r/EPA
United States Region VIII June 1990
Environmental Protection
Agency
DENVER'S WATER CONSERVATION PROGRAM
COMPUANCE REVIEW FOR 1989
PURSUANT TO THE FOOTHILLS CONSENT DECREE
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TABLE OF CONTENTS
I. Executive Summary
IL Background
ill. Previous EPA Evaluations
A. 1982 Conclusions
B. 1986 Conclusions
IV. Process for 1989 Compliance Review
V. EPA Recommended Water Conservation Program
A. Key Program Elements of the EPA Recommended Program
B. Other Water Conservation Program Elements by DWD
C. Effective Administration of Conservation Programs
VI. Recommended Program for Additional Water Savings
A. Expand Successful Program Elements
B. Non-potable Reuse for New Developments
C. Low Water Use Landscape Retrofits
D. Pricing for Conservation
VIL Major Policy Issues
A. Interpretation of the Consent Decree Goads
B. GAD versus GCD
C. Measurement of Accomplishments Based Upon Goals Versus Programs
D. Water Conservation Impacts to Stream Flow
VII Achieving Water Conservation by DWD in the Future
IX. Conclusions
X. References
XL Glossary of Terms
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DENVER'S WATER CONSERVATION PROGRAM
COMPLIANCE REVIEW FOR 1989
PURSUANT TO THE FOOTHILLS CONSENT DECREE
prepared by the
U.S. Environmental Protection Agency
Region VIII
I. Executive Summary
The 1979 Foothills Consent Decree provides that Denver, through the Denver Water Board
(DWB), implement water conservation measures to reduce water consumption. The Region VHI
Office of the Environmental Protection Agency (EPA) was assigned responsibility for
monitoring Denver's conservation program to evaluate Denver's progress and good faith efforts
to attain the goals, or targets, listed in the Consent Decree and recommend future water use
goals.
EPA has completed its third compliance review of Denver's water conservation program,
pursuant to the Consent Decree. EPA concludes that Denver has progressed in good faith to
implement water conservation as specified in the FoothBs Consent Decree. However, Denver's
water conservation efforts to date have not achieved the water use goads which should have
been attained by 1989. Denver's water use for 1989 was five percent higher than the goal
established under the Consent Decree.
Information provided in a study conducted by Water Resources Engineering (WRE), as wefl as
comments received from the Denver Water department (DWD) and the public, have been
considered in preparation of this compliance review. Comments directed specifically to the
WRE study are addressed in the report entitled "Analysis and Evaluation of Denver's Water
Conservation Program, Addendum to Parts I and H Find Draft Reports", presented to the
National Environmental Health Association and the U.S. Environmental Protection Agency,
Region VID, June 8, 1990. Copies of this report are available from EPA. Replies to public
comments received on water conservation poficy issues pursuant to the Consent Decree are
provided in this document.
Quantifying of water savings requires the selection of an appropriate indicator of water
consumption. The Foothills Consent Decree water use goals for Denver were calculated using
the target consumption for a given year, as a percent reduction from the base period of the
1968-1977 water use in terms of gallons per capita per day (GCD). One problem with the use
of the GCD statistic is the uncertainty of yearly population data and the dependence of GCD
on this data EPA concludes that water use is more appropriately defined in terms of gallons
per account per day (GAD) and recommends that GAP be used in future evaluations. EPA's
previous compliance reviews in 1982 and 1986, refied upon DWD's statistical procedure to
normalize the data to account for changes in water use based upon weather variables,
primarily temperature and rainfall. EPA concludes that the anomalies of weather are just as
readBy accounted for using long term (9-year) running average of water use. The advantage
of the long term running average water use statistic ii that it provides a unique and certain
assessment of water use goals suitable for public comprehension of whether the goals of the
Consent Decree are attained.
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Previous EPA evaluations have focused on numerical targets in establishing future water
conservation goals. This compliance review has taken a dfferent approach and recommends
program monitoring and implementation of certain programs, or their functional equivalent in
terms of program accomplishments, in addtion to numerical goals. EPA's established goal for
1999 recommends DWD meet the goals it should have attained by 1989, plus an additional
6 percent reduction from the 1989 goal. The water conservation program needed to meet the
additional reduction of 6 percent by 1999, incorporates the established water program currently
being implemented by DWD, with expansion of program monitoring, direct delivery of
replacement household plumbing, and provision of professional landscape services to commercial
properties. EPA's recommended program would require substantial additional costs and staffing
by DWD to meet the 1999 goal Initial costs for EPA's recommended program are nearly
$2.8 mfflion in 1991 for water conservation elements designed to reduce water demand (known
as demand-side elements). This is compared to the 1990 DWD budget of $ 1.7 million for
demand-side water conservation program elements. DWD has budgeted $4.2 million in 1990 for
mandatory metering and leak detection program elements. These efforts are intended to
augment supply, known as supply-side elements. EPA recommends a supply-side budget of
$4.7 milfion for 1991. Denvers mandatory metering program is acceptable to meet the goals
EPA recommends for 1999. Leak detection efforts should be expanded to meet the EPA
program recommendations. EPA also recommends that DWD establish an annual pubic audit
evaluating water conservation program accomplishments.
Substantial changes in the Denver Water Board's water conservation policy occurred in
1989. During that year, DWB modified its rate structure to foster conservation, expedted a
mandatory residential metering program, and began an $80 toflet retrofit rebate program.
DWB has substantially improved its water conservation program with adoption of these efforts.
These new conservation efforts represent the organization's current commitment to water
conservation aimed at achieving firm water savings in addtion to promoting the virtues and
ethics of water conservation through public educational efforts.
II. Background
The Foothills Project is comprised of Strontia Springs Dam in Waterton Canyon, a 3.4 mile
dversion tunnel, and the Foothis Water Treatment Plant In reviewing the DWD application
for a right-of-way permit across federally-managed land, the Department of the Interior
determined that an Environmental Impact Statement (EIS) was required by Section 102(2)(c) of
the National Environmental Policy Act (NEPA). In addition to the NEPA requirements, right-
of-way permits were required from both the U.S. Bureau of Land Management and the U.S.
Forest Service and a "404" Dredge and Fill permit was required from the U.S. Army Corps of
Engineers.
As the Foothills Project was under review from 1976 through 1978, it generated considerable
public controversy over environmental impact, the adequacy of alternatives, the efficiency of
water use in Denver, the potential impact of the project on residential development patterns
and subsequently, the ambient air quality in Denver.
In 1978, the City and County of Denver, through DWB, and the Homebuilders Association of
Metropolitan Denver, filed suit against the Secretary of the Interior, several Federal agencies
(includng EPA), and organizations and indviduals in response to concerns regardng the
possibity of permit denial, as well as delays in the federal decision (City and County of
Denver, et aT, v. Cecil D. Andrus, et.al.). A counter suit was filed by opponents of the
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Foothills Project in Federal District Court in Washington, D.C. (National Wfldife Federation
et. al., Plaintiffs, v. Secretary of the Department of the Interior, et aL, Defendants).
These two suits were settled out of court in February 1979, through the signing of the
Foothills Consent Decree, also referred to as the FoothBs Settlement Agreement. In signing
the Consent Decree document, the Ktigants agreed to permit the Foothills Project to proceed
and that, among other provisions, a water conservation program would be implemented by
DWB. EPA has the responsibility to monitor the program, evaluate DWD's progress in meeting
the conservation goals, and to recommend future water use goals.
The Consent Decree assigns the following responsfoities to the Regional Administrator of
EPA Region VBI:
1) Monitor the water conservation program of the Denver Water Board;
2) Evaluate Denver's progress and good faith efforts to attain the water conservation
goals set forth in the decree; and,
3) Recommend water conservation goals for 1984, 1989, and 1999.
III. Previous EPA Evaluations
The previous EPA evaluations, pursuant to the Consent Decree, were conducted in 1982 and
1986. Below are extractions from the conclusions of those EPA evaluations.
A. 1982 Conclusions
The DWD's Water Conservation Program reflects an effort to foster water conservation.
The program contains innovative concepts to develop a conservation ethic which is
essential to the goal of more efficient water use. In particular, the DWD is to be
complimented on its Evapo-Transpiration and Xeriscape (public educational) programs as
they both provide practical, cost-effective approaches to promoting water conservation.
However, the overall program, as implemented thus far, is stffl developing and continued
emphasis is necessary for the goals of the program to be fully reafized There is room
for program expansion and improvement, particularly in the areas of public education and
awareness.
The DWD has not linked the elements in the Institutionalized Water Conservation Plan
to specific water conservation goals. The absence of this correlation could make
scheduling implementation of needed conservation measures more dfficult.
The DWD stM has not published a schedule to progress toward the Board's commitment
to achieve 100% metering. Metering affords water management benefits far beyond water
conservation, but could save 12,000 to 19,000 acre-feet per year (AFY). The absence of
toted metering also limits DWD's ability to consider potential rate structure mocfifications
which other communities have found useful for managing water supplies.
The baseline 209 gallons per-capita per-day (GCD) ten-year average water consumption
stated in the Consent Decree was based on inaccurate population estimates and water use
which resulted in a goal in 1981 of 203 GCD. When corrected, the actual 1981 goal
should have been 211 GCD. The actual water use in the Denver system in 1981 was
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226 GCD. Measured against this recalculated goal, it is obvious that overall water
consumption was not reduced, in spite of the water conservation effort. However, if
weather history and water use are considered, the expected consumption would have been
245 GCD. This suggests that the water conservation program may have resulted in a
19 GCD, or about an 8% reduction."
B. 1986 Conclusions
"EPA has suggested that the original 1984 goal of 199 GCD be adjusted to 208 GCD,
based on corrected population figures and water sales. Actual water use in 1983 was
205 GCD. Furthermore, the expected consumption or anticipated demand would have been
232 GCD. This suggests, but does not prove, a reduction of 27 GCD over what might have
been. Therefore, from a quantitative analysis (recognizing the limitations discussed in
Chapter III) the DWD has exceeded the 1984 goal of a 5% reduction in per capita water
consumption.
Although the Department met the adjusted conservation goals established in the Consent
Decree, there appears to be substantial opportunity to improve the overall commitment to
water conservation, as well as to improve program effectiveness. In EPA's 1982 report,
"Evaluation of Denver's Water Conservation Program", EPA noted that the DWD had not
finked the elements of the Institutionalized Water Conservation Plan." To date, there has
been no internal comprehensive programmatic review of the DWD conservation efforts and
only recently has the original 1979 Conservation Plan been updated There is no long-
range plan which would establish standard guidelines for water conservation practices,
in general, there appears to have been little or no follow-up to determine program
effectiveness. The absence of conservation planning and drection raises questions about the
Water Department's commitment to the principje of water conservation. However, the March
4, 1986 Policy Statement incficates a definite interest to implement an effective conservation
program.
The previous ambiguity of roles and responsfoity for water conservation within the
Department may have been solved by the recent reorganization. Hopefully, the new
conservation section will provide the focal point needed to establish and implement a
successful program. Unfortunately, general water conservation activities (exdudng the
successive use pilot plant) have accounted for only 0.1 % of the DWD's annual budget
(1983) which reflects a tow priority for water conservation.
EPA's 1982 report recommended that the Department broaden its public awareness
efforts by initiating a cooperative metro-wide attempt to foster water conservation.
A metropolitan-wide water conservation organization, Metropolitan Water Conservation, Inc.,
has recently been founded and Denver is a Charter member. WhPe it is too early to judge
the effectiveness of this new organization, it is clear that "there currently exists a void in
terms of measuring general pubfic awareness of the benefits and trade-offs of water
conservation.
Despite the support for metering, the DWD still has not published a plan or schedule to
progress toward the Board's commitment to achieve 100% metering. Metering affords
water management benefits far beyond water conservation, and couid save approximately
10,000 acre feet of water per year based on the DWD's own estimates. This is about the
same yield as the Williams Fork Project The absence of total metering also limits DWD's
abity to consider potential rate structure mocfifications which other communities have
found useful for managing and conserving water supplies.
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In summary, the DWD appears not to have aggressively pursued the previous EPA
recommendations. Even though there have been reduced GCD levels, these "calculated"
reductions appear inconsistent with the past limited commitment to promote and implement
water conservation. Hopefully, the Board's recent (March 4, 1986) Policy Statement,
which directs the Department to develop a comprehensive water conservation program, will
elevate the priority given to water conservation within the Department."
IV. Process for 1989 Compliance Review
To obtain national expertise and working experience, EPA chose to utilize the services of a
consultant to sestet in the 1989 evaluation. Through an EPA grant administered by the
National Environmental Association, Water Resources Engineering (WRE), located in Freemont,
California was awarded the contract The primary consultant evaluation team included:
Gustavo Arboleda, President of WRE; Dr. Wffliam Bruvold, Professor, University of California
at Berkeley; Richard Bennett, Manager of the Water Conservation Department of the East Bay
Municipal Utilities District; and John Nelson, Chairman of the American Water Works
Association Conservation Committee and Manager of the North Marin Water District in Novato,
California WRE, and their special consultants, were tasked with examining DWD's water
conservation program from 1979 through 1989, as wefl as evaluating successful conservation
programs in other communities and their applicability to Denver. WRE developed
recommendations for cost-effective conservation programs that would be achievable by Denver,
without change in lifestyle.
V. EPA-Recommended Water Conservation Program
The following program elements, or their functional equivalent in terms of program
accomplishments, are recommended to achieve the FoothMs Consent Decree goals for 1999 (See
Table 1 and Figure 1 on the following pages). EPA believes these programs would be cost
effective for DwD and are based upon achieving what DWD should have attained by 1989 plus
6 percent reduction between 1989 and 1999. DWD needs to implement a water conservation
program that will reduce water use by 10 percent by 1999 to "catch up" to the Consent
Decree goals which would then total 16 percent total water use reduction for the 20-year
period between 1979 and 1999. To reach this goal, average consumption per account should be
reduced from the current average of 831 GAD to 744 GAD. The is a 6 percent reduction
from 792 GAD, which is the 1989 consent degree goal in GAD. With the exception of
conservation pricing and public education, the details of the fotowing program elements are
descrfoed as Program & in the WRE Part I report (WRE 1990b, Chapter 4, Appendix B, and
Appendix C).
To understand how EPA's recommended program compares with DWD's current water
conservation program, Table 2 presents DWD's currently implemented water conservation
program. Estimated water use savinas from the DWD program were provided for the year
2010, rather than 1999 as provided in the WRE reports pursuant to the Consent Decree.
Of particular interest is DWD's 1990 demand-side water conservation budget which increased
438 percent in two years from the $388,000 actual expenditures in 1988 to the projected
1990 budget of $ 1.7 million for demand-side program elements.
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TABLE 1
EPA-Recommended Water Conservation Program
Estimated Estimated Key Program
DWD 1991 Water Savings Accomplishment
Annual Costs by 1999 by 1999
Water Conservation Program Element (1000 $) ' (AFY) 1
Demand-side Elements
Single and Multi- Family Residential
Water Audits—Device Installation $836 3,327
Single and Multi-Famfly Residential
Ultra Low Volume Toilet Ordnance
(1.6 gallons per flush) 60 1,730
Single and Multi-Family Residential
Ultra Low Volume Toilet Rebates 1,578 4,178
Commercial Water Aucfits 78 390
Industrial Water Audts 24 243
Large Turf Audfts (parks 82 1,404
and public land irrigation)
Ascending Block Rate Structure minimal 3,500 3
Public Education and ET program 1374
including Xeriscape demonstration
Sub-Total Demand-side elements $2,795 14,772
30% single, 60% multi-
family residences audited2
ordinance by 1992
25% penetration
17.5% penetration
25% penetration
80% penetration
312.5 acres/year
effective March 1, 1990
Supply-side Elements
Metering 4,122 s 11,827
Leak Detection 531 890
Non-Potable Reuse/Denver Airport NA 6 2,300
Sub-Total Supply-side elements $4,651 15,017
Total Costs and Water Savings $7,446 29,789
complete by 1993
1,154.5 miles/year
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Footnotes for Table 1
WRE 1990b. The WRE report estimates annual costs of each of these program elements
from 1991 through 1999. The estimated costs for 1991 are listed here to show the initial
direct annual costs only. These costs do not include administration and management
WRE 1990b. The residential aucfit program should achieve 9,300 single-family and 731
multi-family audits per year with the following market penetrations by 1999 for single and
multi-family residences respectively: 15.6 percent and 39.9 percent penetration for
showerheads, 20.3 percent and 54.2 percent penetration in toilet displacement bags, 4.8
percent and 9.6 percent penetration for toilet leak repair, and 8.4 percent penetration in
irrigation audits (WRE, 1990b, Appendix B).
DWD 1989b. DWD estimated 3,500 AFY water savings by 2010 associated with the rate
structure change effective March 1, 1990.
DWD 1990b. Water savings from public education, including the ET program element, are
attributable to other programs.
DWD 1990b. This annual cost would continue until metering is completed by 1993.
Richard P. Arbor Associates 1989. Costs are not appficable since the cost for wastewater
reuse at the New Denver Airport is expected to be less than conventional wastewater
treatment.
FIGURE 1
Consent Decree Goals and Estimated Water Use with EPA's Recommended Program
900
aso
o
< 800
o
750
700
UNRESTRICTED
INITIAL GOAL
10% GOAL
3X COAL
EPA PROGRAM
1979
1984
1989
YEARS
1994
1999
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TABLE 2
Denver Water Department Water Conservation Program
Water Conservation Program Element
Budgeted
DWD 1990
Annual Costs
(1000 $)'
Estimated
Water Savings
by 2010
(AFY) 2
Notes
Demand-side Elements
Single and Multi-Family Residential
Water AucKts, toilet dams installed
showerheads distributed $ 142 1,600
Single and Multi-FamBy Residential
Low Volume Toilet Ordinance
(3.5 galons per flush) minimal 3,400
Single and Multi-Family Residential
Ultra Low Volume Toilet Rebates 300 1,400
Commercial and industrial Water
Audts 216 1,200
Large Turf AucKts (parks 165 900
(and pubfic land irrigation)
Ascending Block Rate Structure minimal 3,500 3
Public Education and ET program 137 « 2,200
including Xeriscape demonstration
General Conservation 741 5
Sub-Total Demand-side elements $ 1,701 14,200
Supply-side Elements
Metering 4,122* 13,800
Leak Detection 45 400
Non-Potable Reuse/Denver Airport NA 7
Sub-Total Supply-side elements $4,167 14,200
Total Costs and Water Savings $5,868 28,400
volunteers based upon
installing new meters
ordinance adopted State-
wide in 1989
contract for industrial
audits awarded May 1990
budget is for the parks
demonstration program
effective March 1, 1990
20% participation in ET
10% reduction in water use
complete by 1993
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Footnotes for Table 2
1 DWD 1990b. This document shows the budget for 1990 and actual expendtures through
the period January 1, 1990 until March 31,1990. In May 1990, DWD awarded a contract to
the firm of Black and Veatch for a total of $215,617 to conduct industrial aucfts, most of
which wi be spent in 1990.
* DWD 1989b. This document estimates water savings for the year 2010. DWD has not
produced estimates of water savings for each year as shown in the WRE reports, nor provide
information on the expected market penetration to be achieved for each program element
3 DWD 1989b. DWD estimated 3,500 AFY water savings by 2010 associated with the rate
structure change effective March 1, 1990.
* DWD 1989c. Water savings from pubic education are attributable to other programs.
Waters savings from voluntary compliance with the ET program is assumed by DWD to
provide 1,200 AFY reduction by 2010. DWD estimates an addtional 1,000 AFY savings
associated with the retrofit of 5 percent of existing and 10 percent of new lawns to low
water use landscaping
5 DWD 1990b. DWD has budgeted $740,742 for general conservation activities in 1990
which includes administrative overhead. Of this amount, $7,415 was spent between January
1 and March 31, 1990.
6 DWD 1990b. This annual cost would continue until metering is completed by 1993.
7 Richard P. Arbor Associates 1989. Costs are not applicable since the cost for wastewater
reuse at the New Denver Airport is expected to be less than conventional wastewater
treatment Total wastewater reuse savings are expected to be 3,900 AFY when the airport
project is complete (DWD, 1990). The City of Denver is studying reuse at the new airport
ana has not yet committed to this water conservation program element
In order to compare the Consent Decree goals in GCD with GAD, the following tables are
presented. Table 3 shows the FoothHs Consent Degree goals in gallons per capita per day
(GCD). Table 4 shows these same goals in gallons per account per day (GAD) and the
EPA-recommended goals for 1999.
TABLE 3
Foothills Consent Decree Goals
Period
Ending
Consent Decree Percent Incremental
Goal (GCD) Decrease
Percent Total
Decrease
1968-77 (base) 219 1
212
208
202-198
184-173
3
5
8-10 2
13-21
1981
1984
1989
1999
3
2
3-5
5-10
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Footnotes for Table 3
1 This is the adjusted base period use to reflect 1980 census population data The 1979
population estimate implied in the Consent Decree was erroneously high. The Consent
Decree base period use was estimated to be 209 GCD.
2 In 1986, EPA selected an additional 3 percent goal to be achieved by 1989. This was
based upon normalizing the data to correct for weather factors. Using the normalized
procedure, EPA concluded that DWD had achieved an 8 percent reduction by 1984. With the
additional 3 percent goal, a goal which totalled 11 percent reduction by 1989 from the base
period was established by EPA.
TABLE 4
EPA-Recommended Water Conservation Goals
Period Consent Decree Percent Incremental Percent Total
Ending Goal (GAD) Decrease Decrease
1968-77 (base) 877
1981 851 3 3
1984 834 2 5
1989 792' 52 10
1999 744 6 16
Footnotes for Table 4
Denver's average usage per account for 1980-1989 was 831 GAD which is 5 percent
above the 1989 goal. To obtain the EPA-recommended goal of 744 GAD by 1999, a total
reduction of 10 percent is needed from current use.
The 5 percent goal is selected by EPA for this compfiance period since the normalized
procedure is no longer useful which established a total of 11 percent reduction goal by this
period.
A. Key Program Elements of the EPA-Recommended Program
The following discussion highlights those key elements of a water conservation program
necessary for DWD to meet the goals of the Consent Decree based upon achieving the
1989 goal plus an additional 6 percent reduction in water use by 1999. In general, these
program elements are being implemented by DWD at the current time. However, DWD's
current water conservation program, with the exception of the mandatory metering program,
should be expanded to obtain the percentage of customer participation necessary and other
objectives to obtain water savings at the recommended level. EPA's recommended program
concentrates on permanent or firm water savings based upon updating the city's plumbing,
improving irrigation procedures, and providing wastewater reuse at the New Denver Airport.
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1. Program Monitoring
The effectiveness of conservation practices can only be determined by detailed monitoring
A detailed schedule for implementation of each program element is essential For example,
annual program accomplishments would specify completion of a certain number of residential
aucits, inspection of a certain number of acres of large commercial landscapes, or other
such program accomplishments. Funds spent on each conservation program element should
be accounted for separately to judge success. This information would be used to determine
if the expencfitures were cost-effective. Cost-effective means whether reduced water use
was accomplished at less cost to DWD than the cost of the next water supply component
(Le. based upon marginal cost avoidance).
It is essential that water use patterns be analyzed by customer class (WRE 1990b,
page 5-13.) DWD's biffing procedures include multi-family accounts and commercial accounts
in a single code, thus negating the abity to cfistinguish water conservation success or
failure between these accounts. DWD's computerized data base should be revised to provide
monthly use of metered water consumption by customer class and biffing sector and to
generate statistical assessments of this information. Residential water use should be
monitored on a pilot basis to access the water use change anticipated for low flow
showerheads, toilet displacement devices, and the $80 toilet rebate program. Similarly, the
accounts associated with large turf aucfits and industrial water aucits should be monitored
for water savings progress. Newly metered account monitoring should be given high priority
since 40 percent of the estimated water savings is associated with converting flat rate
accounts to metered accounts. Data are needed to test the assumptions of growth rates,
customer acceptance, retention, and current market saturation. EPA recommends customer
surveys annually to judge satisfaction and retention of instaBed devices. DWD's existing
biffing system is near maximum capacity and for this reason wH be improved in the next
two or three years. Including conservation monitoring data in the revised biffing system is
essential for effective program administration. See WRE's Part H report for a complete
description of the elements of the recommended monitoring program (WRE 1990b,
pages 5-12 through 5-18).
2. Residential Water Audits
DWD should expand its residential water aucits program. Single-famOy and multi-family
aucfits recommended by EPA would include instalation of low flow showerheads, toilet
displacement devices (dams or bags), toilet leak repairs, and landscape irrigation guidance.
The estimated cost is $61 per household. A total of 9,300 single-famBy residential and
731 multi-family water aucits annually should be completed to have 30 percent of Denver's
single-family residences and 60 percent of multi-famiy residences participating by 1999.
Water savings for this program element are estimated to be 3,327 AFY by 1999. The
residential aucfits should achieve the fofowing market penetrations for single and multi-
famiy residences respectively: 15.6 and 39.9 percent penetration for showerheads,
20.3 percent and 54.2 percent penetration in toilet cfisplacement bags, 4.8 percent and
9.6 percent penetration for toilet leak repair, and 8.4 percent market penetration in
irrigation aucfits (WRE, 1990b, Appendx B).
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3. Ultra Low Volume (ULV) Toilet Ordinance for New Construction
Ordinances requiring installation of toilets in new single and multi-family construction
using less than 1.6 gallons per flush should be adopted for the DWD service area ULV
toilet ordinances for new and renovated construction are in effect for a large percentage of
the nation, including New York, Massachusetts, the Delaware Basin States, Minnesota, and
California Renovation of existing toilets would be covered by the ULV Toilet Rebate
Program. There is no adcfitional direct cost to DWD since the ULV fixtures would be
required by the ordinance. Costs are associated with reduced revenue. About 7,500 new
residences in the Denver service area annually would be affected by these ordinances.
Water savings for this program element are estimated to be 1,730 AFY by 1999. According
to WRE, to achieve this water savings, the ULV ordinance should be in affect by 1991.
DWD observes it will be dffficult to get such an ordinance by 1991 to cover its entire
service area since a statewide ordnance is unlikely (DWD 1990, page 11). Implementation by
each district, city, or county is another possibity. Delay in passing the ULV ordinance
would dminish the estimated savings. EPA believes it reasonable to expect a ULV ordinance
could be in passed by 1992 to cover the entire DWD service area
4. Ultra Low Volume Toilet Retrofit/Rebate
DWD began a program in January 1990 to provide a rebate of $80 for the installation of
ULV toilets. ULV toilets used 1.6 gallons or less per flush. This program would replace, or
retrofit, existing toilets which used 3.5 to 7 gallons per flush. A total of 13,960 toilets in
single-family and 3,950 toilets in multi-famly residences need to be installed annually to
have 25 percent of Denver residences with new ULV toilets by 1999. Water savings for this
program element are estimated to be 4,178 AFY by 1999. DWD observes that the estimate
provided in the WRE report for water use savings from ULV retrofits may be too high since
the assumption was based on converting toilets using 5.5 gallons per flush (DWD 1990a).
The sale of toilets using 3.5 gajlons per flush has been common since the early 1980s, but
the current market penetration in Denver has not been well established. If the current
market penetration in Denver of 3.5 gallons per flush toilet is significant, then this program
element would not achieve the anticipated water savings estimated by WRE. For 1991, the
budget needed for this program element Is $ 1,578,000, while the 1990 DWD budget for this
program element is $300,000. The $80 toilet rebate program is the most expensive
demand-side conservation element It yields 35 percent of the estimated total water savings,
but requires 58 percent of the total demand-side budget.
5. Commercial Water Audits
Commercial water audrts include inspection otplumbing, cooling equipment, instructions on
efficient landscape practices, and identrfication of repair or replacement of fixtures. A total
of 850 commercial water audfts annually are needed to have 70 percent of Denver's
estimated 11,000 commercial accounts participating in this element by 1999. Water savings
for this program element are estimated to be 390 AFY by 1999 . To achieve this water
savings, commercial audits should achieve a market penetration of 17.5 percent
(WRE 1990b, page B-26).
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6. Industrial Water Audits
Industrial water audits would examine process and cooling water systems for leaks and
assess improvements to inefficient equipment The potential for water conservation by
industry in Denver is not well established. This element assumes 15 percent water reduction
per participating account can be achieved A total of 60 industrial water audits annually
are needed to all of Denver's estimated 300 industrial accounts participating in this element
by 1996. Since there are a small number of industrial accounts, it is assumed that this
program would last five years and then be dscontinued. Water savings for this program
element are estimated to be 243 AFY by 1999. To achieve this water savings,
25 percent on these accounts need to implement water conservation measures.
7. Large Turf Audits
DWD staff would evaluate commercial and public large turf areas on-site to produce
customized irrigation schedules for each site. Specific information about the rate and timing
for each irrigation zone would be developed using sol infiltration rates and irrigation
application rates. Water savings for this program element are estimated to be 1,404 AFY by
1999. A total of 312.5 acres of large turf aucfts annually are needed to have 80 percent of
Denver's estimated 3700 acres of parks, golf courses and highway medians audrted by 1999.
8. Leak Detection
Denver should expand its on-going leak detection program using sound amplifying
equipment to cover the entire system every other year. The approximate cost is $457 per
mile surveyed. Water savings for this program element are estimated to be 890 AFY by
1999. The total estimated costs per year would be $531,000. To achieve this water
savings, 1154.5 miles of leak detection surveys would be needed each year.
9. Metering
Metering involves the installation of water meters at all previously unmetered residential
accounts. DWD proposes to complete a mandatory metering program by December 31,1993
(DWD 1989b). As of October 1989, DWD had completed 24,050 meter installations with
approximately 63,000 remaining. Water savings for this program element are estimated by
DWD to be 11,827 AFY by 1999. The total costs for 1990 would be approximately
$4.2 million. This cost would continue annually until metering is completed by the end of
1993.
10. Non-potable Reuse Associated with the New Denver Airport
This element includes the use of non-potable treated sewage effluent for irrigation
associated with the New Denver Airport and the surrouncSng Airport Gateway Development.
Water savings for this program element are estimated to be 2,300 AFY by '1999
(DWD 1990a, page 6). The estimated costs, determined to be less than conventional
wastewater treatment costs, were outfined in a report-prepared for Denver's New Airport
project (Richard P. Arbor Associates, 1989, page 3.)
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11. Pricing — Denver's Ascendng Block Rate Structure
Some forms of rate structures, including seasonal and ascending block rates have been
observed to provide incentives for reducing water use and therefore would contribute to
water conservation efforts. Beginning March 1990, DWD changed its declining rate structure
to an ascending block rate structure. The residential rate for use above 15,000 gallons per
month per residential user is 24 percent greater than the first 15,000 gallons per month
(DWD 1989c, page 2). This assumes that the fixed $6 bi-monthly service charge is not
considered as part of the initial block rate. In order to keep the revised rate structure
revenue neutral (Le. neither increase nor decrease total revenues to DWD), the first block
of water use is 19 percent lower than the declining block rate structure used prior to
March 1990. The effect this water rate change will have on customer water use is
uncertain.
The consultants retained by EPA to evaluate DWD's conservation program did not agree on
the effectiveness of DWD's or other ascending block rate structures. Mr. Nelson believed
that fittle or no water savings would result because consumers are unlikely to change water
use when the cost is low (EPA 1990, page 46). Mr. Nelson referred to a California
community near Novato, where the price of water was four times Denver's rate, yet the
community was having trouble getting 10 percent water conservation. Mr. Nelson pointed
out that the programs recommended in WhE's Part H report are more cost-effective to the
customer since DWD would transfer money directly to the customer in terms of rebates and
aucfits. Professor Bruvold, another expert participating in EPA's review, observed that water
use wfll decline with increased marginal costs ana referred to research studies that appear
to establish the elasticity of demand for urban water use. Elasticity is the percentage of
change in demand associated with a one percent increase in price. A survey conducted for
the U.S. Army Corps of Engineers showed a wide range of estimated elasticities of demand
for urban water use from 0 to -1.41 (Roy F. Weston, 1984). A study in Tucson, Arizona,
estimated an elasticity of -0.7, based upon an average price model (Bmngs and Day 1989).
DWD estimated water savings for its ascending block rate program based upon an elasticity
of -.05 in the winter and -.43 for summer use. Based upon these assumptions and reductions
for interactions with other conservation programs, DWD estimated 3,500 AFY in water
savings would result from its conservation pricing change by 2010 (DWD, 1989b).
EPA recommends that the results from DWD's 1990 rate structure change be evaluated and
tested against the elasticity estimates provided by DWD. If these factors are appropriate,
then water savings would progress towards the 3,500 AFY estimated savings by 2010.
DWD should monitor its rate change effects. This could be accomplished by having control
groups of residences inside and outside the city where rates differ substantially.
12. General Education aid Public Information
DWD water conservation programs that involve education and informational efforts are
focused in three areas: 1) promotion of the ET program; 2) promotion of low water use
landscaping; and, 3) general information provided to the pubfic and students at secondary
schools ana high schools regarding water use practices.
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a ET Program
DWD has an on-going program which publishes the daily evapotranspiration (ET) rate
primarily for guidance for Kentucky Blue Grass lawn watering DWD estimated 1,200
AFY water savings by 2010 based upon 20 percent participation and a reduction of 10
percent for each household following the program. It is recognized that 20 percent
participation is an optimistic goal significantly higher than current levels of
participation (WRE 1990b, page 2-12).
b. Low Water Use Landscaping
DWD has an on-going public education program which promotes the value of low
water use landscaping using drought-tolerant shrubs and grasses. This program
includes distribution of literature, demonstration gardens, sponsorship of public
seminars in low water use landscaping, public service announcements concerning
alternative plants and turfs, and irrigation methods and scheduling DWD estimated
1,000 AFY water savings by 2010 based upon changes in residential landscaping
(DWD 1989c). DWD assumed market penetration by 2010 of 5 percent for existing and
10 percent for new homes which is consistent with values reported in California
(WaterPlan 1989). DWD assumed a reduction of 30 percent of outdoor water use for
low water use landscaping WRE observes this value could range from 5 percent to
50 percent depending upon the details of the landscape plan and its management
(WRE 1990b, age 2-15). Since 51 percent of residential water use in Denver is
associated with lawn watering, conversion of existing and new homes to low water use
landscaping could make a significant contribution to water conservation goals.
Conversion of existing lawns, either at single-famSy residences or commercial areas,
was evaluated by WRE using the WaterPlan analysis and based upon the assumptions
used, was determined to lack cost-effectiveness. The cost and water savings
assumptions used to evaluate landscape conversions included a savings of 15 percent in
outdoor water use and an installation cost of $5000 dollars per average size tot These
costs are associated with obtaining the services of a professional landscape architect,
the retail price of replacement shrubbery, and labor for installation. DWD should
monitor the sales of low water use trees, shrubs, and turf in the Denver area for
estimates of series of drought-tolerant plants. Such monitoring would be used to test
the assumption of the market penetration of low water use landscaping
c. Public Information and Educational Programs
The public information and education portions of DWD's water conservation program
are considered the "foundation of the water conservation effort" (WRE 1990b,
page 2-18). (In 1989, DWD adopted mandatory metering, rate structure changes, and
the toilet rebate program to augment its program.) No water savings are attributable
to the pubic information and education portions of the water conservation program.
Reductions in water savings by plumbing improvements, improved irrigation management,
and behavioral changes resulting from public education efforts are assumed to be part
of other program elements. EPA agrees with DWD's observation that many "traditional"
water conservation elements, such as public education, are based ipon the "habits and
attitudes of water users which may not be reiable over the long term" (DWD 1990a,
page 1). DWD devotes a significant amount of staff time, inducing that of its Water
Conservation Officer, to general pii>lic, secondary, and high school education.
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EPA concludes DWD should expand its water conservation emphasis from general
education to water conservation programs designed for firm water savings.
B. . Other Water Conservation Program Elements by DWD
There are several other water conservation program elements currently undertaken by
DWD. Water savings associated with these program elements do not contribute directly to
water savings. These other program elements include the potable reuse pilot program,
emergency measures to conserve water, and the use of aHuvial groundwater for park irrigation.
1. Potable Reuse — Successive Use Program
DWD has invested heavily in a pilot potable reuse facility designed to treat 1.0 million
gallons per day. The Denver pilot stuaes, which began in 1979, have been a technical
success demonstrating the necessary water treatment technology for safe reuse. The
pilot plant is expected to cease operations in 1991. Due to the nigh cost of reclaiming
wastewater to drinking water standards, potable reuse is not planned as an element of water
conservation in the foreseeable future.
2. Emergency Measures to Conserve Water
DWD's water conservation program includes a procedure to impose voluntary and
mandatory water use restrictions due to a drought or other emergency (such as dam or
conduit failure). Since such measures are imposed only during emergencies and then
rescinded, no water savings are attributable to imposing emergency measures to conserve
water. ,A drought contingency plan would be implemented in stages according to the
severity of the drought The first stage involves voluntary outdoor use restrictions.
At the second stage, mandatory restrictions are imposed employing "the regulations used in
1977" (DWD 1989a, page 25.) DWD should consider amendng these regulations to determine
if recent California experiences in reducing demand during drought would be useful in
Denver. Among the strategies to consider is restricting outdoor water to night and early
morning hours and the imposition of substantially higher rates during a drought.
3. AHuvial Groundwater for Park Irrigation
DWD is considering the use of groundwater from Cherry Creek or the South Platte River
alluvium to irrigate Cherry Creek Park, Pulaski Park, Burns Park, City ofTakayama Park,
City of Karmue Park, JFK Golf Course, Willis Case Golf Course, Washington Park, and other
open space in the area (Presentation by Dave Little, DWD, Citizen's Advisory Committee
meeting, May 2, 1990). These parks and open space are irrigated with treated potable water
and thus such measures would save the cost of water treatment. Irrigation from an alluvial
groundwater source would reduce surface waterTows since the water would be directly
drawn from stream flow. Pursuant to Colorado water law for prior appropriation, DWD
would exchange these diversions in lieu of other direct stream aversions. This program
element would not provide water savings to DWD in the same manner other water
conservation program elements which would, if proven firm, delay the need for additional
water supplies.
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C. Effective Administration of Conservation Programs
The foBowing are some observations regarding the leadership, organization, and budget
necessary for more effective water conservation administration by DWD.
1. Leadership and Organization
As in previous EPA reviews, this review indicated the conservation program continues to
lack a definite focal point within the DWD's organization. Water conservation was not
identified as a major function under any of the DWD's civisions. An organizational change
occurred in 1990 which placed most of the conservation function in the Administration
Division. Activities described in the Water Conservation Plan of DWD, Summer 1989, are
carried out by a number of operational civisions. While a Water Conservation Officer is the
focal point for pubfic education and informational programs within the Public Affairs
Department, monitoring of water conservation efforts is carried out by the Planning
Division, and the metering program by the Administration Division. An organizational chart
for water conservation is not presented in DWD's Water Conservation Plan. The Water
Conservation Ran "is one of concepts" (DWD 1989a, page 3.) The entire section of this
report devoted to "Staff and Budget" reads:
"This proposal is one of concepts. When the Board approves the concepts and
anticipated water savings, then specific personnel and budget requirements will be
assimilated. Those items are not included hera The only dollar amounts are
occasional references to value of water saved as compared to costs of developing new
supplies.
In the 1960s, President John F. Kennedy directed the National Aeronautics and Space
Administration (NASA) to "put a man on the moon by the end of this decade." NASA
at the time cfid not have the research data, the technology, the budget nor the vision.
We, however, are more fortunate than they. We have the vision, much of the data,
most of the technology and a portion of the budget The Denver Water Department
and staff will find the ways and means to accomplish the goals directed by the Board"
EPA finds this generalized approach inadequate. The DWB agreed to the basic concept of
water conservation eleven years ago. That was the appropriate time to estabfish generalized
concepts and objectives. Making suitable budget and staff commitments to accomplish water
conservation should have become an established procedure eleven years into the program.
To accomplish the task of updating the city's plumbing and irrigation equipment to meet the
goals agreed to by Denver in the Foothils Consent Decree, appropriate staff and budgets
should be specified Education and public information, which were considered the
"foundation of the water conservation effort" from 1979 through 1989, have been shown to
be inadequate to meet the goals of the decree. The WRE 1990 Part H report presents the
type of detailed budget and personnel requirements for specific water conservation program
elements DWD should pursue to achieve the goals EPA has recommended pursuant to the
Consent Decree.
Substantial changes in the DWB's water policy occurred in 1989. In 1989, DWB modffied
its rate structure, expedted its metering program, and began the $80 toflet rebate program.
The DWB has substantially improved its water conservation program with adoption of these
conservation efforts. These programs represent the organization's current commitment to
specific water conservation programs aimed at firm water savings, which is an expansion of
its efforts beyond promoting the virtues and ethics of water conservation.
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2. Budget
The above described EPA-recommended conservation program would be expected to result
in 29,789 AFY of water savings by 1999 (See Table 1). This program includes initial
expenses for demand-side elements in 1991 of about $2.8 million, plus $400,000 in lost
revenues from reduced consumption due to conservation. These costs do not include
administrative and management costs by DWD. Foregone revenue would eventually amount
to $3.3 million in 1999 as the program succeeds in reducing water use. In contrast, the
1988 DWD budget for its water conservation program was only $388,000 in demand-side
elements, which does not include reduced revenues. For 1990, DWD has budgeted
$ 1.7 million for demand-side conservation efforts and another $4.2 mWon for tne
metering and leak detection program elements. The total demand-side costs for the
EPA-recommended program at the 6 percent level (i.e. excluding metering and leak detection
costs) would have an estimated present value cost of $33.5 minion with a benefit/cost
ratio of 1.4 for DWD (WRE 1990b, page F-2).
EPA estimates that the DWD staff would need to be increased from its current
3 employees to approximately 15 employees to accomplish these demand-side conservation
programs. Approximately 10 employees would conduct the residential audts (assuming teams
of two accomplishing four audts per day). For the employees conducting these residential
audts, one should have practical experience in the installation and repair of househojd
plumbing and the other practical experience in the design and operation of commercial lawn
watering systems, as well as turf and soil concfitioning experience. One or two staff would
be involved with the commercial and industrial audits and will need to have mechanical
engineering experience in a wide variety of industrial processes. DWD has issued a contract
to an engineenng firm to begin commercial and industrial audts (Presentation by
Dave Little, DWD, Citizens Advisory Committee Meeting, May 2, 1990). Two staff will be
needed to perform large turf audts (WRE, 1990b, page B-33). These employees should be
professional landscape architects with several years field experience in commercial turf
management.
VL Recommended Program For Addtional Water Savings
The following program elements may be needed to achieve the Foothills Consent Decree goal
for 1999, based upon replacing any unsuccessful program elements or to achieve addtional
cost-effective reductions in water use by DWD. The following dscussion highlights addtional
water conservation program elements which may be needed as a supplement to the
recommended EPA program. These programs are not undertaken by DWD at the current time.
A. Expand Successful Program Elements
If DWD is successful at reducing water demand with a particular program element, that
program element could be expanded, expedted, or otherwise improved. For example, the
residential audt program recommended by EPA is designed to cover 30 percent of the homes
by 1999. Addtional staff could be used to expedte this effort to cover more residences by
1999.
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B. Non-potable Reuse for New Developments
In addtion to the New Denver Airport and the associated Gateway development, Denver
may have cost-effective opportunities during the next decade to use non-potable reclaimed
wastewater for park and open space irrigation. Due to the location of the Metro Sewage
facility and the high cost of new transmission facities, conversion of existing open space
irrigation within Denver to non-potable reuse will reman costly. Opportunities for
wastewater reuse may arise with some of the suburban cfistributors on the DWD water
system, especially if they are near wastewater treatment facilities.
C. Low Water Use Landscape Retrofits
A substantial increase in water rates or substantial reduction in landscaping retrofit costs
is needed to change the high costs and poor economic return in terms of water savings
associated with converting existing lawns to low water uses. Of course, homeowners can
and do decide to convert lawns to less water demanding landscapes for a variety of other
reasons which may include conservation ethic, desire for variety in plantings, and reduction
in maintenance and labor costs. In order to have residential low water use landscape
conversions become cost-effective, DWD could consider the following approaches.
As an incentive to low water use landscape conversions, the North Marin Water District
near San Francisco offers a rebate program which pays the consumer to replace Kentucky
Blue Grass with drought-tolerant grasses or shrubbery- This utifity offers a rebate of
$.50 per square foot for removal of turf and conversion to low water use landscaping The
program has been successful for commercial properties but, thus far, few single-family
residences have taken advantage of the utilities' offer (Presentation by John O. Nelson,
North Marin Water District, EPA's Water Conservation Conference, Tucson, Arizona,
February 15, 1990.)
To successfully implement low water use landscaping in Denver, severed factors would
have to be present First, pubfic interest in the advantages of maintaining an attractive,
but different landscape, would need to be generated. Such interest appears to be growing
in Denver. This is related to Denver's pubfic educational efforts. A recent seminar on low
water use landscape planting, sponsored by DWD, had over 250 people in attendance.
Second, some means of reducing the cost of landscape conversion should be developed
The following means have been suggested:
o A utity rebate offer by DWD equal to the avoided cost of a new water supply perhaps
on the order of $.50 per square foot
o A demonstration program based on obtaining drought-tolerant plants at wholesale cost
Drought-tolerant plants at low cost may become available through the Denver Botanic
Gardens in cooperation with the Center for Plant Conservation, Boston, Massachusetts.
o A demonstration program featuring job training for professional landscapes and a job
training service for summer teenage employment to reduce labor costs of landscape
conversion.
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D. Pricing for Conservation
The reduction in water consumption due to rate modifications will depend upon customer
response. An estimate of water savings from pricing is based upon the expected effect of
elasticity of demand for Denver's water. While Denver's recent rate structure mocfification
incorporates approximately a 25 percent higher ascending block rate, which is generally
viewed as fostering conservation, the success of the rate change remains to be determined.
By 2010, DWD estimates that 3,500 AFY of water savings wffl result from the ascending
block rate structure implemented in March 1990. If this estimate of water savings from the
pricing change proves incorrect, then EPA recommends that DWD modify its rate structure.
If the revised rate structure does not reduce demand as expected, DWD could consider the
following revisions among other strategies: a) further increases in the block rate designed
to provide at least 3,500 AFY in water savings by 2010; b) revising the rates to provide at
least a 25 percent higher rate in the ascendng block, incorporating the $6 bi-monthly
service fee into the first block; c) implement differential rates during drought emergencies;
d) increase the rate up to the marginal cost of the next water supply component;
e) implement rates based upon customer usage with price increases if exceeded; or,
f) rebate a portion of the tap fee in response to proven customer water use reductions.
Further increasing the price to achieve a water use reduction of 3,500 AFY by 2010 would
be consistent with DWB's policy statement of October 3, 1989. Increasing the block rate to
the intended 25 percent difference between the first and second residential rate structure,
including the fixed $6 bi-monthly service charge, would be consistent with the intended
DWD policy direction of having a 25 percent ascencfing block rate.
Increasing the block rate within the constraint of keeping the overall rate revenue neutral
would tend to benefit the smaller residential users at the expense of larger users.
Generally, water use is directly associated with lot size. WRE concluded that less water
waste occurred on larger lot sizes.
Differential rates during drought emergencies may achieve substantial water use savings
according to experiences in Oakland, California Notifying the public of much higher rates
to be expected during a drought emergency may foster changes in landscaping to avoid
higher water bills.
Increasing the rate up to the marginal cost of the next water supply component is viewed
by some as a rational basis for water supply pricing. The use of marginal cost pricing is
based upon anticipated future expenses, rather than the current costs associated with
delivering water. (Similarly, WRE used the cost of future water supplies to judge the cost-
effectiveness of the water conservation prograftf elements.) The Denver City Charter
provides ~ "rates w# be as low as good service wi permit (DWD 1989a, page 22).
DWD has stated ~ "It is not the purpose of a conservation program, nor is it necessary for
water conservation, to charge more for water service within the City and County of Denver
than the costs of providing this service, or to prevent the aggregate rates from being 'as
low as good service wfl permit'" (DWD, 1989a, page 22). It has been suggested that a city
charter amendment may be required in order to implement marginal cost pricing in Denver.
This problem could be eliminated if Denver utilized such increased revenue to pay for
addtional cost-effective conservation measures, such as toilet or landscape rebates.
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One method of conservation pricing is to establish rates based upon current consumption
goals per household and penalize use above such goals. Scottsdale, Arizona is in the initial
stages of implementing a pricing system which would establish higher water costs when a
set water use is exceeded The city is now advising consumers of this new program to
"condition" them to the new system and to assess public reaction. Residential water use
goals per household in Scottsdale would be based upon past consumption considering the
number of persons per residence, lot size, and other factors. As proposed, a progressively
increasing conservation rate would be charged to those customers who exceea their goal and
a discount provided to those who are below their goal (Leonard Dueker, 1990).
Providing a rebate of part of the tap fee in response to customer water use reductions is
a different approach. A recent article, using Denver as a case study, suggested that a rate
structure could be based upon converting tap fees, which are relatively high in Denver, from
a set amount per residence to an amount based upon actual water use (John R. Morris,
1989). The relatively hi^i costs of tap fees in Denver are repaid in the mortgage.
Transferring part of this substantial fee back to the customer could provide a definite
incentive to water conservatioa Minimal administrative costs would be associated with this
approach since the burden of reducing water consumption rests with the residential and
commercial property owner. The North Marin Water District offers cfiscounted tap fees for
new developments when certain water conservation practices are included.
VIL Major Policy Issues
The following are the major poBcy issues raised during EPA's 1989 review of DWD's water
conservation program.
A. Interpretation of the Consent Decree Goals
The Foothills Consent Decree goals have been subject to various interpretations
throughout the years. The WRE report identified and examined three dfferent
interpretations (WRE 1990a, page 4-5). EPA agrees with the WRE finding, that
Case 1 is the most reasonable of the three. The Case 1 interpretation computes the target
consumption for a given year as a percent of the base of the 1968-77 consumption value.
The method does not incorporate a normalization for temperature and precipitation. EPA
concurs, as the WRE report states, that by using a 9-year running average, the effects of
temperature and precipitation are accounted for and therefore do not affect the consumption
target (WRE 1990b, page 4-5).
B. GAD versus GCD
EPA agrees with the conclusion and recommendation provided in the WRE report which
states, "The utilization of GAD as the indicator of water consumption is more accurate
because it does not depend on questionable population estimates, as the GCD unit does;
GAD depends on the consumption from a given sector, avalable from DWD water .
consumption files, and on the number of active accounts within that sector, also available in
DWD files. The GAD is a more flexfcle and representative unit, since practically afl of the
water used in the DWD service area can be associated with an account number, and since
every account has a specific category attached to its identification codes, the use of
GAD allows the tracking of consumption by indvidual bMng sectors and different types of
accounts" (WRE 1990b, page 4-4). EPA recognizes that although GAD is an improvement
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over GCD, it has its limitations. One example is that GAD is affected by changes in the
average number of persons per household Another potential weakness that has been pointed
out, is the method's inability to distinguish larger buildings that may have replaced smaller
ones, which contained fewer occupants.
EPA recognizes that at present, there is no state-of-the-art method of measuring
consumption in a precise manner. However, measuring in terms of GAD remains the most
reasonable method Until a more accurate method is found, EPA recommends that the unit
of measurement be changed from GCD to GAD.
C. Measurement of Accomplishments Based upon Goals versus Programs
Because of the inherent uncertainty of water savings estimates, successful water
conservation efforts should be evaluated based upon specific program accomplishments rather
than estimates of the changes in water use consumption. A program at least as stringent as
the EPA-recommended program, which is described as "Program C" in the WRE report, plus
conservation pricing, is necessary to meet the 6 percent reduction goal by 1999. The
monitoring objectives, parameters, and procedures, as specified by WRE, are recommended
standards to establish that DWD has accomplished these program goals (see WRE 1990b,
pages 5-12 through 5-17). In adcition, periodic evaluations by DWD should be prepared for
public review. Annual program expenditures, staffing, cost, ana accomplishments in terms of
market penetration should be presented in the annual self-monitoring report.
D. Water Conservation Impacts to Stream Flow
DWD incficates that water conservation may reduce return flows to the South Platte River.
DWD observed that water conservation programs aimed at reducing consumptive use, such as
low water use landscaping, would reduce the need for additional water supply projects
without the potential to change downstream flow. According to DWD,. other water
conservation measures which reduce non-consumptive use, such as ULV toilets and metering,
would accomplish the same goal of reducing the need for new water suppfies, but affect the
downstream environment because there would be less return flow (DWD 1990a, pages 2
and 3.) DWD expects to issue new water taps against the "increased" firm water supply
obtained from water conservation. Improvements in efficiency in the non-consumptive
portion of Denver's water use would be water that was formerly returned to the South
Platte River. DWD is obligated to return the non-consumptive use portion of the water it
obtains from the South Platte River basin. This "no-injury" rule is intended to protect the
rights of downstream junior appropriates who are dependent on upstream return flows for
their own rights. As the letter from the east-slope conservancy districts and irrigation
associations demonstrates, downstream juniors gre vigilant in protecting against the change
in use DWD is contemplating (letter to Hubert "Farbes, DWB, from the Central Colorado
Conservancy District, Northern Colorado Conservancy District, and the Irrigationists
Association, November 15, 1989.)
However, DWD imports about one-half of its water supply from the west slope of
Colorado. DWD has a right to consume afl of its transbasin water. Downstream junior
appropriators are not entitled to return flows that result from transbasin (Aversions.
Return flows associated with Aversions frpm the South Platte basin would remain
undiminished by more efficient use of transbasin water. 'The contemplated water
conservation program could be shown to improve the efficiency of use of transbasin sources.
EPA concludes that DWD could expect to issue new taps associated with all the firm water
saved by water conservation efforts.
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Improvements in urban water use efficiency from a successful water conservation program
in Denver may, indeed, cause a reduction in South Platte return flows. From an
environmental prospective, any decrease in return flow to the South Platte could be offset
by a corresponding increase in stream flow in the Colorado River Basin as Denver diverts
less water for its diminished needs.
VBI. Achieving Water Conservation by DWD in the Future
This is the final EPA compliance review under the Consent Decree. At this point, eleven
years since the Consent Decree, there is recognition that DWD has failed to act on previous
EPA recommendations. For example, in prior reviews EPA pointed out the lack of central
management for water conservation, the need to fink the elements of the program to specific
water conservation goals, the need to determine the cost-effectiveness of each program
element, the need for public surveys to establish assumptions of interest and market
penetration, and the need to extensively monitor program activities. EPA recommendations to
complete the metering program, promote public awareness, and promote low water use
landscaping are being pursued effectively. In adcfition, DWD has adopted the new elements of
a toilet rebate program and the ascending block rate structure. Nevertheless, much additional
effort by DWD w'S be essential to budget, staff, and implement the water conservation
xogram elements recommended by EPA. Determined implementation of residential, commercial,
ndustrial, and large turf aucfts, a new ULV ordinance, toilet rebates, non-potable reuse at the
New Denver Airport, and expansion of the leak detection program, in adcfition to on-going
metering, are necessary for DWD to achieve the goals of the Consent Decree. DWD should
implement a program designed to achieve the intent and purpose of the Consent Decree in a
clear and unambiguous manner.
IX. Conclusions
Based upon the information presented in this statement, I have concluded that the Denver
Water Department failed to obtain its water conservation goals for 1989 consistent with the
Foothills Consent Decree. I have estabfished the goal for 1999 to be a further reduction of
6 percent based upon gallons per account per day (GAD). By 1999, the average consumption
per account in Denver should not exceed 744 GAD. The current average consumption is
estimated to be 831 GAD. To achieve this goal, the Denver Water Department should
undertake the specific pro-ams recommended in this statement, or their functional equivalent
in terms of program accomplishments, and prepare an annual public report on the progress of
these efforts. Should the Denver Water Department depute the establishment of this water
conservation goal, the Department may appeal the matter to the U.S. Army Corns of Engineers
District Engineer in Omaha, Nebraska, pursuant to the concftions and terms of Section 5(c) of
the 1979 Foothills Consent Decree.
JameS J.
lerer, Regional Administrator
EPA Region VBI
Date
V
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X. References
Richard P. Arbor Associates. 1989. Memorandum. (November 10, 1989)
Billings and Day. 1989. Demand Management Factors in Residential Water Use: The Southern
Arizona Experience. AWWA Journal (March 1989)
Denver Water Department (DWD). 1989a Water Conservation Program, Summer 1989.
Denver Water Department (DWD). 1989b. Press Release. (September 19, 1989)
Denver Water Department (DWD). 1989c. Additions to Water Conservation Plan.
(October 3, 1989)
Denver Water Department (DWD). 1989d Statement regarding new pricing change.
(October 3, 1990)
Denver Water Department (DWD). 1990a Comments on the WRE Final Draft Report.
(April 26, 1990)
Denver Water Department (DWD). 1990b. Executive Summary, Conservation for AH Divisions,
Year to Date. (March 31, 1990)
Leonard Dueker, et. al., City of Scottsdale, Arizona 1990. Goal Billing as a Water
Conservation Tool.
EPA, Transcript of Public Meeting 1990. Public meeting on the final draft of the WRE
report "Analysis and Evaluation of Denver's Conservation Program". (April 12, 1990)
John R. Morris. 1989. Pricing for Conservation (July 1989)
Roy F. Weston. 1984. Algorithm for Determining the Effectiveness of Water Conservation
Measures. (March 1984)
Water Resources Engineering (WRE). 1990a Analysis and Evaluation of Denver's Water
Conservation Program, Part I, Final Draft. (March 26, 1990)
Water Resources Engineering (WRE). 1990b. Analysis and Evaluation of Denver's Water
Conservation Program, Part II, Final Draft. (March 26, 1990)
WaterPlan, Department of Water Resources, State of California 1989. Benefit/Cost Analysis
Software for Water Management Planning (October 1989)
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XI. Glossary
ascerxfng block rate structure - higher cost per unit of water as consumption increases
AFY - acre feet per year
demand-side measure - those measures affecting the water user; including education and public
information, aucits, replacement of fixtures, rate notifications, and incentive and regulatory
programs
DWD - The Denver Water Department
DWB - The Denver Water Board
elasticity - percentage of change in demand associated with a one percent increase in price
Evapo-Transpiration rate - a unit of measurement, derived from a model incorporating
temperature and rainfall to obtain an efficient irrigation rate (The ET rate in Denver is
designed primarily for Kentucky Blue Grass.)
GAD - gallons per account per day
GCD - gallons per capita per day
low volume toiet - a toilet using 3.5 gallons per flush
market penetration - the percent of the homes or businesses retaining the water saving device
throughout its useful life
non-potable reuse - water not fit for human consumption, used for other purposes including:
landscape irrigation or, potentially, waste transport in toilets
normaize - in this text, normalization refers to the correction in the water use demand model
by regression analysis to correct for temperature and precipitation effects upon water use
retrofit - refers to the replacement of plumbing (toilets, showerheads) and landscapes to a
water saving device, or low water use landscape
supply-side measure - those measures which impact the utity's infrastructure but have no
direct effect on customer water use patterns; inducing the measuring and monitoring of water
consumption, leak detection and repair to improve the supply and djstribution systems
efficiency, and to minimize water losses; also encompasses metering
ULV toiet - ultra-low volume toilet, using less than 1.6 gallons per flush
Xeriscape - the term developed by DWD for low water use landscaping
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