r/EPA
United States
Environmental Protection
Agency
FL
it
RESILIENCE
A Basic Guide for Water and Wastewater Utilities
Select a menu option below.
First time users should start with the Overview.
Approach
Mitigation Options
FLOOD HAZARD MITIGATION PROGRAM
"Protecting Lives. Properly s Ihe Environment"
Pilot Project
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RESILIENCE
A Basic Guide for Water and
Wastewater Utilities
September 2014
EPA 817-6-14-006
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
&EPA
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FLOODS AND UTILITIES
Flooding is one of the most common hazards in the
United States, causing more damage than any other
severe weather-related event. It can occur from tropical
storms, hurricanes, swollen rivers, heavy rains, tidal
surges, spring snowmelt, levee or dam failure, local
drainage issues and water distribution main breaks.
Impacts to drinking water and wastewater utilities can
include loss of power, damage to assets and dangerous
conditions for personnel. As storms become more
frequent and intense and as sea levels rise, flooding will
be an ongoing challenge for drinking water and
wastewater utilities.
Click Next to learn more about flood
resilience and mitigation.
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
&EPA
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WHAT IS FLOOD RESILIENCE AND MITIGATION?
For the water sector, "flood resilience" refers to the ability of
water and wastewater utilities to withstand a flooding event,
minimize damage and rapidly recoverfrom disruptions to
service.1 Utilities can build resilience by implementing
mitigation measures. A mitigation measure can be an
emergency planning activity, equipment modification/upgrade
or new capital investment/construction project. Examples of
mitigation measures include:
Emergency response plan
Barriers around key assets
Elevated electrical equipment
Emergency generators
Bolted down chemical tanks
Implementing these mitigation measures requires financial
investment by the utility; however, flood mitigation could
prevent costly damage and enable the utility to provide more
reliable service to customers during a disaster. To help pay for
flood mitigation measures, a utility can also apply for federal
disaster mitigation funds.
Mitigation Success Story
in Alabama
During major flooding, power outages at the
Geneva Water Works resulted in sewer backups.
Geneva County received a FEMA Hazard
Mitigation Grant to procure an emergency backup
generator and fuel tank as well as to elevate
critical motors and blowers. Two years later,
Geneva experienced another major flood, but this
time the system was unaffected.
1 For more information on resilience, see Presidential Policy Directive 21 (accessed August 21, 2014).
Click Next to learn more about this Guide
and to watch a video on flood resilience.
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
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ABOUT THIS GUIDE
&EPA
The U.S. Environmental Protection Agency (EPA) developed
this guide to help drinking water and wastewater utilities
become more resilient to flooding.1 In the approach, the utility
would examine the threat of flooding, determine impacts to
utility assets and identify cost-effective mitigation options. This
approach was successfully tested during a pilot project at a
small drinking water system, the Berwick Water Department
(BWD), in Berwick, Maine. Click on the video to learn why and
how BWD assessed their resilience to flooding.
This guide is particularly useful for small and medium utilities.
It provides easy-to-use worksheets with corresponding videos
(based on the Berwick pilot). To increase your resilience to
flooding, consideryour utility's priorities and available
resources. Although this guide focuses on flood resilience, the
same approach can be applied to enhancing resilience to other
hazards (e.g., earthquakes, tornadoes).
Surviving the Flood
Click on the image to view the video.
You have completed the Overview.
Click Next to continue to the 4-Step Approach.
1 For more on EPA's Water Security tools and resources, visit http://water.epa.gov/infrastructure/watersecurity/.
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
OOOO
vvEPA
Approach to Flood Resilience
4-STEP PROCESS
There are four basic steps involved in increasing your utility's resilience to flooding.1
STEP1
Understand the
Threat of
Flooding
STEP 2
Identify Vulnerable
Assets & Determine
Consequences
STEPS
Identify &
Evaluate Mitigation
Measures
STEP 4
Develop Plan to
Implement
Mitigation Measures
Click on each step above and:
Read the step description
Watch the corresponding video
Complete a worksheet and fill in accompanying blank tables with your utility data
WORK WITH A TEAM
To help you through this process, work with a team of your partners and
stakeholders. This team could include your utility staff (e.g., operators,
supervisors, field staff), other partners from local government (e.g., town
engineer, public works staff, floodplain managers, emergency response
personnel) and state government (e.g., primacy agency staff, hazard mitigation
officers). It will be helpful to hold a kick-off meeting with this team to discuss
goals and responsibilities to complete the assessment and implement mitigation
measures. The four steps should be completed sequentially; however, they do not
have to be completed all at once. Complete the steps as time and resources
permit.
This basic approach is consistent with other water sector guidelines and standards, including ANSI/AWWA 0440-11: Emergency
Preparedness Practices, ANSI/AWWA 0430: Security Practices for Operations and Management, AWWA M-ig Emergency Planning for
Water Utilities, JAWWA Jioo-io Risk and Resilience Management of Water and Wastewater Systems and the Vulnerability Self-
Assessment Tool (VSAT).
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
OOOQ
&EPA
Approach to Flood Resilience
STEP1
[I
Understand the
Threat of
Flooding
STEP 2
Identify Vulnerable
Assets & Determine
Consequences
STEPS
Identify &
Evaluate Mitigation
Measures
STEP 4
Develop Plan to
Implement
Mitigation Measures
STEP 1: UNDERSTAND THE THREAT OF FLOODING
Flooding depends on various factors including
rainfall, topography, river-flow, drainage and
tidal-surge. The threat of flooding is based on
the likelihood that such a flooding event will
occur. Learn how the Berwick Water
Department (BWD) evaluated theirthreatof
flooding from the video. Also, the Federal
Emergency Management Agency (FEMA) is a
resource to help you. FEMA produces maps of
a uioo-year flood" (a flood event that has a
one percent chance of occurring in a given
year) and a more catastrophic "soo-year
flood" (a flood event that has a two tenths of a
percent chance of occurring in a given year).
Click on the Step i worksheet icon below so
that you can document the flooding threat
and obtain FEMA Flood Maps.
Understand the
Threat of Flooding
Click on the image to view the video.
STEP 1 Worksheet
Click here to document the threat of flooding to your utility.
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
OOOQ
&EPA
STEP 1: Worksheet
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
4>EPA
STEP 1: Worksheet (page 2 of 2)
EXAMPLE OF COMPLETED TABLE 2 - UTILITY SYSTEMS WITHIN FLOODPLAIN
Utility System
100-year
Floodplain
Flood Reaches
Elevation (237 ft)
500-year
Floodplain
Flood Reaches
Elevation (240 ft)
Intake (235 ft)
Treatment (238 ft)
Distribution/Collection (237 ft)
Storage Tank (252 ft)
Pump Stations (238 ft)
V
V
V \
V
V
V
Note: Changes in climate
and land use can affect a
utility's flooding threat. For
a more advanced evaluation,
EPA's Climate Resilience
Evaluation and Awareness
Tool (GREAT) can provide
data on projected changes of
extreme precipitation events
and sea-level rise by location.
1.5 What flooding threat do you want to prepare for?
Using your utility's information from Table 2, decide which flood threat will be the focus for protecting your
utility. Select the flooding level that you would like to address.
loo-year flood
] 5oo-year flood
Other:
Elevation.
Elevation.
Elevation
.ft
ft
ft
(e.g., add elevation for climate change impacts or freeboard1 for
local building requirements)
Note: A recent FEMA publication2
recommended elevating critical
infrastructures above the 5oo-yearflood
elevation. This level of protection may
be necessary to obtain federal funding.
To illustrate how a utility might make this decision, below are three potential options based on the
sample data in Table 2 above.
Option A: Select loo-year flood. The utility is unwilling to tolerate a one percent probability of a
flood that would damage its intake and distribution systems. The utility is not concerned about the
more remote possibility of a 5oo-year flood at this time.
Option B: Select soo-year flood. Although the utility will have some impacts from a loo-year flood,
the intake and distribution systems are generally well protected. However, the entire facility,
including a new expensive treatment system, would be a total loss with a 5oo-year flood.
Option C: Select loo-year flood plus 2 feet. The facility has assets located along the coast and
experienced two floods in the last 5 years that approached this elevation and caused significant
disruption to service.
-"Freeboard is a safety factor expressed in feet above a flood level for purposes of floodplain managers.
2 "Reducing Flood Effects in Critical Facilities," FEMA RA2 (accessed August 21, 2014).
You have completed Step 1. Click Next to continue to Step 2.
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
OOOQ
&EPA
/ I Return to Step 1 Worksheet
Interpreting FEMA Flood Maps (page 1 of 2)
FLOOD MAP
Flood Map is the common term used to referto a Flood Insurance Rate Map (FIRM) developed by FEMA. Local and
state governments use these maps to understand the threat of flooding and to devise hazard mitigation plans
(including possible projects) to mitigate the effects of flooding in their communities. Flood Maps can be obtained
through FEMA's Map Service Center. To identify your relevant Flood Map, enter the address of your facility or
vulnerable asset(s). An example map including legend, index and title box is provided below.
EXAMPLE FLOOD MAP - JEFFERSON CITY MISSOURI
- , -.| -.,, ,1 hi II KM PA M-1 UK MtUt »A< RAM
Legend
Depicts
Which Area
Is Shown on
Map/Panel
Panel Number
Community Name
and Number
Date
Index
Title Box
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
OOOQ
&EPA
/ I Return to Step 1 Worksheet
Interpreting FEMA Flood Maps (page2 of 2)
FLOOD MAP
The figure below presents a close-up view of the Flood Map shown on the previous page. Water and wastewater
utilities can use Flood Maps to determine if their facility locations (e.g., treatment, culverts, water storage) are in
a loo-year flood zone, a 5oo-year flood zone or outside of a 5oo-year flood zone. Although the format and
content may differ, information on a Flood Map includes:
Common physical features, such as major highways, lakes, railroads and waterways
Areas subject to a loo-year flood (one percent annual chance of such flooding), also known as Special
Flood Hazard Areas (SFHAs) and base flood areas
Areas subject to a 5oo-year flood (two tenths percent annual chance of such flooding)
Areas outside of the 5oo-year flood zone
Base flood elevation (BFE) or depths
Flood insurance risk zones
To illustrate how to interpret a Flood Map, a hypothetical water utility building is shown.
CLOSE-UP OF EXAMPLE FLOOD MAP
OTHER FLOOD AREAS
Areas of 0.2% annual chance flood; areas of 1%
ZONE X annual chance flood with average depths of less than
i foot with drainage areas less than i square mile; and areas
protected by levees from 1% annual flood chance.
Includes areas in the goo-year floodplain
FLOODWAY AREAS IN ZONE AE
The floodway is the channel of a stream plus
any adjacent floodplain areas that must be kept free of
encroachment so that the 1% annual chance flood can be
carried without substantial increases in flood heights.
Hypothetical Water Utility
Building located outside
the soo-year flood zone.
of
Special Flood Hazard Areas
(SFHAs) Subject to inundation
by the 1% annual chance of flood.
Depicts areas in the loo-year floodplain
More information on how to read a Flood Map can be found at
http://www.floodsmart.qov/floodsmart/paqes/floodinq flood risks/understanding flood maps.jsp.
Base Flood Elevation
line and value.
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
OOOQ
&EPA
Approach to Flood Resilience
STEP1
Understand the
Threat of
Flooding
STEP 2
i
Identify Vulnerable
Assets & Determine
Consequences
STEPS
Identify &
Evaluate Mitigation
Measures
STEP 4
Develop Plan to
Implement
Mitigation Measures
STEP 2: IDENTIFY VULNERABLE ASSETS &
DETERMINE CONSEQUENCES
Often located in low lying areas, water and
wastewater utilities are particularly
vulnerable to flooding. Waterand debris can
inundate the facility, thereby damaging
equipment and structures and causing
power outages. Such impacts can lead to
various consequences including costly
repairs, disruptions of services, hazardous
situations for personnel and public health
advisories. In this step, identify the assets
that are vulnerable to flooding and
determine the resulting consequences to
those assets and to overall utility
operations. Using this information and your
judgment, determine the assets/operations
that you will need to protect from flooding.
Identify Vulnerable Assets
& Determine Impacts
Click on the image to view the video.
Click the video to learn how BWD identified vulnerable assets and determined consequences to their utility. Use
the worksheet below to conduct Step 2. It includes a checklist to inspect your utility and determine elevations of
assets/operations. It is important to understand how your drinking water or wastewater utility may be impacted
by flooding events so that you can identify appropriate mitigation actions to eliminate or reduce asset damage
and prevent service disruptions.
STEP 2 Worksheet
Click here to identify assets that are vulnerable to
flooding and determine consequences.
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
SEPA
STEP 2: Worksheet (page 1 of 2)
To identify which key utility assets/operations are vulnerable to flooding, you should conduct an on-
site inspection to locate assets and document elevations. Compare these elevations with the threat
elevations in the FEMA Flood Map. The assets/operations that are vulnerable to flooding and that
result in significant consequences for the utility are candidates for mitigation and protection. Below
are instructions for evaluating vulnerabilities of assets and the resulting consequences at your utility.
The tables below have sample data. Use the blank tables (double click icon)
to input your utility's data.
2.1 Measure elevations of utility assets to determine vulnerability to flooding.
Conduct on-site inspections of your utility system and then determine the elevation for each critical
asset/operation. To assist you, use the On-Site Asset Inspection Form found in the blank tables. Summarize
the elevation data for all assets/operations in the vulnerability columns in Table 3.
Write in the asset/operation (column i)
Measure the height of the asset/operation above the floor
(column 2)
Determine the elevation of the floor (above sea level) using
as-built design drawing or layouts
Determine asset elevation (column 3) by adding floor
elevation and asset height above the floor
Write in flood threat elevation into column 4. (from Step 1.5)
Compare asset elevation (column 3) to flood threat elevation
(column 4.) and determine which assets/operations are
vulnerable to flooding (column 5)
Tip:
During the inspections, consider flood
water entry points. For example,
assets/operations below ground may
be vulnerable due to leaks from first-
floorflooding.
Although an asset may be located
within a floodplain, it may not be
vulnerable to flooding if, for example, it
is built on an elevated platform or
within a bermed area.
2.2 Determine consequences based on replacement costs and impacts to
facility operations.
Assuming that an asset/operation is flooded, determine the consequences. Estimate replacement costs for
assets based on the best available data, vendor costs or Recommended Practices.1 Record this in column 6
of Table 3 and characterize impacts to the utility operations in column 7.
2.3 Determine priority need for mitigation to improve flood resilience.
For each asset/operation, use your judgment to determine the
priority need for mitigation measures. Base your decision on
both the vulnerability of the asset/operation to flooding
(column 5) and the consequences for the utility (columns 6 and
7) inTable3. Enteryourjudgment into column 8.
Tip: In the example table, note that
the automatic transfer switch has a
high consequence to the utility, but is
located above the flood threat
elevation, so the switch ultimately
has a low priorityfor mitigation.
1 AACE Recommended Practice lyR-gy: Cost Estimating and Budgeting: Class 5 - Process Industry Planning Level estimate
http://www.aacei.org/non/rps/i7R-Q7.pdf (accessed August 21, 2014).
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
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STEP 2: Worksheet (page 2 of 2)
EXAMPLE OF COMPLETED TABLE 3 - SUMMARY OF VULNERABLE ASSETS, CONSEQUENCES OF FAILURE
& PRIORITY FOR MITIGATION
Asset/
Operation
Vulnerability
Height
of Asset Elevation
Above of Asset
Floor (ft)2
Consequences
Elevation Vulnerable
of Flood 1
Threat Flooding?
,.;)3 (Yes/No)4
Replacement
Costs ($) for
Asset
Impact to Facility
Operations from Asset
Failure
Priority for Mitigation5
Low Moderate High
K) K) K)
Raw Water
Pump
Air
Compressor
Automatic
Transfer Switch
0.5
0.75
2.5
Electrical Outlets 2.5
238.5 240
238.75
240.5
240
240
240.5 240
Yes
Yes
No
No
Inability to feed raw water to
20,000 the process tanks will render
the facility inoperable.
15,000
5,000
Inability to provide high air
pressure will limit the
operation of pneumatic
valves on the treatment
process systems. This will
render facility inoperable.
If water damaged the
Automatic Transfer Switch,
the facility would be
inoperable.
The outlets for general use
are not critical to facility
5,000 operations and they are
V
V
located above the 500-year
flood elevation.
V
1The distance between the floor and the bottom of the utility asset.
2 Elevation of the asset = elevation of floor (in this example, 238ft based on design drawing of utility) plus height of asset above floor (column 2).
3 In this example, elevation of flood threat for the 500- year flood is 240 ft (obtained from Step 1.5).
Mf elevation of flood (column 4) is higherthan elevation of asset (column 3), then yes.
s Based on qualitative judgment considering both vulnerability and consequences.
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You have completed Step 2. Click Next to continue to Step 3.
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
OOOQ
Approach to Flood Resilience
STEP1
Understand the
Threat of
Flooding
STEP 2
Identify Vulnerable
Assets & Determine
Consequences
STEPS
Identify &
Evaluate Mitigation
Measures
&EPA
STEP 4
Develop Plan to
Implement
Mitigation Measures
STEP 3: IDENTIFY & EVALUATE MITIGATION MEASURES
First, identify possible mitigation measures that
can protect the key vulnerable assets and
operations prioritized in Step 2. Then, evaluate
which mitigation measures make sense to pursue
and implement.
A mitigation measure can be any emergency
planning activity, equipment modification or new
capital construction project. Examples of each
include:
Emergency procedure to top off water
storage tanks in advance of flooding.
Bolting down chemical tanks and
elevating equipment.
Constructing flood barriers and installing
backup generators.
Click the video to learn how BWD identified and
evaluated appropriate mitigation measures. Click
on the worksheet icon below to conduct Step 3.
How to Protect Your
Utility from Flooding
Click on the image to view the video.
STEP 3 Worksheet
Click here to identify and evaluate mitigation measures.
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
&EPA
STEP 3: Worksheet (page 1 of 5)
To improve your utility's flood resilience, you should identify and evaluate which mitigation
measures to pursue based on cost, effectiveness and practicality. It is possible that some
mitigation measures could be implemented at little to no cost to your utility. Below are
instructions for evaluating mitigation measures at your utility.
The tables below have sample data. Use the blank tables (double click icon)
to input your utility's data.
3.1 What are your utility's requirements to maintain a minimum level of service
during a flood?
Enter capacities/requirements to maintain a minimum level of service at your utility into Table 4.. See below
for an example of Table 4. completed with sample data. This information may help you choose mitigation
measures that can sustain your minimum level of service.
EXAMPLE OF COMPLETED TABLE 4 -
CAPACITIES/REQUIREMENTS TO MAINTAIN A MINIMUM LEVEL OF SERVICE
Sample Asset/Operation
Capacity/Requirements
Finished Water
Chemical and Fuel
Electricity
Water Pressure at Treatment Plant
Pressure of Booster Pumps
3,500gpd
500 Ibs chlorine/day
Varies
60 psi
80 psi
TIP- 1
requi
flood
from
TIP: The level of service
required following a
flood event may differ
from "normal" demands.
3.2 What flood mitigation measures can prevent damage to key assets and
disruptions to critical operations?
For assets/operations that have a moderate or
high priority for mitigation (column 8 in Table 3),
you may consider consulting with a team of
operators, mitigation officers, town engineers,
neighboring utilities, vendors, etc., to identify
potential options. Click the icon to help you
identify mitigation measures.
FLOOD HAZARD MITIGATION PROGRft
"Protecting Lives, f'rojioittj 6 the Invironmont"
TIP: General examples
include waterproofing,
elevating or upgrading
equipment; using flood
control methods to
modify runoff and
managing stormwater
through green
infrastructure.
Mitigation Options
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
oooo
STEP 3: Worksheet (page 2 of 5)
What flood mitigation measures can prevent damage to key assets and
disruptions to critical operations? (cont'd)
Populate the first two columns m Table 5 with mitigation measures that _._ _..... .
r , , r-"r-.». i -i TIP: Consider listing several
you propose for each asset/operation. FEMA also provides some .,, ... .. c
' r r r r possible mitigation measures tor
guidance for selecting mitigation measures to protect against flooding.1 a specific asset or operation (e.g.,
multiple rows for one
asset/operation).
3.3 Evaluate mitigation measures.
Evaluate the mitigation options based on various criteria including effectiveness, practicality and cost.
Descriptions of these sample criteria are in Matrix i. Also, your utility might want to consider other
factors such as:
Availability of funding from federal/state sources,
Selecting a mitigation strategy that addresses a group of similar assets/operations (e.g., pumps for
raw water and pumps for intake water) or
Bundles of mitigation measures that can better address a flooding threat (e.g., bundle sandbags and
water-proof doors).
For each mitigation measure, use your professional judgment to classify the criteria as low, medium or
high. In columns 3-5, rate each criterion and, in column 6, write your thoughts in evaluating the
mitigation option. Finally, in column 7, provide your recommendation. For each mitigation measure,
complete columns 3-7 in Table 5.
1 Selecting Appropriate Mitigation Measures for Floodprone Structures, FEMA 551 (2007), Section 7-2,
Technical Considerations (available at http://www.fema.gov/li bra ry/viewRecord.do?id=2737 [accessed August 21, 2014]).
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
-S-EPA
STEP 3: Worksheet (page 3 of 5)
MATRIX 1 - DESCRIPTIONS OF EVALUATION CRITERIA
Priority Evaluation Criteria
Effectiveness
This evaluates the ability of a mitigation
measure to increase resilience. For the water
sector, "flood resilience" refers to the ability of
water and wastewater utilities to withstand a
flooding event, minimize damage and rapidly
recover from disruptions to service. This can be
measured against the requirement for a
minimum level of service (see Table 4).
Practicality
This is a measure of the ease to
implement the mitigation option. For
example, consider whether the
mitigation option requires ongoing
operations and maintenance or
special training or certification.
Consider replacement costs for the asset, up-front costs for the
mitigation measure, operations and maintenance costs as well as
indirect costs such as staff training. Sources of cost estimation include
vendors, trade publications or industry standards. Consider whether the
mitigation measure can be implemented internally or if it requires
outside contractor assistance. Also, consider calculating net present
value costs and compare the costs of the mitigation measures to the
costs of replacing flood-damaged equipment and the costs of disrupted
operations, as outlined in Table 3.
Funding Sources
Consider the likelihood of applying and receiving
federal funding for the mitigation measure. Be
aware that for FEMA Hazard Mitigation Grants,
you need to use FEMA's more comprehensive
Benefit-Cost Analysis Tool to assess mitigation
costs.
Other Evaluation Criteria
Single Mitigation Solution for Groups of Assets
You may want to consider a mitigation strategy for a
group or bundle of assets/operations that are threatened
in the same way. For example, several critical pumps
(raw water, backwash and finished water) that are co-
located at similar elevations could be considered a single
group of assets that need protection. It may be more cost
effective to protect all the pumps with a retaining wall
rather than invest in submersible versions of the pumps.
Bundle Mitigation Strategies
Sometimes, combinations or bundles of mitigation
measures can better address a flooding threat.
Often, such bundles can be provided at a lower
cost. For example, you may want to bundle
sandbags and water-proof doors to provide
complementary reliable protection.
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
-S-EPA
STEP 3: Worksheet (page 4 of 5)
m
EXAMPLE OF COMPLETED TABLE 5 -
IDENTIFY & EVALUATE MITIGATION MEASURES FOR POWER SUPPLY
Mitigation Measures
Evaluation Criteria
Recommendation
Assets/
Operations
Possible
Mitigation
Measures
Effectiveness
(Low, Med,
High)
Practicality
(Low, Med,
High)
Estimated Cost ($) Evaluation of Mitigation Measure
Recommend
Mitigation
Measure
(Yes/No)?
Procure
Power Supply emergency
generator
Fdtahlkh
agreements
Power Supply with suppliers
tn fnpl
Power Supply
generator
Procure
vehicle to
obtain/
distribute fuel
for generator
High
High
Medium
Medium-High:
$100K; Cost-Benefit
Medium analysis indicated a 7-
year return on
High
Low
investment
Low: $5K
Medium: $30K plus
costs for operations &
maintenance
Significant benefit over current
situation - highly effective. Would
propose to bundle the procurement of
a generator and fuel agreements to
ensure power resilience in floods.
FEMA mitigation can fund generators
so we will plan to apply.
Initial conversation with vendors looked
promising. Bundled with generator
procurement. Influenced by high
effectiveness and low cost.
Strongly influenced by low practicality.
There is no need for fuel truck beside
emergencies and it may require
hazmat driver certification. Also, the
vendor agreed to stage a fuel vehicle in
advance of hurricanes.
Yes
Yes
No
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
-S-EPA
STEP 3: Worksheet (page 5 of 5)
EXAMPLE OF COMPLETED TABLE 5 -
IDENTIFY & EVALUATE MITIGATION MEASURES FOR PUMPS
Mitigation Measures
Evaluation Criteria
Recommendation
Assets/
Operations
Possible
Mitigation
Measures
Effectiveness
(Low, Med,
High)
Practicality
(Low, Med,
High)
Estimated Cost ($) Evaluation of Mitigation Measure
Recommend
Mitigation
Measure
(Yes/No)?
Pumps (raw, Replace with
finished, submersible
backwash) pumps
Pumps (raw,
finished,
backwash)
Pumps (raw,
finished,
backwash)
Increase
capacity for
sump pump
Install
watertight
doors and sand
bags for
waterproofing
Medium
Medium
Medium
Medium
High
High
High: $1 50-21 6K for ... . , . ,.
. a High cost because there are six pumps
six pumps
($25K/pumpto
replace or $36K/pump
to upgrade to
submersible)
Low: $7K
Low-Medium: $20K
at similar vulnerable elevation; medium
practicality because would also need to
upgrade electrical panel. Look for other
short term fixes.
Larger sump pump capacity may give
staff additional time to plan for
mitigation efforts. Low cost is
attractive.
Relatively easy to install water
proofing, but relies on labor for heavy
lifting. Worthwhile given that preventing
water from entering building protects
six pumps totaling more than $1 50K in
replacement costs.
No
Yes
Yes
[ Previous )
You have completed Step 3. Click Next to continue to Step 4.
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
OOOQ
Approach to Flood Resilience
&EPA
STEP1
Understand the
Threat of
Flooding
STEP 2
Identify Vulnerable
Assets & Determine
Consequences
STEPS
Identify &
Evaluate Mitigation
Measures
STEP 4
Develop Plan to
Implement
Mitigation Measures
STEP 4: DEVELOP A PLAN TO IMPLEMENT
MITIGATION MEASURES
Your utility will need to develop a plan to
implement mitigation measures to reduce or
eliminate asset damage and service
disruptions during flood ing. The plan should be
revisited periodically and address actions,
schedule, funding, responsibilities, etc. For
example, flood mitigation measures that
involve major capital and infrastructure
investments should be integrated into the
utility's overall scheduling in the asset
management planning process (e.g., phasing
in flood-resistant pumps). Click on the video to
learn how BWD developed a plan to implement
mitigation measures. To help your utility
complete Step 4., click the worksheet icon
below.
How to Protect Your
Utility from Flooding
Click on the image to view the video.
STEP 4 Workshee
Click here to develop a plan to implement mitigation measures.
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
SEPA
STEP 4: Worksheet (page 1 of 2)
Now that you have selected mitigation measures, develop a plan to implement them.
Below are instructions for developing an implementation plan at your utility.
The tables below have sample data. Use the blank tables (double click icon)
to input your utility's data.
4.1 Develop an implementation plan for selected mitigation measures.
Develop a plan, with specific timeframes, to implement your recommended mitigation measures
(identified in Table 5). Consider coordinating with the following contacts: Utility Board, Local
Government, Emergency Management Agencies, State Hazard Mitigation Officer, Other Utilities and
Vendors.
Decide when and how to implement mitigation measures
Identify if the mitigation measure is to be implemented in the short-term (requiring less
planning and resources, yet filling an urgent need), medium-term or long-term (requiring
more planning/resources and protecting your utility from more intense events).
Determine when your utility will be making other planning decisions (e.g., updating capital
improvement plans or conducting capacity building) and incorporate mitigation activities into
these decision-making processes.
Consider general operations and maintenance activities that are planned (e.g., replacing
equipment at the end of their life cycles) and how they might factor into the timeline for
implementing mitigation measures.
Use Table 6 to structure the plan.
EXAMPLE OF COMPLETED TABLE 6 -
PLAN TO IMPLEMENT SELECTED MITIGATION MEASURES
Mitigation Actions to Implement Mitigation Measure & Timeline for
Measure Completion
Develop proposal that outlines basic engineering plans
and cost/benefit analysis for generator; include costs
for operations, maintenance, fuel (within 2 months)
Talk to power utility about priority restoration of
electricity as well as possibility of generator (within 2-3
months)
Total Time
to
Lead
Individual
Implement or Agency
Funding
Source
Emergency
Generator
and Fuel
Vendor
Agreement
Talk to fuel vendors to establish agreements (within 2-
3 months)
Take proposal to town managers for preliminary
approval to pursue (4 months)
Work with local mitigation official and explore idea of
getting Federal Emergency Management Agency
(FEMA) Mitigation Funds for generator perhaps
bundled with other measures, etc. (4 months to 1 year)
1 year
Operations
and Finance
Capital
Funding and
FEMA Hazard
Mitigation
Grant
Program
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
&EPA
STEP 4: Worksheet (page 2 of 2)
4.2 Explore funding sources for mitigation measures.
Internal utility capital improvement funding.
Local/State funding/bonds.
Federal funding: EPA's tool Federal Funding for Utilities-Water/Wastewater- in National Disasters
(Fed FUNDS) provides comprehensive information on funding programs from various federal
agencies including FEMA, EPA, the U.S. Department of Agriculture (USDA), the U.S. Department of
Housing and Urban Development (HUD) and the Small Business Administration (SBA). For exam pie,
because of flooding from Hurricane Sandy, EPA's State Revolving Funds have refocused efforts on
encouraging flood resilience for both water and wastewater utilities. To access Fed FUNDS, click the
icon below.
Which Funding Is
Right for You?
Currently in a Disaster?
Be Prepared to Tap
into Funding
Here are forms to document
the damage, costs, and repairs.
Federal Disaster
Funding Programs
Utility Examples,
Training, & Assistance
Federal Funding for Utilities Water/Wastewater
- In National Disasters (Fed FUNDS)
4.3 Follow your implementation plan.
Tip: Utilities applying for FEMA
Hazard Mitigation Grants must use
FEMA's Benefit-Cost Analysis Tool
to evaluate the cost-effectiveness
of the mitigation measure.
Implement measures according to the adopted implementation plan.
Update emergency response plans based on new mitigation measures and procedures to maintain
operations.
Evaluate the actual effectiveness of mitigation measures and reassess mitigation
decisions/approaches.
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
&EPA
rn to Step 3 Worksheet
Mitigation Options
IDENTIFY MITIGATION MEASURES
This guide provides two ways to identify mitigation measures:
i. Practical Mitigation Measures. Click the clipboard icon fora one-page list of
practical mitigation measures to help your utility prevent flood water intrusion,
protect assets/operations if flooding does occur and ensure power reliability.
Practical
Mitigation
Measures
2. Mitigation Options for Specific Assets/Operations. Click the photographs of assets/operations
at drinking water (DW) and wastewater (WW) utilities and get tables of flood mitigation
measures for those assets/operations. The tables also provide relative costs for various
mitigation options.
DW
Assets
DW&WW
Assets
WW
Assets
Water Intake, Distribution
and Storage
Booster Stations and
Other Pumps
Drinking Water
Treatment Plant
Chemical and Other
Storage
Instrumentation and
Electrical Controls
Wastewater Treatment
Plant
Remember, before you select the mitigation measures to implement, know the vulnerabilities of the
assets/operations and the costs and effectiveness of those mitigation measures (Step 3 Worksheet). You may be
able to relocate certain assets/operations outside of the floodplain. Also, find out if your local government
requires critical infrastructures to elevate assets to certain heights (e.g., 2 feet above loo-year floodplain).
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
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rn to Mitigation Options
Practical Mitigation Measures for Flood Resilience
PREVENT INTRUSION OF FLOOD WATER
Implement a program to keep all drains and culverts clear of
debris to reduce possible flooding.
Use sandbags to make a quick and low-cost barrierto minor
flooding. Have sand and bags available.
Install backflow preventers on low-lying overflow pipes to protect
finished water.
Sandbags to prevent
intrusion of water
PROTECT ASSETS AND OPERATIONS
Secure or elevate chemical and other tanks to prevent them from
floating away, releasing contents or damaging other equipment.
Plan to move vehicles to high ground. Develop alternative methods to
access the facility if entry is blocked by high flood waters or debris.
Elevate or relocate instrumentation, electrical controls, computers and
records.
Fill finished water storage tanks to full capacity if a flooding event is
anticipated.
Maintain sufficient supplies of chemicals and fuel in anticipation of
supply disruptions during a flood.
Wellhead above
loo-year flood
ENSURE POWER RELIABILITY
Contact your local power utility and local emergency management agency to
plan for priority restoration of power to your water or wastewater utility.
Ensure backup power for pumps, treatment facilities and remote units.
Purchase, rent or borrow generators (e.g., through mutual aid). Install
connections to enable your utility to rapidly hook up generators to your
system.
Make sure generators, electrical connections and fuel supplies are protected
from flooding (e.g., elevated, easy to access).
Arrange for priority access to fuel supplies (e.g., vendor contract).
Elevated Emergency
Generator
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
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Mitigation Options
n to Mitigation Options
BUILDINGS (page 1 of 2)
Drinking water
Wastewater
It is important for drinking water and wastewater utilities to protect
their buildings and other structures from floods. This includes any
entryways, both obvious (e.g., doors, windows, floor drains) and not
so obvious (e.g., wiring conduits, overflow drains, cracks) where water
can enter structures. Significant damage can result from flood waters
entering a building; water can damage or destroy the structure,
process equipment, communications and controls, records and field and administrative equipment. Flood waters
can also restrict access to the facility. These impacts could result in loss of service for your customers and
significant repair costs for the utility. Utilities should establish emergency monitoring and warning systems
(alarm systems where possible), emergency preparedness protocols and evacuation procedures for all buildings
and facilities.
See the following checklist for potential flood mitigation options for your utility buildings.
Mitigation Options for Buildings
Cost
1. Prevent buildings from flooding.
a. Caulk and/or seal wall and floor penetrations.
b. Install backflow prevention devices on sewers, drains and other buildings.
c. Install waterproof protection (e.g., removable/semi-permanent structures, sealed
doors, shields) for building entry points (e.g., windows, doors, garages).
d. Install floodwalls, levees or berms around buildings.
$
$
$$
| 2. Protect critical components if buildings do flood. ^|
a. Train staff how and when to shut down and start up power and gas supplies,
electrical controls, operating systems and other equipment in system facilities.
b. Identify locations outside the flood zone where utility equipment (e.g., heavy
equipment, vehicles, replacement parts, backup generators, pumps) can be stored
safely, permanently or temporarily, to prevent damage from flood waters or debris.
c. Have an alternative access plan in case normal access to buildings is blocked.
Consult with other entities (e.g., Department of Transportation) to consider alternate
road/transportation options (e.g., watercraft).
$
$
$
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
4>EPA
Mitigation Options
BUILDINGS (page 2 of 2)
Return to Mitigation Options
d. Elevate or relocate equipment (e.g., computers, desks, work benches) to prevent
damage if water does enter the facility (i.e., move control centers and/or
laboratories to a second floor).
e. Maintain a cache of spare parts.
3. Maintain operations when the electrical grid is down.1
$-$$$
a. Maintain a generator above flood levels.
4. Maintain continuity of operations during flooding.
a. Regularly backup electronic and paper files outside the flood zone either on-site
(e.g., an upper floor) or off-site. Include all permits and compliance documentation,
designs and as-built drawings, process diagrams, operations and maintenance
(O&M) records, standard operating procedures, process and equipment manuals,
material safety data sheets, asset management data, purchasing records,
operations data, customer records and other critical information.
$
b. Have the capability to operate remotely in case buildings are inaccessible.
c. Establish interconnections or other partnership opportunities to share resources
with neighboring water utilities.
Cost Key (Provides relative costs of mitigation measures - actual costs may differ for your utility)
$ - Little to no cost. Some internal level of effort required, but no contractor support needed.
$$ - Moderate cost/complexity. Likely involves contractual costs.
$$$ - High cost/complexity. Will require one or more contractors to implement this option.
See Mitigation Options (Power Supply)
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
Mitigation Options
CHEMICAL AND OTHER STORAGE
&EPA
rn to Mitigation Options
Drinking water
Wastewater
Aftera flooding event, adequate supplies of chemicals and fuel are
vital to maintain utility operations during the days and weeks that
follow. Chemicals are needed for continued treatment of water and
wastewater and fuel is needed to run equipment including emergency
generators. Flooding may impact these resources in several ways.
Deliveries of chemicals and fuels can be disrupted if access to the
facility is restricted due to high flood waters or debris.
Without necessary chemicals or fuels, utility service could be disrupted for a prolonged period of time. Storage
tanks are also at risk of being damaged from a flooding event. For example, chemical or fuel tanks that are not
properly secured can be carried away, damaged or ruptured, potentially resulting in leaks and spills that may
contaminate utility assets and the environment.
See the following checklist for potential flood mitigation options for your utility chemical and other storage.
_
Mitigation Options for Chemical and Other Storage
a. Elevate or relocate tank platforms above flood levels (e.g., 100- and/or 500-year
flood) or install physical barriers around the tanks.
b. Secure tanks to platforms (i.e., bolt tanks down).
c. Install larger capacity chemical storage tanks to ensure a sufficient supply through
and beyond an emergency until the supply chain is restored.
d. Establish emergency contract provisions with various fuel vendors and chemical
suppliers and inform them of estimated fuel/chemical needs (type, volume and
frequency).1 Work with your local emergency management agency to prioritize
chemical/fuel needs.
e. Ensure chemicals and fuels are topped off in advance of a potential flood.
f. For systems that work on groundwater well supply, procure or get access to a
portable chlorinator.
r i
Cost
$
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
&EPA
irn to Mitigation Options
Mitigation Options
INSTRUMENTATION AND ELECTRICAL CONTROLS
Drinking water
Wastewater
Instrumentation, electrical controls and electrical wiring are critical
components of drinking water and wastewater treatment processes
and should be protected from flood damage to prevent a potential
service interruption. Motor Control Units (MCUs) may be co-located
with the equipment they monitor/control or they may be located in a
central control room. Typically, MCU clusters are co-located with the
pumps and other equipment that they control. With some modification they can be made more resilient to
flooding. Supervisory Control and Data Acquisition (SCADA) systems also may be at risk of failure during a
flood. Loss of SCADA systems can impact operations and data collection in operations centers, treatment
facilities, processes and remote locations in distribution and collection systems such as valve chambers and
pump stations. Utilities should be able to monitor and control operations manually if instrumentation and
controls are off-line due to flooding impacts.
See the following checklist for potential flood mitigation options for your utility instrumentation and
electrical controls.
-ir ^
y' Mitigation Options for Instrumentation and Electrical Controls Cost
1. Protect instrumentation and electrical controls from flood damage. I
a. Elevate individual instrumentation/controls, control centers and MCUs or relocate to
remote locations outside of the flood zone.
b. Maintain a cache of spare parts to restart operations as soon as possible.
c. Purchase and have available portable equipment if permanent equipment becomes
disabled.
d. Train staff to shut down electrical equipment and controls (e.g., SCADA systems,
computers, field instruments) prior to a flood to minimize damage.
e. Replace instrumentation and control enclosures with waterproof models.
v>
$££
"vPvP
$$
$$
$<£<£<£
-CpCpvP
2. Maintain continuity of operations (e.g., redundant controls at another
location) if instrumentation and controls are damaged by a flood.
a. Have redundant controls at another location and/or remote access capabilities.
b. Train staff and plan for manual operation of your water system.
$$
$
Cost Key (Provides relative costs of mitigation measures - actual costs may differ for your utility)
$ - Little to no cost. Some internal level of effort required, but no contractor support needed.
$$ - Moderate cost/complexity. Likely involves contractual costs.
$$$ - High cost/complexity. Will require one or more contractors to implement this option.
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
Mitigation Options
POWER SUPPLY (page 1 of 3)
&EPA
rn to Mitigation Options
Drinking water
Wastewater
Floods often result in power outages that have major implications for
drinking water and wastewater utilities. Without a backup solution,
outages can disrupt service leading to boil water advisories, sewer
backups or the discharge of raw sewage. To ensure continued service
in the event of a power outage, a utility should consider a number of
different strategies (e.g., backup generators, alternative/auxiliary
source of power, energy efficient equipment) to run the critical components of its system keeping in mind that
the minimum level of service required after a flood may differ from "normal" demands. Deciding on a strategy
requires that you identify and evaluate your facility's sources, reliability, redundancies and critical power needs.
To get started, use the EPA's publication Is Your Water or Wastewater System Prepared? What You Need to
Know About Generators (EPA goi-F-og-o27, September 2009).
See the following checklist for potential flood mitigation options for your utility power supply.
/ I Mitigation Options for Power Supply
1. Long before a flood, take measures to reduce the duration of power o
Prepare a list of key utility facilities (e.g., intake works, pump stations, treatment
facility) that require critical power restoration and include the physical locations of
the facilities and their corresponding power company account numbers. Provide
this information to the power company during an outage to expedite electricity
restoration.
Cost
$
b. Talk with your local emergency management agency and local power utility to
increase the priority of power restoration for your utility's facilities.
$
c. Working with the power utility, consider installation of two independent power feeds
to your utility, elevating substations and/or ways to avoid downed power lines.
d. Establish more reliable connection to power source (e.g., install substation
expressly for your utility or a dedicated feeder between the power station and the
treatment plant).
2. Secure backup generators.1
a. For your electrical requirements, document the size and type of backup generator
that you need including voltage, phase configuration, horsepower/amperage, fuel,
etc.
$
Regularly test/service backup generators and ensure that permanent/mobile generators are elevated or outside of flood zone.
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Mitigation Options
POWER SUPPLY (page 2 of 3)
b. Have pump stations wired to accept a portable generator. Ensure that "quick
connect" capability is installed and ready, and that on-site personnel are trained.
c. Arrange to get portable generators in an emergency by maintaining a call list of
multiple vendors that rent portable generators, entering into an agreement with a
particular vendor or joining a mutual aid network (e.g., Water/Wastewater Agency
Response Network [WARN]) to allow sharing of backup generators. During
widespread flooding events, demand and competition for portable generators will be
high.
d. Procure and install your own portable or permanent generators. Consider multi-fuel
generators.
$
$
3. Secure a source of fuel for backup generators.1
a. Fill fuel storage tanks in anticipation of flooding.
b. Establish an agreement with your fuel supplier and provide estimates of fuel needs
(e.g., volume and frequency) in the event of a power outage. Also, secure a list of
alternative fuel suppliers. Maintain communication with your local emergency
management agencies for priority in getting fuel supplies.
c. Install fuel tanks on your utility's vehicles and train staff in moving the utility's fuel in
an emergency.
d. Perform an energy audit of your facility to identify energy saving opportunities via
operations and equipment modifications. Implement recommendations of the audit
(e.g., replace equipment with energy efficient models) to extend the life of your
backup power supply.
e. Install additional and/or larger fuel storage tanks.
$
$
$$
v>
v>
4. Install an alternative energy system. |
a. Install solar panels or wind turbines to reduce dependence on the electrical grid and
to potentially supplement your backup power supply (ensure your utility has the
proper technical switches).
b. Install cogeneration units and/or a waste heat recovery system at wastewater
treatment plants to reduce or eliminate dependence on the grid.
5. Prepare/protect electrical connections/equipment.
a. Train staff to shut down electrical equipment (e.g., Supervisory Control and Data
Acquisition [SCADA] systems, computers, field instruments) prior to a flood event to
minimize potential damage from flood waters.
b. Develop "start and connect" checklists specific to each piece of equipment.
$
$
Regularly inspect/service fuel storage tanks and ensure that permanent/mobile fuel tanks are elevated or outside of flood zone.
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Return to Mitigation Options
Mitigation Options
POWER SUPPLY (page 3 of 3)
c. Equip generators and motors with disconnect fittings that can be removed before a
flood and then restored.
d. Evaluate existing electrical panels to determine the best method of connecting
external portable generators to the facility or to individual pieces of equipment.
e. Replace/upgrade electrical connections/motor controls/junction boxes with
watertight panels.
f. Relocate or elevate electrical vaults and service panels outside of the flood zone.
$
$
$$
Cost Key (Provides relative costs of mitigation measures - actual costs may differ for your utility)
$ - Little to no cost. Some internal level of effort required, but no contractor support needed.
$$ - Moderate cost/complexity. Likely involves contractual costs.
$$$ - High cost/complexity. Will require one or more contractors to implement this option.
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Mitigation Options
WATER INTAKE, DISTRIBUTION AND STORAGE (page 1 of 3)
Drinking water
Flooded rivers and lakes can pose threats to source water intake
structures by clogging them with excess silt/debris or by physically
damaging them with debris. Flood waters that do enterthe intake
may carry increased contaminant loads and/orturbidity levels that
may impact water treatment plant processes. Distribution system
piping and appurtenances that are underground, along culverts and
under bridges can be washed out by fast and high flowing flood
waters. Finished water storage tanks also can be damaged by the
force of flood waters.
Groundwatersources also may be prone to damage. Flood waters can overtop wellheads, causing damage to
the casings as well as contaminating the well water. Shallow we I Is near a flood zone can be contaminated even
if the wellhead itself has not been overtopped. Distribution lines for ground water sources can be equally
vulnerable to flooding.
See the following checklist for potential flood mitigation options foryour utility surface or groundwater
intakes, distribution systems and storage facilities.
SURFACE WATER UTILITIES
Mitigation Options for Surface Water Utilities
Cost
from flooding.
a. Relocate or elevate pump house and distribution system appurtenances that are in
the flood zone.
2. Protect critical components if intake, distribution and storage
of finished water do flood.
a. Protect or reinforce surface water intake structures from floating debris, erosion and
siltation to prevent damage or blockages during floods. Install jetty or breakwater to
divert debris/silt away from structure. Install/upgrade screen at the intake to prevent
debris blockages.
b. Waterproof, relocate or re-enforce distribution system appurtenances (i.e., fire
hydrants, valve vaults) susceptible to flooding or damage from debris.
c. Install submersible pumps or waterproof pump motors.
d. Ensure that distribution lines across streams are sufficiently below streambed.
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Mitigation Options
WATER INTAKE, DISTRIBUTION AND STORAGE (page 2 of 3)
3. Maintain delivery of safe drinking water during flooding. 1 f
a. Sign up for U.S. Geological Survey (USGS) alerts for stream and river gauges:
WaterAlert - Select gauges of interest, and USGS will send an email/Short
Messaging Service (SMS; i.e., text) message when parameters exceed user-
defined thresholds.
WaterNow - Receive current conditions for water data at a specific gauge
directly to your mobile phone or email.
b. Install monitoring equipment upstream of intakes to provide an early warning of raw
water conditions (e.g., turbidity, flow) if no state or federal monitoring is available.
Adjust the treatment process as necessary (e.g., chemical addition, residence time)
to account for higher contaminant loading or increased turbidity.
c. Have an alternative access plan in case normal access to intake structure and/or
pump house is blocked. Consult with other entities (e.g., Department of
Transportation) to consider alternate road/transportation options (e.g., watercraft).
d. Establish a plan to fill finished water storage tanks to capacity prior to a storm event.
e. Stock spare parts to repair damaged equipment.
f. Explore interconnections or other partnership opportunities to share resources or
facilitate emergency public water supply services with neighboring water utilities.
$
$$
$
$
$-$$
ipip~ipipib
GROUNDWATER UTILITIES
Mitigation Options for Groundwater Utilities
1. Prevent well field/pump house from flooding
Cost
a. Procure temporary flood barriers (e.g., sandbags) for use in minor floods.
b. Re-grade land surrounding well field so that it slopes away to prevent flood water
from flowing toward the wells. Ensure that the casing terminates at least twelve
inches above grade. Also, extend well casings above the flood zone.
c. Relocate or elevate well field pump houses that are in the flood zone.
$
$q>
See Mitigation Options (Drinking Water Treatment Plant)
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Mitigation Options
WATER INTAKE, DISTRIBUTION AND STORAGE (page 3 of 3)
2. Protect critical components if ground water intake and supply do flood.
a. Seal the top of well casings, waterproof well caps that are in the flood zone and
extend vents above the flood zone elevation.
$
b. Periodically evaluate the integrity of surface seals outside casings and check that
there has been no soil settling or that no cavity has developed around the outside of
well casings where surface water would be able to flow down to the aquifer.
$
c. Install submersible pumps or waterproof pump motors and other equipment.
3. Maintain delivery of safe drinking water during flooding. 1
a. Plan to fill water storage tanks to capacity prior to a storm event.
b. Have an alternative access plan in case normal access to wellhead/pump house is
blocked. Consult with other entities (e.g., Department of Transportation) to consider
alternate road/transportation options (e.g., watercraft).
$
$
Cost Key (Provides relative costs of mitigation measures - actual costs may differ for your utility)
$ - Little to no cost. Some internal level of effort required, but no contractor support needed.
$$ - Moderate cost/complexity. Likely involves contractual costs.
$$$ - High cost/complexity. Will require one or more contractors to implement this option.
See Mitigation Options (Drinking Water Treatment Plant)
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rn to Mitigation Options
Mitigation Options
BOOSTER STATIONS AND OTHER PUMPS (page 1 of 2)
Drinking water
Flood waters can severely damage pumps, thereby impacting the
entire drinking water system from intake through distribution.
Similarly, loss of facility power could render pumps inoperable
without adequate backup power. Vulnerable water facility control
systems include pump controls, variable frequency drives, electrical
panels, motor control centers and Supervisory Control and
Data Acquisition (SCADA) systems.
See the following checklist for potential flood mitigation options for your utility booster station/pumps.
Mitigation Options for Booster Stations and Other Pumps
Cost
1. Prevent booster stations from flooding.
a.
b.
Procure temporary flood barriers (e.g., sandbags) for use in minor floods.
Install permanent physical barriers (e.g., flood walls, levees, sealed doors).
$
$$
2. Protect critical components if booster stations do flood. |
a.
b.
c.
d.
e.
f.
9-
During upgrades or design of new equipment, develop capability to temporarily
remove and safely store vulnerable components in advance of a flood.
Waterproof, relocate or elevate motor controls, variable frequency drives, computers
and electrical panels to a higher elevation by constructing platforms or integrating
controls into existing buildings or infrastructure on-site.
De-energize systems prior to flooding to mitigate damage to electrical components.
Replace non-submersible pumps with submersible pumps, if cost effective.
Replace standard electrical conduits with sealed, waterproof conduits. Replace
electrical panels with submersion rated enclosures.
Install sump pumps for below-ground facilities. Although not typically used to protect
against flooding events, sump pumps may provide additional time to take other
mitigation measures.
Replace a below-grade booster station with an above-grade station elevated higher
than the flood stage.
$
-------
FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
SEPA
Return to Mitigation Options
Mitigation Options
BOOSTER STATIONS AND OTHER PUMPS (page 2 of 2)
3. Maintain pumping operations when the electrical grid is down.' |
^^^^m
a. Store temporary or replacement pumps out of the flood zone.
b. Install energy efficient equipment to increase the longevity of the fuel supply for
backup generators.
c. Replace pumps with diesel driven or dual-option counterparts.
d. Consider options for procuring generators (permanent or portable) or an alternative
energy supply.
$
$$
vP
v>
4. Maintain pumping operations. |
a. Maintain a call list of multiple vendors that can provide "pump around" services in an
emergency or enter into an agreement with one.
b. Procure extra portable pumps or specialized parts to repair damaged pumps.
Consider stockpiling major components of specialized high capacity pumps.
$
\P\P~\P\b\P
Cost Key (Provides relative costs of mitigation measures - actual costs may differ for your utility)
$ - Little to no cost. Some internal level of effort required, but no contractor support needed.
$$ - Moderate cost/complexity. Likely involves contractual costs.
$$$ - High cost/complexity. Will require one or more contractors to implement this option.
See Mitigation Options (Power Supply)
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
&EPA
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Mitigation Options
DRINKING WATER TREATMENT PLANT (page 1 of 2)
Drinking water
Flood waters may inundate a treatment facility and wash out open
tanks and filter beds, damage mechanical equipment, render
electrical power and controls useless, spoil finished water storage,
deposit debris on-site or wash contaminants into the treatment
process. Flood waters may also alter source water chemistry and
turbidity, posing treatment challenges to utilities that continue to
operate during a flood. For example, residence times may need to
be significantly longerfollowing a flood to attain safe drinking
water standards due to high turbidity and the potential influence of contaminants in the flood waters.
See the following checklist for potential flood mitigation options for your utility treatment plant.
Mitigation Options for Drinking Water Treatment Plant
Cost
a. Install physical barriers to protect the entire facility from flooding (e.g., flood walls,
levees) or be able to deploy temporary systems that achieve the required
protection.
b. Install green infrastructure within or beyond the boundaries of the treatment plant to
attenuate, divert or retain flood water and storm surges.
c. Install flood water pumping systems and/or channel/culvert systems to collect and
divert flood water away from treatment processes.
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2. Protect critical components if the treatment plant does flood. 1
a. During upgrades or design of new equipment, develop capability to temporarily
remove and safely store vulnerable components before a flood when there is
enough advanced notice to do so.
b. Install saltwater-resistant equipment and storage tanks (e.g., for chemicals and
fuel).
c. Waterproof electrical components (e.g., pump motors, monitoring equipment) and
circuitry.
d. Elevate, relocate or cap individual assets to prevent damage from flood waters;
vertically extend the walls of a treatment structure (e.g., basin, tank, filter) above
flood stage; and/or flood-proof/seal structures to prevent seepage of flood water
into the treatment train.
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
SEPA
Return to Mitigation Options
Mitigation Options
DRINKING WATER TREATMENT PLANT (page 2 of 2)
e. Replace motorized and electrical equipment with submersible equipment (e.g.,
submersible pumps).
3. Maintain delivery of safe drinking water during flooding.
a. Monitor the quality of raw water entering the treatment plant and be prepared to
adjust the treatment process as necessary (e.g., chemical addition, residence time)
to account for higher contaminant loading or increased turbidity.
b. Purchase portable, handheld testing equipment to serve as a backup to permanent
mounted testing equipment that may be inoperable during a flood.
c. Develop process guidelines or models to understand potential water quality
changes, adjustments that may have to be made to attain drinking water standards
and the potential costs of changes in treatment.
d. Explore interconnections or other partnership opportunities to share resources or
facilitate emergency public water supply services with neighboring water utilities.
$
$
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4. Maintain operation of treatment plant if electrical grid is down. 1 H
a. Install energy-efficient equipment to increase the longevity of the fuel supply for
backup generators.
b. Replace motorized equipment with diesel-driven or dual-option counterparts.
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5. Increase storage capacity in preparation for floods. |
a. Consider filling finished water storage tanks to capacity prior to a storm event to
maximize storage if service is interrupted or if the utility is damaged.
b. Install larger capacity chemical storage tanks to ensure a sufficient supply through
and beyond an emergency until the supply chain is restored.
c. Determine if increased finished water emergency storage capacity would be
beneficial (as opposed to water age/quality concerns).
$
$$
$$
Cost Key (Provides relative costs of mitigation measures - actual costs may differ for your utility)
$ - Little to no cost. Some internal level of effort required, but no contractor support needed.
$$ - Moderate cost/complexity. Likely involves contractual costs.
$$$ - High cost/complexity. Will require one or more contractors to implement this option.
See Mitigation Options (Power Supply)
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
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Mitigation Options
LIFT STATIONS (page 1 of 2)
rn to Mitigation Options
Wastewater
Lift stations are typically located at the lowest points in gravity-fed
sewer systems and are therefore prone to flooding. Lift stations are
also vulnerable to power outages. When lift stations lose power and
do not have adequate emergency power, untreated sewage can back
up into homes and businesses, flood streets or run off into local
waterways.This presents a serious threatto public health and the
environment. Utilities should analyze various lift station failure
scenarios (using flood stage in the flood zone for hydraulic
calculations) and determine potential impacts to help inform mitigation decisions. Mitigation decisions will
also depend on the type of lift station (e.g., wet or dry well), location (above or below grade), existing
enclosure and ancillary equipment (e.g., minimal electrical/mechanical control equipment versus grit
chambers, screens, electrical panels and other equipment).
See the following checklist for potential flood mitigation options for your utility lift stations.
Mitigation Options for Collection System Lift Stations
Cost
1. Prevent lift stations from flood
a. Procure temporary flood barriers (e.g., sandbags) for use in minor floods.
b. Extend vent lines above anticipated flood stage to prevent floodwater from entering
the lift station.
c. Install gates and backflow prevention devices on influent and emergency overflow
lines to prevent inundation of the lift station by the collection system and the
overflow.
d. Install permanent physical barriers (e.g., flood walls, levees, sealed doors).
e. Install green infrastructure to attenuate or divert flood water and storm surges away
from lift stations.
$
$q>
$
$$
$$
2. Protect critical components if lift stations do flood. ^
a. Install unions in the conduit system to reduce the time required to repair damaged
sections.
b. During upgrades or design of new equipment, develop capability to temporarily
remove and safely store vulnerable components before a flood when there is
enough advanced notice to do so.
$
$
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
4>EPA
Mitigation Options
LIFT STATIONS (page 2 of 2)
Return to Mitigation Options
c.
d.
e.
f.
3. Mainta
a.
b.
c.
Waterproof electrical components, controls and circuitry.
Relocate or elevate electrical components (e.g., motors, switchgears, motor control
centers, cathodic protection systems, exhaust fans, etc.) above the flood stage.
Replace vulnerable components with a submersible option (e.g., pumps, flow
meters, gate/valve operators, etc.).
Replace a below-grade lift station with an above-grade station elevated higher than
the flood stage.
Consider options to procure generators (permanent or portable), increase fuel
storage capacity or install an alternative energy supply. The generators should be
elevated above the flood stage, have automated controls and be sized
appropriately. On-site fuel storage should also be elevated and secured to prevent
floatation.
Install energy efficient equipment to increase the longevity of the fuel supply for
backup generators.
Replace pumps with diesel driven or dual-option counterparts.
vP
vP
vP
vP
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4. Have a means of bypassing normal lift station operations when necessary. ^1
a.
b.
c.
Maintain a call list of multiple vendors that can provide "pump around" services in an
emergency or enter into an agreement with one.
Procure portable pumps to restore operation of a damaged lift station following an
event.
Implement a regionalization project to enable diversion of wastewater flows to an
alternate system for emergency wastewater collection and conveyance.
$
$$
Cost Key (Provides relative costs of mitigation measures - actual costs may differ for your utility)
$ - Little to no cost. Some internal level of effort required, but no contractor support needed.
$$ - Moderate cost/complexity. Likely involves contractual costs.
$$$ - High cost/complexity. Will require one or more contractors to implement this option.
See Mitigation Options (Power Supply)
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
&EPA
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Mitigation Options
HEADWORKS (page 1 of 2)
Wastewater
The headworks includes the structures and equipment at the
beginning of the wastewater treatment plant, such as gates and flow
controls, metering equipment, pumps, mechanical screens and grit
removal systems. This equipment is often at a lower elevation
compared to the rest of the facility, increasing its vulnerability to
flooding. If the headworks is off-line due to flooding, the rest of the
plant would be inoperable. A failure of the headworks without a relief
or bypass may also create backwater effects on the collection system
that could flood streets and basements. Utility operators should identify how a headworks failure would affect
the collection system and wastewater treatment plant performance using flood water elevations in the flood
zone for hydraulic calculations and then implement the appropriate mitigation measures.
See the following checklist for potential flood mitigation options foryour utility headworks.
T T
S Mitigation Options for Headworks Cost
1. Protect critical headworks components from flooding. 1
a. Install nonelectrical backup controls where possible (e.g., float switches for pumps).
b. During upgrades or design of new equipment, develop capability to temporarily
remove and safely store vulnerable components before a flood when there is
enough advanced notice to do so.
c. Upgrade mechanical screens to prevent debris blockages and hydraulic restrictions
in anticipation of higher than normal sand, grit, trash and debris loading during and
immediately after a flood event.
d. Waterproof or elevate motor control units, instrumentation and controls, electrical
panels, variable frequency drives and other systems.
e. Elevate pump and screen motors and other process mechanical/electrical
equipment above flood stage.
f. Replace dry well pumps with submersible pumps; consider increased capacity
needed during storm/flood events.
$
$£££
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
SEPA
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Mitigation Options
HEADWORKS (page 2 of 2)
2. Maintain headworks operation when the electrical grid is down.1 ^1
a. Secure backup power supply for the headworks. Consider installing a generator just
for the headworks or procuring a mobile generator with sufficient output for the
same purpose.
b. Replace motorized equipment with diesel driven or dual-option counterparts.
vP
v>
Cost Key (Provides relative costs of mitigation measures - actual costs may differ for your utility)
$ - Little to no cost. Some internal level of effort required, but no contractor support needed.
$$ - Moderate cost/complexity. Likely involves contractual costs.
$$$ - High cost/complexity. Will require one or more contractors to implement this option.
See Mitigation Options (Power Supply)
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
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Mitigation Options
WASTEWATER TREATMENT PLANT (page 1 of 2)
rn to Mitigation Options
Wastewater
Wastewater treatment plants are typically located at low elevations
and near a receiving water body, which may pose a significant flood
risk to a facility. Coastal facilities face additional risk from storm
surges and saline flood waters that can corrode storage tanks,
circuitryand equipment.
Flood waters can wash out primary and secondary clarifiers,
aeration tanks and chlorine contact chambers, as well as upset
bioreactors. Other impacts from flood waters include damage to mechanical and electrical
equipment/controls, interference with biosolids handling and disposal systems as well as washing of
contaminants into the treatmenttrain.Treatment plants that are still operational during a flood need to be
prepared to accommodate higher flow rates and increased pollutant loads.
See the following checklist for potential flood mitigation options for your utility treatment plant.
Mitigation Options for Wastewater Treatment Plant
Cost
1. Prevent treatment plant from flooding.
a.
b.
c.
d.
e.
f.
Install physical barriers to protect the entire facility from flooding (e.g., flood walls,
levee, sealed doors) or be able to deploy temporary systems that achieve the
required protection.
Install green infrastructure within or beyond the boundaries of the treatment works
to attenuate, divert or retain flood water and storm surges.
Install flood water pumping systems and or channel/culvert systems to collect and
divert flood water.
Correct infiltration and inflow problems to reduce flows to the treatment works in a
flood.
Separate combined sewers to reduce flows to the treatment works in a flood.
Construct a large storage tank to store overflows for future treatment (e.g., a large-
capacity combined sewerage overflow (CSO) tunnel).
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2. Protect critical components if treatment plant does flood. |
a.
b.
Secure air tanks to prevent floatation if flooded.
During upgrades or design of new equipment, develop capability to temporarily
remove and safely store vulnerable components before a flood when there is
enough advanced notice to do so.
$
$<£<£<£
-$$$
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
4>EPA
Mitigation Options
WASTEWATER TREATMENT PLANT (page 2 of 2)
Return to Mitigation Options
c. Install saltwater resistant equipment and storage tanks (e.g., for chemicals and
fuel), if near a coastline/brackish water.
d. Waterproof electrical components (e.g., pump motors) and circuitry.
e. Elevate, relocate or cap individual assets (e.g., blowers, chemical/fuel/air tanks,
instrumentation/controls) to prevent damage from flood waters; vertically extend the
walls of a treatment structure (e.g., clarifier, basin, tank) above flood stage and/or
flood-proof/seal structures to prevent seepage of flood water into the treatment
train.
f. Replace motorized and electrical equipment with submersible equipment (e.g.,
submersible pumps).
g. Have an alternative access plan in case normal access to the treatment plant is
blocked. Consult with other entities (e.g., Department of Transportation) to consider
alternate road/transportation options (e.g., watercraft).
$
$$
$
3. Maintain treatment plant operations when the electrical grid is down1 and/or access
a. Install larger capacity chemical and fuel storage tanks to ensure a sufficient supply
through and beyond an emergency until the supply chain is restored.
b. Install energy efficient equipment to increase the longevity of the fuel supply for
backup generators.
c. Replace motorized equipment with diesel driven or dual-option counterparts.
d. Consider options for procuring backup generators or an alternative energy supply.
$
$$
v>
vP
4. Have a means of bypassing normal treatment plant operations when necessary.
a. Install an external connection to the facility's compressed air system to allow a
temporary, portable air compressor to be used if the main air compressor becomes
disabled.
b. Procure portable pumps or maintain a call list of multiple vendors that can provide
"pump around" services in case part of the treatment train is off-line.
c. Implement a regionalization project to enable diversion of wastewater flows to an
alternate system for emergency wastewater collection and treatment services.
$
$$
Cost Key (Provides relative costs of mitigation measures - actual costs may differ for your utility)
$ - Little to no cost. Some internal level of effort required, but no contractor support needed.
$$ - Moderate cost/complexity. Likely involves contractual costs.
$$$ - High cost/complexity. Will require one or more contractors to implement this option.
See Mitigation Options (Power Supply)
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FLOOD RESILIENCE: A Basic Guide for Water and Wastewater Utilities
&EPA
Pilot Project at a Small Drinking Water Utility
BERWICK, MAINE
A small drinking water utility in Berwick, Maine was
concerned about flooding events from a nearby river. In May
2006 and April 2007, the Berwick Water Department (BWD)
was impacted by two consecutive loo-year storms. In both
instances, road access to the BWD facility was cut off by high
flood waters. BWD was concerned that it may be vulnerable
to more intense floods in the future.
At the request of BWD, utility operators and EPA engineers
conducted a pilot resilience project to evaluate the flooding
risk and determine what actions could improve the utility's
resilience to flooding. EPA and BWD staff carried out the four
steps described in the selection, Approach to Flood Resilience.
Using FEMA floodplain information and incorporating future uncertainties such as land use changes,
urban development and climate change, BWD characterized the impact of three flood levels (loo-year
flood, 5oo-year flood, and a 5oo-year flood plus 2 feet freeboard). Critical assets that needed to be
protected from flooding included process pumps; heating ventilation and air conditioning (HVAC),
instrumentation and electrical controls as well as chemical storage tanks. The utility operators and
engineers estimated the costs to repair/replace flooded assets and determined the potential impacts to
operations.
Finally, the BWD operators and engineers identified mitigation options to protect their systems and provided
recommendations to their management. Short-term mitigation options included placing sandbags at utility
entryways, installing backflow preventers on low lying overflow pipes, securing or elevating tanks to prevent
floating and ensuring adequate finished water storage priorto storm events. Many of the mitigation options
were low cost or would have other benefits to operations. EPA helped BWD develop a plan that calls for
implementing certain measures in the short-term to address immediate utility needs. The plan also allows for
flexibility in applying other measures when additional utility resources become available and when conditions
require increased flood protection. Since the assessment, BWD has secured an alternate access road so staff can
enterthe plant if the main road is inundated during a flood.
Quotes from Berwick Water Department
"When you realize that a flood could
come and bring [your workable plant]
all to an end in a couple of hours, and
you'd be down for potentially weeks,
that makes you ...want to know,
what can I do to avoid this?"
"I'd be implementing some planning
and some low cost alternatives
right away, and then looking at the
big budget picture for other things."
"Think ahead. Make plans
now. Reduce the risk, and
you'll be happy in the end."
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Flood Resilience: A Basic Guide for
Water and Wastewater Utilities
Office of Water (4608T) - EPA 817-B-14 -006- September 2014
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