation requirements (Le., the demand for electricity) at minimum cost. Generally,
utilities prepare plans to meet this objective assuming future climatic conditions are the same as or similar to
those that have occurred in the recent past. That is, utility plans assume continuation of "typical weather
conditions," and do not explicitly consider the possibility of climate change.7 Because our focus is on estimating
how climate change may affect key utility planning factors, planning scenarios assuming no change in climate can
serve as a basis for comparison with planning scenarios under alternative assumptions of climate change.
7 Exceptions are utilities for which hydropower is an important source of generation. These utilities often
conduct extensive analyses of the potential effects of changes in rainfall or run off on the availability of
hydropower. However, these analyses typically consider variability around the existing means of these weather
variables, and not long-term changes in the means.
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TABLE 3
Temperature-Sensitivity Values by Utility Area
(% change per degree C) Under
Utility Area Peak Demand Annual Energy
Maine/Vermont/NH -1.35 -0.27
Mass./Conn./RI 1.35 -0.54
New York, Upstate 1.35 -0.27
New York, Downstate 2.70 0.45
Pennsylvania 1.35 0.45
New Jersey 2.70 0.45
Maryland/Dela'.-are/DC 2.70 1.35
Virginia 5.40 1.35
West Virginia 1.35 0.45
N. & S. Carolina 5.40 1.35
Georgia 5.40 1.35
Florida 5.40 2.70
Ohio, North 1.35 -0.27
Ohio, South 2.70 0.45
Michigan 1.35 -0.27
Illinois 2.70 0.45
Indiana 1.35 0.45
Wisconsin 1.35 -0.54
Kentucky, East 2.70 1.35
Kentucky, West 2.70 1.35
Tennessee, East 2.70 1.35
Tennessee, West 2.70 1.35
Alabama 2.70 1.35
Mississippi 5.40 2.70
Minnesota 1.35 -0.27
N. & S. Dakota 1.35 -0.54
Iowa 2.70 0.45
Missouri 5.40 1.35
Kansas/Nebraska 5.40 1.35
Arkansas 5.40 2.70
Oklahoma 5.40 2.70
Louisiana 5.40 2.70
Texas, East 5.40 2.70
Texas, South 5.40 2.70
Texas, West 5.40 2.70
Montana -1.35 -0.27
Wyoming -1.35 -0.27
Idaho 1.35 -0.27
Colorado 1.35 -0.27
New Mexico 2.70 0.45
Utah 1.35 0.45
Arizona 5.40 2.70
Nevada, North 1.35 -0.54
Nevada, South 5.40 2.70
Washington/Oregon -1.35 -0.54
California, North 1.35 0.45
'California, South 2.70 1.35
Weighted Average 3.07 1.00
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TABLE 4
Linder
Estimated Change In Peak Demand and
Annual Energy Requirements Induced by Climate Change (%)
2010 2055
GISS A GISS B GISS A
Utility Area Aim. Peak Ann. Peak Ann. Peak
Maine/Vermont/NH -0.288 -1.144 -0.267 -1.473 -1.196 -5.996
Mass./Conn./RI -0.576 1.737 -0.534 1.273 -2.391 5.538
New York, Upstate -0.302 1.097 -0.224 0.298 -1.270 5.588
New York, Downstate 0.480 3.474 0.445 2.547 1.993 11.076
Pennsylvania 0.504 1.097 0.373 0.298 2.117 5.588
New Jersey 0.480 3.474 0.445 2.547 1.993 11.076
Maryland/Delaware/DC .534 2.924 1.231 0.893 6.131 11.707
Virginia 1.557 7.310 1.342 2.382 5.911 24.476
West Virginia 0.511 1.462 0.410 0.447 2.044 5.853
N. & S. Carolina 1.557 7.310 1.342 2.382 5.911 24.476
Georgia 1.557 7.310 1.342 2.382 5.911 24.476
Florida 2.685 4.942 2.711 3.619 9.259 20.043
Ohio, North -0.302 1.097 -0.224 0.298 -1.270 5.588
Ohio, South 0.504 2.193 0.373 0.596 2.117 11.175
Michigan -0.283 1.025 -0.220 0.263 -1.234 5.131
Illinois 0.482 2.438 0.477 2.165 2.045 10.109
Indiana 0.407 0.883 0.352 0.194 1.937 4.218
Wisconsin -0.488 0.883 -0.423 0.194 -2.324 4.218
Kentucky, East 1.557 3.655 1.342 1.191 5.911 12.238
Kentucky, West 1.899 3.783 2.181 5.722 6.789 13.455
Tennessee, East 1.557 3.655 1.342 1.191 5.911 12.238
Tennessee, West 1.899 3.783 2.181 5.722 6.789 13.455
Alabama 1.899 3.783 2.181 5.722 6.789 13.455
Mississippi 3.799 7.567 4.362 11.444 13.579 26.910
Minnesota -0.301 1.296 -0.241 0.573 -1.177 4.233
N. & S. Dakota -0.675 1.417 -0.464 1.038 -2.264 4.647
Iowa 0.468 2.131 0.374 0.892 1.924 8.765
Missouri 1.673 6.222 1.806 7.888 6.463 23.564
Kansas/Nebraska 1.654 6.789 1.319 5.196 5.674 22.087
Arkansas 3.799 7.567 4.362 11.444 13.579 26.910
Oklahoma 3.074 7.852 2.766 6.590 11.295 25.325
Louisiana 2.940 7.628 2.736 7.986 10.195 23.387
Texas, East 3.074 7.852 2.766 6.590 11.295 25.325
Texas, South 3.259 9.976 1.682 5.091 10.617 24.634
Texas, West 3.136 8.560 2.405 6.091 11.069 25.095
Montana -0.363 -1.756 -0.279 -1.869 -1.158 -5.650
Wyoming -0.400 -1.398 -0.293 -1.670 -1.208 -5.082
Idaho -0.316 1.458 -0.282 1.201 -1.112 5.512
Colorado -0.377 1.683 -0.272 1.130 -1.174 5.659
New Mexico 0.496 1.604 0.298 -2.838 2.083 14.270
Utah 0.610 1.557 0.425 0.400 2.037 6.782
Arizona 2.977 3.207 1.788 -5.676 12.495 28.540
Nevada, North -0.651 0.954 -0.576 0.755 -2.190 4.693
Nevada, South 3.095 6.880 2.581 6.025 9.554 22.362
Washington/Oregon -0.637 -1.492 -0.552 -1.607 -2.117 -4.585
California, North 0.525 1.473 0.447 1.197 1.670 5.168
California, South 1.548 3.440 1.291 3.012 4.777 11.181
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Linder
The first step in implementing this approach is to characterize the base case (i.e., no climate change)
planning scenarios. For 2010, we have used an existing base case developed by ICF for use in acid rain analyses
conducted for EPA. This base case was developed using ICFs Coal and Electric Utilities Model (CEUM). The
CEUM is a large scale linear programming model which - among its many capabilities — can determine a
minimum cost investment and operating strategy to meet future electric demands subject to important utility
operating and reliability constraints. The 47 utility areas described above are the analytic elements of the model.
Generating capacity and electricity generation must be sufficient to satisfy demand in each area; economic
transmission of power between areas is permitted up to existing or planned transmission capacities. Outputs of
the CEUM include capacity expansion schedules, fuel use by type, and capital and operating costs for each area
For this analysis, the area outputs are aggregated to provide results for the Great Lakes, Southeast, Southern
Great Plains, and California regions and for the U.S. as a whole.
The 2010 base case is characterized by:
o Increasing prices for oil and natural gas (used primarily to generate electricity during peak periods)
relative to prices for coal (used primarily for baseload generation).
o Moderate growth in electricity demand (about 2,1% per year from 1986 to 2010).
o Assumed life-extension to 60 years for coal and oil/gas steam plants, implying that few existing plants
are retired by 2010.
o Shorter assumed lifetimes for nuclear plants (35 years) and no new capacity additions, resulting in a
lower market share for nuclear generation than at present.
o No changes in regulation beyond current requirements; e.g., the base case assumes no federal acid rain
legislation.8
A base case planning scenario also needed to be developed for 2055. Given the substantial uncertainties
in demand growth, technological change, energy policies and regulation, and so forth, any view of the
characteristics of the electric utility industry in that year or the pattern of investments undertaken by the industry
from the present to 2055 is purely speculative. However, for purposes of this analysis, a base case planning
scenario was developed using the CEUM and a number of assumptions regarding future utility market
conditions. Key assumptions are:
o Two alternative electricity growth rates were assumed, and therefore, two base case scenarios were
developed for 2055. The use of two demand growth assumptions recognizes the importance of this
variable in determining overall utility capacity requirements. Further, the alternative rates reflect an
important sensitivity case, since climate change effects could be substantially different under the two
growth assumptions. The average annual growth rates between 2010 and 2055 are assumed to be 1.1%
O
This is not a-critical assumption for our analysis. Proposed acid rain legislation principally would affect
the operating and production cost characteristics of existing generating capacity. Our focus, on the other hand,
is on long-term changes in the requirements for new generating capacity induced by changes in customer
demands for electricity; Le., increments to the base case.
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Under
and 1.9% in the "lower growth" and "higher growth" scenarios, respectively. These electricity growth rates are
consistent with the range of alternative GNP growth rates being used by EPA to develop energy use scenarios
in its report to Congress on atmospheric stabilization.
o World oil prices are assumed to grow in real terms at 1.5% per year from 2010. Real natural gas prices
also are assumed to grow at L5% per year from 2010, and the growth rate in real coal prices is
forecasted by the CEUM to range from 0.5 to 2.0% per year.
o For modeling purposes only, we have assumed that there will be no nuclear generating capacity on line
in 2055 (i.e., existing capacity will have been retired, and no new nuclear capacity will be built). This is
not a critical assumption; in any case nuclear capacity would be assumed to be "baseloaded," or
inframarginal, and fossil-fired capacity (coal, oil, or natural gas) would be on the margin and subject to
changes in generating capacity requirements induced by climate change. All existing (built by 1985 or
earlier) coal, new coal built by 1995, and existing oil/gas steam plants also are assumed to be retired by
2055.
o Two generic types of capacity are assumed to be available to meet incremental demands associated with
customer responses to climate change: coal-fired generating units to meet base and intermediate
requirements and oil-/gas-fired generating units to meet peaking requirements.10 Capacity costs per
kilowatt are assumed to stay constant in real terms at 2010 levels. The capital costs are approximately
$1300-1,600AW for coal-fired baseload capacity and $400-500/kW for oil/gas-fired peaking capacity.
o Imports of electricity from Canada and Mexico are maintained at their 2010 levels; however, power from
cogeneration, renewables, and other sources is assumed to increase only to the extent that their market
shares for these sources in 2055 are the same as the market shares assumed in 2010.
9 Recent trends indicate that electricity growth rates are about 90% of GNP growth rates, although the ratio
varies year to year. This relationship could change in the future, but is assumed to be stable in our analyses.
One factor that could change the relationship is technological change leading to improvements in energy
conversion efficiencies. This would tend to lower electricity growth rates relative to GNP growth rates. The
electricity growth rates reported in the text are based upon alternate real GNP growth rate assumptions of:
o 2.25% per year from 2010 to 2025 and 10% per year from 2026 to 2055, and
o 1.75% per year from 2010 to 2025 and 1.0% per year from 2026 to 2055.
10 We recognize that new, innovative technologies will characterize power markets in the future. However,
our analysis is focused on distinctions between requirements for peaking capacity vs. baseload capacity in a
generic sense, and not on choosing among specific technologies. Substantial uncertainties regarding the cost and
performance characteristics of technologies are emerging. Distinctions in our analysis would depend only on
current assumptions, and would imply more certainty regarding the eventual development and commercialization
of new technologies than is warranted
11 These costs vary somewhat by region of the country to account for differences in labor costs,
environmental regulations, fuel characteristics, and other regional factors. Capital costs include the generating
equipment, pollution control equipment, and transmission Tiook up" charges.
1-22
-------
Linder
A critical input to the operation of the CEUM -- and for estimating the potential impacts of climate
change on utilities - is the demand for electricity, or generation requirements. The level and patterns of these
requirements are important for determining (1) the amount of capacity and the types of capacity that constitute
a utility area's optimal (i.e., least cost) investment plan as well as (2) the dispatch of this capacity to meet
hour-to-hour customer demands.12 A device for summarizing the characteristics of generation requirements over
a period of time is a load duration curve (LDC). An LDC is an ordering of hourly generation values from
highest (peak) demand to lowest demand over a period of time (month, season, or year). An example of an
LDC is presented in Figure 3. LDCs often are used to represent customer demands and generation
requirements in planning optimization or simulation models.
In this study, a single LDC is used to represent annual generation requirements for each utility area
The shape (though not the amplitude) of the base case LDCs for 2055 are assumed to be the same as in the
2010 base case. Changes in peak demand and annual energy demand induced by climate change — from Table
4 -cause the LDCs to change shape in 2010 and 2055. These adjusted LDCs are input to the CEUM, and the
resulting output values for capacity, generation, and fuel utilization, costs, and other factors from the CEUM will
differ from the base case values. The differences in the values provide the estimates of climate change impacts.
SUMMARY OF KEY UNCERTAINTIES AND LIMITATIONS
As indicated in the above discussion, a number of key uncertainties and limitations affect the impact
analysis, and the results of the analysis are dependent upon several important assumptions. As a result, the cases
analyzed should be considered as "scenarios" as opposed to "projections" or "forecasts." Principal uncertainties
and limitations include:
o A narrow focus on impact pathways. The analysis addresses only the potential effects of temperature
change on the demand for electricity and the consequences of these changes in demand. While this is
a critical impact pathway, climate change potentially could affect utilities in several other ways.
o Limited availability of climate change information. In particular, electric utility planning and operations
depend critically on variation in weather conditions and the occurrence of extreme events. Available
climate change scenarios focus only on changes in average values.
o Uncertainties associated with the development and characterization of climate change scenarios for
individual utility areas from grid square data Included here is our focus only on temperature change
scenarios.
o Uncertainties regarding the concept, methods, and assumptions in developing and applying the estimates
of the temperature-sensitivity of peak demand and annual energy requirements. Of particular importance
here are (1) the "parameterization" of findings from our case study analyses and a set of diverse utility
weather-normalization studies; (2) "extrapolation" of the results broadly to the 47 individual utility areas;
and (3) the assumption that the estimated (linear) relationships between temperature change and
electricity demand will continue in the future across the range of postulated temperature changes in the
alternative scenarios.
12 Generation requirements differ from customer demands (or sales of electricity by the utility) principally
by the amount of losses incurred in transmitting and distributing electricity from the generator to the customer.
1-23
-------
Linder
Dtmaod
(MW)
Hours
Figure 3. Example load duration curve.
1-24
-------
Linder
o Uncertainties regarding market, regulatory, technological, and other conditions that will be facing the
utility industry in the future independent of climate change, i.e., characterization of the base case utility
investment and operating plans.
We have designed a few, select sensitivity cases to address some of these uncertainties and limitation*
As described in previous sections, the sensitivity cases include alternative climate change scenarios (GISS A and
GISS B in 2010) and alternative GNP/electricity demand growth scenarios. In addition, we have designed a
"higher sensitivity" case in which our estimates of the temperature-sensitivity of demand are increased by 50%.
Our discussion of temperature-sensitivity suggested that actual sensitivities would be more likely to be higher
than lower hi comparison with the estimates we developed. Figure 4 summarizes the nine alternative cases
reported from the CEUM outputs. Note that the higher temperature-sensitivity estimates are considered only
in two cases: in 2010 and in 2055, both assuming GISS A climate change.
1-25
-------
Figure 4
SUMMARY OF ALTERNATIVE CASES
2010
Base Case
GISSA
Climate Change
Higher
Temperature
Sensitivity
2055 Base:
Lower
Growth
GISSB
Climate Change
GISSA
Climate Change
2055 Base:
Higher
Growth
GISSA
Climate Change
Higher
Temperature
Sensitivity
-------
Under
CHAPTERS
RESULTS
The results of our analyses are sumarized in five tables. One table is presented for each of the following
regional aggregations of the CEUM utility areas:
o The Great Lakes (Upstate Ne » York, Pennsylvania, Ohio North, Ohio South, Michigan, Illinois, Indiana,
Wisconsin, and Minnesota),
o The Southeast (North and South Carolina, Georgia, Florida, Tennessee East, Tennessee West, Alabama,
and Mississippi),
o The Southern Great Plains (Kansas, Nebraska, Oklahoma, Northern (West) Texas),
o California, and
o The United States as a whole.
Each table presents results for the 2010 and 2055 lower growth and higher growth base cases and for the
alternative climate change cases. The tables contain esimates of peak demand and annual sales, new capacity
requirements (peaking, baseload, and purchased capacity), annual generation (oil/gas-fired, coal-fired, purchased
energy, and other), cumulative capital costs, and annual costs for fuel, O&M, capital, and purchases. The entries
for the base cases represent totals, while the entries for the climate change cases are increments from the
relevant base case. The increments are our estimates of the potential impacts of greenhouse gas-induced
temperature change on the demand for electricity and the implications of these demand changes for values of
select utility planning factors.
It should be noted that the values presented for new capacity requirements represent only the additional
peaking and baseload capacity or capacity purchases from other utility areas that is at the margin: utilities can
plan to build or purchase more or less of this capacity to accomodate projected changes in future demands for
electricity. Finn scheduled capacity presently in utility plans and assumed levels of hydro, geothermal and other
renewables, cogeneration, and other miscellaneous sources of power have been fixed in the model runs and do
not vary from case to case. The capital and other costs associated with these sources are included in the base
case cost figures. However, these costs do not vary across cases, and therefore, are not included in the
incremental costs shown for the climate change cases.
GREAT LAKES REGION
Table 5 presents the results for the Great Lakes region. The table indicates that under base case
conditions about 64 GW of new capacity — as defined above — would need to be added by 2010 and an
additional 300-430 GW between 2010 and 2055, depending upon the assumed growth rate in demand. (To put
these numbers in perspective, total generating capacity in the United States currently is on the order of 700 GW.)
In the climate change cases, new capacity requirements in the region are estimated to increase by 1.7 to 5.1 GW
by 2010, representing an increase of up to 8% as compared with the base case. A large proportion of the
increase is in peaking capacity; in fact, baseload capacity requirements are lower in all three of the alternate
climate change cases. This result reflects (1) the generally greater sensitivity of peak demand than seasonal or
annual energy demands to changes in temperatures and (2) our assumptions that changes in peak are positively
correlated with changes in temperature in all utility areas comprising the region, but that changes in annual
energy requirements are negatively correlated with changes in temperature hi half of these areas. (See Table 3.)
Thus, under assumed climate change conditions, the region's economically optimal generation mix includes
relatively more peaking capacity and relatively less baseload capacity.
1-27
-------
Under
TABLE 5
Sunary of Clinate Change Inpacts:
Great Lakes
2010
BASE
Peak Demand (GW) 189.1
New Capacity Reqts. (GW)1
• Peaking 17.9
• Baseload 46.1
• Purchases --
• Total 64.0
Annual Sales (bkWh)J 1009.4
Annual Generation (bkWh)2
• Oil/Gas 28.4
• Coal 768.8
• Purchases 73.0
• Other 214.9
• Total 1,085.1
Cumulative Capital Costs3
(millions of 1986 $) 158,419
Annual Costs
(millions of 1986 $)
• Fuel 15,493
• 06M 6,544
• Aimualized Capital315 , 943
• Purchases4 3.285
• Total 41,265
GISS A
2.8
4.9
-2.2
0.7
3.4
1.1
-1.7
-4.8
6.2
L5
1.2
309
-151
-4
53
279
^••BMM
177
GISS B
1.3
3.3
-3.1
_LI
1.7
1.0
0.7
-7.1
5.0
2^
1.1
-1309
-47
-50
-112
225
16
3
GISS A
Hi Sens
4.1
6.1
-1.0
o.o
5.1
1.7
-1.5
1.9
0.2
L2
1.8
2,370
6
47
261
9
2055:
Lower Growth
Inpacts
BASE GISS A.
331.0 21.9
26.4 29.2
287.2 6.4
-9.0 -12.2
304.6 23.4
1766.5 8.1
39.5 9.3
1,726.7 23.4
14.7 -20.9
118.1 zU
1,899.0 8.5
487,934 22,546
41,310 1,886
16,931 428
63,816 2,331
735 -1.045
2055:
Higher Growth
Impacts
BASE GISS A
435.0 28.8
43.1 37.9
394.7 6.6
-8.5 -12.6
429.3 31.9
2321.7 10.7
54.0 12.2
2,280.3 25.6
25.0 -21.0
136.5 -5.6
2,495.8 11.2
714,878 24,868
58,409 3,214
22,510 410
86,469 2,796
1.250 -1.050
323 |122,792 3,600 | 168, 638 5,370
GISS A
Hi Sens
43.4
52.5
6.7
-11.2
48.0
16.1
13.7
31.9
-22.7
-6.0
16.9
33,117
3,826
572
3,938
-1.135
7,201
1 Includes reserve margin requirements; does not include "firm scheduled" capacity. Base case
capacity purchases in 2010 set equal to zero.
2 Includes transmission and distribution losses.
3 Base case values include regional capital expenditures for utility-related equipment (e.g.,
transmission facilities) in addition to new generating capacity.
4 Valued at 45 mills/kwh in 2010 and 50 mills/kwh in 2055.
1-28
-------
Under
A somewhat curious result appears in reviewing the annual generation results for 2010. Even though
annual energy sales are increasing slightly in the region as a whole in the climate change cases (by about 1.0 to
1.7 bkWh), generation from oil/gas and/or coal-fired powerplants within the region falls in the climate change
cases. The reason is that the CEUM allows interregional bulk power sales to take place where economically
beneficial and subject to constraints on transmission capacities. The Great Lakes region is a net importer of
electricity. In the climate change cases, increasing temperatures in neighboring regions result in additional
capacity being built to meet increases in peak and annual energy demands. To the extent that this capacity is
not utilized fully in these regions, additional power is available for sale to utilities in states bordering the Great
Lakes. Based upon the relative economics of power production in neighboring regions, the CEUM model
outputs confirm that net power imports to the Great Lakes region do increase in the climate change cases,
resulting in somewhat less reliance on the region's own generating capacity. In the high sensitivity case, however,
this effect is very small; capacity is built to meet the more substantial increases in peak demands and annual
energy requirements.
Cumulative capital costs to 2010 reflect the changes in new capacity built within the region, and are
estimated as $03 billion in the GISS A case and $2.4 billion in the GISS A higher sensitivity case. Cumulative
capital costs are lower in the GISS B case than in the base case - by about $13 billion -- even though net new
capacity additions are slightly positive. The reduction in costs results from the change in capacity mix Re
that new baseload capacity is assumed to be on the order of $1300-1,600 per kW, while new peaking capa.
costs $400-500 per kW. In this case, the reduction in baseload requirements of 3.1 GW more than offsets the
cost of an increase in peaking requirements of 33 GW.
The changes in capacity and generation mix for 2010 are reflected in the annual costs for that year.
Climate change assumptions result in increases in annual costs of $16-323 million. While these values may seem
large, they represent less than 1% of the total annual costs in the 2010 base case. In addition, it is interesting
to note the important role of power purchases in determining the overall level and mix of annual costs among
cost categories. In the GISS A and GISS B cases, costs for power purchases more than offset reductions in
regional fuel, O&M, and capital costs. In the high sensitivity case, more generating requirements are met by
resources within the region, and costs for purchases are not much different than in the base case.
By 2055, the impacts are greater as would be expected. New capacity requirements are from 7 to 11%
higher in the climate change cases than in the base cases. There is still a predominance of requirements for
peaking capacity; in fact, in two of the climate change cases, peaking capacity additions more than double as
compared with the base case. Changes in baseload capacity requirements are a more modest 1 to 2%.
The increases in total generation requirements due to climate change are less than 1%. The increases
are being met with capacity located within the region. In fact, the change in generation mix in the region by 2055
(i.e., greater reliance on less costly regional coal-fired generation) results in an increase of 2% in generation from
regional resources and.the displacement of about 20 bkWh of net power imports in that year.
Cumulative capital costs from 2010 to 2055 are estimated to increase by $23-33 billion, and annual costs
for 2055 are estimated to increase by $4-7 billion. These represent cost increases of 3-4% compared with the
base case costs. While significant, the climate change-induced cost increases are substantially less than the
almost 40% differences in costs resulting from the alternative (lower and higher) base case demand growth
assumptions. We have not bounded the uncertainty in climate change or demand growth in our analysis;
however, the implication is that there are other uncertain conditions that may affect utility planning in the region
that are potentially as important or more important than climate change in the long term.
SOUTHEAST REGION
The results for the Southeast region are presented in Table 6. Generally, the base case new capacity
requirements and generation are lower than in the Great Lakes region, but the estimated climate change impacts
1-29
-------
TABLE 6
Under
Sunary of Cliaate Change Inpacts:
Soudieast
Peak Demand (GW)
New Capacity Reqts. (GW)1
• Peaking
• Baseload
• Purchases
• Total
Annual Sales (bkWh)2
Annual Generation (bkWh)2
• Oil/Gas
• Coal
• Purchases
• Other
• Total
Cumulative Capital Costs-*
(millions of 1986 $) 1!
Annual Costs
(millions of 1986 $)
• Fuel :
• 06M
• Annualized Capital313,688
• Purchases^
• Total
2010
BASE
149.9
15.0
53.5
--
68.5
714.5 '
50.1
588.7
-50.1
190.4
779.1
37,770
15,162
5,539
13,688
-2 254
^^StLA^BK**
32,135
GISS A
8.8 .
6.3
4.4
--
10.7
14.5
-1.9
21.4
-5.9
_
13.6
9,866
526
165
1,021
-266
^^••^BXiA
1,446
GISS B
5.7
1.4
5.4
QJ.
6.9
14.4
-1.6
21.8
-6.9
_
13.3
9,064
479
185
902
-310
^•••Sv&M
1,256
3
GISS A
Hi Sens
13.2
11.0
5.0
OJ,
16.1
21.8
-3.8
23.3
2.0
„
21.5
13,429
506
201
1,412
§0
2,209
2055:
Lowei
BASE
262.3
3.4
232.8
0.4
236.6
1250.3
16.0
1296.7
-30.2
76.8
1,359.3
349,896
33,350
12,334
47,965
-1.510
92,139
• Growth
Impacts
GISS A
54.4
20.4
37.7
-2.2
55.9
• 91.8
-12.2
131.0
-19.0
0.2
100.0
67,646
1,303
1,670
7,798
-950
9,821
2055:
Higher Growth
Imoacts
BASE
344.7
17.3
319.3
-1.8
334.8
1643.3
29.9
1697.9
-33.2
92.0
1,786.6
507,317
47,631
16,319
64,551
-1.660
126,841
GISS A
71.5
45.6
27.3
.3_,9
76.8
120.7
4.5
125.5
1.6
-0.1
131.5
68,032
4,578
1,440
8,073
§Q
14,171
GISS A
Hi Sens
107.1
77.8
33.5
3.9
115.2
181.1
17.2
178.2
2.3
-0.9
196.8
96,687
8,324
1,969
11,552
m
21,960
2
3
reserve margin requirements; does not include "firm scheduled" capacity. Base case
capacity purchases in 2010 set equal to zero.
Includes transmission and distribution losses.
Base case values include regional capital expenditures for utility-related equipment (e.g.,
transmission facilities) in addition to new generating capacity.
Valued at 45 mills/kwh in 2010 and 50 mills/kwh in 2055.
1-30
-------
Under
are substantially greater. The incremental amount of new capacity induced by climate change by 2010 ranges
from 10-16 GW, or 15-23% above base case requirements. In addition to overall lower capacity requirements,
the GISS B results indicate much lower additions of peaking capacity than in either of the GISS A cases in 2010.
This is because the temperature change scenarios show a much lower change in peak demand in the GISS B
scenario (5.7 GW) than in the GISS A scenarios (8.8-132 GW). The annual temperature change values are
more comparable in GISS A and GISS B for the areas in this region, however, and new baseload capacity and
annual generation requirements are more comparable across the cases.
Changes in inter-regional bulk power sales affect annual generation in the Southeast as they did in the
Great Lakes region, but in the opposite direction. The Southeast is a net exporter of electricity (indicated in
Table 6 by a negative number). In the GISS A and GISS B cases using the "base" estimates of temperature-
sensitivity of demand, the additional capacity built to meet regional reliability requirements is also used to
increase generation for sales outside of the region. In the higher sensitivity case, on the other hand, the
economics of bulk power sales to other regions also responding to climate change result in a reduction of net
exports by about 2 bkWh. The net effect is that the change in annual generation by sources within the region
is very similar across the three climate change cases, about 20 bkWh.
The change in cumulative capital costs to 2010 range from $9.1 to 13.4 billion in the climate change cases.
The increases are from 6 to almost 10% of the base case costs. The increase in annual costs are on the order
of 4 to 7%. These are very significant changes, implying substantial increases in capital requirements to build
new generating plants and additional annual costs of $13 to over 2.0 billion.
In 2055, the climate change impacts are much larger. New capacity requirements increase by 23-34%.
and annual generation increases by 75-11.0%. The impact on cumulative capital costs is an increase ci
97 billion, and annual costs increase by $10-22 billion for 2055.
In the Great Lakes region, we pointed out that the increases in costs induced by climate change were
substantially lower than the potential impacts of uncertainties in the base case growth in demand. In the
Southeast, however, the potential impacts of climate change are of the same magnitude as the impacts of the
assumed demand growth uncertainties. For example, the difference in annual costs between the 2055 lower
growth base case and the 2055 higher growth base case is about $35 billion. This can be compared with the
estimated annual cost increases induced by climate change of $10-22 billion.
SOUTHERN GREAT PLAINS
The results for the Southern Great Plains are summarized in Table 7. The impacts of climate change
in this region are more comparable — on a percentage basis - to our findings for the Southeast than for the
Great Lakes. For example, new capacity requirements by 2010 increase by 15-28% in the climate change cases
as compared with the 2010 base case. We also see a reduction in oil/gas generation, and a fairly substantial
increase in baseload coal generation (5-9%). Net imports of power from other regions are relatively small, as
are the impacts of climate change on net imports.
Cumulative capital costs induced by climate change increase by $3.7-6.7 billion during the period to 2010,
and annual costs increase by 3 to 6%. These represent fairly substantial changes.
In 2055, peak demand increases by 24-36% in the climate change cases, and there are comparable
increases in new capacity additions. As hi the other regions, new capacity requirements are relatively higher for
peaking capacity as compared with baseload capacity. Note that in the two higher growth cases, the region
changes from a net importer of purchased capacity to a net exporter of purchases capacity, although the absolute
values of total capacity purchases are small. Generation in the region increases by about 10-14% under the
climate change scenarios.
1-31
-------
Under
TABLE 7
Sunary of Cliaate Change Inpacts:
Soutiiern Great Plains
Peak Demand (GW)
New Capacity Reqts. (GW)1
• Peaking
• Baseload
• Purchases
• Total
Annual Sales (bkWh)
BASE
49.3
4.6
15.3
--
19.9
220.0
GISS A
3.9
1.1
2.2
-------
Linder
Cumulative capital costs in the region increase by $20-53 billion in the climate change cases, which can
be compared with the difference in cumulative capital costs between the lower growth and higher growth base
cases of $50 billion. Here, the climate change impacts nearly equal the load growth uncertainty reflected by the
alternative base cases. Similarly, the estimated changes in annual costs induced by climate change range from
$5-10 billion, nearly the same as the difference in base case estimates of $11 billion.
CALIFORNIA
The estimated temperature-sensitivities of demand and the climate change scenarios for California result
in an estimated increase in generating capacity requirements up to 3 GW in the state by 2010 as indicated in
Table 8. New baseload coal and peaking capacity additions in the base case are relatively small because of
significant amounts of geothermal, cogeneration, renewables, and other dispersed sources of power assumed to
come on line during the period. In the higher sensitivity case, annual generation is estimated to increase by
about 5.8 bkWh, cumulative capital costs by $4.5 billion, and annual costs by almost $300 million.
By 2055, the estimated'impacts are greater. New capacity requirements increase by 13-20%, and annua
generation increases by 3-5%. However, baseload (designated here as "coal") generation in the region increases
by 12-17% in the high-growth case, displacing significant amounts of power purchases. Siting of baseload coal
generating plants in California is problematic at present, and a more constrained analysis likely would result in
fewer additions of baseload capacity in the state, and greater continued reliance on generating resources outside
the state.
The change in cumulative capital costs ranges from $6.6 billion (7%) in the lower growth case to $23.0
billion (15%) in the higher growth, higher sensitivity case. Annual costs increase by 7-11%, reaching $4.7 billion
in the highest impact case for the year. As in the Great Lakes region, these increases tend to be smaller in
magnitude than the impacts of the assumed levels of load growth uncertainty in the base cases.
UNITED STATES
Table 9 presents the aggregated results for the United States. In 2010, climate change is estimated to
induce increases in new capacity requirements of 9-19% - up to 54 GW, or more than 1 GW per state on
average. As we found with the regional results, the majority of the increase is in peaking capacity to meet the
estimated increase in peak demands and maintain utility system service reliability. Increases in peaking capacity
range up to 65%, while increases in baseload capacity are less than 10%. Note that as an alternative to building
substantial amounts of peaking capacity, utilities may consider options — such as load management programs or
innovative rate designs like time-of-day rates - to shift customer usage patterns, thereby reducing peak load
impacts.
Although total generation increases from 43 to 73 bkWh, the CEUM results indicate an overall reduction
in oil-/gas-fired generation in 2010 in the climate change cases. The reason is that the new coal-fired baseload
capacity built to meet the additional energy demands induced by climate change is not fully utilized in this
pursuit This makes these plants available to generate additional electricity and displace more expensive oil/gas-
fired generation from existing baseload and intermediate plants. This result was one of the principal findings
of our earlier case studies, since both New York and Florida are states with substantial amounts of existing oil-
/gas-fired generating plants. By 2055, all the uneconomic oil-Xgas-fired baseload and intermediate generating
plants are retired; climate change leads to positive impacts on oil-/gas generation where necessary to meet peak
loads.
1-33
-------
TABLE 8
Under
Sunary of Cliaate Change L^ucts:
California
Peak Demand (GW)
New Capacity Reqts. (GW)1
• Peaking
• Baseload
• Purchases
• Total
Annual Sales (bkWh)
Annual Generation (bkWh)2
• Oil/Gas
• Coal
• Purchases
• Other
• Total
Cumulative Capital Costs3
(millions of 1986 $) :
Annual Costs
(millions of 1986 $)
• Roel
• 06M
• Aimualized Capital3 3,343
• Purchases4
• Total
2010
BASE
63.8
0.0
6.8
--
6.8
305.7
25.9
39.9
99.4
180.2
345.4
13,528
2,180
1,084
3,343
4.473
LI, 080
GISS A
1.7
0.0
1.7
0^
2.0
3.4
-5.1
9.8
-1.1
_£L2
3.8
2,978
-118
73
291
^Q
196
impacts
GISS B
1.4
0.0
1.4
l*fi
2.4
2.8
-4.1
7.7
-0.7
_0^1
3.2
2,382
-98
59
232
31
161
GISS A
Hi Sens
2.5
0.0
2.5
0*5
3.0
5.0
-7.5
14.6
-1.7
J^4
5.8
4,455
-172
110
434
Jl
295
2055:
Trnjer Growth
BASE
111.6
24.6
37.9
_*£
70.7
535.1
10.8
218.9
146.0
228.7
604.4
94,784
7,470
2,462
12,923
7.300
30,155
Impacts
GISS A
9.6
8.7
0.6
QJ.
10.0
18.3
1.2
11.6
7.1
0.8
20.7
6,630
545
139
1,029
—255
2,068
2055:
Hieher Growth
BASE
146.6
29.2
63.1
10.4
102.7
703.3
14.7
332.6
160.2
286.8
794.3
156,370
11,688
3,912
19,046
8.010
42,656
Tinna
GISS A
12.6
8.3
5.5
^1
13.5
24.0
1.4
40.0
-15.1
-I-fl
27.3
15,544
1,588
467
1,893
zZ5S
3,193
cfs
GISS A
Hi Sens
19.0
12.6
8.0
JL6
20.2
36.1
2.0
57.3
-19.0
_JLI
41.0
23,006
2,204
676
2,809
-950
4,739
1 Includes reserve mar-gin requirements; does not include "firm scheduled" capacity. Base case
capacity purchases in 2010 set equal to zero.
* . Includes transmission and distribution losses.
3 Base case values include regional capital expenditures for utility-related equipment (e.g.,
transmission facilities) in addition to new generating capacity.
4 Valued at 45 mills/kwh in 2010 and 50 mills/kwh in 2055.
1-34
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TABLE 9
SuBoary of Cliaate Chaise Impacts:
United States
Under
Peak Demand (GW)
New Capacity Reqts. (GW)
• Peaking
• Baseload
• Total
Annual Sales (bkWh)
BASE
774.0
1
50.4
225.7
276.1
3,846.8
Annual Generation (bkWh)2
• Oil/Gas 287.3
- Coal 2,797.5
• Purchases
• Other
• Total
..
1.092.0
4,176.8
Cumulative Capital Costs3
(millions of 1986 $) 668,740
Annual Costs
(millions of 1986 $)
- Fuel
• O&M
69,015
26.085
• Annualized Capital366 , 578
• Purchases^
• Total
161,678
GISS A
29.4
21.9
14.4
36.3
44.5
-18.4
68.0
_.
J-2
48.4
32,302
188
614
3,279
4,080
2010
Impacts
GISS B
19.7
12.9
11.4
24.3
39.4
-12.4
54.0
--
J-2
42.8
24,700
257
478
2,484
3,219
GISS A
Hi Sens
44.2
32.5
21.6
54.1
66.8
-29.4
102.8
--
-0.9
72.5
48,230 1
238
918
2055:
Lower
Growth
TmnactS
BASE
1,354.6
175.7
1,011.2
1,186.9
6,731.9
221.4
6,241.6
--
846.4
7,309.4
765,315
1172,218
1 60,793
4,900 |241,129
• «• | » *
6,056 474,140
GISS A
181.1
117.8
67.0
184.8
281.4
1.7
305.3
2055:
Higher Growth
BASE
1,780.3
253.7
1422.9
1,676.6
8,847.8
308.2
|8,295.4
- 1
-13
|1.003.1
305.4 |9,606.7
173,362 2,650,037
7,788 |244,143
3,992 | 81,853
21,279 |329,015
---
33,059 655,011
Imoai
GISS A
238.0
182.0
73.6
227.1
369.8
26.8
381.8
* "
401.4
221,913
16,839
4,689
26,597
~ ™
48,125
cts
GISS A
Hi Sens
356.9
285.8
98.2
384.0
c - •
51.2
559.8
— —
611.0
328,072
26,488
6,855
39,593
*
72,936
1 Includes reserve margin requirements; does not include "firm scheduled" capacity. Base s
capacity, purchases in 2010 set equal to zero.
2 Includes transmission and distribution losses. ,
3 Base case values include regional capital expenditures for utility-related equipment (e.g.,
transmission facilities) in addition to new generating capacity.
4 Valued at 45 mills/Mi in 2010 and 50 mills/kwh in 2055.
1-35
-------
Under
Climate change-induced cumulative capital cost increases range up to $48 billion by 2010. This is an
increase of about 7% compared with the base case. Annual costs increase by up to $6.0 billion, or 4%. Note
that the annual fuel costs in the GISS A and GISS A higher sensitivity cases are lower than in the GISS B case,
despite lower total generation in the latter case. This results from the greater displacement of oil/gas use in the
GISS A cases, and more reliance on less costly coal as a generating fuel.
By 2055, new capacity requirements induced by climate change increase by 14-23% over base case values,
or by 185-384 GW. Recall that total U.S. generating capacity currently is about 700 GW. Clearly, this is a
significant potential impact. A mitigating factor is that much of the increase is in short lead-time, lower capital
cost peaking capacity. Investment in this type of capacity can be deferred, pending resolution of uncertainties
related to potential changes in climate. The cumulative capital costs for total capacity additions ranges from
$173 to 328 billion, or up to 12% above the base case values.
Climate change is estimated to induce annual generation increases of about 5-7%, or 305-611 bkWh in
2055. The adequacy of coal reserves to support these levels of generation or, as an alternative, technological
change designed to increase the efficiency of energy resource conversion and utilization are issues requiring
further analysis.
The annual costs in 2055 for fuel, O&M expenses, and capital are estimated to increase by $33-73 billion.
These figures represent increases from base case values of 7-11%.
1-36
-------
Under
CHAPTER 4
IMPLICATIONS OF RESULTS
The results presented in the previous chapter indicate that temperature change potentially can have
significant impacts on peak demands, annual electricity sales, electric generating capacity requirements, annual
generation and fuel utilization, and i^sts. Based upon the climate change scenarios, estimated temperature-
sensitivities of demand, and other assumptions, significant impacts — involving billions of dollars for the United
States as a whole - may occur by 2010, well within utility long-term planning horizons of 20-30 years. The
potential impacts are substantially greater by 2055.
The results indicate that climate change impacts are uncertain — they could be higher or lower than we
have estimated -- and that their estimated orders of magnitude are sensitive to a number of assumptions made
in the analysis. Thus, additional research must be conducted to refine the data and methods to test the
robustness of the findings and to expand the analysis to include other impact pathways. However, as concluded
in our case study report, the results imply that utility planners and policy makers should begin now to asse
more fully and to consider climate change as a factor — along with other uncertainties and issues — affecting their
planning analyses and decisions.
More specific implications of the results include the following:
o Climate change can affect utilities with different characteristics differently. Impact analyses based upon
climate change scenarios covering broad geographic areas (e.g., grid squares) are not likely to capture
the unique types of responses from individual utilities or utility areas. Additional research should include
data and methods for developing climate change scenarios at the local level.
o A related point is that there clearly are regional differences in the direction and magnitude of the
impacts. The differences relate importantly to the utilities' customer mix, weather-sensitive equipment
holdings and utilization, general climatic conditions, and other utility area characteristics as well as tr
the estimated responses to the climate change scenarios. For example, the results point to substantu-
differences in estimated impacts between the Great Lakes and Southeast regions.
o The regional differences suggest that there may be important, new opportunities as a result of climate
change for bulk power exchanges or capacity sales. The results indicate changes in net imports or net
exports of power for individual regions across the various climate change cases. In addition, the mix of
additional new peaking and baseload capacity requirements in response to climate change differs by
region. Diversity in season or time of peak across regions may permit firm capacity sales or sales of
emergency power to meet these peaks more efficiently (i.e., investment in fewer plants nationally). To
these ends, utilities and regulators would need to give more attention on planning and construction of
transmission facilities to alleviate possible constraints on power exchanges.
o To the extent our result is confirmed that the majority of new capacity requirements in response to
temperature change is for peaking capacity, this implies a new technological and market focus on these
types of generating plants. Current technology R&D and market interest are concentrated more on
plants operating in baseload. Related to this would be increased R&D on electricity storage
technologies, which would allow electricity to be generated at off-peak times by lower cost, more efficient
generating plants for use during peak periods.
o Peaking capacity typically is less capital-intensive and has shorter lead times than baseload capacity. A
greater focus on peaking capacity at the margin affords utilities more planning flexibility to respond to
short-term changes in climate or other uncertain conditions.
1-37
-------
Under
Because increases in customer demands for electricity may be particularly concentrated in certain seasons
and at peak periods, conservation and (especially) load management programs that improve the efficiency
or change the patterns of customer uses of electricity could be more cost-effective when considered in
light of potential changes in climate. On the other hand, increased electricity demands could increase
the difficulty of achieving energy conservation goals that represent one policy option contributing to
atmospheric stabilization.
Because of the nature and patterns of weather-sensitive demands, climate change could result in different
overall fuel mixes than would be expected under base case conditions. This was seen, for example, in
the results for the Southeastern and southern Great Plains regions and for the United States as a whole
in 2010. Fuel needs to support fossil-fired generation (assumed to be on the margin) increased
substantially in most of the climate change cases in 2055. The implications are that climate change could
affect utility fuel planning as well as long-term energy resource policies and planning more generally.
The impacts of uncertain climate conditions in the long term potentially can pose significant planning and
economic risks to the utility industry. The magnitude of the risks estimated here for some regions (e.g.,
the Southeast and the southern Great Plains) are similar to other uncertainties utility planners and
decision-makers must face.
1-38
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IMPACT OF GLOBAL CLIMATE CHANGE ON URBAN INFRASTRUCTURE
by
J. Christopher Walker
Ted R. Miller
G. Thomas Kingsley
William A. Hyman
The Urban Institute
Washington, D.C 20037
Contract No. CR-814883-01-0
-------
CONTENTS
CHAPTER 1: INTRODUCTION AND GENERAL CONCLUSIONS 2-1
ANALOG CITIES WERE USED IN SOME ANALYSES 2-2
CHAPTER 2: IMPACTS IN MIAMI 2-3
SUMMARY 2-3
INTRODUCTION 2-6
FEW DEVELOPED MAINLAND AREAS WILL BE INUNDATED IF SEA LEVEL
RISES 3 TO 5 FEET 2-6
DADE COUNTY IS RECLAIMED FROM WATER 2-6
THE POROUS AQUIFER MEANS DIKING ALONE WILL NOT CONTROL SEA LEVEL
RISE 2-10
OCEANGATES WILL NEED UPGRADING 2-11
WATER SUPPLY WILL BE REDUCED UNLESS HURRICANES INCREASE 1-'
BUILDING FOUNDATIONS ARE ADEQUATE -
ONE-THIRD OF THE STREETS WILL NEED TO BE RAISED 2-^_
MANY CAUSEWAYS AND BRIDGES SHOULD BE RAISED AT RECONSTRUCTION 2-12
AIRPORTS WILL NEED BETTER DRAINAGE 2-13
EFFECTS ON SOLID WASTE DISPOSAL SHOULD BE MINIMAL 2-13
SANITARY WASTE SYSTEMS WILL REQUIRE ADJUSTMENTS, PRIMARILY TO CONNECTOR
PIPES 2-14
STORM SEWERS AND DRAINAGE TRENCHES WILL REQUIRE MAJOR UPGRADING 2-15
HURRICANES WILL INFLICT MORE SEVERE DAMAGE 2-15
CHAPTER 3: IMPACTS IN CLEVELAND 2-16
INTRODUCTION AND SUMMARY 2-16
CLEVELAND'S INFRASTRUCTURE CONDITIONS 2-17
IMPACTS ON ROADS AND BRIDGES WILL BE POSITIVE 2-P
ENERGY COSTS IN PUBLIC BUILDINGS PROBABLY WILL RISE 2-20
IMPACTS ON TRANSIT SHOULD NOT BE SIGNIFICANT 2-22
SNOW AND ICE CONTROL COSTS WILL DROP DRAMATICALLY 2-23
THE STORM/WASTEWATER COLLECTION SYSTEM SHOULD NOT BE ADVERSELY AFFECTED 2-24
A DROP IN THE WATER LEVEL OF LAKE ERIE SHOULD HAVE LITTLE IMPACT 2-24
CHAPTER 4: IMPACTS IN NEW YORK CITY 2-25
INTRODUCTION: WATER SUPPLY AND OCEANGATE NEEDS WILL BE THE
LARGEST 2-25
WATER SUPPLY SYSTEM CHARACTERISTICS 2-"
GENERAL EFFECTS OF CLIMATE CHANGE ON SYSTEM PERFORMANCE 2-29
POLICY RESPONSES TO CLIMATE EFFECTS 2-32
REFERENCES 2-35
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Walker
CHAPTER I1
INTRODUCTION AND GENERAL CONCLUSIONS
This report examines the likely impacts on urban infrastructure of global climate change due to an
effective doubling in atmospheric carbon dioxide. It provides case studies of probable impacts on three cities:
Cleveland in the Midwest, Miami in the Southeast, and New York City in the Northeast. A fourth case,
examining San Diego in the West, was planned, but subsequently was replaced by a cross-cutting impact analysis,
which is included in the main text of the EPA Report to Congress.
The study sites were selected jointly by EPA and The Urban Institute based on three criteria:
o A preference for cities/regions where EPA was focusing other effects studies,
o A desire for geographic spread, and
o The existence of Institute contacts and knowledge about area infrastructure conditions that would
facilitate study performance in the 3-month period required by EPA's overall study schedule.
A comprehensive examination of infrastructure impacts in three cities would not have been feasible given
the study budget and time frame. Recognizing that information about some sites already was being gathered by
other EPA contractors and that some impacts would be generic, specific infrastructure elements were picked as
primary emphases at each site.
In Cleveland, the Institute already had an inventory of infrastructure conditions and capital needs, which
made a comprehensive impact examination feasible. In Miami, the impacts on water distribution, solid waste
disposal, sewage treatment, and bridges were targeted for investigation. Three other EPA studies were
examining other infrastructure issues in Dade County: Weggel et aL (1989), levees and dikes; Leathennan
(1989), beach nourishment and other responses to sea level rise in Miami Beach; and Diamond (1988), water
supply. Because the impacts of sea level rise on different infrastructure elements proved to be intertwined, the
Miami case subsequently was expanded to cover impacts on streets, drainage, water supply, and oceangates (the
structures and strategies used to defend against a rising sea). The infrastructure in New York City is so vast that
the case study was largely confined to a single issue, the effects on water supply and demand. Weggel et al.
(1989) estimates the impact of sea level rise on the city's oceangates.
Findings by city are presented at the beginning of the individual chapters. Some of the general conclusions
that can be drawn from a look at climate effects across the three cities are:
o Climate change will create clear regional winners and losers. Miami and New York stand to incur
substantial capital costs; Cleveland, overall, will benefit from milder weather.
o The largest expenses are likely to address water supply and oceangate needs.
'Although the information in this report has been funded wholly or partly by the US. Environmental
Protection Agency under contract no. CR-814883-10-0, it does not necessarily reflect the Agency's views, and no
official endorsement should be inferred from it.
2-1
-------
Walker
o Some infrastructure areas do not warrant particular policy attention now. For example, Cleveland air-
conditioning costs will rise, but the effect will be gradual, and incremental design adjustments will be
an appropriate response.
o Institutional changes likely will result. Because of the need for regional water project financing and
resource management, both New York City and Miami will experience greater pressures for
intergovernmental cooperation.
o Some immediate policy responses are warranted, particularly in the area of infrastructure planning.
Supply and demand projections for New York's water supply, for example, should incorporate climate
effects given the long lead times in water project development.
The infrastructure cost implications of global climate change will be much larger if local infrastructure
systems experts fail to respond to incremental changes or if change comes through abrupt sawtooth shifts.
Tremendous cost savings can be achieved by responding to changes in temperature and sea level at appropriate
points in the infrastructure replacement cycle. To assure timely response, the federal government needs to
educate infrastructure engineers, planners, and managers about current and projected climate changes and about
probable sea level rise. These individuals, in turn, will have to educate State and local elected officials.
The National Flood Insurance Program (NFIP) and national organizations that develop infrastructure
standards and model building codes also must anticipate or respond to changes that occur. NFIP floodplain-
floodway maps and related local requirements for coastal communities must anticipate sea level rise by SO to 60
years to avoid huge, yet preventable future insurance losses in the NFIP program. Standards for coastal bridges
need to be adjusted slightly in recognition that water levels will rise between reconstruction cycles. And
pavement construction standards by climate bands, which require thicker and more costly roadway surfaces in
colder climes, must be updated periodically to achieve the savings in paving costs made possible by rising winter
temperatures.
ANALOG CITIES WERE USED IN SOME ANALYSES
Some parts of the analysis are based on infrastructure cost experience in cities with current climates similar
to the anticipated future climates in New York City and Cleveland. The analog cities were identified in
Kalkstein (Volume G), based on a correlation analysis of present temperatures in 48 cities with projected
temperatures in the cities of interest after a 7°F temperature rise. The summer analog for New York City is
Louisville, Kentucky, which coincidentally is also the summer analog for Cleveland. Cleveland's winter analog
is Nashville, Tennessee, while New York's is Portland, Oregon. Each case study includes estimated changes in
heating and cooling degree days. These were computed as variations in average daily temperatures above and
below 6S°F, a definition that is consistent with National Weather Service data. The underlying temperature
projections and other weather projections were derived by applying GISS and GFDL estimates of the percentage
impacts of an effective doubling in atmospheric carbon dioxide (Jenne, 1988) to historical weather data.
2-2
-------
Walker
CHAPTER 2
IMPACTS IN MIAMI
SUMMARY
The rise in sea level anticipated in the next century will severely aggravate ponding and flooding problems
in Greater Miami due to the rise in the water table, encroachment of seawater, and the effects of storms.
Preventing inundation and mitigating the impacts on infrastructure could cost more than $600 million, as detailed
in Table 1.
TABLE 1
PROBABLE INFRASTRUCTURE NEEDS AND INVESTMENT IN MIAMI
IN RESPONSE TO A DOUBLING OF ATMOSPHERIC CARBON DIOXIDE
(millions of 1987 dollars)
Raising Canals/Levees $60
Canal Control Structures $50
Pumping not estimated
Raising Streets $250 added to reconstruction
cost
Raising Yards not estimated
Pumped Sewer Connections estimated
Raising Lots at Reconstruction not estimated
Drainage $200-300
Airport $30
Raising Bridges not estimated; retrofitting
much more costly than raising
bridges during reconstruction
Sewer Pipe Corrosion minimal
Water Supply not estimated
The impacts of rising temperatures in Miami should be minimal compared to the effects of sea level rise.
With an effective doubling in carbon dioxide levels, both the GISS and GFDL models predict an average
temperature rise from 75 to 80°F. Precipitation is assumed to remain relatively constant, although modest
changes are likely. The GISS model projects a 4-inch annual rise in rainfall, while the GFDL model projects
a 2-inch drop.
Table 2 indicates the projected impacts on various types of infrastructure in Greater Miami Cost-effective
adaptation to global climate change will require complex, careful decisions about how and when to adapt the
infrastructure. A strong emphasis on life cycle costing and the courage to undertake expensive upgrading in
anticipation of future changes will be essential. This will require leadership. It will also require careful
examination of the available options for controlling the sea. Hard political decisions will be required about how
well Dade County can afford to protect its coastal exposures and how the costs will be split among affected
property owners, local governments, the Metropolitan Dade County government, the State of Florida, and the
federal government.'
2-3
-------
Table 2
Potential Impacts of the Greenhouse Effect on the
Infrastructure of Greater Miami, Florida
(3.3-Foot Sea Level Rise; 5.5 °F in Temperature Rise)
Type of
Infrastructure
Canals, levees,
control structures
Streets and
Highways
Bridges and
Causeways
Water Supply
Impact of
Climate Change
Loss In freshwater
head and change
In hydraulic gradient
More flooding and
ponding In wet season
magnified by hurricanes.
Potential destruction
of Everglades and Dade
County agriculture.
Increased likelihood of
Intractable water
management conflicts.
Gradual structural
weakening and eventual
pavement failure of
streets at elevations
less than 6 feet due to
saturation of base.
Risk of structural
weakening and failure of
portions of causeways.
Washouts more likely
wKh hurricanes. Vertical
underclearances of
bridges reduced, thus
Increasing flood
backwaters and ob-
structing a few boats.
Potential lifting of
culverts. Increased
humidity likely to
reduce life-cycle of
painting systems.
Erosion beneath bridge
abutments likely to cause
differential settlement.
stresses, and strains.
Wells near coast might
become brackish.
Increased droughts unless
hurricanes Increase.
Increased water demand.
Public Sector
Responses
Build more and raise
existing levees based on
hydrologlc studies.
Reconstruct control
structures. Add sub-
stantial pumping capacity.
Dredge canals more
frequently.
Gradually raise elevation
of 34% of Miami's streets
and highways, driveways.
access roads, and buildings
3 feet Install Improved
drainage to prevent flooding.
Gradually raise some
parts of causeways as
they reach end of service
lives. When bridges
due for replacement raise
raise structure height
Raise fenders. Install
redesigned culverts over
time. Pursue mitigation
measures to orevent erosion
beneath bridge abutments.
Regulatory Design
Adjust control
structure stages
to fit water
management objectives.
Effect on
Capital Costs
$108 million.
Effect on
Operating Costs
Much more pumping.
Incrementally revise
design features of
streets end highways.
Revise bridge design
features and criteria
such as design storms.
$237 million to
reconstruct 34% of
Miami streets with
minimal allowance
for Improved transitions
and drainage.
but much teas
at reconstruction
retrofit
Large, but m
costly at rec
than through
Significant reconstruction
traffic delays and disruption.
Uneven streets to affect
motor vehicle operating costs.
Small, but could adversely
affect bridge Inspection
and maintenance of low-
elevatJon structures on
nonnavlgable waters.
Increase water conservation.
Move selected wells Inland.
Possibly desalinate water.
Revise water management
objectives.
Not estimated.
Cost of desalinated water
will be three times cost of
water from aquifer.
1
-------
Table 2 continued.
Potential Impacts of the Greenhouse Effect on the
Infrastructure of Greater Miami, Florida
(3.3-Foot Sea Level Rise; 5.5 ° F Temperature Rise)
Type of
Infrastructure
Impact of
Climate Changes
Building and Negligible overall effect
Structure Foundations since footings, seatings.
and pilings overdeslgned
by a factor of 1.5 to 2.0.
Airports
Solid Waste
Sanitary Waste
Storm Sewers
Risk of prolonged disrup-
tion of airport operations
after storms due to
flooding, toss of
drainage capacity.
Negligible.
Severe hurricanes
combined with sea level
rise could wash consider-
able Virginia Key fill
and sludge Into Blscayne
Bay. More freshwater and
saltwater sewer pipe
Infiltration. Higher air
temperatures could cause
sewer pipe failures due
to hydrogen sulflde
corrosion. Higher
temperatures Increase
rate of bacteriological
action and removal of
pathogens.
Lose reduced ponding and
flood control benefits
of S267 million. 12-year
storm drainage capital
Improvement program.
Public Sector
Responses
Confirm structural stability
of foundations through
detailed engineering
analysis.
Rebuild drainage system
for stormwater runoff
and add considerable
pumping capacity.
Select sites
carefully.
Continue to fight
Infiltration and
hydrogen sulflde
corrosion. For raised
buildings, adjust pipe
connectors and Improve
pumping. Raise manhole
covers.
Make substantial storm
drainage Improvements.
Regulatory Design
Requirements
Potential revisions In
building regulations.
Gradually raise Dade
County flood criteria
and reassess flood
Insurance maps.
Possibly revise design
details for airfield
pavement reconstruction.
Develop new drainage
design criteria.
Raise flood criteria.
Modify regulations
affecting sewer pipes.
Raise flood criteria.
Effect on
Capital Cost
Negligible.
$30 million.
Negligible.
Large. Significant
private cost to
realign sewer pipes
from buildings rebuilt
at higher elevations.
Effect on
Operating Cost
None.
Small operating costs
for pumping. Temporary
disruption during
reconstruction.
Negligible.
Small.
Modify regulations
and design criteria
affecting storm.
$200-300 million.
Moderate
pumping costs.
I
-------
Walker
INTRODUCTION
The Miami area exists within an unusually complex environmental setting. An intricate water management
system already has evolved to protect the area against flooding, to provide fresh water, to irrigate nearby
agricultural lands, and to limit saltwater intrusion, which could harm the Everglades National Park and
contaminate much of the potable water supply. The likely impacts of an effective doubling in carbon dioxide
on the infrastructure are shaped by the hydrology and existing water management system.
This case study discusses the impacts of global climate change on a wide range of infrastructure ~ water
supply, canals, levees, water control structures, building and structure foundations, highways, bridges, airports,
solid waste disposal facilities, sanitary waste facilities, and storm drainage. Nevertheless, it does not cover all
infrastructure impacts. Notable exclusions are the impacts on beach erosion and nourishment and on air-
conditioning costs.
FEW DEVELOPED MAINLAND AREAS WILL BE INUNDATED IF SEA LEVEL RISES 3 TO 5 FEET
Importantly, Figure 1 shows a 3- to 5-foot rise in sea level will not inundate much of the developed portion
of the Miami mainland, although it will increase flooding risk considerably, especially during hurricanes. One
area at risk of inundation is the large, low-lying area south of Miami, which is a low-density residential area built
on land reclaimed by adding fill. Levees and water control structures used for flood protection in these areas
should prevent inundation if they are upgraded. Structures build in these areas generally sit on piles and fill
raised 3 to 5 feet above the land surface to reduce flood risks.
DADE COUNTY IS RECLAIMED FROM WATER
Miami is a hydrologic masterwork, a densely populated area bounded by water from below and on all sides.
When the city was first developed, the entire southern tip of Florida was a mangrove swamp called the
Everglades or River of Grass. The Everglades often was awash in fresh water. The initial settlement was built
on local high points of the Atlantic Coastal Ridge, 10 to 23 feet above sea level, and immediately adjacent to
Biscayne Bay and the Atlantic Ocean.
As Figure 1 shows, today most of Greater Miami is on lower ground. It was made habitable through
drainage and reclamation (Metropolitan Dade County Planning Department, 1979). Water drainage from the
Kissimmee River basin and Lake Okeechobee begins northwest of Miami and runs through canals to Miami and
other coastal cities. Also to the northwest are three water conservation areas used in the South Florida water
management system. South and west of the inhabited area is the Everglades National Park, a unique ecology.
On the east, Miami is bounded by the Biscayne Bay and the Atlantic Ocean.
Just a few feet below Miami's surface lies the Biscayne aquifer, the major freshwater supply for the area.
Maps in the Dade County Comprehensive Plan show that the height of the water table varies by about 3 feet
between seasons, but always exceeds sea level in most of the aquifer. Figure 2 shows the average annual highest
level of water in the aquifer. A comparison of Figures 2 and 3 reveals that the water table is very close to the
surface except along the high points of the Atlantic Ridge. In the wet season, water flows less than 5 feet below
34 percent of Miami streets (measured by Dan Brenner, Assistant Highway Engineer, City of Miami Department
of Public Works, 1988).
2-6
-------
ELEVATION ABOVE MEAN SEA LEVEL
Figure 1. Miami Topography.
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Walker
EVERGLADES
NATIONAL
PARK
AVERAGE YEARLY
HIGHEST
GROUNDWATER LEVEL
1965-78
CONTOURS IN
FEET ABOVE
MEAN SEA LEVEL
f ^SOURCE: METRO-DADE COUNTY
r PUBLIC WORKS DEPT., 1983
Figure 2.
METRO-DADE COUNTY PLANNING DEPT.
2-8
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Walker
BISCAYNE
NATIONAL
PARK
THICKNESS OF THE
BISCAYNE AQUIFER
ELEVATION OF
BASE OF THE
AQUIFER RELATIVE
TO SEA LEVEL
(NGVD, 1929)
EXTENT OF
SALT INTRUSION AT
BASE OF AQUIFER
..r* U
Lv-f
FLORIDA BAY C
Figure 3. Biscayne aquifer thickness and well locations.
METRO-OADE COUNTY PLANNING DEPT.
2-9
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As Figure 3 illustrates, the Biscayne aquifer is wedge-shaped It is 100 to 200 feet deep along and below
Biscayne Bay and averages 100 feet in depth in the developed area. West of the city, it falls off rapidly and ends
near the Dade County line. Because of the aquifer's shape, much of the water only can be tapped by wells dug
in or just west of Miami. Figure 4 shows current public well locations.
As indicated in Figure 3, the seaward edge of the aquifer is saltwater. In many cases, the cone of
depression for the wells comes close to the salt line in the dry season. Since the 1940s, Miami has used
freshwater pressure to prevent further saltwater intrusion into the aquifer. Currently, control structures and
canals are used to create a 2- to 3-foot head differential (Metropolitan Dade County Planning Department,
1979). This results in saltwater intrusion from 025 to 2 miles inland in the developed areas and about 5 miles
in the Everglades National Park where the aquifer is shallower.
The Biscayne aquifer is one of the most permeable in the world, an extraordinarily transmissive layering
of sand, solution-riddled limestone, and sandy limestone roughly 100 times more permeable than packed sand
(Metropolitan Dade County Planning Department, 1979). Wellfields are recharged simply by channeling water
across the aquifer and letting it percolate down (South Florida Water Management District, 1987). The height
above sea level and groundwater discharge areas of the aquifer change constantly in response to such relatively
minor factors as rainfall and tides (Metropolitan Dade County Planning Department, 1979).
Because of Miami's high temperatures, reduced evaporation loss makes the Biscayne aquifer a much better
place than shallow surface lakes to store water for use in the dry season (Metropolitan Dade County Planning
Department, 1979). Furthermore, overuse of surface storage would destroy the unique Everglades ecology,
which requires cyclic drying.
THE POROUS AQUIFER MEANS DIKING ALONE WILL NOT CONTROL SEA LEVEL RISE
In most coastal communities, the major challenge of a 3-foot rise in sea level is to control surface
inundation. The solution in both New Orleans and the Netherlands has been to dike the water at the surface
and pump out the modest seepage into ditches behind the dikes.
To do this in Miami, one would have to construct a dike that holds water back for the entire depth of the
Biscayne aquifer. Essentially, one would have to construct a water-impermeable barrier along the length of
Broward and Dade Counties to a depth of 100 to 150 feet Otherwise, the pressure of the seawater merely
would cause the sea to rush into the aquifer below the surface and push the freshwater in the aquifer up 33 feet,
very close to the surface. If one pumped the freshwater out, it gradually would be replaced by saltwater and the
freshwater storage capacity of the aquifer would be lost.
A very preliminary analysis suggests a two-pronged approach. One prong is to raise the land in low areas
rather than trying to dike. The second is to increase the freshwater head roughly in proportion to sea level rise,
thus maintaining the freshwater storage capacity of the aquifer. This method will not raise the water table
notably more than sea level rise alone.
Thus, if sea level rises 33 feet, Miami could raise its freshwater head by 2 to 3 feet to control subsurface
seawater infiltration into the aquifer, as well as by raising or building surface levees and adding pumping capacity
in developed low-lying sections. Even this approach may not work because the necessary water simply may not
be available, especially during droughts. According to the Dade County master planning staff, Miami will face
a water supply deficit in the 21st century. The most practical solutions appear to be purifying sewage effluent
or desalinating water at three times the cost.
A detailed examination of the issues and options is needed For the purposes of this report, consistent with
Rhoads (1987), we have assumed that selective retreat, levees with pumped outflows hi selected low-lying areas,
and elevation of some faculties and structures, as well as an increase in the freshwater head to protect the
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aquifer, will prove to be the most cost-effective solution on the mainland. Information about the appropriate
intervention for Miami Beach and other developed barrrier islands, primarily beach nourishment, is given in
Leatherman (1989).
OCEANGATES WILL NEED UPGRADING
Dade County's water management system includes an extensive network of oceangates - about 600 miles
of canals, 200 miles of levees, and >0 control structures (County Planning Department, 1979). The canals
probably will not require rebuilding, but probably will have to be dredged more frequently. The levees probably
will have to be raised in selected areas, which can only be identified through detailed studies. Robert Hamrick
at the South Florida Water Management District estimates it would cost approximately $15,000 per linear mile
to raise the levees 2 feet with mounds of crushed limestone, which is extensively quarried locally in open pits.
The fill is scooped from a copious supply lying virtually at the surface on public lands, then loaded on flat-
bottomed barges and sprayed onto the tops of the levees. Interpolating from the analysis in Weggel (1989), we
estimate that $60 million would be spent on canal and levee improvements if sea level rose 33 feet over the
next 100 years. Hamrick also suspects that the 30 control structures in Dade County would have to be
redesigned and replaced at an estimated cost of $1.6 million each, a total of $48 million in 1988 dollars.
The current water management system relies mainly on gravity drainage. With sea level rise, much
pumping capacity would have to be added to prevent subsurface saltwater intrusion. Both the capital and
operating costs would be large.
WATER SUPPLY WILL BE REDUCED UNLESS HURRICANES INCREASE
Miami's water supply will be reduced by water use to prevent saltwater infiltration. Some wellfields almost
certainly will have to be relocated further inland. Potentially, more important than the actual water expenditure,
the aquifer will rise closer to the surface, putting it in easy reach of the roots of more plants. Using evapo-
transpiration and soil moisture models, Rhoads (1987) estimates that soil moisture deficiency probabilities will
double due to the 5°F rise in average temperature associated with an effective doubling of carbon dioxide,
assuming no change in rainfall.
Water supply will be adversely impacted by temperature-related evaporative water loss in the water
conservation areas. Furthermore, temperature rise will increase cooling degree days by roughly 2000, about a
50 percent rise. That means more water consumed for air-conditioning, agriculture, and urbaculture, i.e.,
gardening in yards and parks. To make matters worse, an effective doubling of carbon dioxide is likely to reduce
rainfall in the dry winter months from the current 1.9 inches a month to 1.6 inches according to the GISS model
or 1.7 inches according to the GFDL model (Jenne, 1988).
The solution to these problems will require detailed study. One alternative is increased capacity to produce
desalinated water — e.g., by boiling and cooling, reverse osmosis filtration, or some new technology - or to use
purified effluent as a backup supply for drought periods. Full cost pricing of this water should encourage greater
conservation, reducing demand Another complexity requiring study is the need to maintain some water in the
water conservation areas, since the water containments are designed to function with a vegetative lining.
The largest uncertainty about water supply is the impact of climate change on hurricanes. Hurricanes
historically have contributed substantially to aquifer recharge (Metropolitan Dade County Planning Department,
1979). Rising temperatures could increase hurricane frequency and intensity. This would be a mixed blessing,
assuring an adequate water supply but inflicting billions of dollars in wind and flood damage.
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BUILDING FOUNDATIONS ARE ADEQUATE
A preliminary examination of structural stability of footings and pilings suggests that buildings are not likely
to suffer structural instability from a 33-foot rise in the water table. When a building is on coral rock or
limestone, concrete footings with reinforcing steel frequently provide structural support. A monolithic slab with
flared ends to a depth of 18 to 24 inches is a typical foundation for a residence, since most residential structures
and commercial buildings are too close to the water table to have basements. Larger residences might have both
seatings and footings. Tall buildings including residential condos are most likely to rest on piles, although other
techniques are used to provide structural support including spread footings and compacting.
Flooding raises little possibility of structural instability due to settling, foundation cracking, and so forth,
because the foundations are overdesigned by a factor of 1.5 to 2.0, according to engineers at Florida Atlantic
University.
Regulations and permitting procedures, including Dade County Flood Criteria and those of the National
Flood Insurance Program, require most new construction to be on raised lots to prevent flood damage. These
regulations and permitting procedures will need to be modified to protect new buildings and other types of
infrastructure in areas that sea level and water table rise will make vulnerable to more severe flooding.
ONE-THIRD OF THE STREETS WELL NEED TO BE RAISED
A typical city street consists of a 1.5-inch layer of asphalt constructed over an 8-inch limerock base. Beneath the
base is a subgrade, with its top 6 inches compacted to a minimum of 95 percent of its maximum density. If the
sea level and water table rose roughly 33 feet, given the annual fluctuations in the water table and its proximity
to the surface, the subgrade and/or base of many city streets would be subject to a certain amount of saturation.
This could cause complete structural failure if a heavy load were to pass over the surface. To prevent this,
vulnerable streets would have to be raised by 33 feet.
Dan Brenner of the City of Miami Department of Public Works estimates that approximately 34 percent
of street and highway mileage — 257 miles — is 5 feet or less above the water table. Raising streets by 33 feet
during reconstruction, according to the Department of Public Works, would raise reconstruction cost from $150
to $175 per linear foot (remember that fill is cheap) with minimally improved transitions to adjacent properties.
The cost of reconstructing the 257 miles to adjust for a 33-foot rise in sea level would be roughly $237 million.
Omitted from this cost estimate are substantial private costs that will be incurred for better drainage, raising of
some yards (especially at newer buildings where the structure itself already is raised), raising lots at
reconstruction, and positive sewage pumping from the houses to the mains in some areas.
The aesthetic drainage impacts of this change will be dramatic. Except recently constructed houses, which
often are raised to meet flood ordinances, people's houses, yards, and garages would be 3 feet below the streets
(and canals), a situation strongly reminiscent of the Dutch countryside. Imagine standing in your front yard and
looking up at the street. Undoubtedly, some yards and houses will be raised when they are reconstructed, and
yards are likely to be raised or flanked by covered exfiltration trenches. Fortunately, there are no basements.
The projected rise in temperature should have negligible impact on streets and highways, since asphalt
pavement withstands substantial temperature variations.
MANY CAUSEWAYS AND BRIDGES SHOULD BE RAISED AT RECONSTRUCTION
The causeways running from Miami across Biscayne Bay to Miami Beach are between 5 and 10 feet above
sea level and might be at risk of structural weakening and failure. They would also be vulnerable due to the
increased size of hurricane storm surges. These potential impacts could be avoided with reconstruction over the
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next 100 years involving design features to mitigate the effects of the sea level rise. Except for steel drawbridges,
most bridges in Miami are constructed of concrete and steel, with a life expectancy of 50 years. Only those near
the coast have epoxy coated reinforcing bars, a practice introduced in 1970 to fight corrosion. Without remedial
action, the effects of sea level rise will include:
o Pavement failure in low-elevation bridge approaches.
o Erosion beneath low-tying bridge abutments and consequent differential settlement, stresses, and
strains.
o Potential lifting of corrugated steel and box culverts.
o A drop in the elevation of fenders on the piers over navigable waters. Fenders protect against damage
from vessels bumping into the substructure.
o Reduced underclearances on navigable waterways.
o Reduced accessibility inhibiting proper inspection and maintenance.
o Added wave "slapping action."
o Increased likelihood of flood backwaters, particularly for bridges that have underclearances of 3 to 6
feet over nonnavigable waters.
Regardless of improvements over the next 100 years, bridges with piers and piles in both Biscayne Bay and
in rivers would experience deeper scouring, but the velocity in nonstorm conditions would decrease due to the
increased water depth. Scouring would increase if storms became more frequent or severe.
The projected temperature increase should not cause bridge expansion outside design limits. Increased
humidity, however, could accelerate paint deterioration.
AIRPORTS WILL NEED BETTER DRAINAGE
Miami International Airport is a major international hub. Located in northwest Miami, its airfields and
aprons cover 7,000 acres. Unlike the majority of major commercial airports, most of the surface area is asphalt
pavement. The aprons are concrete. The asphalt varies in thickness from 2 to 17 inches depending on the base.
Its extensive drainage system allows storm runoff to empty into ditches by the airfield, which in turn empty into
the Blue Lagoon and the Tamiami Canal. The groundwater elevation ranges from 2 to 3 feet, runways 9 to 10
feet, and taxiways and aprons 8 to 9 feet. A 33-foot rise in groundwater would not flood the pavement or base,
but would affect drainage retention capacity and exfiltration during a storm. If several large pumping stations
were constructed to draw down the airport water table at the onset of a storm, acceptable operating conditions
could be maintained. Drainage interconnections and related improvements such as pump stations, dikes, and
culverts might cost $30 million (Tripp, 1988).
EFFECTS ON SOLID WASTE DISPOSAL SHOULD BE MINIMAL
Dade County currently disposes of its solid wastes at a resource recovery plant with landfill, a reduction
shredding facility with land fill, and a shredder pulverizer used for resource recovery. There are also three
transfer stations and over 50 inactive solid waste disposal sites, including landfills and incinerators (South Florida
Water Management District, 1987). Proposed expansion of solid waste disposal capacity is expected to handle
growth until at least 2012, and additional staged expansion should be able to meet the solid waste disposal needs
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of the population until 2020 or 2030 (Downtown Development Authority, 1988). The incremental manner of
disposal site selection reduces potential problems due to sea level rise.
We did not estimate the impacts of a rise in sea level on solid waste disposal. The elevations and locations
of the landfill sites have not been identified as part of this study, and their current propensity to leaching under
normal or flooded conditions is not fully known. Most inactive landfills, however, reportedly have already
leached out. Recently constructed landfills are lined, and the active ones have sophisticated drainage and are
connected to the sewage treatment systc-m to minimize leaching.
Landfill subsidence is sensitive to temperature, moisture, the nature of waste (coarse, medium, fine),
percentage of paper, whether cells are in aerobic or anaerobic condition, etc. The literature on subsidence
suggests that a 5 degree temperature increase will increase subsidence by some unpredictable amount
(Department of County Engineer, 1973).
SANITARY WASTE SYSTEMS WILL REQUIRE ADJUSTMENTS, PRIMARILY TO CONNECTOR PIPES
Dade County has separate wastewater and storm sewer systems. Wastewater treatment capacity has been
keeping pace with population growth and business activity, increasing approximately 3 percent per year. Current
capacity is 276 million gallons per day (mgd) with peak flows of 222 mgd (Downtown Development Authority,
1988). Of the three regional wastewater treatment districts, the central district has the largest capacity of 120
mgd with two sludge plants, one a high purity oxygen activated and the other a modified activated. Both the
north and south districts have high priority oxygen activated sludge plants. The north district's plant has a
capacity of 80 mgd and the south district's, 76 mgd.
A vast system of underground pipes carries the sewer and other processed waste to the wastewater
treatment facilities from homes, commercial buildings, and industrial facilities. The largest uncertainty about
water supply is the impact of climate change on hurricanes. Hurricanes historically have contributed substantially
to aquifer recharge (Metropolitan Dade County Planning Department, 1979). Rising temperatures could increase
hurricane frequency and intensity. This would be a mixed blessing, assuring an adequate water supply but
inflicting billions of dollars in wind and flood damage.
While there have been extensive efforts to reduce infiltration, one half inch of rain during the dry season
increases wastewater flow to the Central District plant by 10 to 20 mgd During the wet season, many pipes are
surrounded by water. A 33-foot rise in groundwater in the Miami area could significantly increase infiltration
during the dry season and possibly require additional pumping capacity. A severe hurricane with flooding would
produce saltwater intrusion into the sewer pipes.
Temperature increases hydrogen sulfide corrosion within sanitary sewer pipes. Due to hydrogen sulfide
corrosion, the 42-inch vitrified day pipe under the Miami River recently collapsed, releasing effluent. The fact
that the pipes lie underground mitigates the effect of the surface temperature increase, so it is not dear how
much more of a problem hydrogen sulfide corrosion would become.
A significant problem associated with sea level rise is that not only must streets, houses, and other buildings
be raised in low-lying elevations, but also that the connectors from buildings to the sewer interceptors will
require adjustments. Pump stations will have to be raised and modified to maintain the same driving force
(pressure differential inside versus outside). Overflow structures would require improvements.
In the City of Miami, the costs of adapting elevated houses and other building connections to existing sewer
lines would be the responsibility of private property owners. The remainder of the costs would be public. The
Miami Department of Public Works estimates thai the costs to raise and modify pump stations, modify overflow
structures and miscellaneous appurtenances, and raise manholes alone is $8 million (in 1988 dollars).
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The likely impact on one of Miami's wastewater treatment facilities, located on Virginia Key, also was
assessed. Since Virginia Key has no freshwater beneath the surface, intrusion is not an issue. The treatment
plants are approximately 10 feet above sea level Berms and dikes reach elevations of approximately 13 feet,
while sterile fill material from the sludge plants has accumulated to elevations around 30 feet. A severe hurricane
producing higher storm surges still could wash out portions of the island. If the activated sludge treatment plants
are still in operation as sea level rise accelerates, the berms and dikes on the island will have to be raised to
prevent processed sludge from being washed into Biscayne Bay. Another possible effect of a hurricane is that
dirt beneath the plant could be washed out, causing the piping to collapse.
Higher surface air temperatures increase bacteriological action and increase the rate at which pathogens
are removed by the activated sludge treatment process. Any temperature related problems associated with
activated sludge plants are likely to be easily resolved through plant modifications and improved controls.
STORM SEWERS AND DRAINAGE TRENCHES WILL REQUIRE MAJOR UPGRADING
Miami relies primarily on localized drainage and canal systems, involving exfiltration that carries surface
storm water to subsurface groundwater. Highly permeable soils make this a cost-effective form of storm water
drainage, except in low-lying areas where there are fine soils that do not drain well. Where natural drainage
systems are not effective, and in instances where tidewaters and easterly winds increase the water head pressure
at discharge outlets to the bay, a positive drainage pipe system is required.
Standards for storm sewers vary among federal, state, and local agencies. Interstate highway storm sewers
are designed for 10-year storms. On arterial streets in areas of high population density, 3-year storms serve as
the design standard On local streets, Miami's system is designed for a rainfall rate of 1.5 inches per hour.
Ponding will occur three or four times per year on local streets with this type of storm drainage (City of Miami
Department of Public Works, n.d.).
In 1988, Miami started a 12-year, $267 million program to reduce flooding and ponding. This includes
constructing 750,000 feet of exfiltration trenches at a cost of $105 million. It also includes constructing $55
million of positive drainage. These systems are designed to provide protection against flooding from 25-year
storms (Department of Public Works, 1986).
Even with these planned improvements, if sea level rises 33 feet, flooding and ponding problems probably
would be worse than they are today, especially because the water table will be closer to the surface. The costs
of adequate future flood protection almost certainly will be several hundred million dollars.
HURRICANES WILL INFLICT MORE SEVERE DAMAGE
Miami has not experienced a direct hit by a major hurricane in 55 years. When it does, more than 400,000
people will have to be evacuated. The developed barrier islands — Miami Beach and Key .Biscayne — and
portions of the mainland will be hit by a 15-foot wall of water. The barrier islands will be completely submerged
to a depth of at least 5 feet. Along with the surging sea will come at least 10 inches of rain (Metropolitan Dade
County Planning Department, 1979). Flood control systems, which currently are being upgraded to cope with
the 10- to 25-year storm, will be pushed beyond their capacity. Property losses obviously will be substantial
The higher sea level and higher water table that will result from global climate change will increase the
potential destruction, making the future effects of a moderate hurricane almost as bad as the current effects of
a major one. If hurricanes also become more frequent and intense, as some experts predict, more flood control
investment and a strategic retreat from the coast in some areas may be necessary.
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CHAPTERS
IMPACTS IN CLEVELAND
INTRODUCTION AND SUMMARY
Located on Lake Erie, Cleveland is prone to harsh winters and mild summers. The banks of the Cuyahoga
River, which bisects the city, are lined with industrial plants.
Cleveland is likely to experience a marked change in climate over the next century. Its summer climate
will be wanner, similar to current summers in Louisville, Kentucky. Its winter climate also will be much milder;
rather like that of Nashville, Tennessee.
o The GFDL and GISS scenarios project seasonal temperature increases ranging from 7 to 12°F. Whiter
temperatures under both scenarios are to increase about 10° bringing average temperatures above
freezing. Summertime increases will be from 7 to 12* above the current 66° average.
o The number of heating degree days will drop by about 36 percent (from a 1987 base of 6,513), but the
number of cooling degree days will increase by a much wider margin (by 169 percent to 269 percent
over a base of 615).
o Snowfall is likely to be dramatically reduced with average annual accumulations declining by roughly
85 percent (from 50 inches to about 8 inches).
This case study examines the possible impacts of these changes on selected elements of public infrastructure
budgets: streets and bridge decks, public buildings, the transit system, and snow removal The results
(summarized in Table 3) suggest both increases and decreases in outlays for different reasons. Costs related
to public buildings and transit are likely to go up because substantial increases in air-conditioning requirements
exceed likely reductions in heating expenses. The net increase in the annual space conditioning budget for public
buildings, for example, could be as much as $7.1 million. On the other hand, savings can be anticipated due to
less severe winters. Yearly reductions could include $200,000 due to less reconstruction and resurfacing on roads
and bridges, $490,000 due to lower road and bridge maintenance requirements, and another $4.4 million due to
reductions in the need for snow removal
Given the many uncertainties involved, these estimates are far from reliable enough to support conclusions
about whether the net effect will be negative or positive. They do suggest, however, that the impact will be small.
A net increase of even $7.1 million, for example, would add only about one percent to today's operating budgets
for Cleveland's city government and school system. In other words, the likely impacts of warmer temperatures
create no demands for emergency response in Cleveland Prudent incremental planning for capital replacement
and maintenance should be sufficient to assure a smooth adjustment
This case study also includes preliminary evaluation of another predicted change: the possibility of a 2- to
4-foot drop in the level of Lake Erie. Here again, Cleveland seems unlikely to experience serious impacts,
although this change could cause navigational difficulties and other problems elsewhere in the regioa Cleveland's
water intakes arc far enough out in the lake so that they would not be affected, and variations of these
magnitudes at the shore line would not be sufficient to disturb present uses or structural conditions.
Overall, this picture represents a stark contrast to the detrimental effects of sea level rise for coastal cities
like Miami and of drought and extremely high temperatures expected for many inland cities to the south. While
it appears that its infrastructure ^-editions will not be much affected, Cleveland is likely to benefit substantially
in other ways from a balmy climate and from being one of a much reduced number of American cities with an
ample freshwater supply. An image change from "rust belt" to "garden spot" is not an outlandish prediction.
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TABLE 3
ESTIMATED IMPACTS OF A DOUBLING OF ATMOSPHERIC CARBON DIOXIDE
ON CLEVELAND'S ANNUAL INFRASTRUCTURE COSTS
(Millions of 1987 Dollars)
Annual
Cost Category Operating Costs
Heating -2.3
Air-Conditioning +6.6 to 9.3
Snow & Ice Control -4.5
Frost Damage to
Roads -0.7
Road Maintenance -0.5
Road Reconstruction -0.2
Mass Transit summer increase offsets
winter savings
River Dredging +0.5
Water Supply negligible
Storm Water System negligible
Total -1.6 to +1.1
CLEVELAND'S INFRASTRUCTURE CONDITIONS
Population and employment losses in Cleveland in the 1960s and 1970s took their toll in the form of a
stagnating tax base and cuts in municipal expenditures. This was reflected in the condition of the area's
infrastructure, which by reputation and some objective measures was in worse condition than that of most other
US. cities of comparable size. In the early 1980s, however, local governments in the area banded together in
a campaign to address these problems (Peterson et al., 1982). The task is far from complete (the area's total
capital need for roads and bridges, transit, water supply, and sewers for the 1988-1992 period is estimated at $12
billion), but investment has gone up considerably over the past few years and the campaign has been successful
in raising more local as well as state and federal funds for these purposes (Walker and Friedman, 1988). Thus
we judge that the area has much better than average institutional preparedness to deal with any additional
infrastructure demands motivated by climate change.
IMPACTS ON ROADS AND BRIDGES WILL BE POSITIVE
Like most cities, Cleveland maintains an extensive road and bridge network: some 1450 miles of road and
93 bridges with a total surface area of 1.8 million square feet (Parham, 1985). By some measures, Cleveland's
road and bridge stock is in poorer condition than is typical for US. cities. Among 34 cities with road condition
data readily available for 1983, Cleveland road mileage ranked last in the percentage rated as 'good" (5.6 percent)
as opposed to "fair" (91.8 percent) or "poor* (2.7 percent) (Peterson et al., 1981).
Similarly, the city's bridges included on the Federal bridge inventory are in relatively poor condition.
Among 62 major U.S. metropolitan areas in 1980, the Cleveland area ranked 12th in its share of structurally
deficient bridges: 23 percent of the areas's 279 bridges fit this category. Indeed, among the 93 bridges for which
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the city has sole maintenance responsibility, 75 are structurally deficient by the Federal Highway Administration
definition (Peterson et al., 1981).
The deteriorated state of the city's transportation infrastructure is the combined product of environmental
and budgetary factors (Bowersock, 1988; Getz, 1988). Years of underfunded capital programs and deferred
maintenance contributed to the need for major capital renewal. Nevertheless, engineers responsible for road
and bridge design attribute a large share of the blame for poor road pavement and bridge deck performance to
environmental factors: moisture and temperature effects in the former case; use of salt in deicing efforts in the
latter.
Low-Temperature Damage To Roads and Bridges Will Be Reduced
The most serious low-temperature effect on flexible (e.g., asphalt) pavement performance is frost heaving,
which occurs when free water in the roadbed soil collects and freezes to form ice "lenses" (American Association
of State Highway and Transportation Officials (AASHTO), 1987). The accumulation of thickness from these
lenses causes localized heaving of the pavement surface during extended frozen periods. The principal variable
affecting the amount of heave that occurs is the depth of frost penetration, which is directly correlated with the
number of consecutive low-temperature days. The amount of heave, and hence the potential loss in serviceability,
also is affected by the quality of drainage.
Currently, the mean annual number of days with maximum temperatures below freezing is 46. According
to local highway engineers interviewed for this report, these subfreezing days, on average, produce about five to
six deep freeze/thaw cycles annually. Under both the GISS and GFDL scenarios, the number of days below
freezing, and hence the estimated number of cycles, will decline dramatically over the coming century. The GISS
scenario results in a mean annual number of days with maximum temperatures below freezing of 13, roughly a
quarter the total mean number of days currently. If the number of days below freezing are taken as a proxy of
the number of freeze-thaw cycles to be expected per year, 75 percent fewer days below freezing produces an
estimated 1.5 deep freeze cycles per year. City engineers estimate the current depth of frost penetration for
bare pavement at 4 feet, with good drainage. Applying these factors in the AASHTO equations yields an
improvement in the serviceability index value for Cleveland of 11 percent.
An alternative approach that suggests impacts of a roughly similar magnitude is the Moisture Accelerated
Distress (MAD) Index, which classifies subsoil and drainage types for geographic regions across the nation
according to their potential for abetting "pavement distress" attributable to environmental factors (Carpenter et
al., 1981). Pavement distress is observable in the cracking of flexible (largely asphalt) or rigid concrete
pavements, frost heave of flexible pavements, or joint failure or spalling of rigid pavements.
The MAD Index is based on the interaction of four factors: temperature, moisture, roadbed material, and
drainage. The last two factors, as defined in the Index, will be little affected by climate change. City highway
engineers rate the typical subgrade in Cleveland as "moderately drained," and the granular layer as "free draining."
Whatever improvement in drainage is attributable to lake level drop will not produce a shift in broad drainage
categories.
The GFDL and GISS scenarios suggest that temperature and moisture changes attributable to global
climate wanning will produce winter conditions in Cleveland roughly akin to those prevailing today in Nashville,
Tennessee (estimated from Kalkstein, 1988). This will produce a change in temperature zone, for purposes of
calculating the MAD Index, resulting in an approximate 7 percent decrease in potential for moisture-accelerated
damage.
Another impact to be considered is design requirements for new or replacement road surfaces. AASHTO
has defined a Regional Factor for use in the design of roadways using flexible pavements (FHWA, 1983). This
factor essentially is a summary measure of adverse weather conditions. It is used to weight the axle-load factor
used to determine asphalt pavement thickness. This factor ranges from 0.5 in the far Southwest to a U.S. mean
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value of 1.7 to a maximum value of 3.5 in northern Minnesota. The Cleveland area value is L5. With an
increase in mean temperature, and using Nashville as Cleveland's winter analog, the value for Cleveland would
drop from 1.5 to 1.0. This change results in a 7.5 percent decline in the required thickness of asphalt overlay in
roadway construction.
Maintenance Costs Will Be Reduced About 10 Percent
Roughly estimated, the amounts to be saved in road and bridge repair costs as a result of decreased
pavement and bridge deck stress are modest, but not negligible. Currently, Cleveland spends about $4.9 million
per year on street repair: filling potholes, cracks, and other surface defects. An additional $100,000 is expended
on bridge deck repair (Parham, 1985). This amount is almost entirely devoted to routine pothole repair, filling
of joint and other surface cracks, and other maintenance activities associated with routine treatment of ordinary
surface wear and tear.
Roads. As seen in the preceding section, the change in the present Serviceability Index due to frost heave
is an estimated 7 percent. The estimated MAD Index change, accounting for all sources of moisture-accelerated
distress including frost heave, is 11 percent. If these changes are correlated with actual incidence of pavement
damage, then a conservative estimate of savings due to reduced damage frequency is roughly 10 percent or
$490,000.
Bridges. The city performs only emergency repair on bridges. City engineers indicate that of an average
annual bridge maintenance budget of about $1 million, about 10 percent is expended on the repair of bridge
decks, the remainder supporting maintenance of lift bridge mechanisms (Browersock, 1988). Though some
deterioration of bridge decks can be attributed to the effects of temperature and moisture alone, these effects
are minimal compared with the use of road salts. With milder winters meaning sharply reduced snow and ice
control efforts, far less corrosive salt will need to be spread on the area's bridges. Nevertheless, we judge that
negligible economic benefit will be credited to this development since new techniques in bridge construction,
principally the use of epoxy-coated reinforcing steel as a means of preventing contact between the bare steel and
deicing salts, should reduce corrosive impacts long before milder winters become the norm (Vinnani, et aL,
1983).
Capital Costs Will Drop 1 to 3 Percent
AASHTO design guidelines, including the regional factors used in the flexible pavement design equation,
represent the best way of estimating changes in capital costs attributable to climate change. The expected change
in winter temperatures, using an analog of Nashville, Tennessee, means a reduction in the AASHTO Regional
Factor from 1.5 to 1.0. Based on the equations developed in FHWA (1983), each unit change in the Regional
Factor produces a 13 percent change in the structural number (thickness) of flexible pavement. For roadway
construction or reconstruction jobs, roughly 26 percent of total construction costs are attributable to pavement
costs. Of this figure, 70 percent of costs are variable with thickness. Therefore, 18 percent of total construction
costs are potentially affected by weather (26 percent X 70 percent). Thus, a change in the Regional Factor from
1.5 to 1.0 on roadway reconstruction jobs means a drop in total costs of approximately 1 percent.
Resurfacing jobs, however, contain a higher percentage of pavement costs to total job cost than do
reconstruction jobs - approximately 60 percent. Using the 70 percent of costs that are variable with thickness,
as before, 42 percent of total resurfacing costs can be viewed as weather-influenced. If a 0.5 drop in the Regional
Factor means a 7.5 percent change in structural number, then total cost reductions on resurfacing work are
estimated at 3 percent.
Table 4 presents Cleveland's road resurfacing and reconstruction costs for 1983-1987. Assuming that the
city's capital investment levels change proportionately over time and that the climate-adjustment factors are
approximately correct, a* 5-year estimated saving of about $1 million can be expected on a total budget of $76
million.
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TABLE 4
CLEVELAND ROAD RESURFACING AND RECONSTRUCTION OUTLAYS
1983-1987 (Dollars in Thousands)
Year Reconstruction Resurfacing Climate-Savings
1983 $5,184 $1,930 $110
1984 6,233 2,179 127
1985 5,334 2,391 124
1986. 26,544 2,166 330
1987 21,913 2,166* 284
Total $65,208 $10,832 $977
Notes: * » Estimated Climate change savings are computed as 1% of reconstruction costs, 3% of resurfacing
costs.
Source: Compiled by The Urban Institute based on unpublished material supplied by the City of Cleveland
Budget Office (1987 figures), and data from the Mayor's Estimates, 1983-86.
ENERGY COSTS IN PUBLIC BUILDINGS PROBABLY WILL RISE
Cleveland has 254 public buildings with a total of 19.4 million square feet of floor space. This count
includes only facilities used by the City of Cleveland (owned and rented) and the Board of Education and, as
such, is not all inclusive (e.g., universities, hospitals, public housing, and state and federal offices are excluded).
Nonetheless, it encompasses most buildings of relevance. As in most cities, the nonresidential public building
stock is dominated by education facilities (accounting for 70 percent of all floor space).
The increased winter and summer rainfall predicted for Cleveland should have no measurable impact on
the operation of public buildings themselves. The substantial declines in snowfall and freeze-thaw events that
are anticipated should have some positive effects (less snow shoveling to maintain access, some reduction in
structural deterioration and thus maintenance), but we judge that those effects will be too small to warrant
analysis in this context. Temperature change appears to be the only long-term outcome that could have notable
impacts on buildings. As noted earlier, the annual number of heating-degree days is expected to decline by about
35 percent and the number of cooling-degree days may expand to 2.7 to 3.6 times the present level.
Comprehensive data on existing space conditioning systems in Cleveland's public buildings are not available.
Nonetheless, interviews with those responsible for property management offer enough evidence to support basic
judgments about impacts.
The Capital Costs of Heating Systems Should Not Be Affected
As would be expected given Cleveland's present climate, all of the buildings in the inventory have heating
systems. There is considerable variation in system types, ages, and energy efficiencies. Assuming a 30-year
replacement cycle, these systems will be replaced at least three times on average over the next century. In many
cases, installation will take place as a part of the construction of new buildings that replace structures in the
existing stock that are demolished or converted to other uses.
The stream of replacement outlays seems unlikely to be altered noticeably one way or the other by the
climate change scenarios discussed here. Even though Cleveland's winters will be much milder on average, all
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buildings will still need heating systems that produce adequate warmth on very cold days. Thus basic capacity
requirements will not change. Although systems will not have to operate as many hours per year, interviews with
space conditioning engineers suggest that those effects will not alter replacement rates significantly.
More Buildings Will Require Air-Conditioning
Climate change could make more of a difference in air-conditioning capital requirements, although not as
much as might be supposed. No cost will result from replacing units in buildings that are presently air-
conditioned. Most air-conditioning equipment now in place was built with sufficient capacity to handle very hot
weather, even though it does not occur very often in Cleveland at present. More hot days will simply imply
longer hours of operation — not changing capacities.
The only possible difference of note for air-conditioning capacity would be the one-time capital cost of
providing systems to buildings that are now without service altogether. These include roughly 65 percent of
Cleveland's schools and large "nonoffice" spaces in other facilities, including repair spaces in garages and gyms
in recreation centers.
The costs of installing new systems in these spaces would vary dramatically with conditions of the
structures involved. Accurate estimates are clearly beyond the scope of this study. To get some sense of the
order of magnitude, we assumed that systems would be required for 90 buildings averaging 90,000 square feet
in size and asked space conditioning engineers to estimate a rough typical cost The results ranged from $720,000
to $900,000 per building, from $65 million to $81 million in total. These amounts represent 28 to 34 percent
of the combined city and Board of Education capital budgets for 1988, but outlays would of course be spread
over a long period. Also, the per building cost would probably be reduced by 5 to 20 percent where air-
conditioning is provided as a part of the construction of new replacement buildings rather than being installed
in existing structures.
Much of this expenditure might be made even without the temperature increases resulting from increasing
atmospheric carbon dioxide. As air-conditioning costs have declined over the past few decades, coverage has
expanded dramatically. Most notably, if the Cleveland system adopted the frequently heard proposal for more
intensive, year-round use of school facilities, pressures to provide comprehensive air-conditioning would be very
strong regardless of expected climate change.
Operating Costs Should Rise 50 to 90 Percent
Since the early 1980s, the City of Cleveland has implemented a program to improve the energy efficiency
of city operations (City of Cleveland, 1982). Their baseline analysis showed that the city spent $33.2 million for
energy in 1981 - 15 percent of the total general fund expense budget for that year but second only to personnel
costs in size among major categories of expenditure. Of the energy total, $8.2 million (one fourth) went for
lighting, space conditioning, and other uses in public buildings. As one outcome, the program has begun fairly
careful tracking of energy use in its facilities.
Unfortunately, the data do not isolate the costs of heating and air-conditioning per se, but they offer a basis
for some rough estimates. For city buildings, we assumed that 15 percent of all electricity use goes for air-
conditioning and all of the costs of steam, and 65 percent of the costs of natural gas goes for space heating
(estimates derived from partial data and judgments by Cleveland's Energy Office). For Board of Education
facilities, we assumed the same distribution of energy use per square foot as for city offices and the same
percentage allocations to heating and air-conditioning.
Under these assumptions, current annual costs for space conditioning would be about $8.5 million ($6.7
million for heating and $1.8 million for air-conditioning). An additional $13 million would be spent for cooling
at present if all buildings had air-conditioning equipment.
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We next assumed that the changes in heating and air-conditioning energy use and costs over the next
century will be proportional to the projected decreases and increases in heating and cooling degree-days.
Assuming further that all schools would be air-conditioned by then, the changes from current expenditure levels
would be as follows:
Cooling-Degree-Days Est.
GISS GFDL
Reduced heating cost ($23)0,000) ($2300,000)
Increased air-conditioning 5300.000 8.000.000
Net increase $3,000,000 $5,800,000
Assuming no efficiency or price changes, annual expenses for space conditioning would increase from $8.5
million to between $12£ million-and $15.6 million in 100 years. The largest difference ($7.1 million), however,
represents only about one percent of the combined City General Fund and Board of Education expense budgets
for 1988. The gap in these estimates occurs largely because air-conditioning relies solely on electricity, which
currently has a per BTU price about three times the average for steam and natural gas.
IMPACTS ON TRANSIT SHOULD NOT BE SIGNIFICANT
The Greater Cleveland Regional Transit Authority (RTA) operates a fleet of 815 buses and 207 railcars
that carry over 88 million passengers per year.
Air-Conditioning on Transit Vehicles Has Minimal Cost
Analysis does not suggest any significant impact on RTA capital costs due to climate change. Neither the
rail nor the bus fleets now have special equipment mandated by snow conditions that could be eliminated (and
thus save costs) in subsequent replacements. All vehicles are equipped with heating systems, which will still be
needed. All rail cars have two 7-ton air-conditioning units. These should have adequate capacity to handle much
longer hot weather seasons and RTA staff suggest that, if anything, more regular use would probably improve
their operation since lubricants would circulate more effectively.
None of the Cleveland buses are presently air-conditioned, so equipment would probably have to be added
in this category at some time over the coming century. However, given an estimated average 10- to 14-year
replacement cycle and considering the expected pace of temperature increases, there would be no justification
for accelerating replacements on these grounds alone. Also, the American Public Transit Association indicates
that most buses now being sold are equipped with air-conditioning and that the percentage continues to increase.
Price differentials for buses with and without such equipment are already small and are narrowing. Therefore,
it appears that adding air-conditioning for Cleveland area buses during regular bus replacement cycles over the
next century would not have a notable effect on total capital outlays.
Savings in Snow-Related Operating Costs Will Offset the Cost of Fuel Used For Air-Conditioning
Similarly, while climate change will alter RTA operating costs, our interviews suggested that all effects will
probably be too small to warrant quantification. On one hand, heavy snow accumulations at present do create
problems, particularly for the rail system. Snowflakes that work their way into power systems can produce
"flashes" (shorts) that demobilize the equipment and yield large repair bills. RTA will be able to reduce
allocations for snow clearing and other outlays for prevention/correction as snow diminishes in the future. On
the other hand, some increase in fuel consumption is likely to result from more frequent use of air-conditioning
equipment In relation to the overall size of RTA's $126 million expense budget for 1987, both effects will be
small Furthermore, they will offset one another.
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SNOW AND ICE CONTROL COSTS WILL DROP DRAMATICALLY
As in many other northeastern cities, snow removal operations in Cleveland receive high priority from city
administrators and agencies during the winter months. The Streets Division, responsible both for roadway
maintenance and snow removal, maintains four stations throughout the city during summer months. Two are
manned at three shifts per day, one at two shifts, and one at one shift. These stations primarily do street
sweeping and repair. However, during winter months, six stations are activated, all manned at three shifts per
day and all engaged primarily in snow and ice removal. Limited street repairs are undertaken throughout the
winter months. The personnel used in city snow removal operations all are city employees and the equipment
consists of Division of Streets vehicles.
Ordinarily, at the onset of snow or ice precipitation, the city will salt streets using employees and equipment
assigned to their regular shifts. At this stage, some 45 units will be employed in salt spreading. If snow
accumulates at 1/2 inch per hour, or if a 2-inch accumulation is reached, the second shift will be called four
hours early, while the first shift will be kept on four hours overtime. This brings total equipment on the road
to 81 salt and plow units, and 15 graders. Typically, for any storm between 4 and 12 inches over a 12-hour
period, the city will average 50 to 75 vehicles for the first 12 hours, and 95 to 100 over the second 12 hours.
In addition to drivers, foremen and mechanics responsible for vehicle maintenance work similar shift patterns.
The Operating Budget Will Drop Almost 2 Percent Due To Reduced Snow Removal
The annual cost of removing snow consists principally of labor costs attributable to snow removal activity,
and the cost of expendable materials, such as salt, used in deiting. Table 5 presents Cleveland's annual snow
removal budget for recent years, and the associated inches of accumulation. As the table shows, removal costs
roughly track total accumulation.
As noted earlier, the average amount of snow accumulation projected for Cleveland under each climate
change scenario is about 8 inches per year, a mere 16 percent of the current annual average. The winter
comparable for the Cleveland area, Nashville Tennessee, registers average annual snow accumulation in amounts
roughly equal to those projected for Cleveland.
TABLES
SNOvV AND ICE CONTROL COSTS
Year Cost Accumulation
1980 $3,477 38.7"
1981 4,282 60.5"
1982 5,646 100.5"
1983 4,069 38.0"
1984 5,379 79.4"
SYrAv. $4.571 63.4"
Source: City of Cleveland Mayor's Estimates, various years; and U.S.
Climatic Research Center.
Nashville snow removal costs from 1982 to 1987 averaged about $200,000 per year. Data from other cities
confirm that Nashville's approximate level of expenditure is an appropriate benchmark for accumulation of that
magnitude.
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This implies that Cleveland's snow removal budget could decline from its current annual average of $4.6
million per year to about $200,000 per year. The decline of 95%, for an annual savings of $4.4 million, represents
about 1.9 percent of the city's $235 million operating budget.
THE STORM/WASTEWATER COLLECTION SYSTEM SHOULD NOT BE ADVERSELY AFFECTED
Cleveland's combined storm and wastewater collection system presents problems for the area, primarily the
effluent treatment difficulties associated with all such combined systems. (See the discussion in Peterson et al.,
1982.) It does not appear likely, however, that these problems will be exacerbated by the effects of long-term
climate change because both the GISS and GFDL models project decreased precipitation in the rainy season.
A DROP IN THE WATER LEVEL OF LAKE ERIE SHOULD HAVE LITTLE IMPACT
Recent analyses suggest that global warming should cause some lowering of the water levels in the Great
Lakes. This would occur due to both increased evaporation from the lake surfaces themselves and increased
evapotranspiration from the land, which would result in less runoff into the lakes. Quinn (1987) has worked with
scenarios in which a doubling of carbon dioxide in the atmosphere yields estimated drops in Lake Erie's surface
ranging from 1.7 feet to 3.5 feet He suggests that reductions in this range would adversely impact the Great
Lake system as a whole, affecting hydropower generation as well as navigation and recreational boating. Would
they, however, have a notable impact on Cleveland's infrastructure?
Our inquiries, albeit preliminary, suggest that they would not, in part because the estimated drops in surface
levels due to global warming would not be extreme in relation to past variations. The minimum level ever
recorded for Lake Erie (in 1936) was 63 feet below the highest recorded level (in 1986 • Raoul and Goodwin,
1987). Seasonal variations in levels of the Great Lakes range from 1.0 to 13 feet, and storm surge and wind set-
up can raise water levels by as much as 8.2 feet (Quinn, 1987).
With these data in mind, we asked several professionals generally familiar with relevant infrastructure
elements in Cleveland if they would expect any notable costs or savings arising due to a 2- to 4-foot drop below
Lake Erie's present level over the coming century. Their responses can be summarized as follows:
(1) If it occurred now, a decline in this range would be helpful in some respects. The record high water
levels of the past few years are beginning to create problems in low-lying areas of the city adjacent to the lake -
- problems with sewage disposal, storm-water drainage, and in some locations, shore erosion. Considering its
timing, however, this impact would not eliminate the need for expenditures to address these issues in the short
term.
(2) The city's water intakes are about 2 miles off shore and 20 feet to 30 feet below the lake surface, so
the estimated drop would have no effect on this element.
(3) The navigability of rivers that flow through the city into Lake Erie (most important, the Cuyahoga)
could be affected somewhat, necessitating dredging in some places. However, given the magnitudes and the time
period involved, this would not be likely to have a notable budgetary impact.
(4) A 2- to 4-foot drop should not require the alteration of structures (predominantly piers) at the shore
line.
Other factors could combine with climate effects to yield a more serious drop in the lake level over the
coming century. Further analysis would be warranted if significant trends in that direction were noted.
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CHAPTER 4
IMPACTS IN NEW YORK CITY
INTRODUCTION: WATER SUPPLY AND OCEANGATE NEEDS WILL BE THE LARGEST
New York City infrastructure may be affected in many ways by global climate change. Temperature
change could have much the same effects as in Cleveland The heat wave of 1988 illustrated another probable
impact. In Manhattan, heat exacerbated the effects of long-standing leaks in 256 km of steam pipes, causing the
asphalt to soften. As vehicles kneaded the soft asphalt, thousands of bumps formed on city streets, requiring
extensive repairs (Hirsch, 1988).
Interpolation of the data in Weggel et al. (Volume B) suggests that upgrading dikes and levees in response
to a 33-foot rise in sea level might cost $85 million over a 100-year period A senior member of the city's Office
of Environmental Protection indicated that all sanitary and much storm sewage is pumped (Schwarz and Dillard,
1988). The roughly 450 outfalls use gravity flow into tidal areas. With rising sea level, these outfalls would have
to be inspected more frequently and pumps might run more, but the official felt the system capacity and design
would not need revision. Higher sea level, nevertheless, could increase sewer backups, ponding, and basement
flooding in a few low-lying areas when high tides coincided with high runoffs. The official noted that the city
already has hedged against the possibility of sea level rise by raising an outlet on a drainage structure for a water
tunnel it is building.
A study by Linder et al. (1987) suggests that increased air-conditioning use could raise peak electric
demand by 10 to 20 percent in the New York metropolitan area.
The most pressing, and perhaps largest, problem facing the city may be the impacts of global climate change
on water supply adequacy. Because of its complexity, the New York City case study was restricted to this issue.
The City of New York is served by one of the most extensive water supply networks in the eastern United
States: a product of over 350 years of water supply planning and capital project development. Served principally
by surface sources that ultimately feed estuarine waters, the city's water supply is a complex hydrologic system,
dependent on the continued high quality and quantity of water in upstate watersheds, and the behavior of ocean
tides in the Hudson and Delaware Rivers. It also is an extensive physical network of dams, transmission facilities,
and distribution and treatment works, representing not only an enormous financial investment but also an
essential component in the overall economic vitality of the region. Analysis of the city's system and speculation
as to its future can lend valuable insights in water planning and management to other coastal cities in the United
States.
The City of New York water supply network currently faces a modest deficit; a gap between what
consumers typically demand from the system and what the system can dependably supply during drought
conditions. By some accounts, this deficit is expected to increase over the next 50 years to more serious
proportions as a result of population and office employment growth, continued increases in per capita
consumption, and the addition of new communities to the system.
The principal effect of global climate change on the New York City water supply network will be increasing
water supply deficits over those already projected as:
o rising mean temperatures and sharp increases in cooling degree days result in increased recreational
and air-conditioning water use;
o increased variability in precipitation, from year to year, could produce more severe droughts, thus
reducing the dependability of the existing network; and
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o rising sea levels cause up-river movement of the salt front in both the Delaware and Hudson Rivers,
forcing cutbacks in the amount of water that can be taken from both sources during drought.
As a result of these climate effects on the water supply network, it is highly likely that new region-wide water
supply impoundments will have to be created, and new water management institutions put hi place. Probable
effects include:
o creation of new capital supply projects serving communities along the Delaware River Basin, Northern
New Jersey, and the Lower Hudson and Long Island, at an estimated capital cost in the range of $3-
7 billion;
o integration of regional communities in a single water supply and management system; and
o creation of new water management institutions at the State level to finance capital project development
and allocate water among competing communities and competing uses.
WATER SUPPLY SYSTEM CHARACTERISTICS
The New York Water Supply System is in Deficit
Water supply to the City of New York and those systems served by the city's water supply system is
provided by four supply systems: the Delaware River Basin Watershed, the Roundout Reservoir, the Catskill
System, and the Croton System (see Figure 4). With appropriate reserve capacities maintained in each system
- 25 percent for the Roundout, Catskill, and Croton reservoirs - and the Supreme Court-mandated flow rates
in the Delaware for the Delaware watershed, the system can safely supply 1^290 million gallons per day under
the worst drought of record (Mayor's Intergovernmental Task Force, 1987).
This means that currently, the New York water supply network is a system in deficit. Average daily demand
on the system now averages somewhat over 1^500 million gallons, meaning an approximate supply deficit of 200
million gallons (Citizens Union Foundation, 1986). In other words, if the drought of the 1960s was to be
repeated, consumers in the City of New York, and in systems supplied by the City of New York, would have to
cut demand by about IS percent
Reductions on this scale are achievable with the introduction of emergency restrictions on water
consumption, but such reductions will become more difficult to effect hi the future. First, water consumption
will continue to increase, and second, new claimants for water from the system are likely to be absorbed into the
New York water supply network.
Currently, New York City is served by two systems, the New York City System and the Jamaica Water
Supply Company (WSC). These serve between 7.1 and 7.6 million people in the city (Jamaica WSC about
500,000) and another 800,000 people in upstate counties (Hazen and Sawyer, 1987). Assuming a modest increase
in consumption due to population growth and no increase in per capita consumption, but allowing for new users
upstate and on Long Island, an estimated 1,700 million gallons of water daily will be demanded by 2030. The
currently available supply, thus, will leave a deficit of 400 million gallons daily for New York City and the other
locations that the system supplies or has agreed to supply.
These projections should be viewed in the context of overall regional water supply needs: those of the Long
Island communities, New Jersey, and those parts of Pennsylvania and Delaware served by the Delaware River.
If current supply deficit estimates made by the Delaware Regional Basin Commission (DRBC) and those
produced hi support of the New Jersey Water Supply Master Plan are conservatively adjusted by a 1 percent per
annum increase in consumptive use, deficits exceeding 600 million gallons per day can be projected for the
Delaware River Basin communities (Hull et aL, 1986) and New Jersey for the year 2030 (State of New Jersey,
1987). Plans are being made to address this deficit, as noted below.
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NEW YORK
DELAWARE
WATERSHED
.• MASSACHUSETTS
CATSKILL WATERSHED
WATERSHED
... Montague' .•
.••* / 3 / •
JAMAICA NYC
WELLF1ELU
• ••••• Limlti of the Hudson and Delaware
River Btuns
NewYorkCity Supply Watersheds
Ntw Cretan Aqueduct
Ctttklll Aqueduct
Aqueduct
«p MHIS
o zo «o to 10 100 mourn ts
Walker
SOURCE: Citizens Union Foundation of the City of New York, Inc.
Thirsty Cityt • A Plan of Action for New York City Water Supply, 1986.
Figure 4. The sources of New York City's water supply.
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New York City and the other regional water users compete for water supply from the Delaware. The
Delaware River Basin Compact is the fundamental agreement structuring water allocation in the region. Backed
by a 1954 Supreme Court decree, the DRBC limits water withdrawals by the New York water system to maintain
a specified flow rate in the Delaware. The specified flow controls the salinity of the Delaware estuary. It
preserves the habitat of current aquatic inhabitants, ensures that chloride concentrations at the Camden and
Philadelphia water supply intakes do not exceed accepted standards, and prevents contamination of suburban New
Jersey's aquifers.
Current Policy Responses Include Conservatfap ^d Construction
Current responses to the current and projected water supply deficits include a combination of demand
management and capital project development.
Both the State of New Jersey and the DRBC (also including State of New Jersey participation) have made
plans to address their current and projected deficits. Current projects already built, or on line, are expected to
increase the dependable yield of the regional system by slightly over 500 million gallons per day, leaving a
modest supply deficit to be addressed by projects currently being actively considered (State of New Jersey, 1987).
If these projects are fully developed (all planned by the State of New Jersey under the Master Plan), the resulting
yield will be more than adequate to meet projected water supply requirements.
New York City and the communities supplied by New York City currently are considering water supply
alternatives to meet the existing, and projected, deficit. Demand management measures include leak detection
and repair and universal metering of a now largely unmetered system. The likely result of demand management
measures is unclear. The amount of water that can be saved from the repair and detection of leaks is estimated
at about 25 million gallons per day. Together with the savings projected to be achieved from metering, estimated
at 133 million gallons per day, about 158 million gallons per day, total, can be saved with demand management
(Mayor's Intergovernmental Task Force, 1987).
This estimate, however, is unreliable, since in the absence of an already metered system, demand forecasts
are very difficult to make; the actual savings may be higher or lower than indicated. And while the contribution
of full-system metering to the effectiveness of local water management is clear, extreme care should be taken
in projecting major savings due to metering alone. First, the price elasticity of water consumption is low; it
appears to be somewhat elastic for urbaculture ~ the watering of lawns and gardens ~ but not very elastic for
commercial or domestic consumption (Morgan and Smollen, 1976). Second, the current per capita consumption
for New York City is in line with consumption in other major cities, suggesting that there is not a great deal of
careless use now without metering. That part of the system currently serving New York City alone consumes
about 206 gallons per capita per day (Hazen and Sawyer, 1987). This compares with survey data showing a mean
per capita use of 183 gallons per day for cities over 1 million in population and is well within one standard
deviation of the mean for systems of this size (Temple et aL, 1982). Third, reduced discretionary water use as
a result of metering will reduce the yield from emergency reductions in water use during droughts.
Proposed capital project measures include activation of the Chelsea water intake on the Hudson, and
artificial recharge of the aquifer under Brooklet, currently supplying the Jamaica wellfield (Mayor's,
Intergovernmental Task Force, 1987). The most likely scenario calls for reactivation of the Chelsea intake for
drought emergency use, or some variant involving withdrawals at Newburgh or Kingston; from 100 million to 200
million gallons a day of added temporary capacity can be produced from this source, costing between $223 and
391 million (1986 dollars).
Assuming that demand management measures result in the water savings estimated above, and that
currently considered capital projects are developed, the existing water supply deficit will be eliminated over the
next 10 years.
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GENERAL EFFECTS OF CLIMATE CHANGE ON SYSTEM PERFORMANCE
An effective doubling in atmospheric carbon dioxide will change the water supply balance in the region
dramatically. Increased salinity in the Delaware estuary and large movements of the salt front mean that
increased flows will be needed to maintain the quality of community supplies in the lower Delaware. At the
same time, shifts in seasonal precipitation in the Hudson watershed will mean reduced safe yields. In addition,
movement of the salt front up the Hudson River may jeopardize the viability of currently planned solutions to
New York City supply problems, and saltwater infiltration into the Long Island aquifer will increase regionwide
demand for surface water sources. Finally, the projected size of the New York City deficit probably will be
increased by climate change-induced increases in consumption, and more uncertain supplies due to more frequent
drought events.
Climate Change Will Raise Water Demand
As indicated in the first section, temperatures in the region will rise under both climate scenarios, in all four
seasons. The GFDL 2XCO2 scenario calls for increases of 11-12*F in summer, autumn, and winter, and 8°F in
spring. The GISS scenario calls for more modest increases, ranging from 6 to 8°F. If Louisville is used as the
summer analog, based on summer mean, maximum, and minimum temperatures, and the number of days with
maximum temperatures over 90°F (Kalkstein, 1988), the number of cooling degree days for the city will increase
21 percent, from an annual average of 1048 to a projected 1268, in response to an effective doubling of carbon
dioxide.
The likely effect of this increase on water demand cannot be projected precisely. Currently, abnormally
hot days can produce increases of 50 percent in the amount of water use typical for summer days. Air-
conditioning use, unauthorized and authorized hydrant openings, urbaculture, and recreational use in Queens and
suburban areas served by the city system all increase. Reduced summer precipitation also produces an increase
in lawn watering unless usage restrictions are imposed
The amount of increased use attributable to increased air-conditioning is difficult to estimate. Since the
current water supply distribution system is unmetered, it is uncertain how much water large residential customers
consume. The allocation of water use between air-conditioning and other uses also is unknown. Nevertheless,
the amount of water consumed by large water-cooled building air-conditioning systems can be estimated by
applying design standards to estimated climate effects on air-conditioning use. If half of the projected 800
gigawatt-hour increase in demand for electric power for air-conditioning in downstate New York due to climate
change is attributed to large building systems (Linder et al., 1987), the added cooling load is about 400 million
tons annually (Norman, 1988). That cooling load implies an estimated 50 million gallons per day of cooling tower
water loss through evaporation (Fulkerson, 1988).
Holding the cost of water, the irrigable area, and the value of dwelling units constant, Morgan and Smollen
(1976) showed water consumption for urbaculture historically has varied significantly depending on weather
conditions. The largest suburban consumers of water for urbaculture are in Queens (estimated 61 mgd in 2030)
and Westchester (estimated ID mgd in 2030). Adding remaining upstate counties in the Lower Hudson Region
and some Long Island communities (estimated 71 mgdX 245 mgd, or about 14 percent of total projected average
daily demand, will be for urbaculture by 2030 (Hazen and Sawyer, 1987). With summer consumption averaged
over the year, the additional demand, even if consumption increased 50 percent during summer months, is about
30 mgd. In sum, a rise of about 80 million gallons in average daily demand is probable. This is about 5 percent
of estimated demand in 2030 without climate change.
Cliiqate Change Will Have Detrimental Effects on Watershed Hydrology
The effect of doubled atmospheric carbon dioxide on current sources of supply is more difficult to predict,
given the sensitivity of watersheds to small variations in regional climate and the difficulty of predicting the
frequency of droughts.
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Walker
On an annual basis, the amount of precipitation projected for the 2XCO2 scenario is little changed from
current patterns. Nevertheless, sharp changes in the precipitation expected for certain seasons are predicted.
The GFDL scenario calls for increased seasonal precipitation in all but the summer season, while the GISS
scenario produces sharply reduced summer and fall amounts. Nevertheless, increased evaporation due to higher
temperatures is the primary hydrologic response to climate change (Rind and Lebedeff, 1984.) The GISS and
GFDL scenarios show annual declines in water runoff of about 16 and 17 percent, respectively.
TABLE 6
PROJECTED PERCENTAGE CHANGE IN SELECTED
HYDROLOGIC VARIABLES FOR AN EFFECTIVE DOUBLING IN ATMOSPHERIC CO2
Season Precipitation Runoff
GFDL GISS GFDL GISS
Winter
Spring
Summer
Autumn
Annual
+ 113
+ 7.4
- 29.7
+ 1L2
+ .1
+ 4.6
+ 123
- 4.4
- 21.7
- 33
+ 42
- 11.5
- 97.7
+ 64.9
- 172
• 103
+ 10.1
- 22.6
- 42.0
- 15.8
Source: Scenarios supplied by Roy Jeime, National Center for Atmospheric
Research.
Application of the water balance model developed for use in the Great Lakes region (Cohen, 1985)
produces an estimated reduction in streamflow for the Great Lakes basin of between 12 and 29 percent and a
supply loss of 10 to 24 percent, depending on whether reduced evaporation due to lower windspeeds will partially
offset temperature effects (ICF, 1987).
Moreover, increasing variability in climate may produce more frequent droughts. Though recent research
on this issue focuses on North American regions other than the Northeast, the general rule is increased variability
in precipitation in higher latitudes. Average changes are from 10 to 20 percent, although these changes vary
widely in magnitude across gridpoints and seasons (Rind et al, 1988). Thus, changes in precipitation may cause
more droughts. Increased variability in climatic circumstances probably implies increased severity as well (Rind
and Lebedeff, 1984). Therefore, the design drought probably will have to be redefined, and the system safe yield
will drop.
Based on the estimated decline in net basin supply alone - 10 to 24 percent - the 2030 supply deficit for
the New York City system will amount to about 155 to 374 mgd, assuming that current projects are completed
and that savings from demand management meet projections. This estimate does not include a downward
adjustment in safe yields due to increased drought severity. Substantial additional research would be required
to make that adjustment
Sea Level Rise Will Cut Safe Yields and Cause the Salt Line to Rise Above Proposed New Water Intakes
Without overstressing the uncertainty of these projections, it seems quite likely that rising sea levels over
the next 100 years, based even on the most conservative projections, will have dramatic effects on supply
availability from current and projected water sources.
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Walker
The behavior of the saltwater interface in estuarial waters is a function of the tidal pressures acting to move
the salt front upriver and the opposite flow of freshwater downriver. Under circumstances of low freshwater
flows, as occurs typically during drought, the freshwater-saltwater interface moves up-river. It is precisely this
phenomenon that prompted issuance of the Supreme Court decree fixing the limit of New York system
withdrawals from the Delaware, in order to protect both estuarine aquatic life and community water supplies
from changes in salinity.
With sea level rise, saltwater pressure upriver increases. During the 1960s drought, the salt front in the
Delaware River moved from its average location at river mile 69 to mile 102. Acceptable chloride concentrations
were not exceeded during any tidal cycle (Hull et aL, 1986). Under assumptions of a 14- and 8.2-foot rise in
sea level, a movement of the salt front an additional 10 miles upriver during a repeat of the drought of record
could be expected. This is sufficient to increase salinity at Camden and Philadelphia intakes beyond tolerable
levels during 15 percent of tidal cycles, for a 14-foot rise, and 50 percent of tidal cycles for a 8 .2-foot rise (Hull
et aL, 1986). Increased salt water infiltration into the Mahogothy aquifer serving southern New Jersey also is
likely, meaning increased flows in the Delaware will be required to preserve this source of supply.
Reasoning by rough analogy to the Delaware River's behavior under increased sea levels is an inherently
unsatisfactory analytic technique. The geometries of the Delaware and Hudson estuaries are different now and
would alter with rising sea level (Hull et al., 1986). Nevertheless, the absence of any modeling studies designed
explicitly to account for sea level rise means that such an analogy is the only practical way to make projections.
For estimating potential order of magnitude effects, the analogy is reasonable. (In addition, the average flows
in both rivers are roughly comparable: 21,500 ft3/sec. average flow into the Delaware estuary; 17,700 ftVsec in
the Hudson at Poughkeepsie (Hull et al., 1986, and Pirnie, 1986).
Currently, the maximum reach of the salt front during summer in the Hudson under normal flow conditions
is at Peekskill, at river mile 45, although in a typical year, the front (chloride concentration of 50 mg/L) fluctuates
from 20 to 60 miles north of the Battery (Pirnie, 1986). If the percentage change in salt front location estimated
for the Delaware is applied to the Hudson - adding 10 river miles to the 30 already experienced during drought
-- the Chelsea and Poughkeepsie water intakes are rendered unuseable given current standards of drinking water
taste and odor. During the drought year of 1981 the salt front fluctuated between river miles 30 and 80, with
a median location roughly at river mile 55. On this basis, a 33 percent increase in the projected advance would
place the salt front at river mile 58, with fluctuations between miles 33 and 87. Based on the 1982 experience,
the Chelsea station would be rendered inoperative roughly 7 months out of the year, the Poughkeepsie intake
3 months. A local water supply planner estimates even a 0.8-foot rise in sea level would render the proposed
Chelsea intake inoperative during droughts (Schwartz and Dillard, 1988).
An additional constraint is that salt front movement in the Delaware due to sea level rise means current
New York system withdrawals from the basin would adversely impact communities in the lower Delaware,
including Philadelphia. Cuts in Delaware withdrawals under a revised consent decree are likely.
If the Chelsea were unavailable during droughts, no increase in dependable yield could be credited to this
potential source, thus removing 200 mgd emergency capacity from the network as currently projected. If the
net basin supply behaves as estimated in the preceding section, producing an estimated loss of between 12 percent
(155 mgd) and 29 percent (375 mgd) of current supply, the total loss in dependable yield could range from 355
mgd to 575 mgd. With a conservative estimate of 12 percent supply loss, and assuming that demand management
efforts are as effective as now projected, the estimated supply deficit for the New York system will increase from
about 361 mgd to 7% mgd, as shown in Table 7.
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Walker
TABLE?
SUMMARY OF CLIMATE EFFECTS ON SAFE YIELD
MOD
Demand
Projected 2030 1,651
Climate-induced additions
Recreational and urbaculture 30
Air-conditioning 50
Total . 1,731
Safe Yield
Projected 2030 1,290
Climate-induced subtractions
Chelsea intake **
Basin supply 355
Total 935
Current projected deficit 361
Climate-induced deficit 796
NOTE: Projected demand of 2030 is Hazen and Sawyer's projection of 1709, net
demand management savings of 158 mgd.
** Loss of temporary capacity of 200 mgd from Chelsea intake, and 50 mgd
from Brooklyn groundwater not calculable as safe-yield loss.
POLICY RESPONSES TO CLIMATE EFFECTS
Despite an increasing trend in recent years toward noncapital project solutions to water supply deficits,
the combined effects of climate change and sea level rise almost certainly will require capital solutions.
Moreover, increasing regional scarcities will demand increased regional cooperation in water supply development
and allocation, making closer linkage of water management institutions probable.
Capital Project Responses Mav Cost Billions
Under the scenario examined above, a possible outcome of global climate change from the standpoint of
New York water supply alone is an increased supply deficit of about 435 million gallons per day, assuming current
projects yield additional supplies as projected.
The additional impoundments required to address the water supply deficit projected for New Jersey and
the Delaware River Basin may create enough capacity to cover at least part of this deficit Delaware River flow
augmentation studies estimate that about 100 million gallons per day of additional storage capacity will be
required (Hull and Titus, 1986), roughly one-fifth of the estimated storage capacity of the Tock*s Island
Reservoir, once project J for development on the Delaware, or half the storage capacity available if a series of
smaller projects in the region moves forward.
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Walker
The ecologically undesirable Tock's Island development on the Delaware River, projected to yield 650
million gallons per day, would cost $850 million (U.S. Army Corps of Engineers, 1977). In addition to its role
in Delaware River flow augmentation, a portion of the additional supply created through this development
would almost certainly be used to augment system yields in northern New Jersey. The augmentation is needed
to offset climate-induced supply deficits caused by increased demand and probable limits on withdrawals from
the Raritan and Passaic Rivers resulting from sea level rise. Therefore, even with development of Tocks, or
especially a regional network of smaller reservoirs that would deliver a smaller supply, some regionwide shortfall
would remain.
Therefore, climate-induced water supply deficits in New York and the lower Hudson region probably will
prompt development of a project similar to the currently proposed Hudson River flood skimming project. This
project would require the development of new impoundments and transmission facilities, and would produce an
estimated increase in safe yields of about 800 millions gallons per day. This solution would be expensive — about
$2.8 billion (in 1986 dollars). In the long run, it also leaves little room for additional growth. An alternative
project currently in initial planning stages, the Hudson River phased flood-skimming project, would yield 1,500
million gallons per day at a projected cost of $7-14 billion (Mayor's Intergovernmental Task Force, 1987).
With New York system capital project development of this magnitude, the Delaware River Basin/northern
New Jersey water supply solution likely could be scaled down to an overall development less demanding in terms
of capital and political costs than would be the case with Tocks Island. This linkage points up an important
institutional consequence likely to result from global climate impacts on water supply availability — the increased
need to coordinate water management responses.
Water Management Responses Will Be Controversial
Though the immediate solution to water supply deficits would be development of impoundments sufficient
to ensure overall safe yield to the system, the ultimate response of water management agencies in the region may
have to be creation of new water management institutions.
As indicated in the preceding discussion, water supply decisions made by any single actor in the region have
important implications for other actors. The Supreme Court decision limiting New York withdrawals from the
Delaware is only the most visible manifestation of this interlinkage. Under conditions of global climate change,
new sources of water will have to be developed, and new competitors for regionwide water supplies will emerge.
Thus, two critical issues will have to be faced. Who will plan and finance the new capital projects necessary for
growth? Who will play the central role in water allocation? In other States, New Jersey a prime example, when
regional water management issues become critical, the State takes the lead role in financing and management.
Localities with a traditional bias toward self-sufficiency in water supply tend to resist centralization of water
management decision-making. In addition, the siting of capital projects involves clear winners and losers. For
example, one prime site for an impoundment currently considered a long-range solution to the New York supply
deficit would involve reservoir construction in Adirondack State Forest, a solution prohibited by New York
State legislation. Increased water scarcity would doubtless alter political balances. Acrimonious fights over
capital project siting are likely.
The Response Must Start Now
Although the rise in sea level is projected to occur gradually over the next 100 years, the long lead times
in water project development argue for the incorporation of climate effects in water supply planning now. One
early step that can be taken is to include modeling of sea level effects in upcoming work by the U.S. Geological
Survey to evaluate the behavior of the saltwater front in the Hudson River. Clearly, the viability of several
projected water supply solutions is keyed to the behavior of the Hudson River saltwater-freshwater interface.
The additional analysis required to include sea level rise effects would not be substantial and is an important
example of how incremental changes in current water supply planning practices can forestall potentially serious
future adverse effects.
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Walker
In addition, incremental capital project changes that have no large cost implications can be made. Recently,
a routine design decision on the placement of an outfall of the Third Water Tunnel incorporated an extra margin
of safety, designed to allow for sea level rise. Though no formal analysis was conducted to guide this decision,
it represents the kind of planning adjustment that should be made part of the design calculus of future water
planning and management decisions.
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Walker
REFERENCES
American Association of State Highway and Transportation Officials, Manual for the Design of Pavement
Structures, Appendix G, Treatment of Roadbed Swelling and/or Frost Heave in Design," 1987.
Bowersock, John, Interview with The Urban Institute, March 17,1988.
Carpenter, Samuel H., Darter, M.I., and Dempsey, G J., and Herrin, Stan, "A Pavement Moisture-Accelerated
Distress (MAD) Identification System," Volumes 1 and 2, FHWA/RD-81/079, September 1981.
Chang, F.F.M., A Statistical Summary of the Cause and Cost of Bridge Failures. Federal Highway Administration,
US. Department of Transportation, Washington, D.C, 1973.
Citizens' Union Foundation of the City of New York, Thirsty Citv: A Plan of Action for the New York Citv
Water Supply. 1986.
City of Cleveland, Energy Planning and Management: A Project Report, prepared for the Urban Consortium
Energy Task Force, Cleveland, December 1981
City of Miami Department of Public Works, Storm Drainage in South Florida. Miami, Florida, (o,d).
City of Miami Department of Public Works, Storm Drainage Master Plan. Executive Summary, September 1986.
Cohen, Stewart J., "Impacts of CCylnduced Climate Change on Water Resources in the Great Lakes Basin,"
Climate Change. 1985.
Department of County Engineer of the County of Los Angeles and Engineering Science, Inc, Development of
Construction and Use Criteria for Sanitary Landfills. Report PB-218-672, US. Environmental Protection Agency,
1973.
Diamond, Craig, Senior Research Associate, Florida Atlantic University-Florida International University Joint
Center for Environmental and Urban Problems, Interview with The Urban Institute, September 1988.
Downtown Development Authority of the City of Miami, Florida, Consolidated Application for Development
Approval for Downtown Miami as Development of Regional Impact Miami, Florida, February 1988.
Energy Information Administration, Annual Outlook for US. Electric Power, 1987, Department of Energy, 1987.
Federal Highway Administration "Section 137 Studies: Climate and Apportionment and Interstate 4R
Apportionment, prepared for the United States Congress, December 1983.
Fulkerson, R., Chairman, Technical and Performance Committee, Cooling Tower Institute, personal interview
with The Urban Institute, June 1988.
Getz, Robert, "Interview with The Urban Institute," March 16,1988.
Gurwitz, Aaron S., and Kingsley, G. Thomas, The Cleveland Metropolitan Economy, prepared for the Cleveland
Foundation, Rand Corporation, March 1982.
Hazen and Sawyer, P.C., Delaware-Lower Hudson Regional Water Resources Management Strategy. New York
State Department of Environmental Conservation, September 1987.
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Walker
Heath, Ralph C, Basic Ground-Water Hydrology. ILS. Geological Survey Water Supply Paper 2220, US.
Government Printing Office, 1987.
Hirsch, J., "As Streets Melt, Cars Are Flummoxed by Hummocks," The New York Times 137 (47599). August
16, 1988, pp. Bl, B5.
Hull, C.HJ. and Titus, J.G. Greenhouse Effect Sea Level Rise, and Salinity in the Delaware Estuary.
Washington, DC: U.S. Environmental Protection Agency, Delaware River Basin Commission, May 1986.
Jenne, Roy, "GISS and GFDL Climate Projections: National Center for Atmospheric Research, 1988.
Under, K.P., M J. Gibbs, and M.R. Inglis, "Potential Impacts of Climate Change on Electric Utilities",
Albany, NY: New York State Energy Research and Development Authority, Report 88-2, December, 1987.
Mayor's Intergovernmental Task Force on New York City Water Supply Needs, Managing for the Present.
Planning for the Future. December 1987.
Metro Dade County Florida, Comprehensive Development Master Plan. April 1988.
Metropolitan Dade County Planning Department, Comprehensive Master Plan for Dade County. Florida. Miami,
Honda, July 1979.
Morgan, W. Douglas, and Smollen, Jonathan Cn "Climate Indicators in the Estimation of Municipal Water
Demand," Water Resources Bulletin. 123,1976, pp. 511-515.
Norman, J., American Society of Heating, Refrigerating, and Air-Conditioning Engineers, personal interview with
The Urban Institute, June, 1988.
Parham, David, Infrastructure Condition and Financial Monitoring Data Base Report, Urban Institute Report
submitted to the Greater Cleveland Growth Association, September 1985.
Peterson, George E., Miller, MJ., Godwin, S.R., and Shapiro, C., Guide to Benchmarks of Urban Capital
Condition, Urban Institute Press, 1981.
Pirnie, Malcolm, Drought Operation of the Hudson River Pumping Plant Located at Chelsea. Dutchess County.
New York. Draft Environmental Impact Statement, November 1986.
Post, Buckley, Schub and Jerrican, Inc. and Department of Army, Corps of Engineers, Lower Southeast Florida
Hurricane Evacuation Study, prepared for Monroe, Dade and Palm Beach Counties, June 1983.
Quinn, Frank H. (1987), "Likely Effects of Climate Changes on Water Levels in the Great Lakes, in Preparing
for Climate Change. Proceedings of the First North American Conference on Preparing for Climate change: A
Cooperative Approach, Washington, D.C, October 1987.
Raoul, Joseph and Zane M. Goodwin (1987X "Climatic Changes - Impacts on Great Lakes Levels and
Navigation," in Preparing for Climate Change. Proceedings of the First North American Conference on Preparing
for Climate Change: A Cooperative Approach, Washington, D.G, October 1987.
Rhoads, P.B., Shin, C.C. and Hamrick, R.L., "Water Resource Planning Concerns and Changing Climate: A
South Florida Perspective," in Proceedings of the Symposium on Cflinate Change in the Southern United States:
Future Impacts and Present Policy Issues, conducted by the Science and Public Policy Program, University of
Oklahoma and sponsored by the U.S. Environmental Protection Agency, 1987.
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Rind, D., and Lebedeff, S., "Potential Climate Impacts of Increasing Atmospheric CO2 with Emphasis on Water
Availability and Hydrology in the United States," NASA Goddard Space Flight Center Institute for Space Studies
April, 1984.
Rind, D., Goldberg, R., and Ruedy, R., "Change in Climate Variability in the Century", Goddard Space Flight
Center Institute for Space Studies, unpublished draft, 1988.
Schwarz, Hair E., and Lee Dillard, "Chapter ffl-D Urban Water," in AAAS Global Climate Change Report,
Washington, D.C., 1988.
Shih, George, "Everglades National Park and the Rising Sea Level," Memorandum, South Florida Water
Management District, January 9,1984.
South Florida Water Management District, Water Resources Data and Related Technical Information to Assist
Local Government Planning in Dade County. West Palm Beach, Florida 1987.
State of New Jersey, Department of Environmental Protection, Division of Water Resources, The New Jersey
Statewide Water Supply Master Plan. Draft Update, August 1987.
Temple, Barker & Sloane, Inc., "Survey of Operating and Financial Characteristics of Community Water
Systems", Office of Drinking Water, U.S. Environmental Protection Agency, October, 1982.
Tripp, R., Communication to the Urban Institute from Howard, Needles, Tammen and Bergendoff, 1988.
U.S. Army Corps of Engineers, North Atlantic Division, Northeastern United States Water Supply Study.
Summary Report July 1977.
U.S. Department of Commerce, Bureau of the Census, County and City Data Book. 1983.
U.S. Geological Survey, Resource-Management Evaluation and Study of Salt-Water Movement Within the
Transition Zone of the Hudson River Estuary. New York, 1988.
Vermani, Y.P., Clear,, K.C., and Pasko, TJ., Time-to-Corrosion of Reinforcing Steel in Concrete Slabs,
FHWA/RD-83/012, September 1983.
Walker, J. Christopher, and Friedman, Mark A, "The Greater Cleveland Community Capital Investment Strategy:
Five Years Later," Project Report prepared for the Greater Cleveland Growth Association, March 16, 1988.
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IMPACTS OF EXTREMES IN LAKE MICHIGAN LEVELS
ALONG ILLINOIS SHORELINE: LOW LEVELS
by
Stanley A. Changnon, Jr.
Steven Lefiler
Robin Shealy
Illinois State Water Survey
and
University of Illinois
Champaign, IL 61820
Contract No. CR-814658-01-0
-------
CONTENTS
Page
FINDINGS 3-1
CHAPTER 1: INTRODUCTION 3-3
GOALS AND OBJECTIVES 3-3
Central Concept of the Study 3-3
Two Discoveries Affecting the Study and Its Findings 3-3
CHAPTER 2: METHODOLOGY 3-5
MEASUREMENT OF EFFECTS AND ADJUSTMENTS TO RECORD LOW LAKE
LEVELS 3-5
Data Sources 3.5
Climate Scenarios 3-5
Development Process 3-5
CHAPTER 3: RESULTS 3-11
IMPACTS OF LOW LAKE LEVELS 3-11
Data Sources 3-11
The Physical Setting: Climate and Other Factors Relevant to Lake-Level Extremes ... 3-12
Climate Influences on Levels of Lake Michigan 3-12
Other Factors Influencing Levels of Lake Michigan 3-14
Climate Conditions During 1964-65 3-15
Variability of Lake Levels 3-16
Land Use 3-19
Effects and Adjustments to Low Lake Levels in 1964-1965 3-21
General Effects on the Great Lakes 3-21
Effects and Adjustments on the Illinois Shoreline 3-21
Damage to Shoreline Protection Structures 3-28
Encroachment Land Use Problems 3-29
CHAPTER 4: INTERPRETATION OF RESULTS 3-31
SUMMARIZATION OF RESULTS 3-31
SIGNIFICANCE OF FINDINGS 3-31
CHAPTER 5: SOCIOECONOMIC AND ENVIRONMENTAL IMPLICATIONS 3-32
NEEDS FOR PHYSICAL INFORMATION AND RESEARCH 3-32
MAJOR POTENTIAL IMPACTS 3-32
Assumptions 3-33
Impacts 3-33
Recreational Facilities and Harbors 3-34
Commercial Harbors 3-34
Beaches 3-36
Environmental Impacts 3-36
Water Intakes 3-36
Water Supplies 3-36
Outfalls 3-39
Encroachment 3-39
Other Possible Impacts 3-39
Conclusions 3-39
Future Adjustments 3-40
u
-------
CONTENTS (continued)
CHAPTER 6: POLICY IMPLICATIONS 3-42
Acknowledgments 3.43
REFERENCES 3.44
APPENDIX I: NEWSPAPER CONTENT ANALYSIS FOR 1964-1965 3-45
APPENDIX n: QUESTIONNAIRE FOR ASSESSING EFFECTS OF LOW LAKE LEVELS 3-48
111
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Changnon
FINDINGS1
The 9-month investigation studied the effects and adjustments from the record low levels of Lake
Michigan during 1964-1965. The focus was on the effects along the 101-km shoreline of Illinois. The expectation
was that this case study would provide a basis for estimating future effects of altered lake levels due to future
climate change, and that the results would be potentially transferable to other similar urban shoreline areas of
the Great Lakes.
The data collection effort revealed that locating quantified data on the impacts of the low lake levels in
the early 1960s was very difficult. Many original institutional records were destroyed or lost, and a newspaper
content analysis was of marginal value. Hence, it was impossible to do an in-depth quantified analysis of the
direct, secondary, and tertiary impacts. We depended on structured interviews with local experts in various
public and private sector positions to provide much information on the impacts and responses of the 1964-65 low
levels, and in turn to assist us in assessing future impacts of extreme climate change. We believe the analysis
was sufficient to detect the impacts of significance and to develop useful qualitative assessments of these. As in
any study attempting to estimate future socioeconomic and physical effects from extreme climate conditions never
before sampled, the estimated impacts and responses must be considered speculative.
Analysis of the physical factors affecting low-water conditions revealed that the record low-level period
of 1964-65 would have been worse if precipitation over Lake Superior had been below average (it was near
normal). A series of climate scenarios based on (1) three global climate model estimates from doubling of CO2
with atmosphere, and (2) on extreme annual precipitation values of the last 134 years on the Great Lakes Basin,
were used to derive estimates of potential low lake levels in future years. These provided a variety of estimates
of lake level lowerings ranging from 0.4 to 15 meters, and were used for estimating future 'impacts. The
interannual variability of lake levels in low-level (dry) periods was studied and found to be slightly greater than
in extremely wet periods. This would be an important factor needed for estimating future effects of low levels.
The climate scenarios did not provide estimates of interannual variability or of long-term fluctuations apt to
occur.
An important concept about the effects of low (or high) lake levels is the fact that neither extreme is
desirable. In low lake level periods, detrimental shoreline effects are minimized, relevant to those in high levels,
but during low level periods, considerable economic loss is experienced by shipping and power generation
interests across the basin. In general, the reverse situation occurs during high lake level periods.
Analysis of the effects of low lake levels during 1964-1965 along the Illinois shoreline of Lake Michigan
revealed seven areas of impact. Effects on shorelines were mixed, and in general, local shipping was hurt.
Effects on recreation were mixed, and in general, industry and most commerce were hurt. Problems developed
in the water management and water supply areas, along with problems in land use management that evolved
during and after the low water period. Some institutional impacts were positive, but in general, the effects led
to adjustments that were costly to local, state, and federal government entities.
The two major impacts discerned, damage to shoreline structures and encroachment of structures closer
to the lake, developed during the 1964-1965 low levels, but both also required a sequence of low and then high
water levels. The City of Chicago frontage repairs relating partly to the low-water-induced dry rot to wooden
structures and subsequent high water wave action may cause up to $800 million to repair. Damage to buildings
and houses built too dose to the lake during the low water periods has been excessive with many damaged and
a few destroyed
1Although the information in this report has been funded partly by the US. Environmental Protection Agency
under contract CR-814658-01-0, it does not necessarily reflect the Agency's views, and no official endorsement
should be inferred from it.
3-1
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Changnon
In summary, the low lake levels of the 1960s did not provide many major economic impacts or require
adjustments at the time of their occurrence. The economic effects were mixed, some gains and some losses.
The low-water period was too short to lead to many adjustments. An important finding about impacts was the
"low-high problem." Impacts of future lower lake levels, when the climate changes occur to produce these, will
depend extensively upon the degree of long-term oscillations (decadal) in levels that occur with the lower lake
levels.
The second major part of the "low lake stud/ concerned what may occur in the next 30 to 70 years as
the Illinois area and the basin experience a drier and warmer climate than any of the past 200 years. We had
planned to estimate the future impacts, responses, and policy actions largely on the data/findings of the record
low-water period of the 1960s. However, the data were poorer than we hoped and we learned that the low
period was too short to cause many impacts or adjustments. Hence, our futuristic estimation had to be more
speculative than desired. Each climate scenario involving a different lowering of Lake Michigan was studied.
The economic impacts of future lake levels projected to be reduced from current averages by 05 to 1.0
meter during the next 50 years were not seen as too severe. It appears these can be adjusted largely by normal
maintenance and replacement costs to affected facilities. Illinois shoreline impacts will probably cost $100
million. However, the lake levels will be sufficiently low and the water quality decreased to make meeting water
demands very difficult and controversial. A more arid climate will mean less water to serve Illinois areas beyond
the basin with attendant problems in meeting needs of the Illinois and Chicago River and canal systems, as well
as for public and industrial water requirements upped by population growth and a warmer-drier climate.
Increased diversion of lake waters will be sought but resisted by national and international interests; this will lead
to increased use of groundwater, already a partly depleted resource in the region. Impacts to the environment
will include loss of the Illinois wetlands and habitats if the lake falls too rapidly and degradation of the quality
of lake water and groundwater in aquifers affected by the lake. Increased water temperatures will make cooling
more difficult, and shipping of Illinois goods will become more expensive. The net effect is extremely
detrimental to the economy of Illinois and to the future of the Chicago Metropolitan Region. The related policy
implications are considered to be major.
If the average lake level falls farther to 125 or 15 meters, even more sizable economic impacts will
occur, costing an estimated $280 million and $540 million, respectively. Parts of these costs could be ameliorated
within normal replacement costs, particularly if a master plan for changing affected facilities is developed and
implemented. The degree of climate change and ensuing lake level greatly affect the seriousness of the economic
outcome, but the environmental and water resource effects are extremely serious in all three climate scenarios.
Development and use of a master plan for the Illinois area (and Great Lakes), possibly under the program of
planning called for in the 1985 Great Lakes Charter, would be one important activity to launch now.
More specification about the nature of the climate-lake change (rate of lowering, total amount of
lowering, and variation around the new mean) is needed. Variations of levels of 3:1 from the models reveal
sufficient uncertainty to make management actions based on any one of them difficult, yet some can begin.
It would appear, given current problems with transboundary issues on the basin, that major policy issues
will be created at the community scale up through the state, regional, national, and international levels. New
approaches and institutions to deal with the scope and magnitude of the problems will be necessary.
Certain research recommendations appear. Clearly, the GCMs most be more thoroughly developed to
achieve greater regional specificity and uniformity in their projected outcomes. Pressures will develop for
increasing lake water supplies in prolonged low-level periods. This will call for research on subjects such as
climate prediction, weather modification, and evaporation suppression. We lack sufficient information on how
climate change affects our physical systems and economy; hence applied research in these areas is needed.
Studies of policy options and institutions to address the problems and to manage the jointly shared resource of
the Great Lakes also are in order.
3-2
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Changnon
CHAPTER 1
INTRODUCTION
GOALS AND OBJECTIVES
This document reports on a limited (8-month) study of the physical and socioeconomic effects and
responses along the Illinois portion of the Lake Michigan shoreline resulting from extremely low levels of Lake
Michigan that occurred in past years (1963-1965), plus speculations about effects and responses that may occur
with lower lake levels due to future climate change.
The project had three objectives. The primary objective was to provide a measure of the types of
physical and socioeconomic effects resulting from recent record low lake levels. The second objective has been
to measure and assess the adjustments that the private and public sectors in Illinois have made as a result of
these extremes. The third objective was to provide speculations about the effects and adjustments relating to
future low lake levels due to a wanner and drier climate.
Central Concept of the Study
The first important concept is that a short-term (8-month) study of the effects of low lake levels on
shorelines and the related socioeconomic impacts and responses using the 101-km Illinois shore was useful for
two reasons. The Illinois shoreline (largely Chicago and suburbs) samples the variety of lake frontages typically
found in all metropolitan areas (harbors, intakes and outlets, diversion lockages, beaches, shore protection
structures, parks, urban buildings, and residences). However, the shoreline did not sample agricultural frontages
and had only minimal natural environmental frontage (limited wetlands). Second, such an investigation by a state
agency and university with easy access to institutional historical records and key individuals allowed for a
meaningful analysis hi a short time period if the project's scope was not too broad.
The second important concept of this study relates to its scope. The time limitations meant it had to
be confined to the dimensions of the physical impacts and socioeconomic impacts and responses along the
Illinois shoreline. This was not a study of the effects of low lake levels on Lake Michigan including the quality
of its waters, shipping, or hydroelectric power generation on the Great Lakes, or of environmental impacts
beyond those identifiable along the Illinois shore. The issue of altered water quality in the lakes is a central
question related to a major change in climate leading to lower water supplies in the basin. However, analysis
of this major issue was beyond the scope of this study. The U.S. EPA did not provide to this study estimates
(as they did for changed lake levels) of the potential changes in water quality; thus, we did not address this issue
in any substantial way.
The third central concept is that the study was designed: (1) to investigate the impacts and responses
to the record low lake levels during the 1960s, and (2) to use these as a basis for estimating future impacts and
desired policy actions from presumed climate changes. This approach was considered meaningful because the
low level period was sufficiently recent to have sampled socioeconomic conditions generally representative of
present and near-future conditions. Hence, findings were to have been transferable for consideration of future
effects to metropolitan areas of lower lake levels resulting from a wanner and drier climate.
Two Discoveries Affecting the Study and Its Findings
As the data collection and analysis progressed, we found two limitations that greatly altered the study's
design, analytical approach, and findings.
The first major limitation encountered related to the data on effects and responses during the low lake
levels of 1963-65. We were unable to locate many of the expected records of actions relating to low levels during
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Changnon
1963-65 in the files of the City of Chicago, state agencies, or federal agencies. Most records of that period had
been lost or destroyed during the past 25 years. Our investigation of newspaper records revealed little useful
information. Thus our major remaining source of information was that to be secured from decisionmakers who
held positions in key public and private sectors during the 1960s. We designed the data collection around a
structured interview approach. Through this process we learned that: (1) the impacts and responses during 1963-
65 were largely negligible, but (2) that major impacts related to the low levels occurred when lake levels achieved
record high levels in the 1970s and 1980s.
Second, the analysis of effects of the record low lake levels (which were limited to 1963-65 and followed
by a rapid increase in levels) further revealed that the low period was too short to have caused many major
impacts and few responses. (The only major effects of the low levels occurred from the damages ultimately
created when lake levels subsequently reached record high levels in the 1970s and 1980s.) The lack of utility of
the 1963-65 sampling period forced a shift from the planned approach (based on calculating future effects of
prolonged low levels using the 1963-65 results), to an approach that was more speculative than data based.
Further, two of the three climate models that were used to estimate future lake levels generated levels much
lower than those experienced in 1963-65, further requiring speculation about future effects and responses. This
situation led to a second round of structured interviews using questions based on suspected impacts. From the
responses, estimations were made of potential impacts including their costs, and speculations were made about
institutional/policy responses to deal with the impacts.
This report describes methods used in acquiring data and developing climate scenarios in Chapter 2; the
results available appear in Chapter 3; and the interpretation and significance of these results are addressed in
Chapters 4, 5, and 6.
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CHAPTER 2
METHODOLOGY
MEASUREMENT OF EFFECTS AND ADJUSTMENTS TO RECORD LOW LAKE LEVELS
This study focused on an intensive investigation of the record low lake levels occurring on Lake Michigan
during 1964-1965 for two reasons. First, the projected, most likely climate change in the Great Lakes Basin from
global models is for drier and warmer conditions. This would normally lead to lower lake levels. Second, time
does not permit a thorough effects analysis of both record high and record low conditions. Further, the effects
of record high levels have been documented in recent publications (Changnon, 1987).
Data Sources
Data collection for the effects and adjustments from the record low lake levels during 1963-1965 included
five areas of activity. These included telephone interviews and discussions with individuals who played key roles
in affected organizations during .the low-levels period. Second, it involved visits and structured interviews with
certain experts to gather data. A third means of data collection involved searches of records of public agencies
affected by the record low lake levels. A review of newspaper contents during this low lake level period was
used as a fourth data source. Finally, aerial photographs of the shoreline were obtained during low and high
level periods.
Climate Scenarios
It was recognized as the project began that several of the impact studies under the broad charge of the
EPA Climate Change Program were attempting to quantify, through use of various global climate models
(GCMs), the effects of a very severe climate change due to large increases of CO2 (and other trace gases) in the
atmosphere. These models have been based on assumptions from data gathered during a regime of climate
much less severe than that being projected in the models. This brings decided uncertainties, as do any estimates
of possible extreme future conditions. Three GCMs were used, and they projected varying climate conditions
for the Great Lakes Basin. When these were used in lake level models, they led to projections of lowering of
Lake Michigan by 0.86 m, 1.25 m, and 2.5 m.
For this study and as part of the international analysis of lake level problems under the U-S.-Canada
Reference of 1986, record-based future climate scenarios were also seen as valuable for equating the impacts
from the 1963-1965 low levels to those that may occur with more severe future dry conditions (seen as likely as
the GCM projections due to doubling of the atmospheric content of CO2).
For these reasons, this project helped develop "climate scenarios" as estimates of likely extreme periods
of low levels on Lake Michigan (and the other Great Lakes since their levels are interactive). These, along with
the 2xCO2 values in the GCMs were used with lake level models to calculate future levels of Lake Michigan and
other lakes. These help serve the purpose of speculating on the future impacts of low levels by having four
estimates on likely low levels that could be experienced. Paleoclimatic research by Larsen (1985) suggests that
extremes greater than those sampled in recent years have occurred due to climatic factors at several times during
the past 2^00 years (see Figure 2). It is not certain whether future extremes produced by natural causes will
be matched or exceeded by the projected climate changes due to man's influence on the atmosphere. Given
these uncertainties, we concluded that it was reasonable to investigate the effects of the record low lake levels
during the 1960s along the Illinois shoreline. From the types of impacts noted, we hoped to make informed
estimates of the types of effects and adjustments apt to result from future lake levels that might be greater than
experienced in the 1960s.
Development Process. Climate scenarios, defined as descriptions of possible climate conditions at some
unspecified future time, can be developed by various processes. These include those generated from empirical
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Changnon
analysis, stochastic analysis, and by the physically based global climate models. Climate scenarios are not
predictions but serve as plausible examples.
It was decided to develop a set of scenarios for describing possible future climate conditions in the Great
Lakes Basin. These were based on use of historical climate conditions to form climate scenarios.
The development of "climate scenarios," based on use and interpretation of historical climatic data for
the Great Lakes Basin, was based on several important facts for describing, understanding, and using these
analog scenarios of future conditions. We believe these are physically possible for the Great Lakes Basin.
The following conditions relate to the climate scenarios selected
1. Are not predictions of climate based on occurrence at any specific future time.
2. Have no probability for occurrence, and are not based on any frequency assumptions.
3. Are done with the recognition that the levels of the Great Lakes have ranged above and below
those sampled over the past 120 years of usable climatic record.
4. Were developed to produce precipitation and temperature values needed as input for hydrologic
models of the Great Lakes so as to generate lake levels and net basin supply (NBS) values.
5. Would be constructed from the climatic extremes sampled over the past 133 years (that is,
"instrument-based" values).
6. Would represent a "snapshot" of conditions in a period that could occur, without knowing the
likelihood or time of occurrence).
7. Would be constructed from extremes in annual precipitation data. The annual values from
about 1854 to 1986, and their aberrations around the average, would be used to define "extreme
years."
Temperature values with these selected years would be used
From these "boundary conditions," climate scenario models were chosen to reveal one possible dry
period It was to be based on measured historical data from the Great Lakes Basin. It was decided that these
analog-type scenarios would be 12-year periods of time, or composite climatic blocks (Wigley et al., 1986). A
12-year period was chosen, based largely on known response times in the climate-hydrologic models for the
Great Lakes to reach equilibrium. It is also supported by harmonic-spectral analyses of midwestern historical
precipitation data indicating, at varying levels of statistical significance, wavelengths of 10 to 13 years in length
(Neill and Hsu, 1981).
These climate scenarios provide values for input to existing hydrologic models so as to determine net
basin supply (NBS) values for ultimate use in hydrologic models of the Great Lakes Basin so as to project levels
of Lake Michigan (and the other lakes). Since precipitation is a primary factor in determining NBS and the lake
levels, it was decided to develop the climate scenarios solely around precipitation conditions. As will be
described in the following text on scenario development, annual precipitation values for 1854-1986 were used in
selecting the scenario periods, and then actual monthly precipitation values from the selected years were used
as the input to the hydrologic models needed to obtain the NBS values.
Periods to be selected to portray extremely dry periods with a 12-year duration first had to contain (or
exceed) a given number of below-average years. A dry period for consideration would contain 8 or more years
with below-average precipitation to qualify for the dry period analysis. This criterion was based upon the fact
that the frequency of below-average annual precipitation events has been shown to be the most critical factor in
NBS (Quinn, 1986) and lake levels (Changnon, 1987).
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The next aspect considered was the selection of the temperature data Temperature values were not
chosen separately. The precipitation-temperature relationships found in the actual historical data were retained.
Actual daily and monthly data on temperatures (and humidities, winds, and evaporation) were utilized from the
historical records for the years selected on the basis of their precipitation extremes. For years prior to the
availability of daily data (as needed in the scenarios for the hydrologic model), algorithms relating the
precipitation values to temperature and other daily conditions from the 1948-1985 period were used.
The most extreme dry periods extending across the Great Lakes Basin were selected. This was done
by screening the historical annual precipitation values of each Great Lake Basin (1854-1986) and then selecting
the ones extending across the entire Great Lakes Basin.
This initial screening identified all candidate 12-year periods based on the presence of 8 or more years
with below (dry) the average precipitation. The net departure of the total precipitation in each candidate period
was also determined, yielding negative values for the candidate dry periods.
Once the candidate periods and their two measurements of severity (the number of extreme years in
the 12 and the total precipitation departure) were completed for each lake's basin, these periods were
intercompared between basins. Those found to be common, or present on all four basins, were the final
candidates for the actual period scenarios for the Great Lakes Basin. They are listed in Table 1.
Each period on each lake basin was ranked, as shown, based on the magnitude of the 12-year cumulative
precipitation departure. For example, in the Lake Superior Basin, the 1914-1925 value of -9242 mm (Table 1)
was the highest ranked dry value. The four basin ranks thus achieved for each candidate 12-year period shown
in Table 1 were summed to obtain a "basin-wide rank score." As shown in Table 1, this score for 1914*1925 was
7, the lowest of the six candidate dry periods. Hence, it was selected to represent the driest 12-year period in
the Great Lakes Basin.
The desired analog climate scenario was developed from 1914 to 1925. This period was modified
according to the following criteria:
1) The arrays of dry years were retained in the sequence they occurred across the entire Great Lakes
Basin, as based on the sum of the annual departures of each lake basin.
2) The magnitudes of the annual precipitation values were changed if they were negative in the dry
periods. These changes were done for the basinwide annual values (not for each basin).
3) In the 1914-25 dry period chosen, the 8 or more dry years (out of 12) were magnified by
substituting the 8 (or more) driest annual values in 1854-1986.
4) The nondry years in the 12-year dry period would not be altered.
5) The process of substitution of more extreme values began with the ranking of the basinwide mean
departures for each year in the 12-year periods, as shown in Table 2. For example, the 1914
basinwide value was -3992 mm and it ranked as the fourth largest of the 12 values during 1914-
25 (1923 with -5668 mm was top ranked, see Table 1).
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Table 1. 12-Year Dry Periods Common to All Great Lakes1
Suoerlor Mlchioan-Huron
Period
1910-21
1913-24
1914-25
1915-26
1916-27
1930-41
No. dry
^ears
9
9
10
10
10
72
Cumulative
departure, mm
7503
8270
9242
6992
6331
1001
Rank
4
3
1
2
5
6
NO. dry
years
8
8
9
9
8
10
Cumulative
departure, mm
2104
2646
5944
5856
3774
9287
Rank
6
5
2
3
4
1
NO. dry
years
8
a
9
9
8
8
Erie
Cumulative
departure.
5191
4042
5834
5402
3949
6107
mm Rank
4
5
2
3
6
1
No. dry
vearsT
9
9
10
10
9
10
Ontario
cumulative
departure, mm
6130
6019
7092
6162
4282
7513
Rank
4
S
2
3
6
1
Rank
score
18
18
7
11
21
9
1 Based on 8 or more years with annual precipitation below average for 1854-1987.
2 included because of severity In all other basins.
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Table 2. Climate Scenario Values for an Extremely Dry 12-Year Period
Rank Year
Basin-wide
Deoarture. mi
1
• 2
3
4
5
6
7
8
9
10
11
12
1931
1934
1923
1936
1925
1918
1963
1909
1910
1914
1915
1941
-8004
-5760
-5668
-4890
-4502
-4426
-4303
-4072
-4062
-3992
-3959
-3810
Basin-wide
Year Departure. ""
Rank Substitute Superior Michigan-Huron Erie Ontario
1914
915
916
1917
1918
1919
1920
1921
1922
1923
1924
1925
-3992
-3959
3064
-1196
-4426
-1300
-2527
-2911
1181
-5668
-1876
-4502
4
5
10
3
9
7
6
1
8
2
1936
1925
1916
1914
1923
1910
1963
1918
1922
1931
1909
1934
-618
-851
824
-1047
-1463
-1400
-687
-1269
-169
-1346
-1550
-411
-1394
-1395
416
-1090
•1063
•1210
-1164
-1169
1217
•2448
-890
•1675
-1788
-1793
846
-733
•1370
-439
-1430
•1252
175
•2141
-377
•2430
-1090
-463
978
-1122
-1772
-1013
-1022
-736
-42
-2069
-1255
-1244
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6) Annual values (departures) for the Great Lakes Basin for 1854-1987 were used to select the 12 largest
negative (dry) years. Each of the 12 values was ranked, as shown in Table 2. The greatest 1-year
value was -8004 mm in 1931 (rank 1), and the fourth highest ranked value was -4890 mm in 1936.
7) These 12 ranked values for dry (negative departures) were matched with the ranks in the actual
years of each 12-year period, as described in number 4 above). Then, the substitution of values
(and years) was done according to matching of the ranks. For example, in the Great Lakes Basin,
the mean precipitation departure in 1914 was -3992 mm and it ranked fourth among the 12 values
in the 1914-25 period The year with the fourth greatest departure during 1954-86 was 1936 with -
4890 mm. Hence, 1936 became the "substitute" year for 1914 (both ranked as fourth).
8) Once these annual substitutions were identified for each year (except for the 2 wet years in 1914-
25, the actual precipitation values in each lake basin for the substitute years were those used in
determining lake levels (see these values in Table 2).
9) The "climate scenario" selected out of the past had, as initial conditions, those that actually preceded
it (1910-13). These established the NBS when the two periods began.
By this process, annual extremes were used to increase the departures that had been experienced in the
actual driest 12-year period in recorded history (1854-1987). A climate scenario was developed based on
historical values. The adjusted values are considered realistic to help define potential extreme dry periods. It
was designed to retain the mix of dry years that occurred (and are possible) in the extremely driest period, but
with a magnification of the annual values. This approach allowed for interannual variability during such extreme
events as well as persistence of conditions during extreme dry periods. The underlying physical assumption is
that the atmospheric conditions producing the extremely dry years (moved to the selected 12-year sequence) were
possible for this period. That is, temporal transposition of more extreme events is within physical reason.
The extreme 12-year dry scenario was used with the GLERL hydrologic models of the Great Lakes to
calculate lake levels under current conditions. These calculations projected a lowering of Lake Michigan of 0.4
meter below the 1951-80 average.
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CHAPTERS
RESULTS
IMPACTS OF LOW LAKE LEVELS
Data Sources
Each of the five sources of data relating to the effects and adjustments resulting from the record low lake levels
during 1963-65 provided interesting information. The newspaper content analysis (described in the Appendix with
the results presented later in Chapter 3) revealed that few of the impacts denoted from other data sources found
their way into local newspaper reports of the 1964-65 era. Results suggest that a "newspaper content analysis"
of effects of record low lake levels is not a suitable means of collecting extensive data on effects, or that the
effects were marginal.
A second finding about data sources related to records in public and private agencies. Most private, state, and
federal agencies that were impacted by the activities of the early 1960s have since lost or destroyed the detailed
records of activities and financial expenditures that are necessary to develop detailed measurements on effects.
Furthermore, current individuals responsible for corporate or institutional records were generally disinterested
and/or unwilling to locate such records if they exist. This avenue of investigation was greatly hindered by the
unavailability of many activity/financial records for assessment.
A primary means for gathering data on the effects and adjustments on the record low lake levels came through
interactions with individuals who had been in responsible positions with private and public organizations during
the time (1963-1965) of the low lake levels. Interactions with these individuals was complicated by the fact that
most had retired and moved away from the Chicago area during the past 25 years. Extensive telephoning and
letter writing was necessary to locate key individuals in the public and private sectors for these interactions. The
interactions typically consisted of extensive telephone interviews (interview format is described in the Appendix).
The interview process was greatly aided by the fact that most individuals contacted were aware of the scientific
surveys in Illinois, and most were thus willing to take time to cooperate. These semi-structured interviews
typically consisted of an hour or two of telephone conversation with each individual In certain instances where
individuals had extensive data and information, and with whom extensive telephone interviews were impractical,
visits were made. Four trips were made to the Chicago area to interview such individuals; 19 individuals were
extensively interviewed Those interviewed came from the private sector (shipping, harbor and dockage
construction and maintenance, and consulting engineering), and from the local, state, and federal agencies
(experts in park/beaches, water management, water quality, regional planning, environmental sciences, water
policy, harbor and canal maintenance, and water supplies).
Since the 1963-65 data on impacts and responses were so limited, we had to estimate future issues. In
this instance, a list of potential future problems/issues from a drier climate (and lower lake levels) was developed.
Several of those interviewed about 1963-65 conditions were interviewed a second time with this list of future
problems. Views about these were gathered, additional issues identified, and cost estimates for addressing
problems were gathered in the areas of expertise of the person interviewed.
The Illinois State Geological Survey has had a program of studying lake shore erosion and geology for
many years. Their historical files, publications (Larsen, 1985), and aerial
photograph library were invaluable sources of useful information. A recent inventory of lake-related research
(Holms, 1987) was also of use.
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The Physical Setting; (jTlin^te and Other Factors Relevant to Lake-Level Extremes
Assessment of the effects of extremely low lake levels on the Illinois shoreline and related human activities had
to be based on a clear understanding of those factors that help create the extremely low levels. Furthermore,
since this analysis was also to speculate about effects of future low lake levels, and those possibly lower than the
historical record has experienced, it became important to consider and investigate, to some extent, the physical
factors affecting lake levels, the past behavior of lake levels, and potential future climate conditions that might
create extremely low conditions.
Influences on Levels of Lake Michigan. There are three categories of water level fluctuations
on Lake Michigan, each caused by weather and climatic fluctuations. These include short period fluctuations
(hours to days), seasonal fluctuations, and longer-term fluctuations (multiple year). These are of particular
concern in this overall study of low levels.
The short-period fluctuations are caused by weather disturbances. Differences in atmospheric pressure
and winds over the surface of Lake Michigan can create temporary imbalances in the water levels at various
locations with the resulting seiche wherein water literally piles up on one side of the lakes. These types of
fluctuations are superimposed on the more rhythmic seasonal fluctuations and the less rhythmic long-term
fluctuations of lake levels.
The seasonal fluctuations of the levels of Lake Michigan result from the annual hydroclimatic cycle. This
cycle is characterized by higher supplies (greater precipitation) during the spring and early summer, and lower
supplies during the remainder of the year (lesser precipitation and higher evaporation). The magnitude of the
seasonal fluctuation is relatively small, averaging about 30 cm (1 foot) on Lake Michigan. The seasonal
fluctuation is about 1/4 of the long-term fluctuations, and are superimposed on the long-term fluctuations.
The longer-term fluctuations, which are of greatest concern in this study, are the results of persistent
low or high precipitation conditions within the basin that can culminate in extremely low levels, such as those
recorded in 1964-65, or in extremely high levels such as recorded in 1972-73, and again in 1984-86 (Changnon,
1987). Figure 1 presents graphs based on the levels of Lake Michigan from 1860 through 1987. The annual
values (Figure la) reveal many "sawtooth"-type variations, and one notes the extremely low values obtained in
the early 1920s, 1930s, and early 1960s. Figure Ib presents the moving average of annual lake values based on
11-year periods, again showing the general low values in the 1920s and 1930s; the low values again in the early
1960s; and interdispersed higher levels. Statistical analysis of these fluctuations did not reveal any regular,
predictable cycles in lake levels or in precipitation. The intervals between the periods of extremely high and low
levels, and the length of such periods, vary widely and erratically over a number of years.
The maximum recorded range of levels from the extreme high to the extreme low is approximately 1.5
meters on Lake Michigan. Importantly, the timing of record annual lows (Figure la) in the 1960s was followed
within 10 years by record high levels. It should be noted that the data prior to 1900 are suspect for comparison
to later years because of connecting channel changes to the other lakes done in the 19th century. These
effectively lowered the level of the lake by about 20 cm.
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Changnon
582
575
1860 1880 1900
1920 1940 1960 1980 2000 1860 1880
YEAR
1900 1920 1940 1960 1980 2000
Figure LLake Michigan levels (1860-1986) based on annual averages and 11-year moving averages.
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Changnon
Of considerable concern then to the analysis of the extreme low levels and high levels of Lake Michigan
(or any Great Lake) is the tendency of the climate. Inspection of Figure 1 reveals that there have been major
fluctuations in the climate over the last 120 years. Examination of the values of Figure Ib for the period of about
1900 to present (that period unaffected by the changes in lake levels mentioned above) shows a period of
generally increasing levels since 1940. This is substantiated by a recent analysis of precipitation on the Lake
Michigan Basin from 18% to 1985 (Changnon, 1987), suggesting an increasing precipitation regime over the last
50 years. There is a suggestion that the current climatic regime is a part of a period moving towards ever wetter
conditions which also includes increased cloudiness and reduced over lake evaporation.
Another feature of the climate conditions, particularly of recent years, is the high frequency of extreme
events, suggesting a shift to greater climatic variability. Comparison of the annual values (Figure la) for 1900
through 1940, as compared to those from 1941 to 1985, reveals the earlier period had fluctuations but not as large
as those in the last 45 years. This is reflected in high levels in the 1950s, early 1970s, and mid-1980s intermixed
with the record lows in the 1%0's. As will be shown in the effects analysis, such fluctuations in climate are as
important as the general trend to wetter or drier conditions.
Other Factors Influencing Levels of Lake Michigan. The vast surface areas of the Great Lakes, which
are equal to nearly half the land areas that contribute runoff to them, constitute an important factor in their
water levels. Small differences in lake levels represent enormous quantities of water. Both the seasonal and
long-term level fluctuations in lake levels are the result of changes in lake volume. The variation in the supply
of water, which is primarily the difference between the precipitation on the lakes and their basins, and die
evaporation from them, is the primary cause of the seasonal and long-term fluctuations. Net monthly water
supplies to the Lake Michigan Basin, for example, range from a maximum of 594,000 cubic feet/second-months
to a minimum of -86,000 cfs-months. The negative value indicates that losses from evaporation and outflow
exceed the supply from precipitation and inflow (runoff) to Lake Michigan. However, large variations in supplies
to the lake are absorbed and modulated to such an extent that its outflow is remarkably steady. Because of
the large size of the Lake Michigan (and the other lakesX and the very limited natural discharge capacities of
the outflow rivers from them, extremely high or low levels (and flows) persist for some considerable time (months
and years) after the factors that have caused them have changed or ceased.
Of considerable importance to the level of Lake Michigan-Huron is the precipitation and amount of
water in Lake Superior, which drains into Lake Michigan-Huron. That is, the advent of a dry period on Lake
Michigan leading to a lowering lake levels can be either enhanced or ameliorated, depending upon the
precipitation conditions (and basin supply) on Lake Superior. The worst possible situation, of course, for low
lake levels is to have dry conditions on both lakes at the same time, as well as on the other lakes. The
correlation of the average annual precipitation values of Lake Superior with those of Lake Michigan Basin
revealed a coefficient of +0.68 for the 1901-1987 period
The analysis of the precipitation conditions on the two lakes was based on data for 1854-1900 (when few
weather stations existed), and 1901-1986 (when more stations existed and the data are considered better). Table
3 presents an analysis based on when the Lake Michigan 12-year precipitation conditions were classed as dry or
wet.
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Table 3. Precipitation Conditions on the Lake Superior
Basin When Excessively Dry or Wet 12-Year
Periods Existed on Lake Michigan
Percent of Lake Superior Conditions
Dry Period on Lake Michigan for same 12-year period
Dry Wet Neither
Early, 1854-1900 54 13 33
Recent, 1901-1986 85 6 9
Wet Period on Lake Michigan
Early, 1854-1900 0 79 21
Recent, 1901-1986 0 100 0
The dry or wet periods were selected based on 8 or more of the years in the 12 years experiencing
below (for dry) or above (for wet) average precipitation. The results in Table 3 indicate that when a 12-year dry
period exists on Lake Michigan, it is highly likely one will exist on Lake Superior, too.
A dryness index was defined (the number of years of below-normal precipitation in any given 12-year
period), and these indices on Lake Michigan for periods during 1901-1986 were correlated with those on Lake
Superior. Since the dryness index takes on values of 0 to 12 (years) and the relationship is not linear, the index
for each lake was replaced by its ranking in its population. The correlation of these ranks (by Spearman's test)
produced a coefficient of +0.75, higher than all years correlation of +0.68. Thus, when atmospheric conditions
produce below-average precipitation on the Lake Michigan Basin, similar below-normal conditions are very apt
to occur on the Lake Superior Basin.
The mean levels and the outflows of Lake Michigan will also change progressively with time due to other
factors. Included in these is the steadily increasing consumptive use of water in the basin, and a nearly
imperceptible movement of the earth's crust in the region of the Great Lakes Basin. The tilting of the earth's
crust across the basin produces slow but measurable effects on lake levels. The effect on Lake Michigan, for
example, is that in the northeastern portion, land is rising with respect to land at the south end at a rate of about
30 cm per century. This is considered to be due to the rebounding of the earth's crust from the weight of the
Ice-Age glaciers. The net effect of this tilting is to increase, gradually, the mean water elevation of Lake
Michigan. These factors, hi addition to climate fluctuations and trends, affect the lake level.
riimate Conditions During 1964-65. The record low lake levels (monthly and annual values) experienced
in 1964-1965 were a direct result of below-average precipitation on Lake Michigan Basin beginning in 1961. The
greatest departures from average in the basin occurred in 1963 (-1164 mm) and 1964 (-1168 mm), but with values
also below average in 1961 (955 mm), in 1962 (244 mm), and in 1965 (134 mm). The annual average is 3401 mm.
The delay in reaching the record lows until the winter of 1964-1965 is due to the slow response of the basin
system, as described above.
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It was fortuitous that during this extremely dry period on Lake Michigan there were near normal
precipitation conditions on Lake Superior. The Lake Carriers Association (1964, 1965) notes how the Lake
Superior waters were used to try to minimize the fall of the Lake Michigan levels. Their report states,
"fortunately this very serious situation (1964 low levels) was mitigated to some extent by completion of the
connecting channels program and the higher level of Lake Superior." During the latter part of 1964, outflows
from that lake were substantially increased by a series of ever increasing openings of the gates in the
compensating works that limit the flow of water down the St Mary's River (connecting the two lakes). This
program commenced on July 6,1984, and increased gradually until November 10,1964, when all 16 compensating
gates (separating Superior from Michigan-Huron) were opened for the first time in a decade. The outflow had
reached 125,000 cfs, aiding the navigation in the St. Mary's River (below the locks going into Lake Huron). Wide
use was made of the water level prognostications issued by the U.S. Lake Survey.
Variability of Lake Levels. Of considerable importance to the consideration of the impacts of low (or
high) lake levels on shorelines and shore activities is the amount of year-to-year variation in lake levels. Global
climate models used to estimate future low lake levels due to a doubling of CO2 do not provide a valid measure
of this important condition, or of the type of long-term fluctuations that will accompany these extreme levels.
Some modelers believe the interannual and longer term fluctuations will be large and greater than those
previously experienced.
To obtain estimates of possible variability, the lake level data from the nigh and low lake level periods
on Lake Michigan were analyzed to examine their intra-annual (seasonal) variation and their longer term
variations. Table 4 presents results of a statistical analysis based on selecting the 10 periods with the lowest levels
and the 10 periods with the highest levels for two durations, 3-year periods and 5-year periods. In calculating
these variations, the average of the yearly mean lake height for each 3-year (and 5-year) period from 1860 to
1986 was computed. The 10 non-overlapping 3-year (and 5-year) periods with the lowest average lake heights
were then computed, as well as the 10 non-overlapping periods with the highest averages. Table 4 shows four
summary measures. Inspection of the medians for the coefficients of variation (Type 1) m the 10 lowest level
periods reveals that they exceed those medians for the 10 highest periods, for both the 3-year and 5-year periods.
The difference in variances (Type 1 or Type 2) between wet and dry periods is negligible. The differences in
medians for the coefficients of variations indicate that the intra-annual variation is greater during low lake level
periods than in high lake level periods.
An analysis of the rate of change of lake levels before low level periods was also made. There were
eight discrete 5-year low periods during the 1860-1986 period, and these are listed in Table 5 along with the mean
levels during each period. The average change for the 3-, 5-, and 10-year periods preceding each low is shown.
These reveal downward trends for all the 3- and 5-year preceding periods, and the lowest lows (1923-27,1933-
37, and 1962-66) were all preceded by the largest rates of change in the 3 and 5 years preceding them. This
indicates some information on the development of low-level periods is contained in the rate of change of levels
preceding lows.
The changes in levels prior to low level periods were tested against all other changes using the Wilcoxon
test The rates of changes for 3 and 5 years before 5-year lows was found to be larger than the usual changes,
and the differences were highly significant with p values of 0.01. Hence, multi-year decreases in levels of the type
shown in Table 5 should be indicative of a potential 5-year low in the lake levels.
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Table 4. Measures of Intra-Annual Variation in the Lake
Levels of Lake Michigan, During Periods of High
and Low Lake Levels'"
From
Measures of variation for 10 lowest 3-year periods
3-vr average CV type 1 Variance type 1 CV type 2 Variance type 2
.^^_^^^_
1933
1963
1925
1936
1957
1939
1930
1922
1966
1948
From
1860
1884
1876
1985
1863
1881
1973
1887
1869
1873
576.17
576.19
576.63
576.70
577.12
577.27
577.47
577.64
577.70
577.81
Medians :
Measui
3-vr average
581.10
581.08
580.66
580.60
580.54
580.40
580.20
580.03
580.01
579.93
Medians :
1.
1.
29
74
2.21
2.07
2.23
1.41
3.55
2.20
1.97
2.59
2.14
0.91
1,
1.
1.
1.
0.
1.
1.
1.
1.
14
14
27
09
80
20
22
20
52
1.17
0.15
0.33
0.31
0.31
0.28
0.15
1.16
0.34
0.32
0.48
0.32
0.12
0.20
0.16
0.22
0.16
0.11
0.15
0.22
0.18
0.29
0.17
Measures of variation for 10 highest 3-year periods
3-vr average CV type 1 Variance type 1 CV type 2 Variance type 2
1.
1.
1,
2,
2.
2.
1.
2.
2.
2,
53
54
94
06
25
24
61
26
64
00
1.
1.
1.
1.
36
08
11
27
0.90
26
18
25
85
34
2.03
1.25
0.18
0.15
0.25
0.25
0.29
0.26
0.22
0.38
0.56
0.27
0.26
0.18
0.13
0.21
0.18
0.11
0.21
0.18
0.17
0.41
0.26
0.18
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(Table 4, continued)
From
1933
1962
1923
1937
1958
1929
1946
1941
1966
1954
Measures of variation for 10 lowest 5-year periods
5-vr average CV type 1 Variance type 1 CV type 2 Variance type 2
576.29
576.65
576.94
577.08
577.49
577.66
578.14
578.18
' 578.21
578.27
Medians:
1.29
2.56
2.44
36
28
80
89
86
15
80
0.90
1,
1,
1.
1,
1,
1,
1.
1.
1.
14
13
06
28
32
54
23
21
23
2.88
1.22
0.15
0.58
0.40
0.30
0.56
2.05
0.57
0.65
0.66
1.03
0.58
0.11
0.17
0.17
0.18
0.24
0.23
0.30
0.25
0.19
0.19
0.19
From
1860
1883
1874
1984
1862
1879
1972
1870
1866
1887
Measures of variation for 10 highest 5-year periods
5-vr average CV tvoe 1 Variance type 1 CV type 2 Variance type 2
581.08
580.91
580.41
580.29
580.14
580.08
579.99
579.92
579.65
579.63
Medians:
1.53
2.29
2.56
2.59
2.80
2.42
2.56
58
50
06
2.
2.
3.
2.56
,19
,30
.09
,25
.08
,12
,39
,56
,45
,17
1.22
0.15
0.25
0.31
0.47
0.52
0.35
0.33
0.50
0.39
0.56
0.37
0.15
0.20
0.18
0.18
0.16
0.17
0.25
0.32
0.26
0.16
0.18
'The explanations of the statistics in each table:
Col. 1: start year
Col. 2: average of yearly average lake level for the 3- or 5-year period
Col. 3: coefficient of variation (maximum in period, less minimum in
period)
Col. 4: variance of monthly levels in period
Col. 5: average annual CV (maximum less minimum in one year period,
averaged over all years in the period)
Col. 6: average annual variance over period
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Table 5. Average Rate of Change Preceding Low Lake Level
Periods of 5-Year Duration
Period Average 3-Year Period 5-Year Period 10-Year Period
From To Level (ft) Low Level Lows Low Level Lows Low Level Lows
1878 1882 580.02 -0.09 -0.05 0.03
1895 1899 578.28 -0.05 -0.12 -0.22
1911 1915 578.28 -0.07 -0.14 -0.06
1923 1927 576.94 -0.35 -0.36 -0.17
1933 1937 576.30 -0.21 -0.35 -0.06
1946 1950 578.14 -0.17 -0.01 0.12
1962 1966 576.65 -0.24 -0.25 -0.27
1977 1981 578.94 -0.14 -0.21 0.03
Land Use. Relevant to the interpretation and transfer of the finding? from this case study of the effects
of low lake levels on the Illinois shoreline are the actual land uses found along the relatively short segment of
101 km (63 miles). Table 6 shows the distribution of shoreline as to land use and how it compares with the
land use around the remaining parts of Lake Michigan. Most of the shore is beach (largely manmade) although
about 30 kilometers are glacial bluffs.
All major land uses except agriculture were sampled by the Illinois shoreline, the focus of this study.
Thus, certain results, as they relate to recreational, industry/commerce, and residential frontages should be
potentially transferable to other urban areas around Lake Michigan (and the other lakes). An example of the
small undeveloped shoreline area along the Illinois shoreline near Zion is portrayed in Figure 2. These largely
undisturbed areas further reveal the effects of periods of higher and lower lake levels. The "beach ridges" from
periods of oscillating lake levels in the past 2,000 years are revealed by the land forms and the alignment of the
land cover. The periods of extremely higher and lower potential lake levels believed due to climatic fluctuations
over the last 2,500 years have been investigated by Larsen (1985).
Table 6. Percentage Distribution of Shoreline Land Use on Lake Michigan
Illinois Lake Michigan
Land Uses Shoreline (%) Total Shoreline
Recreation 43 11
Industry/Commerce 19 6
Residential 34 33
Agriculture 0 20
Forests/Undeveloped 4 30
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Figure 2. Beach ridged (near Zion, Illinois) left by periods of higher lake levels due to climate fluctuations in
past 2,000 years.
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Effects and Adjustments to Low Lake Levels in 1964-1965
Due to the data limitation problems already noted and the general lack of detailed historical records of
activities by corporate and most public institutions, extensive, highly quantitative assessment of all effects of low
levels was impossible. However, two areas of effects and adjustments could be assessed in detail. Hence, we
chose to do (1) a general effect analysis using the information largely from interviewing (with some support from
the newspaper content analysis and public records; and (2) detailed socioeconomic analyses for areas where
detailed loss and adjustment data could be obtained. Thus, a general, semi-quantitative descriptive assessment
of the effects in all areas has been developed, and more detailed socioeconomic assessment of effects has been
conducted for two effect areas. These are described in subsequent sections. The results of the newspaper
content analysis appear in the Appendix.
General Effects on the Great Lakes. Before considering the specific impacts of the 1964-1965 low lake
levels on the Illinois shoreline area and related activities, it is appropriate to consider the broader context of low
(as well as high) lake levels throughout the Great Lakes Basin. Society has now so developed its use of the Great
Lakes that in essence any fluctuations in lake levels create a problem. Thus, low lake levels are both
advantageous and disadvantageous to different impacted physical and human sectors. High lake levels act to
reverse the impacts, in general. No one level condition is seen as optimum, other than the unlikely possibility
of achieving a single level that remains essentially constant except for the seasonable variations. In general, high
lake levels are of value to two major sectors: navigation and shipping, and to hydroelectric power generation.
Conversely, most shoreline owners are seen to benefit from low lake levels. However, the existing shoreline
environmental conditions (wetlands, shallow groundwater levels, and habitats) suffer from lower levels. These
types of general basinwide impacts of lower levels on the lakes should be taken into consideration when
examining the impacts from the 1964-1965 low lake levels on the 101-km frontage of Illinois along Lake Michigan.
Effects and Adjustments on the Illinois Shoreline. The effects and related adjustments resulting from the
low lake levels along the Illinois shoreline during 1964-1965 were sorted and categorized into seven groups. The
groups include:
1. Shore and near-shore physical effects.
2. Effects on transportation and shipping.
3. Recreational impacts.
4. Effects on industry and commerce.
5. Impacts on water management, supplies and drainage.
6. Land use.
7. Institutional.
The effects on physical features and related structures of the shoreline were extensive and of mixed values.
One of the positive effects was the expansion of the beaches. Figure 3 notes this type of expansion around the
groins of one of the Chicago area beaches.
Several negative effects of low levels along the shores were found. These included making harbors and
their inlets shallower, and effects on pleasure boat and ship traffic. Figure 4 shows an entrance to one of the
urban harbors, which has-become sufficiently silted to require dredging for use. The results of this problem are
further treated under shipping and recreational issues.
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Figure 3. Expanded beaches due to extensions lakeward along groins due to low lake levels, April 1964.
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Another physical impact along the shoreline of the lower lake levels, coupled with onshore winds, is the
movement of beach sand and the formation of dunes, as shown in Figure 5. These new dunes later protected
the shore against high-water conditions and storms. The effects on the wetlands and habitats north of Chicago
were considered nominal, largely because the period of low water was confined to 2 years.
A more major physical effect to structures along the shoreline concerns damage to harbor and shore
protection structures. The impact of low, then high, lake level interactions on the protection structures is such
a major one that a separate special investigation of this problem was conducted. It is reported on in a later
section of this chapter (see page 28).
The primary effects on transportation and shipping related to the low lake level areas occurred in harbors
and canals. Dredging was required in certain harbors, presumably in addition to the normal annual dredging,
because of the low lake levels. However, 1964 and 1965 records of the Corps of Engineers (who handle the
dredging in major ports) make no mention of the effects of the low water on their harbor maintenance operations
for the Calumet Harbor, Chicago Harbor, Chicago River, or the Waukegan Harbor. However, assessment of
the annual dredging costs for the Calumet Harbor showed an increase of $160,000 in 1965 over that in 1964
($284,000), an 85% increase. Special 1965 dredging costs in Waukegan Harbor were $38,000 and this occurred
in April-May 1965, presumably as a result of the low-water problems. No evidence of added costs for dredging
in the Chicago Harbor or Chicago River were found. Furthermore, there were no beach erosion control projects
launched during this period, evidence that that was not a problem in these low-water periods.
A second impact relating partly to transportation was inflow of the water into the Chicago River and Canal
diversion system. This system diverts Lake Michigan water to help sustain flow and the levels of the Illinois River
system adequate for barge transportation and sanitation needs. It was reported that the lowest lake levels were
such that minor problems occurred in sustaining adequate diversion during early 1965.
A third impact related to lower ship loads. Records could not be obtained for various lake carriers for
this period, but experts indicated that loads carried on lake carriers were reduced between 5 and 10%. This
indicates a necessity for more frequent trips and higher costs. Problems due to the low flow of the St. Mary's
River (which connects Lakes Superior and Michigan-Huron) were reported (Lake Carriers Association, 1964-
1965). These problems existed in the Michigan-Huron side and were addressed by greater diversion of water
from Lake Superior by the Corps of Engineers.
Recreational activities received mixed impacts. Problems were related to shallow water in harbors and
their inlets for pleasure craft. In certain cases, additional dredging was done to private and local urban inlets
and small-craft harbors. This included Montrose, Belmont, and Jackson Harbors of the Chicago Park District.
Docking was a problem as shown in Figure 6. In certain cases, docks were extended, and some were lowered.
Ladders were constructed to get from the existing docks to boat level, generally as individual costs.
On the positive side, the swimming beaches along Chicago were widened. However, a major new beach
(Montrose Beach) was constructed on the north side of Chicago during the early 1960s. Large volumes of much
sand were imported to construct this huge beach. Subsequent higher lake levels in the 1970s led to the erosion
of this expensive new beach. Sand from this beach has been scoured and moved several hundreds of meters out
from the lakeshore. Plans to pump this sand back to the beach are being developed. Another recreational
problem related to the launching ramps for pleasure craft. Several had to be extended to reach the edge of the
water.
Impacts to private industry and commerce were difficult to isolate. Clearly, entities depending heavily
upon lake carriers to obtain or ship supplies or products were hurt Shipments were more frequent (with lighter
loads), and the cost of raw materials and supplies reportedly increased by 10 to 15%. Local lake shipping
companies were hurt. The loads carried had to be reduced because of the shallower harbors, and experts
reported that these problems enhanced the carrying of raw materials on regional railroads, as opposed to doing
so on lake carriers.
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Figure 5. Sand dunes forming due to low lake levels and wind action (Illinois Beach State Park, 1964).
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Figure 6. Docking facilities at Wilmette Harbor during record low lake levels in April 1964.
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Dredging companies benefited due to increased harbor and dredging. Problems also developed because
of the difficulty of finding proper areas to dispose harbor sediment considered polluted. This added to the costs
of dredging and disposal, and in turn cost the local communities and local and state government more for
dredging than in past years.
Effects on water management and exchange systems were considerable. In certain cities depending on
lake water supplies, intakes had to be extended, such as at Evanston. In certain instances, intake levels had to
be lowered, and in other instances additional water intakes were built (at three communities). Outfalls for
stormwater drainage were also exposed in certain communities. At Highland Park, a major drainage line had
to be extended 2,000 meters at a cost of $400,000. Certain cooling ponds along Lake Michigan also had to be
dredged because of insufficient depth.
The primary impact on the land use related to the lower lake level related to the wider beaches. As noted
above under impacts on recreation, this enhanced the size of public and private beaches along the lakeshore.
However, the additional beach space offered the opportunity to construct various structures closer to the
lakeshore. This "encroachment" occurred at locations along certain of the suburbs extending north of Chicago.
The socioeconomic and policy ramifications of this encroachment during low lake levels was the subject of such
considerable impact that it too is the subject of a separate detailed investigation. Again, as with the problem to
lakeshore protection systems, this problem developed because of the low lake level followed by higher lake levels:
thus, a "delayed effect." One needs to recognize that persistent lower levels of Lake Michigan would produce
"delayed effects" in environmental conditions, with lowered groundwater levels and greatly altered wetlands.
The institutional impacts and adjustments to the low lake levels and their related problems were
considerable and occurred at all levels of government. Internationally, concerns about the low lake level
problems led to conferences in both the United States and Canada during 1964. As a result, the International
Joint Commission (LJC) convened hearings in May 1964 in Chicago and Sault Ste. Marie. The ILS. and
Canadian governments assembled and called for a "reference," an in-depth study by the UC of the problem with
possible solutions. The reference was issued in October 1964. In turn, the IJC established an International Great
Lakes Levels Board on December 2, 1964 (International Great Lakes Levels Board, 1973). This Board was to
undertake necessary investigations to provide in-depth advice on lake levels and their control This assignment
took nearly 10 years to complete, with the report issued in 1973. Interestingly, by the time of publication, the
lake levels had gone from the record lows of 1964-1965 to new record high levels in 1973, the year the report was
issued. The report provides information about the broad impacts of low lake levels, and in particular on the
economic effects of variations about the mean levels of the Great Lakes.
Most communities along the lakeshore had to react in various ways to the low lake levels, both in positive
and negative ways. Increased costs of local dredging and harboring were met, and water management systems
were altered as noted. Mayors, city engineers, and water and sewage treatment officials had to deal with a variety
of problems and advantages related to the bigger beaches and more difficult problems of water exchange.
The City of Chicago, the Metropolitan Sanitary District of Greater Chicago, and the State of Illinois were
involved in concerns and adjustments relating to the diversion needs and low levels. Chicago Park District
installed a new major beach (Montrose Beach). The Corps of Engineers was involved in greater dredging.
The Center for the Great Lakes instituted a series of meetings related to the lower lake levels, and
developed a long-term program to assess land management techniques and to provide information on what types
of lakeshore techniques had failed and succeeded (Great Lakes Reporter, 1987). Basically this report was related
to the "delayed" impact of the low lake levels of the 1960s and the subsequent high levels in the 1970s and 1980s,
and the necessity to consider methods (including structures) to deal with problems both at the low and high end
of the level spectrum.
In private sector institutions, some of the impacts and adjustments noted were the profits of private
dredging firms; however, after the low period the number of firms decreased. Consulting engineering firms
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Changnon
dealing with lake issues (harbors, docks) received enhanced business, and the number of Finns increased. Certain
small shipping companies were sufficiently hurt to lead to their termination or amalgamation into larger firms.
The diversion of lake water done by Illinois into the Chicago and Illinois River systems, and for water
supplies in the Chicago urban area, was not affected by the low lake level. The subject of the Illinois diversion
has been an issue of contention among the lake states since the 1920s. The U.S. Supreme Court reduced the
diversion, which was 10,000 cfs, in the 1920s to 3,100 cfs by 1938 following the Court's decree of 1930.
Subsequent decrees have monitored and allotted the diversion to 3,200 cfs, including domestic pumpage. This
amount of diversion counts for an annual 0.23-foot decrease of the level of Lake Michigan. The diversion
depends upon gravity flow from the lake into the river and canal system. If lake levels had fallen somewhat lower
than those achieved in 1964-65, natural inflow to the rivers would have been difficult in the cold season (winter)
period of lower lake levels. Lowering of Lake Michigan could become a majf' impact at Chicago, requiring
maior pumping systems, extensive dredging, and costly new lockages to put Lake Michigan water into the
drainage system.
In summary, the institutional impacts were diverse, generally very troublesome and costly, often taking
years to comply or complete. The situation, given only a 2-year low lake level period, suggests that future
persistently lower levels will create institutional problems beyond the ability of our current institutions to address
in any satisfactory manner.
Damage to Shoreline Protection Structures. One of the major effects of the record low levels in the 1960s,
and subsequent increases in the lake levels to much above average levels during the early 1970s and mid-1980s
has been to create major damages to most of the wooden shore protection works of Chicago.
In the early part of this century and extending up through the 1920s, the City of Chicago expended more
than $100 million on the development of its shoreline park system. Roughly $1 billion was spent on landfill along
the Lake Michigan shoreline and in constructing the park system (Mayer and Wade, 1969). This transformation
of Chicago's lake front ranks as one of the world's most vast public works relating to waterfronts and to the
development of parks, recreational facilities, and transportation systems (Real Estate News, 1927). Much of the
38-km frontage owned by the City of Chicago along the lakeshore (nearly 40% of the total Illinois shoreline) was
extended from its pre-settlement shoreline eastward, ranging in distance from tens of meters to more than 3,000
meters eastward in certain locations. More than 1300 acres of new park lands were added south of the city
center (Loop) where no parks existed.
This was accomplished by the construction of a series of protection works along the lake frontage, often
built of wood and steel and filled with rock and cement, with varied structural designs over the entire 38-km
frontage. Behind these protection devices, the area was filled with sands brought in from the lake and with soil
Extremely valuable new property was created. Those portions of the shoreline devices that essentially remained
below water from the time of their construction (1890-1930) up to the low-water period of the 1960s were
exposed to the air during the 1964-65 low-water period. Dry rot set into the planking at that time. Subsequent
increases in lake levels to record high levels in the early 1970s and then ever higher levels in the 1980's with
accompanying wave action from storms have acted on the weakened wooden areas that experienced dry rot,
helping lead to destruction of many of the wooden pilings.
The City of Chicago has established an investigatory commission (Chicago Shoreline Protection
Commission, 1987). The Commission has made an in-depth assessment of the damages to the shoreline
protection structures along the 38 km lake front owned by the city. This report sets forth a range of technical
options and alternatives to obtain a new and long-term shoreline protection system. It cites the "rapid and
effective emergency responses by the city, the Chicago Park District, and the Army Corps of Engineers" to
protect the public from immediate threats, to keep the city functioning during critical storms, and calls for a
program of local, state, federal, and private sector cooperation to begin the process of comprehensive repairing
of the accumulated damage. Again, this damage is partly the result of two things: (1) the sequence of record
low levels in the 1960's (and the dry rot to the wooden support structures), and (2) the subsequent high water
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Cbangnon
levels of the 1970s and 1980s, coupled with the incidence of major storms during the higher levels. That is, the
high water levels increased the power of the lake to erode the shoreline, particularly during storms.
Wind and wave action of the lake erodes the shoreline regardless of water levels, and systematic
maintenance and repairs are needed as erosion occurs. The Commission's report also notes that the shoreline
protection system has not been systematically maintained over the past 50 years (since being completed in the
late 1920s). As a result, it is severely weakened and undermined.
A single storm during the hig.- water levels (on February 8, 1987) with high winds (60 mph) caused
enormous flooding along the lakeshore, causing the closure of major avenues and Meigs Airfield; the evacuation
of property along the shore; and the flooding of sewers, basements, and underpasses, including Navy Pier and
a major water purification plant of Chicago. Severe shoreline damages occurred with much park land eroded.
Costs of emergency responses to Chicago and cleanup were substantial, exceeding $2 million. Physical damage
to city property such as the Navy Pier and the water purification plant exceeded $1 million.
The portion of these damages or of the costs to repair or replace them, resulting directly from the rot that
developed during the low lake levels cannot be assessed independently. It is a part of the problem. Estimates
indicate that more than 60% of the lakeshore devices made from wood were initially damaged by the dry rot
incurred during the 1964-65 low lake levels. These will eventually have to be replaced. The latest figures indicate
that the estimated construction costs for rebuilding the damaged shoreline protection system is $843 million.
Encroachment Land Use Problems. The lowering of lake levels during 1964-1965 resulted in new wide
beaches. This highly valuable "new land" led to the construction of buildings closer to the new beach areas. This
construction largely involved houses, apartment buildings, and condominiums built in places along the lake shore
north of Chicago. These structures, built into the new beach areas, have subsequently become areas of extreme
damages when higher lake levels occurred in the 1970s, within a decade after the record lows. Again, as shown
in the prior section on effects on lakeshore protection works, the long-term (decadal) type oscillations of lake
levels (low then high) have led to this encroachment problems. One area of encroachment along the lake front
is being investigated in detail as to the effects on the shore, the owners and the community where the
encroachment occurred. Permitting relating to lakefront land use changes have been tightened, and this issue
promises to be a future key issue in a future with lower lake levels.
The movement of the lake edge from 1964 to 1987 was measured using the aerial photographs of the
Illinois State Geological Survey. An example of their map analyses of shorelines for the Zion map quadrangle
is shown in Figure 7. This depicts both shorelines. This area last was typically 150 meters wide, and the total
land available in 1964 and underwater in 1987 is 0.9 km2 in the mapped area of Figure 7. This helps illustrate
the problems of encroachment.
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Figue 7. Comparison of the 1964 and 1987 Shorelines as Displayed on the Zion Map Quadrangle (Illinois
Geological Survey).
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CHAPTER 4
INTERPRETATION OF RESULTS
SUMMARIZATION OF RESULTS
This project has already led to the offering and acceptance of three scientific papers relating to various
results. These papers, their authors, and place of presentation are as follows:
1. "Impacts and Adjustments to Record Low Lake Levels: The Illinois Case," Stanley A. Changnon,
Annual Conference on Great Lakes Research, Canada, May 1988.
2. "Climatic Change: The Knowns and Unknowns," Stanley A. Changnon, National Research Council
Colloquium on Great Lakes Water Levels, Chicago, March 1988.
3. "Impacts of Record Low Lake Levels of Lake Michigan," Stanley A. Changnon, G. J. D. Hewings,
and S. Leffler, American Water Resources Association Symposium, Milwaukee, WI, November 1988.
These papers will help transfer the results of the project to the user public including the scientific
community. They each treat portions of the research of the project
SIGNIFICANCE OF FINDINGS
Review of the findings indicate that the most significant social and economic impacts resulting from the
record low lake levels of Lake Michigan during the early 1960s occurred as a result of the subsequent return to
higher water levels 10 to 20 years after the low levels had occurred. The two most major effects, extensive
damages to shoreline protection facilities and the encroachment of buildings and facilities to the new beach areas,
both occurred because of the low levels and then the upward swing of lake levels to 1.5 meters above the record
low levels of the early 1960s. Clearly, if lake levels of 1964-65 had remained low with normal seasonal oscillations
of 30 cm, the impacts to the existing shoreline property would have been much less. However, other detrimental
effects would have developed in groundwater conditions, wetlands and shoreline habitats, shipping, harbors, and
water available for diversion and other uses.
Two important aspects of this study and its results are relevant to the general issue of climate impact
assessment. First, it was impossible to get adequate, extensive quantitative historical data to make in-depth
economic assessments of many effects. Newspaper content analysis is inadequate, and necessary records of public
and private institutions are essentially unavailable (lost or destroyed). It would be particularly beneficial to assess
the impacts of the prolonged low lake levels from the 1920s to the 1930s, if the data existed This suggests the
need to develop and use economic models to simulate the effects of low levels.
Another apparent significant result relates to the general economic impacts of low lake levels." Although
hard to quantify, those relating to the low lake levels of 1964-1965 did not appear to be relatively high. The more
costly impacts related to encroachment of structures into the exposed beach areas and the damage to the
shoreline protection structures occurred only as a result of the combined action of high levels (and storm-
enhanced wave action) following within a few years, the low levels. Thus, the more major economic impacts are
a result of large lake level fluctuations, not just low levels.
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CHAPTERS
SOCIOECONOMIC AND ENVIRONMENTAL IMPLICATIONS
NEEDS FOR PHYSICAL INFORMATION AND RESEARCH
Certain implications can be drawn at this time from the available results. The use of the 1964-1965 results
as an analogy for the impacts from future lower lake levels was limited because these results have shown the
period to be too short to have allowed certain physical changes (erosion and sediment processes) to reach
equilibrium and too short to attain many social and institutional adjustments expected from much lower levels
of Lake Michigan.
One result of the physical assessment of the low lake levels performed for this study is that the period of
about 1910 to 1940 would be an informative period to model for estimating low lake level physical effects.
Although not the record lowest levels, this is a more prolonged period of 20 years of decline to reach a 12-year
period (1930-1941) of prolonged low lake levels. Research on effects during this time period should be
considered.
Results of the study establish that the magnitude of effects of lower levels of the Great Lakes will likely
depend heavily on the magnitude of the longer-term (decadal) oscillations of lake levels around the new mean
low level with a significant climate change. The oscillations hi levels means that controlling land use will have
to be developed (see Policy chapter). The ability to set wise limits for structures and thoroughfares attempting
to encroach in the new exposed land area will depend on the expected future oscillations of lake levels around
the lower average levels. This will be made difficult by the fact that the lower levels will probably develop over
decades, such as the slow decline in the lake level from 1900 to 1940 (see Figure 1).
Climate modeling studies should address the subject of possible climate fluctuations and resulting lake level
oscillations apt to occur with any given lake level (high or low). Results will be essential to a reasoned approach
(1) to develop means to rect to fluctuations in lake levels, and (2) to limit encroachment. Climate modeling of
atmospheric changes and effects on the physical (hydrologjc) conditions beyond the basin is essential
The issue of water diversion, both in and out of the basin, will hinge on the new future values of the
hydrologjc cycle (precipitation, runoff, evaporation), both in and out of the basin. A drier and warmer climate
in Illinois and Wisconsin will lessen runoff in the Illinois River transportation system. This will lead to needs
for more lake water for diversion and greatly altered channels and lockages, both major technical and policy
issues. A drier climate will heighten controversies over the diversion at Chicago.
Any permanent reduction in lake levels whether 0.5 or 2J meters below today's base level, will necessitate
dredging to deepen commercial and recreational harbors and channels. Since the deposition of toxic materials
has occurred in all commercial harbors (and some recreational harborsX the ultimate deposition of these large
volumes of polluted sands and other bottom materials will be a major problem and one requiring both physical
research and sodoeconomic studies.
MAJOR POTENTIAL IMPACTS
Estimations of potential impacts of conditions due to lower lake levels in future years are difficult to
quantify with certainty. Values from three global climate models for the Great Lakes (based on increased
atmospheric CO- and other trace gases) all indicate future lower lake levels but with widely varying heights. The
predicted future levels of Lake Michigan from the models for the Illinois shoreline (and expressed as below the
1951-80 average or base level) are: (1) 0.86 meter (18 feet); (2) 1.25 meters (46 feet); and (3) ZS2 meters (8.2
feet). The climate scenario based on a 12-year period of the driest years of 1900-85 yielded a level of Lake
Michigan that was 038 meter below the average.
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Speculations offered herein about future impacts and adjustments from these lower levels must be
considered within the context of several limitations in the global climate models. Thus, a short discussion of
important key features of all three models is offered for assessing the likelihood of the estimated impacts and
adjustments offered herein. All models are broad treatments of regional conditions and most modelers are
skeptical about using the model-derived values for estimating regional charges. Regardless, all models show (for
the Great Lakes Basin) more moisture in the atmosphere, an increase in high clouds, and a 4°C increase in air
temperature. Their predictions of precipitation levels differ greatly both in the magnitude of change and
placement of change. One model shows a basinwide increase in precipitation of 10%. Some models show
increased precipitation in the west (Superior and Michigan Basins) and decreased in the east (Ontario Basin).
One model expects the interannual variability of precipitation to be greater than in today's climate regime. The
interdecadal variations will probably be large as the climate changes rapidly.
In conclusion, the projected changes in climate (and in lake levels) by all models could be wrong, and their
use is considered scientifically risky to use at the regional level These concerns and lack of other relevant
information required assumptions before we could estimate certain future impacts.
Assumptions
First, the doubling of CO2 and the effects on future climate conditions leading to predicted future levels
of Lake Michigan will be achieved by a process that produces a near linear, continuing decrease of lake levels
requiring at least SO years and up to 100 years to achieve.
Second, since the decadal size oscillations around these future levels due to climate fluctuations are not
predicted with any certainty in these models, and since this is very important in the impact analyses, the
oscillation was assumed to be in the current range, 1.5 meters between the maximum and minimum values over
any 100- or 200-year base period, or +_ 0.75 meters around the mean level.
A third assumption is that relevant current laws and regulations relevant to shoreline impacts will be
retained. Society, in essence, would be continuing its current trend to more control and regulation of natural
resources.
A fourth major assumption is that the use of immediate frontage on Lake Michigan for beaches and
harbors will continue, as will the use of the lake for water supplies and for deposition of storm runoff.
Further, we remind the reader that the study was limited to the Illinois shoreline with its largely urban-
type frontage. We also have not addressed the water quality issue in any substantive way because of the
magnitude of the issue and the lack of information on the qualities of lake waters under the three climate
scenarios.
The model prediction of a future lake level of 0.86 meters below the 1951-80 average closely matches the
lake level achieved during the 1964-65 record low period, 0.92 meters. Of course, an oscillation around that
future average would exist at times, occasionally driving the level more than one meter below the current average.
Most adjustments made to the low levels during 1964-65 are known (see Chapter 3). Experts in harbors,
lakeshore facilities, and water facilities concluded that the 1964-1965 adjustments would largely satisfy the 0.86-
meter predicted decrease in level There would be increased harbor dredging; slightly expanded beaches; and
alterations in slips and piers. There should be relatively few adjustments to serve water exchange needs (intakes
and outfalls). Moreover, many adjustment costs would be met as normal facility replacement costs. Increased
dredging and new facilities would lead to $75 to 100 million (in 1988 dollars) in added costs over 50 years.
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The effects of the predicted future lower lake levels of 1.2 meters and 15 meters were more difficult to
quantify and required more speculation since these were beyond levels experienced since settlement of the Great
Lakes. As noted in the assumptions, attainment of these values was assumed to occur after 50 years of gradual
lowering of lake levels. This assumption is very important in estimating potential economic effects. Efforts to
speculate on effects of the 1.25- and 15-meter lower levels focused on the direct effects on the shoreline and its
immediate facilities.
Recreational Facilities and Harbors. Lakeshore experts agreed that major impacts would occur to pleasure
boat harbors and facilities. Many harbors have wooden slips and docks, and the continuing exposure over time
of the below-water portions of these structures will produce dry rot A major impact is that at 125- or 15-
meter decreases in lake levels, all slips and docks would have to be replaced. A calculation estimation of this
at one recreational harbor facility led to a cost (in today's dollars) of $2 million. However, considering the time
of change involved, 50 or more years, and that the lifetime of these structures is typically 30 to 40 years, at least
one normal replacement would be necessary and occur anyway in the 50-year period of changing climate. Thus,
the cost of modifying slips and docks to adjust to the lower lake levels could be partly handled by normal
replacement costs, not as new, additional costs. Knowledge of the continuing shifts in water levels was seen as
likely to lead to the acquisition of floating docks. In fact, these could be seen as becoming common for the
pleasure boat facilities along Lake Michigan.
The second major area of impact to the pleasure boating facilities was to the harbors. Some experts
predicted that some pleasure boat harbors would become "unusable," particularly with the 15-meter reduction.
All harbors can be adjusted to handle the 125-meter reduction. Specific harbors considered to be nearly
unusable without major dredging were Wilmette, North Point, and Winter Harbor. The cost of deepening
harbors through dredging was seen as necessary and quite high to handle both new future levels. Costs for
dredging and deposition of harbor materials considered to contain toxic materials was 20% higher (1988) than
for handling nontoxic materials. Estimated values for the 125-meter reduction were $3 to 5 million per harbor,
and for the 15-meter departure, $5 to 10 million per harbor. One expert estimated the cost of pleasure harbor
dredging in Illinois at $100 million to address the 23-meter reduction in level The estimate presented in Table
7 is $75 to 100 million, and assumes that all harbors would be dredged and maintained.
A third area of impact to harbors for pleasure boat facilities related to bulkheads. In many areas, harbor
edges must be defined by vertical metal sheeting. In both the predicted future levels, it was estimated that all
existing sheeting along about 4 miles of harbor shores would need to be driven to deeper levels at a cost of $750
per foot In those harbors with natural shorelines, and to maintain harbor size, new piling would need to be
installed along another 4 miles of shoreline. The calculated costs range from $15 million (125-meter level) to
$35 million (15-meter level).
Hotels and restaurants dependent on lake frontage for "lake access" for attracting patrons would suffer.
No economic estimate of this impact was developed but it could be a major problem to selected businesses.
Commercial Harbors. Commercial harbors would also experience major effects. We assumed that all
must maintain an 8-foot (14-meter) draft to be effective for lake carriers. The costs to dredge and modify the
major commercial harbor facilities (Calumet, Chicago, and Waukegan) would be sizable. One expert indicated
that the high cost of keeping the harbor open at Waukegan (at 15-meter lake level) might not be justified by
values gained, leading to its closure, and possibly the Chicago harbor costs would not equate to its value and lead
to its closure. The cost of dredging the harbor at Waukegan ($5/yard) was calculated to be $3 million to meet
the 12-meter level Furthermore, breakwaters would be difficult to support and new supports would have to be
constructed. The dredging costs for the commercial harbors and canals, as accumulated over time, was calculated
at $108 million for a reduction in lake level of 125 meters, and $210 million for a level 15 meters lower (see
Table 7).
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Table 7. Estimated Economic Impacts of Lowerings of the Levels of
Lake Michigan Over a 50-Year Period (1990-2040)
Costs in millions of 1988 dollars to address future lake levels at
indicated depths below average level of Lake Michigan (1951-1980).
1. Recreational Harbors
Dredging
Sheeting
Slips/Docks
1.25 meters lower
30 to 50
15
20'
2.5 meters lower
75 to 100
35
40'
2 .
Harbors
Dredging
Sheet ing/fiulkhe ads
Slips/Docks
108
38
40'
212
38
90'
3. Water Supply Sources
Extending urban intakes
Wilmette Harbor Intake
15
1
15
2
4. Beaches
Facility relocations
1-2
1-2
5. Outfalls for Stormwater
Extensions and modifications 2
TOTALS $270 to $292 million'
$512 to 540 million'
'Some costs could be partly covered by normal replacement expenditures over the
50-year period of changing level.
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Dredging in all commercial harbors and canals would be a problem, particularly for the polluted materials
in their bottoms. This greatly increases the costs for disposal for the polluted material. This would be a
particular problem for the two local "Areas of Concern," the Waukegan Harbor, and the Grand Calumet River.
These were identified in 1973, along with 40 other locations, as particularly heavily polluted areas (Great Lakes
Water Quality Board, 1987). Costs of dredging (Table 7) included higher costs of the polluted sands in these
two areas.
All slips and docks in commercial harbors would have to be rebuilt due to dry rot and to lower levels for
access. However, due to obsolescence and normal depreciation over 50 years or more, normal replacement
would occur with costs not totally related to the climate-induced reduction in lake levels. The estimated
replacement costs shown in Table 7 are indicated to be attributable to normal replacement costs. Costs of
driving existing bulkheads deeper was calculated as $35 million over the 50-year period New bulkheads in a few
areas would cost $2.6 million.
Beaches. Another area of impacts relate to recreational beaches. In this study, we assumed that the
lowering of lake levels would not lead to construction of major new shore protection works to protect beaches.
The benefits of lower lake levels .to beaches are not insignificant. The underwater slopes away from current
beaches along Lake Michigan and Illinois range from 2:1 in fine grain areas to 40:1 in coarse sand areas, with
an average of 20:1. Detailed bathymetric maps (depth of lake bottom from lake levels) were used to calculate
the amount of land to be gained from the lower lake levels. Figure 8 is an example showing the contours below
low water datum, the current shoreline, and historical (pre-1932) shoreline of Lake Michigan before barriers were
built and fill used. Calculations for the beachfront gained between Fullerton Parkway and Ohio Street (on this
map) indicated 0.1 km2 for the 1.25-meter drop and 0.5 km2 for the 15-meter drop in levels. The calculated
increase for the 43 km of beach frontage based on the decrease of 1.25 meters in lake level was an additional
beach area of 1.12 km , and the 23-meter reduction would create 3.24 km2 of additional beach area. Certain
beach facilities would be relocated and/or constructed for an estimated cost of $1 to $2 million (Table 7). No
monetary benefit was assigned to the added beaches. Moreover, the benefits of the lower levels would be
appreciable to the bluff shore area north of Chicago where expensive residential areas exist and where major
bluff erosion occurs in high waters. Major expenditures (>$20 million) by communities and individuals have
occurred in the recent high-level periods (Changnon, 1987), and these would end.
Environmental Impacts. Several of the aforementioned impacts relate to problems of an environmental
nature. This includes the issue of dredging and deposition of polluted sediments/sands of harbors and canals.
A major environmental problem of lower lake levels will be changes in the hydrologic cycle. The shallow and
deeper groundwaters interacting with the lake will be reduced over time. Lowered groundwater levels will
detrimentally affect existing wetlands and lessen ecosystem production. Overtime, new wetlands will develop if
the rate of lake level fall is sufficiently slow. Polluted groundwaters in the urban area will percolate into the lake,
and in turn polluted lake waters will percolate into aquifers; the net result will be reduced lake and groundwater
quality. Thus, it seems likely that unless agricultural and urban pollutants now entering the lake are greatly
reduced, the overall quality of the waters of Lake Michigan at Chicago will be further diminished under a drier-
wanner climate scenario.
Water Intakes. Another area of future impact relates to water intakes in the lake to serve municipal and
industrial water supplies. Most of these are positioned well beneath the lake surface to be free of ice and to
maintain sufficient head for pressure because they are gravity fed. Along the area north of Chicago there are
14 major intake systems (several cities have two intakes at different locations). Analysis of these for varying
future levels of Lake Michigan revealed different outcomes. At the reduced lake level of L25 meters below the
current average, three of the intake systems would have to be altered at a total cost of $2.8 million (see Table
7). With a reduction in lake level of 15 meters (the worst possible outcome), we find that six systems would
require a range of extensions adding up to a cost of $7.4 million ($900/30 cm, in 1988 dollars).
Water Supplies. A major impact of the predicted wanner and drier climate with the lower lake levels and
poorer water quality, will be a reduction in water supplies. Population growth and the more arid climate will
increase usage and demands for water (1) to serve Chicago and its suburbs, (2) for industrial processing, (3) for
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Changnon
EXPLANATION
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. •••••>-.»•? «*»-IM«M:I«>
•Mxliw <•?.!•. I(U-IU)
-C«ri»»« IK »••«
•»•«. I*. «•!•* I
> U>l«v< «!.»,
N*VY PI£g
(
Figure 8. Nearshore Bathymetry Chicago Northside Lakefront (Illinois Geological Survey).
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Changnon
cooling of power plants (such as at Zion), (4) for shipping needs in the Chicago River and Canal system and the
Illinois River, (5) for sewage treatment, and (6) for hydroelectric power generation at Lockport (southwest of
Chicago). Cohen (1987) projected 30 to 40% increases in municipal water uses in the Great Lakes Basin as a
result of the predicted climate change.
The lake as a source would be hard pressed to meet these increased needs. Pressures to maintain lake
levels by the other lake states and Canada would cause serious national and international controversy over any
Illinois requests for increased diversions of lake water. Increased diversion seems an unlikely outcome, as
revealed by the controversy and strong opposition to the idea of increasing diversion during the summer drought
of 1988 to help increase the flow of the Mississippi River. The effects on demand/supplies of water supplies
would then extend to groundwater sources. For example, the suburban communities would likely turn to
groundwater sources (most have wells) to supplement the inadequate lake supplies, which will prove difficult to
obtain and at best be very expensive. This shift, if sizable, would lead to decreased groundwater levels and to
more mining already present in some suburbs. This impact also will create interstate conflicts related to
increased groundwater use and the effect on lake supplies.
Another area of impact from greatly lowered lake levels and decreased runoff relates to the Chicago River
and Canal system. This complex system now depends largely on gravity flow from Lake Michigan to maintain
water levels in the river and canal system. Problems with the low lake levels in 1964-1965 led to the installation
of a major pumping system at Wilmette Harbor to ensure the supply of water out of the lake into the upper
reaches of the system. The predicted reductions of lake levels below 1 meter would bring major requirements
to deepen the Wilmette Harbor system, including its entrance, and the necessity for lowering the pumps to meet
the 12- and 15-meter lake levels. The operation of the river system with lower lake levels would be very
concerned about loss of water at the Chicago River outlet, leading to possible restrictions on the frequency of
entry and exit of boat and ship traffic. Another effect would be reduced water released for power generation
at Lockport Costs for the Wilmette Harbor adjustments in pump levels are shown in Table 7.
A related problem that will develop from the warmer-drier climate conditions will be the effects on the
hydrologic cycle of the streams and rivers in the Illinois River Basin. Presumably this area adjacent to Lake
Michigan, and tied to the lake through the water diversion at Chicago, will experience substantially decreased
runoff due to the suspected climate changes. The Illinois River is a major transportation artery controlled by
a series of locks and dams between Lockport (near Chicago) and its junction with the Mississippi River near St.
Louis. The level of flow in the river to satisfy barge usage is maintained by the diversion of 3,200 cfs of water
at Chicago, the maximum amount allowable under the current U.S. Supreme Court decrees. Basin runoff for
the arid climate outcomes will be reduced by at least 20%. This will make the river system including the locks
unusable. Alternatives include deepening the river and rebuilding the lockages, diverting more water from Lake
Michigan, or loss of the barge transportation. The first case represents an exorbitant expense. The added
diversion seems unlikely with the lower lake levels and extreme pressures against increased diversion. The
resulting inability of the river system to function in its current fashion might lead to increased shipping by
railroad. Pressures would be great to change the lockages and dredge the navigation channel Costs for these
impacts were not estimated but would be sizable.
Water supplies from Lake Michigan for public usage and certain industrial needs could be seriously
affected by major degradations in water quality if they occur with the projected lowerings of lake levels. The
magnitude of this potential problem is unknown but it would increase water treatment costs. A warmer climate
and lower levels of the lake would also cause lake water temperatures to become higher than at present. The
amount of change is unknown but if sizable, it could affect cooling water needs of power plants and industry.
In the net, the future warmer and drier climate will lead to increased needs for water to serve Chicago
and the Illinois area However, the ability of Lake Michigan to provide added water for these demands (or to
sustain the current diversion level) likely will be blocked by institutional forces in the Great Lakes Basin.
Further, deep groundwater aquifers in northeastern Illinois, already subjected to excessive drawdowns, will not
be able to meet the future needs. This situation could very adversely affect the growth and economy of the
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Changnon
Chicago region. It seems likely that effects to develop new sources in the more shallow groundwater aquifer
(heavily mineralized and partly polluted) will be pursued as the only resource.
Outfalls. Another effect relates to outfalls and outlets for storm rainwater for communities along the
lakeshore. For both the 1.25- and 2.5-meter lower lake levels, all 28 existing major outfalls (1 meter or larger
diameter) would have to be extended, ranging from 50 to 150 meters in length. This would lead, as shown in
Table 7, to additional costs to local communities of $2 to 4 million.
Encroachment. The final area of potential impact analyzed as possible from the major reductions in lake
levels relates to encroachment of buildings, thoroughfares, and other structures in the newly formed beach areas
that will occur. This regulatory/policy issue would, under current regulations, be controlled by the fact that
Chicago has a lakefront ordinance, and by the fact that the State of Illinois vigorously enforces the lakefront
usage permit process. The State of Illinois claims ownership of all lands to the edge of the "record high water
level." Thus, private land owners cannot modify or replace land lost due to high water erosion. In essence, if
this theme of strong governmental control was maintained over the 50+ years required for the predicted lake
reductions, the newly formed lands would remain under governmental control and would be free from serious
encroachment for buildings and other structures. However, is this a likely societal outcome? Will this type of
protective legislation develop around other shoreline areas?
A key to this issue will be vigorous enforcement. During recent high lake levels several instances of "self-
help" construction were done without permits and the State did not prosecute.
Other Possible Impacts. Another implication open to speculation relates to the possible advent of a
widespread warmer and drier climate in the United States. If this occurs, an "out migration" from the Sun Belts,
which will become more like "Hot Belts" can be expected. This migration will undoubtedly include movement
into the Great Lakes Basin. A warmer climate will reduce ice coverage on Lake Michigan including shore ice,
and this may lead to more rapid shoreline erosion than currently occurs.
Another potential impact of much lower lake levels and its detrimental effects to basinwide shipping would
be the potential for increase of shipping by railroads. Commercial lake fisheries would presumably be hurt by
lower lake levels, warmer water, and fewer fish.
Table 7 presents the best, albeit qualitative, estimates of the economic influences of the two model
predictions of greatest reductions in lake levels. In summary, these show that along the Illinois shoreline (101
km) the effects of lower levels on harbors, water supply sources, beaches, and urban outfalls would lead to costs
between $270 and 292 million for the 125-meter fall, and between $512 and 540 million (1988 dollars) for the
2.5-meter reduction. Experts in lakeshore issues consider these costs to be justified for maintaining the high
valued harbors and beaches of this major urban area.
Conclusions. The economic effects of one GCM prediction of a mean lake level 0.86 meters down from
the current average, and accomplished gradually over 50 years, is seen to not have serious economic consequences
(<$100 million over 50 years), and to be partly accommodated as part of normal maintenance and replacement
activities and costs. However, the potential effects on water demand and supplies would be serious. Maintaining
supplies to meet increased demands with less lake water (and of poorer quality) would lead to interstate and
international controversy and in turn, increased groundwater usage of an already meager source.
A projected climate change leading to a reduction of the mean lake level of 15 meters produces much
more serious economic impacts. Hence, the character and magnitude of the economic impacts relating to a
changing climate and the lowering of lake levels are very sensitive to the amount of decrease predicted to occur,
and in turn to the seasonal-decadal climate-related fluctuations in levels envisioned around the new mean lake
level.
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These results reveal that the global climate models and climate scenarios they have developed (and their
related assumptions) for the Great Lakes Basin are extremely critical to estimating future impacts, adjustments,
and policy actions. Differences in these models make very major differences in the impacts. Hence, the ability
to undertake major revisions of policy at this time responding to the future increases in trace gases and their
effects on climate appears difficult, at least as far as the Lake Michigan-Illinois situation is concerned. Economic
impacts range from essentially a manageable level to major extremes, greater than $0.5 billion along 101 km of
shoreline. These differences relate to different climate models. These widely different outcomes in lake levels
reveal considerable atmospheric uncertainty in the outcome and in turn suggests it would be very risky to develop
policy actions at this time. More firm and consistent predictions of change in climate are needed along with
indications of change. However, all levels of change will create serious water supply problems and issues
requiring policy actions.
A factor for recommending cautious reaction to this situation, in light of the Illinois shoreline, is that the
rates of lake level change in all models do not exceed the rate that normal replacement costs, or economic life,
could handle in harbor and beach facilities. In other words, a major portion of the dockage changes needed to
address major reductions in lake level could be handled over a 50-year period by normal replacement costs.
However, this would require recognition and acceptance of the ongoing change. Regardless, with the
replacement costs removed, the economic effects from the two most severe predicted lake level reductions, 1.25
meter and 15 meters, would result in costs ranging from about $200 million to $400 million, respectively (Table
7).
Major problems would be realized in the harbors and canals (dredging, bulkheads, slips, and docks), and
in the disposal of polluted wastes. The costs for improving harbors and their facilities and for extending intakes
and outfalls would presumably be met largely by local communities, the state, and the federal government.
Ultimately these costs would be transferred to the public.
The gains to be realized by the lower lake levels would be wider beaches ranging from 30 to 60 meters
with an addition (depending on the lake level reduction) of 1 to 2 km2 of beach area in Illinois. Fortunately, the
widened beach area is likely not sufficiently increased to allow for major expansions into the beach area and the
ensuing need for construction of new shorefront protection systems. The wider beaches themselves will help
protect the shoreline. The private dredging and construction firms that handle harbors and their facilities, and
address water intakes and outfalls, would be beneficiaries of the major reductions in the lake levels.
Future Adjustments
The potential exists for lake levels to be much lower than those experienced in 1963-1965. The GCM
predictions, and the climate scenarios designed for this study, all seen as possible, show a potential for levels that
will be 0.4 to iS meters lower than levels experienced in 1964-1965. What are the potential adjustments that may
and should occur?
A primary one relates to the need to incorporate, in all aspects of harbor and shoreline structures, and
related land use, a "design for lake level fluctuations." A more permanent lower level will provide recognized
gains in valuable lands, particularly along urban frontages of all the Great Lakes. This could benefit
communities, recreation, and certain industries. There will likely be a major push into these lands that must be
carefully weighed
A second series of adjustments that can be predicted to occur will relate to the real and perceived needs
for increased water supplies in the lakes to serve the needs of shipping, urban and industrial water supplies, and
hydropower generation. This demand will create calls for increased diversion, presumably from sources in
Canada, into the Great Lakes, and for decreased diversion at Chicago and elsewhere. Whether such shifts
involving inici-»cuc ou- international negotiations and agreements can be realized seems unlikely under current
institutions and legal agreements.
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Changnon
The additional water needed could also be potentially realized through new technologies to increase
precipitation through weather modification and to reduce evaporation through various physical and chemical
techniques. Exploratory and developmental research will occur in these areas.
Similarly, there will be an increased need to improve predictions of lake levels during a more stressed lake
regime. Research to develop better capabilities, in climatology and hydrology, to predict climate and lake level
fluctuations around a lower mean level will occur.
In summary, comparison of the more direct economic losses with the apparent gains indicates that even
the worst of the projected lake level reductions will not cause unaffordable economic problems along the valuable
Illinois shoreline. All the changes can be handled in an economically effective manner, often by employing
normal replacement and maintenance procedures if master planning for these changes is implemented and if the
decrease occurs gradually over several decades. The Great Lakes Charter (1985) contains the charge to develop
a "cooperative water resources agreement program for the Great Lakes Basin." It could serve as the basis for
proceeding.
The other impacts to Illinois water supplies and to environmental conditions will be major problems. The
increased water demand vs. less available lake water (and of poorer quality) could greatly affect mining of the
local and regional groundwater supplies. We lack the institutional arrangements and laws to address the
magnitude of these problems in Illinois or in the other lake states. The water quality problem of Lake Michigan
will likely become a major issue for Illinois shoreline interests including water for public consumption, industrial
needs, and recreation.
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CHAPTER 6
POLICY IMPLICATIONS
The future incidence of lower lake levels will greatly affect policy at the international, national, state, and
community levels. Potential problems relating to lower water levels and less adequate water supplies will lead
to needs, real and perceived, to divert additional supplies into the Great Lakes from Canadian sources. It will
also lead to desires to increase diversion at Chicago with resulting controversies reaching the Supreme Court and
international forums. The climate change will also reawaken concern over the current amount of water diverted
at Chicago. The amount being diverted will be contested. The likely inability to provide waters of desired
quantity and quality from Lake Michigan to serve Chicago, its suburbs, and the Illinois-Chicago Rivers system
will lead to increased usage of ground water. Deep aquifers will be further depleted leading to disagreements
over water mining between Illinois and adjacent states (Wisconsin and Indiana).
The effects of lower levels will reinstate dredging of all recreational and commercial harbors. Major added
costs for recreational harbor maintenance and intake/outfall extensions will fall largely to local communities, and
these will probably lead to an effort to seek state and/or federal support. Disposal of the polluted harbor
materials from dredging will be costly and of great environmental concern, and will affect federal and state
policies and enforcement strategies.
Increased widening and deepening of certain major connecting channels in the Great Lakes to allow
shipping loads can be envisaged to develop as regional policy issues. All of these concerns/activities will relate
to national policies and in turn to actions by federal agencies such as EPA and COE and their Canadian
counterparts.
The need to resolve the problems of lower levels will also lead to research on atmospheric and hydrologic
issues. This will impact the federal agencies that support research in these areas such as NSF and NOAA.
It seems likely that the problems with encroachment onto beaches, coupled with lake-level oscillations,
even with relatively lower mean levels, will develop. This will likely lead to federal and/or state regulations
concerning land use activities along the shores of Illinois and the rest of the Great Lakes.
Several factors could greatly alter the impacts and the policy adjustments postulated as related to the
lowering of Lake Michigan levels. First, if the changes in climate lead to step-wise shifts creating sharp drops
in lake levels rather than gradual changes in levels, the problems will materially increase and crisis management
seems likely. We need better institutional mechanisms now to deal with the recent fluctuations (record high
levels in 1985-86, and now precipitous declines).
Another factor that could alter the postulated impacts and policy actions concerns the amount of variation
around the future mean lake levels. In this study of potential impacts we have assumed that the fluctuation over
time (> 100 years) would be equivalent to the current +. 0.75 meter; if this is much greater, a variety of other
more serious impacts and different policy actions could occur.
The third factor that could greatly vary the impacts and ensuing policy actions concerns whether sizable
amounts of water could be diverted into the Great Lakes in Canada to help ameliorate the effects of the lower
levels. This would certainty reduce impacts and policy actions, but is probably unlikely in a more arid climate.
Similarly, if new water-adding technologies were developed (weather modification or evaporation suppression),
the levels of impacts and policy reactions would be changed Warmer and drier conditions elsewhere in the U.S.
may also lead to efforts to divert waters from the Great Lakes for irrigation and public water supplies.
A further factor that could influence the policy outcomes relates to the societal attitudes towards the use
of lak<. 'ige and the protection of lake frontage; should this change drastically, the policy outcomes could
be altered greatly from those predicted herein.
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Changnon
Consideration of the impacts and adjustments that would occur to the harbors, beaches, intakes, outfalls,
and transportation reveals that (1) wide acceptance of the ultimate reduction of lake levels over 50 or more years
and (2) recognition of normal replacement of facilities and maintenance of harbors could be sensibly combined
in a "master engineering plan" for the area. That is, wide acceptance by the scientific and engineering
communities that the lake level would be gradually falling by a rate of 0.1 foot/year and that by 2050 the average
level would be 2 meters lower, would be the basis for in-depth planning of all future lake-related activities. For
example, the normal replacements of harbor facilities, including the slips and docks, maintenance of the
breakwaters, and the installation of bulkheads could be geared to the downwind shift in lake level. Replacement
of locks in the river and channel navigation systems would take into account the ongoing climate shift. In
essence, many adjustments could be made in a most cost-effective manner over the 50-year period. However,
a Master Plan would need to be developed to guide these activities based on wide agreement over convincing
evidence of a change. This would be a major policy issue.
In the Great Lakes Charter (1985) the governors of lake states and the premiers of the Provinces
committed themselves to the development of a "Great Lakes Basin Water Resources Management Program."
This could become the basis for addressing the many policy issues raised by a changing climate.
We recommend that policy action for implementing such a plan, and action now in other policy areas,
should begin. The wide variations of model outcomes leading to lake levels ranging from 0.86 meters to 2.5
meters lower than today's average level, produce differences in the magnitude of the economic effects but they
all relate to severe water quantity and quality issues calling for policy development.
A basinwide climate change to more arid conditions in 50 years will create problems similar to those
predicted for Chicago at aJl metropolitan areas around the Great Lakes. One envisions very large expenditures
to maintain shoreline structures and facilities plus enormous conflicts over water supplies and environmental
effects. The inability of the U.S. and Canada and our existing institutions to deal effectively now with recent
transboundary pollution (air and water) problems in the Great Lakes Basin suggests major policy actions must
occur and new institutions must develop to meet the challenge of the envisioned climate change. The Boundary
Waters Treaty of 1909 will certainly undergo modification.
Acknowledgments
This study was the result of the efforts of several people. Charles Collinson, Paul Terptra, and their
colleagues at the Illinois State Geological Survey provided invaluable advice, data, and materials used in this
study. Jean Dennison helped prepare the text and illustrations.
Others were extremely helpful in providing data and information. These included Lewis D'alba, Frank
Quinn, Larry McDonoghue, Ralph Fisher, Malcolm Todd, Daniel Injerd, Luke Cosme; Richard Lanyon, Bill
Eyre, Frank Dalton, Jere Lappish, Peter Wise, Donna Wise, George Ryan and his staff, Zane Goodwin, and Roy
Deda. The staffs of the Chicago Park District, the U.S. Corps of Engineers, the Metropolitan Sanitary District
of Greater Chicago, and the Illinois Division of Water Resources were all helpful in providing data, records, and
maps essential to this study.
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Changnon
REFERENCES
Changnon, SA. "Climate Fluctuations and Record High Levels of Lake Michigan." Bulletin of AMS. 68:1394-
1402, 1987.
Chicago Shoreline Protection Commission. Preliminary Protection Options and Alternatives: Requests for Public
Comment. 1987. pp. 1-33.
Cohen, S., 1987: Projected Increases in Municipal Water Uses in the Great Lakes Due to CCylnduced Climatic
Change. Water Resour. Bull.. 23. 91-101.
Corps of Engineers. Annual Report. U.S. Army, Washington, D.C, 1964. 1109-1163.
Corps of Engineers. Annual Report. US., Army, Washington, D.C., 1965. 1083-1135.
Great Lakes Charter, 1985: Principles for the Management of Great Lakes Policy Resources. 7 pp.
Great Lakes Reporter. Coping with Fluctuating Lake Levels. Special Report, Center for the Great Lakes,
Chicago, 1987. 8 pp.
Great Lakes Water Quality Board, 1987: 1987 Report on Great Lakes Water Quality. International Joint
Commission, Detroit, MI, 236 pp.
Holms N. Inventory of Lake Michigan Research Projects 1984-1987. Environmental Geology Notes 121, State
Geological Survey, Urbana, IL, 1987. 423 pp.
International Great Lakes Level Board. Regulation of Great Lakes Water Levels. Report to UC, 1973. 294 pp.
Lake Carriers Association. Annual Report. Cleveland, Ohio, 1964. 38 pp.
Lake Carriers Association. Annual Report. Cleveland, Ohio, 1965. 48 pp.
Lamb, P J. "On the Development of Regional Climatic Scenarios for Policy-Oriented Climatic-Impact Assess-
ment." Bulletin. Amer. Meteorol. Soc. 68:1116-1123,1987.
Larsen, CE. A Stratigraphic Study of Beach Features on the Southwestern Shore of Lake Michigan: New
Evidence of Holocene Lake Level Fluctuations. Environmental Geological Notes, 112, 111. Geological Survey,
Champaign, 1985. 31 pp.
Mayer, H. and R. Wade, 1969: Chicago: Growth of a Metropolis. Univ. of Chicago Press, 292 pp.
Neill, J.C. and C.-F. Hsu. "Using Non-Integer Spectral Analysis in Discerning Spatially Coherent Rainfall
Periodicities." Times Series Analysis. 5:375-384,1981.
Quinn, F. "Courses and Consequences of the Record High 1985 Great lakes Water Levels." Preprints
Conference on Climate and Water Management AMS, 1986. 281-184.
Real Estate News. South Parks Our Big Public Boon. VoL 22, No. 10, 1927. pp. 1-7.
Wigley, T.M.L., Jones, P.D., and P. Kelly. "Empirical Climate Studies: Warm World Scenarios and the
Detection of a CO, Induced Climate Change Induced by Radiatively Active Gases." Chapter 6, The Greenhouse
Effect Climatic Change and Ecosystems. J. Wiley & Sons, Chichester, 1986. 271-321
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APPENDIX I: NEWSPAPER CONTENT ANALYSIS FOR 1964-1965
Steve Lefller
Department of Geography
INTRODUCTION
During low water periods several problems commonly arise. These problems include the encroachment
of buildings into high risk areas, difficulties with shipping and harbor maintenance, damage to drainage systems,
and even damage to shoreline protection devices. Though these problems are well known, some are difficult to
document. Building encroachment problems and damage to shoreline protection devices become apparent as
the water level rises, but it is quite difficult to document damage to drainage systems, harbor maintenance, and
shipping problems. In the twenty years which have passed since the record low lake levels, most official records
(i.e., surveys, repair cost reports, appraisal studies, etc.) have been destroyed, misplaced, or are otherwise
irretrievable. Likewise, most of the knowledgeable personnel during that time period have retired, and/or
disappeared.
A search through the newspapers of the 1964-1965 period was one method used to document impacts.
Newspapers are a potentially good media to search because they are easily accessible and can cover a wide range
of topics. As we learned, many of the impacts of low lake levels were not perceived as problems at that time,
and those that were problems, may not have been perceived as important enough to warrant an article. This
approach was unpractical for studying the social impacts of low lake levels. Few articles are written about too
much beachfront.
The objective of this newspaper content search was to attempt to document the physical, social, and
economic impacts of the low lake levels. This included looking for any incurred costs due to repairs, dredging,
etc. As a secondary objective, we also attempted to identify persons who might be interviewed for more detailed
information.
METHODS
A thorough examination of the Chicago Tribune (CT) and Chicago Sun Times (CST) was conducted for
most of 1964 and portions of 1965. Both newspapers were available on microfilm at the University of Illinois.
Unfortunately, no indexes were available for this time period, and thus the tedious task of searching each page
of the newspaper was needed. A file at the Illinois State Geological Survey, based on newspaper clippings on
lake related topics going back to 1970 also was analyzed. This file was used for documenting high water
problems further documenting low water impacts. This file was composed mainly of CST and CT articles, but
also included articles from several smaller neighborhood newspapers and a few articles from newspapers of other
big cities.
Month (65/65) JFMAMJJASONDJF MAY
Chicago Tribune XXXXXXXXXXXXXXX
Chicago Sun Times XX XXX X XX
Newspaper search coverage for 1964 and 1965.
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Changnon
DATA
Many articles during the low lake levels period (1964-1965) reported that the lakes had reached another
"record low." These were often accompanied by discussions of the amount of water diverted into the Mississippi
through the Chicago River or notes on the meetings of the International Joint Commission. There were 21
articles of this type (in 15 months).
The following collection of articles (pages 5-7) represents all those found which were relevant to impacts.
The collection consist of articles from both the 1964-1965 search and the ISGS file. Portions of most of these
articles were quite irrelevant and thus only Article #3 is complete. Articles #1-4 discuss shipping and harbor
management problems that resulted from low lake levels. These articles were found during the search of 1964-
1965 newspapers. The remaining articles discuss problems with Chicago's seawall. Through these problems were
not discovered until recently, they stem from the low lake levels when the wood pilings in the shore protection
devices were exposed to air and subject to dry rot.
ANALYSIS
Article #1 discusses both positive and negative impacts of low lake levels. It implies that shipping had
been reduced significantly due to low lake levels, especially in shipments of "heavy commodities." This supplies
a due as to which industries were most impacted by low lake levels. By checking with the harbor, we learned
which companies were shipping ore and limestone during this time and then contacted those companies for more
information. Though only iron ore and limestone were reported on, coal mining is a significant part of Illinois'
economy and it would be interesting to explore how the coal industry was affected. Also mentioned in this article
are a few social impacts of the low lake levels, including increased beach size and easier access to rivers by
pleasure craft.
Article #2 links low lake levels with a loss of shipping business at the Port of Chicago. It reports that
overall shipments were down 20% from the previous year. This loss was mostly in the form of "general cargo"
(Le., machine goods). The cause of the decline in shipments was given as "insufficient water depth in the
Calumet River" and increased competition. It should be noted, however, that the business of other port facilities
was reported as up, implying that this may be an isolated case.
Artide #3 reported mainly on the causes of the low lake levels. It also gave a good rule that could be
used to help estimate the total amount of business lost. That is, for each inch the water level dropped, ships lost
100 tons of cargo they could have otherwise carried.
Artide #4 discusses the deepening of the Calumet River in a flight to curb the 20% loss of shipping at
the Port of Chicago (Artide #2). The total cost of the project was estimated to be $3.5 million.
Artide #5 reports on the findings of a panel of engineers who recently (1987) examined Chicago's seawall.
They found that "11 miles of seawall and 25 miles of breakwater need immediate repair." An estimated total
cost of $200 million was given. This is the first article which directly linked low lake levels to the deterioration
of the seawall It reported "during a low water period in the 1960's, the pilings were exposed to air and dry rot
set in."
The final two articles discuss the findings of an underwater survey of Chicago's seawall which was compiled
using sonar aboard the research vessel "Neecho." Artide #6 reports that the deterioration of the wall had
allowed waves to scour caves 12 feet into the shore and wash large fill rocks out 40 feet from beneath the seawall.
Artide #7 reports that repair work on the seven worst miles will cost "between $37 million and $111 million."
These artides also supplied us with the names of important contacts to whom we referred to for further
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RESULTS AND DISCUSSION
The purpose of this search was to analyze newspapers as a help in documenting the physical, social, and
economic impacts of low lake levels. First, how good was this method in detecting and defining the impacts of
low lake levels?
By far the most costly impact of the low lake levels was the damage caused to Chicago's seawall. This
impact was not detected, or at least not perceived as a problem, until record high lake levels began to cause
major damage. However, once this problem was detected, it drew significant attention.
Probably the second most costly impact of the low lake levels was the difficulties inflicted upon the
shipping industry. These problems manifested themselves in the form of a decrease in the shipments of
manufactured goods and also in the form of increased harbor maintenance. This problem received attention
during the low lake levels. The articles found on this subject helped define the problems.
During the recent high water period, the subject of water encroaching towards housing structures received
coverage, but was never linked to low lake levels. The low lake levels caused these problems by lulling people
into building in an area perceived as low risk. None of the articles written on this subject discuss when the
housing unit(s) were built The newspaper content analysis yields no evidence to show the low lake levels caused
problems with drainage devices or water supply systems. The search did identify some of the social impacts such
as valued larger beaches.
CONCLUSIONS
Is a newspaper search useful in assessing the social and economic impacts of low lake levels? The number
of articles found was disappointingly low, and the articles found only barely documented the many impacts of low
lake levels. Moreover, this was an inefficient method of documentation.
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APPENDIX D: QUESTIONNAIRE FOR ASSESSING EFFECTS OF LOW LAKE LEVELS
A semi-structured interview process was used with those who had been involved in various lake-related
activities during the early I960 period of low lake levels. These interviews were largely conducted over the
telephone, although certain person-to-person interviewing was done.
The initial phase of the interview involved establishment of institutional credentials. This was followed
by a description of the project including its goals and objectives. This was followed by a description of why the
person interviewed was selected. At this stage, we sought their willingness to proceed with the interview.
Following acceptance of willingness to be interviewed, a well-known example of an impact was presented;
typically a case of encroachment of buildings. This was used to illustrate that the impacts could be direct
(physical), occur at the time of the low water levels or later, or could be secondary or tertiary in the socio-
economic-fabric. This portion of the interview was used to allow the person being interviewed to think and recall
events of that time.
At this stage of the interview, obvious or possible impacts in the arena of the expert were illustrated as
introductory statements to general questions of events that developed in 1964-1965. Depending upon the
interviewee's willingness, further probing questions were asked. Questions typically focused on specific
phenomena, periods of time of resulting events, ensuing costs (or gains), and adjustments. Another area of
inquiry after the open discussion questioning related to questions about availability of records that could be
investigated to allow us to find more specific details of dates and financial impacts.
At the end of the interview there were two standard questions in addition to a "thanks" for cooperation.
One of these was related to a personal visit to get more information, or willingness to have us call back to get
more information. If a visit was seen as desirable, dates and place were arranged The other ending interview
question related to any thoughts about persons or places to get further information on the subject
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EFFECT OF CLIMATE CHANGE ON SHIPPING WITHIN
LAKE SUPERIOR AND LAKE ERIE
by
Virgil F. Keith
J. Carlos De Avila
Richard M. Willis
Engineering Computer Optecnomics, Inc.
1036 Cape St. Claire Center
Annapolis, MD 21401
Contract No. 68-02-4532
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CONTENTS
FINDINGS 4-1
CHAPTER 1: INTRODUCTION 4-2
CHAPTER 2: METHODOLOGY 4-3
MODEL ELEMENTS 4-3
Port Dimensions 4-3
Port Vessel Transit Patterns 4-3
Vessel Economics 4-3
Cargo Capacity as a Function of Draft 4-7
Water Level Reduction 4-7
Ice Coverage Reduction 4-7
Dredging Costs 4-7
MODEL OPERATION 4-12
CHAPTER 3: RESULTS 4-13
CHANGE AS A RESULT OF WATER LEVEL REDUCTION 4-13
CHANGE AS A RESULT OF ICE COVER REDUCTION 4-18
DREDGING COSTS FOR ALL LOCATIONS 4-25
CHAPTER 4: INTERPRETATION OF RESULTS 4-33
CHAPTERS: LIMITATIONS OF RESULTS 4-34
CHAPTER 6: IMPLICATIONS OF RESULTS 4-35
REFERENCES 4-36
u
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Keith
FINDINGS1
The potential effects of climate change on the Great Lakes shipping system were evaluated through the
use of a Great Lakes shipping model of six specific locations in Lake Erie and Lake Superior developed by
Engineering Computer Optecnomics, Inc. (ECO). The ECO Great Lakes Shipping Model simulated water level
reductions of from 1 to 5 feet, and showed that the changes in water level and ice cover on the Great Lakes will
have an effect on shipping due to climate changes predicted by various climate change models. The primary
effect of water level reduction will be an increase hi shipping costs due to reduced vessel-carrying capacity. The
reduction in ice coverage will extend the shipping season, and the additional shipping days will be adequate under
most scenarios to compensate for the cargo capacity that was lost due to reduced water levels. Dredging the
locations to maintain existing depths is an achievable alternative but would be dependent on similar dredging and
potential new construction in other parts of the Great Lakes system such as the Sault St. Marie locks and the
St. Marys and St. Claire Rivers.
Six locations were used for the shipping model: Two Harbors, Duluth/Superior, and Whitefish Bay in Lake
Superior; and Toledo, Cleveland, and Buffalo in Lake Erie. Two scenarios of climate change yielded 1- to 2-
foot drops in the water level in Lake Superior. The shipping model showed that a 1-foot reduction in water level
would cause a 1.6 to 33% decrease in cargo capacity for the present fleet at locations in Lake Superior. There
would be a corresponding increase in costs per ton carried of 1.6% to about 3.4%. The reduction in ice coverage
would allow the shipping season to be extended. Up to nine additional shipping days would be required to make
up for the reduced carrying capacity. The climate simulation models predict that between 40 and 60 days may
be added to the shipping season due to reduced ice coverage enabling the present cargo demand to be
accommodated. With the extended season, shipping costs per ton would decrease from the water reduction
scenario to about 1 to 2%.
Two climate scenarios for Lake Erie showed a 2- to 3-foot drop in water levels, while a third showed a
drop of greater than 5 feet. A Moot drop in water level for locations in Lake Erie would result in a 5 to 13%
reduction in cargo capacity, with a similar increase in cost per ton transported Up to 40 additional shipping
days would be required with about 70 additional available days predicted Costs under both the reduced water
level and ice coverage scenario show a combined increased cost of 2.9 to
Dredging costs to maintain the present location channels would range from about $1.4 million for Two
Harbors to over $20 million for the Duluth/Superior location. These costs do not include system costs such as
other channel deepening and lock modification, which would be required for the dredging in the individual
location to have any system benefit, nor do they reflect additional costs that may occur due to construction of
additional disposal sites and associated environmental issues.
'Although the information in this report has been funded partly by the US. Environmental Protection
Agency under contract no. 68-02-4532, it does not necessarily reflect the Agency's views, and no official
endorsement should be inferred from it.
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Keith
CHAPTER 1
INTRODUCTION
Scientists studying the effect of increasing concentrations of greenhouse gases have tried to predict how
quickly, and to what extent, atmospheric temperatures may rise. For analytic convenience, the convention has
been to examine the implications of a doubling of carbon dioxide (CO2) levels. In 1979, the National Academy
of Sciences concluded that such a doubling would lead to an increase of 1.5 to 4-5°C in global air temperatures.
This increase in air temperature and the associated increase in water evaporation could result in a decrease of
water level within the Great Lakes.
A decrease in water levels on the Great Lakes could have a significant impact on the many industries that
ship their goods through the various locations on the Great Lakes. For instance, even a relatively small drop
in die water level would mean that some vessels would no longer be able to operate on the lakes at their existing
drafts. Larger decreases in water levels would mean that fewer and fewer vessels would be capable of traveling
between locations at their design drafts. The lessened drafts result directly in reduced cargo-carrying capacity
per trip and, with the ice-limited shipping season, a potential reduction in present system total carrying capacity.
Conversely, this same increase in air temperature could result in less severe winter ice in terms of thickness
as well as duration of the ice season. This reduction in winter ice could result in an extended shipping season
for many of the vessels on the Great Lakes.
This analysis will examine the effect of the increased temperature levels on the Great Lakes shipping
industry. The analysis will be based on a computer model of the shipping patterns and port characteristics of
selected locations on the Great Lakes; namely, Duluth/Superior, Two Harbors, and Whitefish Bay within Lake
Superior and Toledo, Cleveland, and Buffalo within Lake Erie. These locations were selected to represent the
breadth of conditions within the two lakes. Our study will focus on the change in carrying capacity and associated
change in costs; and will address the changes due to reduced water levels and ice coverage, and the combination
of reduced water levels and reduced ice coverage. In addition, an analysis of dredging required to maintain port
water levels at present conditions, so as to maintain present system port capability, will be presented.
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Keith
CHAPTER 2
METHODOLOGY
The analysis utilizes a Great Lakes shipping model developed for the specific locations derived from
ECOSHEP and ECOPORT, marine databases developed by Engineering Computer Optecnomics, Inc. (ECO),
of Annapolis, Maryland, and integrated with the results of scenarios of changes in lake level and ice cover due
to global warming provided by the Great Lakes Environmental Research Laboratory. A graphic representation
of the model is shown in Figure 1.
A number of assumptions have been made in applying the model to the climate change analysis.
o The base line for the shipping patterns of the specific locations is the 1985 calendar year. The lakes
shipping system shows significant variations from year to year. These significant variations in
year-to-year operations dictate the use of a single representative year rather than a series of years to
isolate the impact of the climate change. The year 1985 is used in the model since it is representative
of average Great Lakes' water levels. It is also the latest year for which data are available on a
consistent basis. Only those vessels in the base line period are assumed to carry cargo in any future
period, and no accommodation is made for newer ship designs or other technological changes and/or
responses to the potential reduced water levels.
o The model does not assume change in future cargo shipments. Rather, it assumes that cargo shipments
will be constant for the period in question. It does estimate cargo capacity limitations as a result of
changes in water levels and ice coverage.
o The dredging analysis treats the individual locations in an independent manner. The analysis does not
attempt to rationalize the different water levels that are projected for either Lake Superior or Lake Erie.
o The model operates in 1-foot increments of water level change. The available input data are not precise
enough to allow fractional changes and still provide realistic model solutions. The analysis does, where
appropriate, interpolate the data to agree to water levels projected by the climate change scenarios.
While specifically tailored for the purposes of this analysis, the model is sufficiently general to enable the
above assumptions to be modified in the future. The main input elements of the shipping model are described
below.
MODEL ELEMENTS
Port Dimensions. As indicated above, six locations will be used for this analysis. The locations are shown in
Figure 2, and their principal physical characteristics are shown in Table 1.
Port Vessel Transit Patterns. Each location exhibits different mixes of vessel class transiting the port due to
individual cargo requirements and importantly, the capacity of the geometric configuration of each location area
to accept various sizes of vessels. The vessel mix for each location is given in Table 3 as a function of draft. This
table illustrates previous comments that locations tend to utilize the largest vessels that can be accommodated
in its boundaries.
Vessel Economics. The cost to transport cargo in a vessel is normally expressed in terms of dollars per ton
carried. The method for ascertaining that cost is determined by amortizing the cost of the vessel over its
economic life, adding the daily operational costs such as fuel and personnel for the number of days in operation,
4-3
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PortCapacily v J SystemCosts
PoriShfoping PortEcTnoYnics
DredgeAlt
DredgingCosts
Fig. 1. ECO Great Lakes Shipping Model.
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W I S C 0 N SIN
Figure 1 Port area iocatioa
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Keith
Table 1. Physical characteristics of locations.
LOCATIONS
Two Harbors
Duluth
Whitefish Bay
Toledo
Cleveland
Buffalo
LIMITING CHANNEL DIMENSIONS
(ft)
WIDTH
600
1100
1300
400
750
1050
DEPTH
28
28
28
28
28
27
*
TABLE 2. Average characteristics of vessel by class.
CLASS
1
2
3
4
5
6
7
8
9
10
LENGTH
OVERALL (ft)
224
429
518
559
624
685
724
780
858
1003
BREADTH
(ft)
37
53
64
58
64
73
77
74
105
105
DEPTH
(ft)
16
29
34
32
35
39
43
38
42
53
DRAFT
(ft)
14
22
25
23
25
28
30
28
28
31
CARRYING
CAPACITY
(tons)
1,971
7,498
12,175
11,945
17,244
24,800
32,680
28,768
44,500
70,142
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Keith
and dividing by the number of tons carried. The value derived can be described by the term, "Required Freight
Rate" or RFR. The derived RFR for each class of vessel affected by the climate change is given in Table 4.
It is important to note that economies of scale are apparent in the shipping industry with the larger vessels with
deeper draft carrying significantly more cargo at a lower cost per ton than vessels of lower classification. As the
water levels drop, this advantage is reduced.
Cargo Capacity as a Function of Draft. A reduction in the water levels of the lakes will have an immediate
effect on the cargo-carrying capacity of vessels transiting the lakes. Ail marine transportation systems are
designed to operate at maximum drafts relative to the water depth. A decrease in the water depth will result
in vessels reducing the amount of cargo that they cany on each voyage to reduce their draft. The reduction
varies among vessels based on their design and normally is described by the amount of cargo in tons required
to reduce the draft of the vessel by 1 inch. The cargo-carrying capacity of each class of vessels on the lakes for
various drafts is given in Table 5.
Water Level Reduction. Three climate change scenarios have been used in the analysis. The scenarios are the
following:
o Goddard Institute for Space Studies (GISS), doubling of carbon dioxide (2xCO2)
o Oregon State University (OSU), doubling of carbon dioxide (2xCO2)
o Geophysical Fluid Dynamics Laboratory (GFDL), doubling of carbon dioxide 2xCO2).
The expected water levels due to the change in climate conditions, as simulated by the climate models, are
shown in Table 6 for Lake Erie and Lake Superior. The lake level analysis for the GISS and OSU scenarios
assumed that the current regulation plan for Lake Superior (Plan 1977-D) is in effect. In the GFDL scenario,
the Lake Superior Regulation Plan was not used. Instead, it was assumed that over a 30-year period, total
inflows in Lake Superior equal total outflows with no resultant change in lake level.
To fit within the parameters of the shipping model, a 1- and 2-foot reduction for Lake Superior and 2- and
3-foot reductions for Lake Erie were felt to be representative of the range of the climate models, and were used
in the discussion of the shipping model to predict the results of change in the shipping industry. Where possible
and appropriate, the discussion of the analysis does refer to the discrete scenarios to provide a feeling for the
sensitivity of the analysis.
Ice Coverage Reduction. The simulations show a substantial effect on the ice coverage of the lakes in question.
Figure 3 compares the duration of ice cover historically with the climate change scenarios for each location and
indicates that the shipping season on the lakes, approximately 270 days, may be increased substantially due to
climate change.
Dredging Costs. One alternative that planners may address in light of the water level reduction is the dredging
of shipping channels to maintain those channels at their present depths. This action would maintain the status
of shipping within the locations. Present dredging costs per cubic yard of dredged material for each location
derived from maintenance dredging contracts currently in place are given in Table 7. These figures include the
costs of maintaining present disposal sites that are used to contain contaminated material dredged from the
confined harbor areas. The large amounts of dredging that may be required with reduced water levels may
exceed the capacity of the existing sites. Costs for the creation of new disposal sites, and associated
environmental protection issues, are not included in the costs in the table and may significantly increase the
overall effective dredging cost.
4-7
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Keith
Table 3. Vessel transits by draft.
(Number of transit)
DRAFT
(ft)
28
27
26
25
24
23
22
21
20
LOCATION
Two Harbors
107
42
9
1
2
1
1
1
Duluth
275
157
292
22
71
74
38
34
26
Whitefish Bay
594
251
149
41
79
92
90
77
67
Toledo
26
93
78
14
141
164
155
103
119
Cleveland
48
9
202
175
97
44
71
32
59
Buffalo
0
7
9
7
22
24
34
23
13
Table 4. Required freight rate by class of vessel.
CLASS
3
4
5
6
7
8
9
10
ANNUAL COST
($/Year)
2,132,000
2,303,000
2,473,000
2.814.000
2,985,000
3,496,000
4,264,000
5,373.000
OPERATING
COST PER DAY
($)
18,613
22.804
23,607
21.845
22.370
23.506
28.690
28.449
CARGO
CAPACITY
(Tons)
10,000
14,000
17,250
24.800
30,500
32,600
44,500
60,020
RFR
($/Ton)
17.04
14.39
12.21
8.36
7.05
7.19
6.43
5.18
4-8
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Keith
Table 5. Ship cargo capacity at various channel depths.
(in tons)
CLASS
3
4
5
6
7
a
9
1 0
CHANNEL DEPTH
2 2
10,200
11.340
14,370
16,160
20.420
21,800
31.540
44.900
^ 1
10,800
12.000
15,330
17,600
22.100
23.600
33.700
47,420
24
11,400
12,000
16.290
19,040
23.780
25.400
35.860
49.940
2 5
12.000
12.000
17,250
20,480
25.460
27.200
38.020
52.490
in feet)
26
12,000
12.000
17.250
21.920
27.140
29.000
40,180
54,980
2 7
12,000
12,000
17.250
23,360
28,820
30,800
42,340
57.500
2 8
12,000
12.000
17,250
24,800
30.500
32.600
44,500
60.020
Table 6. Predicted water level
(in feet)
LAKE
Lake Superior
Lake Erie
reduction.
SIMULATION MODEL
OSU
1.28
2.07
GISS
1.41
3.12
GFDL
N/A
5.41
4-9
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No.
of
Days
120i
100-
80-
60-
40'
20.
0-
i
4
i
i
<
i
1
c
AVERAGE DURATION OF ICE SEASON
(DA YS)
i • *
o *
j O
.
•
•
i n n a o
• Z
a 3
Two Duluth Whitefish Toledo Cleveland Buffalo
Harbors Bay
Ice Level Scenario
• HISTORICAL o osu • GISS ° GFDL
Fig. 3. Average season length in days as function of scenario.
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Keith
Table 7. Dredging cost.
($ per cubic yard)
LOCATION
BUFFALO
CLEVELAND
TOLEDO
WHITEFISH BAY
TWO HARBORS
DULUTH/ SUPERIOR
OPEN*
.
-
1.75
.
.
-
CONFINED**
5.75
3.75
2.70
* • *
6.00
6.00
Operr- areas not requiring confined containment sites; such as open
water dredged channels
** Confined - areas requiring confined containment sites for dredge spoil
due to industrial contamination; such as enclosed harbors
"* Data for Whitefish Bay not estimated due to interaction with lock system
Source: U.S. Army Corps of Engineers
4-11
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Keith
MODEL OPERATION
The ECO shipping model, Figure 1, was run for six different water levels -- the present system and water
level reductions from 1- to 5-feet below the present system. The 5 foot reduction was used as the maximum
reduction because it was the level at which the capacity demand of the most limited location could not be
satisfied, even with a year-round, ice-free shipping season.
Using the existing mix of vessels and the existing cargo demand in each location, the model developed three
measures of change that affect the shipping industry for each location:
i
o Change in the amount of cargo carried by the existing vessel mix in the present shipping season;
o Change in the cost of transporting the cargo due to lower cargo capacity per trip by affected vessels;
and,
o Change in the number of days required to transport the cargo that is lost due to decreased carrying
capacity per trip.
The reduction in ice coverage predicted by the climate models was then interrogated and integrated with
the results of the shipping model. The model was run to evaluate the availability of additional shipping days due
to reduced ice cover with the additional days required to ship the desired cargo in each location. The cost of
transporting the cargo with the additional days was then computed for the locations. Finally, dredging costs were
developed for the six locations and for the OSU, GISS, and GFDL scenarios.
4-12
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Keith
CHAPTERS
RESULTS
As previously stated, the model was run for 1- to 5-foot reductions in water levels. The results of those runs
are given below for each location in terms of change in cargo-carrying capacity, transport cost per ton, and the
days required to carry the cargo lost due to reduced carrying capacity. The explanatory labels on the tables in
the following discussions show the water levels predicted by the three climate model simulations.
The probable increase in shipping season due to reduced ice coverage as a function of climate change
scenario and the transport cost in an extended shipping season are given for each of the locations.
The dredging costs for each location are also presented for each of the three scenarios.
CHANGE AS A RESULT OF WATER LEVEL REDUCTION
Two Harbors
Figure 4 shows the results of the model for water level reductions for Two Harbors. For a 1- to 2-foot
reduction in water level, cargo capacity for the location is reduced by 33 to 7.9%, with the model limit of 5-feet
showing a decrease of 233%. The corresponding increase in transportation cost per ton is 3.4 to 8.5% at the
1- to 2-foot water level reduction, up to a maximum value at 5 feet of 30%. In order to transport the cargo lost
due to water level reduction, 9 to 23 additional days would be required for 1- to 2-foot reductions, with a 5-foot
reduction requiring 82 days.
Duluth/Superior
Figure 5 shows the results of the model for water level reductions for Duluth/Superior. For a 1- to 2-foot
reduction in water level, cargo capacity for the location is reduced by 1.6 to 43%, with the model limit of 5-feet
showing a decrease of 24.1%. The corresponding increase in transportation cost per ton is 1.6 to 4.1% at the
1- to 2-foot water level reduction, up to a maximum value at 5 feet of 29.4%. In order to transport the cargo
lost due to water level reduction, 4 to 12 additional days would be required for 1- to 2-foot reductions, with a
Moot reduction requiring 86 days.
Whitefish Bav
Figure 6 shows the results of the model for water level reductions for Whitefish Bay. For a 1- to 2-foot
reduction in water level, cargo capacity for the location is reduced by 25 to 5.9%, with the model limit of 5-feet
showing a decrease of 24.9%. The corresponding increase in transportation cost per ton is 2^ to 63% at the
1- to 2-foot water level reduction, up to a maximum value at 5-feet of 31%. In order to transport the cargo lost
due to water level reduction, 7 to 17 additional days would be required for 1- to 2-foot reductions, with a 5-foot
reduction requiring 86 days.
Figure 7 shows the results of the model for water level reductions for Toledo. For a 2- to 3-foot reduction
in water level, cargo capacity for the location is reduced by 1.6 to 5.9%, with the model limit of 5-feet showing
a decrease of 233%. The corresponding increase in transportation cost per ton is 1.6% to 5.1% at the 2- to 3-ft
water level reduction, up to a maximum value at 5 feet of 26.8%. In order to transport the cargo lost due to
water level reduction, 4 to 14 additional days would be required for 1- to 2-foot reductions, with a Moot
reduction requiring 82 days.
4-13
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r-ECO-
Percent
Change
35 T
30
25
20
15
10
5
LAKE SUPERIOR
TWO HARBORS, MINNESOTA
234
Water Level Reduction
(feet)
E3 Decrease in Cargo HI Increase in Cost
••- Additional Days
Required
Fig. 4. Water level reduction model results.
-------
ECO
Percent
Change
30
25
20
15
10
5
0
LAKE SUPERIOR
DULUTH, MINNESOTA
234
Water Level Reduction
(feet)
Decrease in Cargo
Increase in Cost
••- Additional Days
Required
Days
90
80
70
60
50
40
30
20
10
0
Fig. 5. Water level reduction model results.
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ECO
LAKE SUPERIOR
WHITEFISH BAY
234
Water Level Reduction
(feet)
(S3 Decrease in Cargo H Increase in Cost
Additional Days
Required
Days
100
80
60
40
20
0
1
Fig. 6. Water level reduction model results.
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—ECO
Percent
Change
30
25
20
15
10
5
0
0
LAKE ERIE
TOLEDO, OHIO
234
Water Level Reduction
(feet)
E3 Decrease in Cargo HI Increase in Cost
Additional Days
Required
Fig. 7. Water level reduction model results.
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Keith
Cleveland
Figure 8 shows the results of the model for water level reductions for Cleveland. For a 2- to 3-fOOt
reduction in water level, cargo capacity for the location is reduced by 1.1 to 13.1%, with the model limit of 5 feet
showing a decrease of 263%. The corresponding increase in transportation cost per ton is 1.1 (o 13% at the
2- to 3-foot water level reduction, up to a maximum value at 5 feet of 31.7%. In order to transport the cargo
lost due to water level reduction, 3 to 41 additional days would be required for 1- to 2-foot reductions, with a
5-ft reduction requiring % days. The significant difference between 2- and 3 feet can be attributed to the mix
of vessels in the location, with vessels in the 26-foot range being prominent in this location; see Table 3.
Buffalo
Figure 9 shows the results of the model for water level reductions for Buffalo. For a 2- to Moot reduction
in water level, cargo capacity for the location is reduced by 5.6 to 12.9%, with the model limit of 5 feet showing
a decrease of 26.7%. The corresponding increase hi transportation cost per ton is 5.4 to 13.1% at the 2- to
Moot water level reduction, up to a maximum value at 5 feet of 32.9%. In order to transport the cargo lost due
to water level reduction, 16 to 40 additional days would be required for 1- to 2-foot reductions, with a 5-foot
reduction requiring 99 days. The significant difference between 2- and 3 feet can be attributed to the mix of
vessels in the location, with vessels below the 25-foot range being prominent in this location; see Table 3.
CHANGE AS A RESULT OF ICE COVER REDUCTION
There are two effects on location shipping due to the reduction of ice cover. The first is the additional days
available to transport the cargo demand for the location. The second is a corollary to the first, and results in
a reduction in the cost per ton to transport the cargo. Under the reduced water level scenario, the locations are
served by vessels carrying reduced cargo per voyage due to the reduction in water level with the result that less
cargo is delivered at the same total cost as the present system. With a reduced ice cover, the shipping season
is increased, and the same vessels can make additional voyages in a single season to, in most cases, deliver
the total demanded cargo tonnage. The increased tonnage derived from the additional voyages is greater than
the costs for additional operating days for those voyages. (See discussion on RFR earlier in analysis.)
Figures 10 through 12 show the shipping season days available as predicted by the various climate scenarios,
compared with the number of days required to transport the individual location's total cargo demand for those
scenarios interpolated from the data curves for water reduction alone. The effect of the reduced ice coverage
on transportation cost per ton in each location is shown for each individual port.
Two Harbors
Comparison of the extended shipping season available due to reduced ice cover versus required shipping
days due to reduced water levels shows that the cargo demand for Two Harbors can be satisfied under all
climate change scenarios. Figure 13 shows that the cost for transporting the location cargo demand with reduced
water levels and reduced ice coverage will be an increase from the present system of 1.9% to 4.7% for a 1- to
2-foot reduction in water level.
Duluth/Suoerior
Comparison of the extended shipping season available due to reduced ice cover versus required shipping
days due to reduced water levels shows that the cargo demand for Duluth/Superior can be satisfied under all
climate change scenarios.
4-18
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—ECO
*
Percent
Change
35
30
25
20
15
10
5
0
LAKE ERIE
CLEVELAND, OHIO
234
Water Level Reduction
(feet)
ESI Decrease in Cargo 9 Increase in Cost
Additional Days
Required
I
Fig. 8. Water level reduction model results.
-------
—ECO
Percent
Change
35
30
25
20-
15'
10
5
0
0
LAKE ERIE
BUFFALO, NEW YORK
234
Water Level Reduction
(feet)
Decrease in Cargo
Increase in Cost
Additional Days
Required
5
1
Fig. 9. Water level reduction model results.
-------
ECO
LENGTH OF SHIPPING SEASON IN DAYS
OSU SCENARIO
Days
400 r
350
300
250
200
150
100
50
0
m
m
%
Two Duluth
Harbors
Whitefish Toledo Cleveland Buffalo
Bay
LOCATION
Days Available H Days Required
Fig. 10. Effect of ice cover reduction on shipping season length.
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ECO
LENGTH OF SHIPPING SEASON IN DAYS
GISS SCENARIO
Days
400
350
300
250
200
150
100
50
0
Two
Harbors
i
'^h.
m
^ ',"
'".*
Duluth Whitefish Toledo Cleveland
Bay
LOCATION
Buffalo
E2 Available • Required
1
Fig. 11. Effect of ice cover reduction on shipping season length.
-------
ECO
LENGTH OF SHIPPING SEASON IN DAYS
GFDL SCENARIO
Days
400
350
300
250
200
150
100
50
0
^
Two
Harbors
Duluth Whitefish Toledo Cleveland Buffalo
Bay
LOCATION
Available 0 Required
Fig. 12. Effect of ice cover reduction on shipping season length.
-------
ECO
LAKE SUPERIOR
TWO HARBORS, MINNESOTA
Dollars
per
Ton
0
2 3
Water Level Reduction
(feet)
E2 Present Ice Season H Reduced Ice Season
Fig. 13. Change in transportation cost due to reduced ice season.
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Keith
Figure 14 shows that the cost for transporting the location cargo demand with reduced water levels and reduced
ice coverage will be an increase from the present system of 1 to 23% for a 1- to 2-foot reduction in water level.
Whitefish Bay
Comparison of the extended shipping season available due to reduced ice cover versus required shipping
days due to reduced water levels shows that the cargo demand for Whitefish Bay can be satisfied under all
climate change scenarios. Figure 15 shows that the cost for transporting the location cargo demand with reduced
water levels and reduced ice coverage will be an increase from the present system of 1.5% to 3.6% for a 1- to
2-foot reduction in water level.
Toledo
Comparison of the extended shipping season available due to reduced ice cover versus required shipping
days due to reduced water levels shows that the cargo demand for Toledo can be satisfied under the OSU and
GISS climate change scenarios but not under GFDL. Under the extreme water level reduction conditions of
GFDL, the number of days required to fulfill the cargo demand exceeds the number of additional days available.
The critical water reduction level for Toledo is 5 feet before the system can no longer satisfy the cargo demand.
Figure 16 shows that the cost for transporting the location cargo demand with reduced water levels and reduced
ice coverage will be an increase from the present system of 1 to 2.9% for a 2- to 3-foot reduction in water level.
Cleveland
Comparison of the extended shipping season available due to reduced ice cover versus required shipping
days due to reduced water levels shows that the cargo demand for Cleveland can be satisfied under the OSU and
GISS climate change scenarios but not under GFDL. Under the extreme water level reduction conditions of
GFDL, the number of additional days required to fulfill the cargo demand exceeds the number of additional days
available. The critical water reduction level for Cleveland is between 4- and 5 feet before the system can no
longer satisfy the cargo demand. Figure 17 shows that the cost for transporting the location cargo demand with
reduced water levels and reduced ice coverage will be an increase from the present system of 1 to 6.9% for a
2- to 3-foot reduction in water level.
Buffalo
Comparison of the extended shipping season available due to reduced ice cover versus required shipping
days due to reduced water levels shows that the cargo demand for Buffalo can be satisfied under the OSU and
GISS climate change scenarios but not under GFDL. Under the extreme water level reduction conditions of
GFDL, the number of additional days required to fulfill the cargo demand exceeds the number of additional days
available. The critical water reduction level for Buffalo is between 4 to 5 feet before the system can no longer
satisfy the cargo demand. Figure 18 shows that the cost for transporting the location cargo demand with reduced
water levels and reduced ice coverage will be an increase from the present system of 3 to 7.5% for a 2- to 3-foot
reduction in water level
DREDGING COSTS FOR ALL LOCATIONS
Using data from Tables 1 and 6 and the predicted water level reductions from the climate models, the costs
to dredge existing location channels to maintain the present shipping patterns were ascertained. The costs for
each of the climate models are given in Table 8. (Note: No dredging is required under the GFDL scenario for
Lake Superior.) As stated earlier, these costs are probably understated as they do not include the development
of new containment facilities that may be required for the increased volume of dredging that would be required
under reduced water levels, nor do they account for the environmental assessments that may be required for the
4-25
-------
ECO
LAKE SUPERIOR
DULUTH, MINNESOTA
Dollars
per
Ton
2 3
Water Level Reduction
(feet)
Present Ice Season
Reduced Ice Season
3
2
Fig. 14. Change in transportation cost due to reduced ice season.
-------
ECO
LAKE SUPERIOR
WHITEFISH BAY
Dollars
per
Ton
0
2 3
Water Level Reduction
(feet)
E3 Present Ice Season
Reduced Ice Season
n
5-
Fig. 15. Change in transportation cost due to reduced ice season.
-------
ECO
Dollars
per
Ton
0
LAKE ERIE
TOLEDO, OHIO
1 2 3
Water Level Reduction
(feet)
E2 Present Ice Season
Reduced Ice Season
1
Fig. 16. Change in transportation cost due to reduced ice season.
-------
ECO
Dollars
per
Ton
0
LAKE ERIE
CLEVELAND, OHIO
2 3
Water Level Reduction
(feet)
Present Ice Season
Reduced Ice Season
I
sr
Fig. 17. Change in transportation cost due to reduced ice season.
-------
ECO
LAKE ERIE
BUFFALO, NEW YORK
Dollars
per
Ton
0
1234
Water Level Reduction
(feet)
E3 Present Ice Season H Reduced Ice Season
3
I
Fig. 18. Change in transportation cost due to reduced ice season.
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Keith
LOCATION
Buffalo
Cleveland
Toledo
Duluth
Superior
Two Harbors
Table 8. Dredging cost.
(1987 dollars)
WATER LEVEL
OSU
$10,800,000
$7,200,000
$8,400,000
$11,900,000
$5.800,000
$300,000
GISS
$17,100,000
$10,900,000
$12,600,000
$13,100,000
$6,400.000
$400,000
GFDL
$30,900,000
$29,000,000
$21,800.000
N/A
N/A
N/A
4-31
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Keith
substantial increase in dredging activity. In addition, these costs do not include costs for other areas, such as
the St. Marys River, which would require dredging and/or additional construction in order for the dredging of
the individual locations to make economic sense.
4-32
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Keith
CHAPTER 4
INTERPRETATIONS OF RESULTS
Climate changes in the midwestern region of the United States resulting in reduced water levels and ice
coverage may have a significant impact on the transport of cargo by vessel on the Great Lakes.
The reduction in water levels may result in less cargo being carried per trip in the vessels affected, due to
the need to reduce their draft. Correspondingly, the cost to transport per ton of cargo will increase. The
magnitude of these changes in cargo carried and cost of the carriage per ton will vary according to the climate
model used to estimate water level reduction, but may be in the range of an increased cost per ton carried of
between 4 and 13% due to water level reduction isolated from any associated change in shipping season due to
other wanning effects such as reduced ice coverage.
The reduction in ice coverage will extend the shipping season. For all climate simulation models with the
exception of GFDL, the availability of increased days exceeds the number of days required to ship cargo capacity
lost due to reduced water levels. The locations in Lake Erie could not fulfill the cargo demand under the water
level ice coverage reductions of the GFDL scenario.
The combined effect of reduced water levels and increased shipping season due to reduced ice coverage
of the lakes will result in overall increases in cargo transportation costs of from 1% to 15% over present levels,
or about half of the increases due to water level reduction without ice coverage reduction.
4-33
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Keith
CHAPTERS
LIMITATIONS OF RESULTS
There are two major limiting areas of the results considered here. The first is that the shipping model, as
it has been applied to this discussion, treats each location independent from any other. This limitation becomes
important when one considers that the climate models predict different changes in water levels and ice coverage
from lake to lake. In reality, a vessel leaving Lake Superior usually delivers its cargo within the Great Lakes
system. Therefore, the vessels in Lake Superior locations will not be affected as much by the changes in Lake
Superior water levels as they will by changes in Lake Erie water levels, the destination of the cargo. These
results tend to understate the changes that will take place in Lake Superior. Likewise, ice coverage duration
in Lake Superior will dictate when vessels can transit from locations in Lake Superior and Lake Erie. Thus,
the availability of ice-free waters in Lake Erie does not necessarily mean that shipping activity can occur if, at
the same time, Lake Superior does have ship-confining ice.
The second area is that the model assumes, particularly in relation to dredging, that any limiting area or
channel that the vessels may transit to the location does not affect the draft of the transiting vessel. However,
the Great Lakes system does have two major areas, the St. Mary's and the St. Claire Rivers, that would be
affected by the water level reduction and that cannot be bypassed by vessels in interlake commerce. The analysis
of location dredging would realistically have to include both the dredging of these areas and the building of new
locks to facilitate the transit of current vessels entering these systems at reduced water levels. Without the
modification of these limiting areas, the availability of deep water at locations on wither side of these areas would
be unnecessary and unused as vessels would have to reduce their drafts at any rate for the limiting area.
4-34
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Keith
CHAPTER 6
IMPLICATIONS OF RESULTS
The results of the ECO Great Lakes Shipping Model show that the changes in water level and ice coverage
on the Great Lakes due to changes predicted by various climate model scenarios will have an effect on Great
Lakes shipping. The primary effect will be an increase in shipping costs due to reduced vessel carrying capacity.
The reduction in ice coverage will extend the shipping season, and additional shipping days will be adequate,
under most scenarios, to ship cargo capacity lost due to reduced water levels.
The increase in transportation costs may require that the maritime industry using the Great Lakes make
substantial changes in their operations to maintain their competitive position. These changes may include
increased support for dredging and construction projects to maintain shipping channels at present depths and/or
may result in changing vessel construction technology or practices to transit reduced shipping channels.
4-35
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Keith
REFERENCES
Assel, Raymond A. "Impact of Global Warming on Great Lakes Ice Cycles," Great Lakes Ice Cycle Data,
Great Lakes Environmental Research Laboratory, National Oceanic and Atmospheric Administration, US.
Department of Commerce, Ann Arbor, Michigan, (Unpublished paper).
ECOPORT, Engineering Computer Optecnomics, Inc., Annapolis, Maryland.
ECOSHIP, Engineering Computer Optecnomics, Inc, Annapolis, Maryland.
"Effects of Climatic Changes on the Laurentian Great Lakes Levels," Lake Hydrology Group, Great Lakes
Environmental Research Laboratory, National Oceanic and Atmospheric Administration, U.S. Department of
Commerce, Ann Arbor, Michigan, (Unpublished paper).
Final Interim Feasibility Report and Environmental Impact Statement on Great Lakes Connecting Channels
and Harbors, U.S. Army Corps of Engineers, Detroit Division, North Central Division, Detroit, Michigan (March
1986).
Greenwood's Guide to Great Lakes Shipping. Freshwater Press, Cleveland, Ohio (April 1987).
4-36
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