TD657
.U732
1990
C.2
United States
Environmental Protection
Agency
Water Division
Chicago, IL 60604
1990
Urban Runoff and
Stormwater Management
Handbook
TD657U732
Printed on Recycled Paper
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Prepared for the U.S. Environmental Protection Agency by
Dynamac Corporation and JT&A, Inc., under Contract No. 68-
C8-OQ52. This project was funded in part by the Office of Water
Enforcement and Permits and managed by Watershed Manage-
ment Unit, Water Division, Region V.
Writer: Betty Bracht
Cover and illustrations: Patricia Perry
Production: Lura K. Svestka
For copies of this publication, contact
The Terrene Institute
1000 Connecticut Avenue, NW, Suite 300
Washington, DC 20036
(202) 833-3380
U.S. Environmental Protection Ag«ncy
Region 5, Library (PL-12J)
77 West Jackson Bpulevard, 12th Floor
L 60604.3590
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Foreword
The 1987 amendments to the Clean Water Act focused atten-
tion on urban runoff, both quality and quantity, by estab-
lishing two programs to assist States and municipalities in
abatement of urban runoff water quality problems: Sections 319
(Nonpoint Sources Control) and 402 (Stormwater Permitting). In
many States, programs to control urban nonpoint source runoff
are less developed in relation to most other water quality
programs. The possible reasons for this include urban nonpoint
source pollution's less extensive distribution; its more complex
natureboth in terms of its many types of sources and the kinds
of pollutants produced; and its closer proximity to point source
pollution problems, which have until recently received the al-
most exclusive attention of government agencies.
Now that urban runoff pollution problems are gaining the in-
creased attention of state water quality agencies and local
governments, the many possible kinds of regulatory and non-
regulatory programs that might effectively control urban runoff
pollution problems must be considered. This handbook was
developed to assist local units of government in focusing their at-
tention on urban runoff pollution problems and getting their
citizens involved in designing control programs.
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This handbook is one in a series of technology transfer docu-
ments EPA Region V is responsible for developing. Future techni-
cal transfer efforts include a Great Lakes Nonpoint Source
Symposium, a workshop on monitoring the effectiveness of best
management practice implementation, an urban nonpoint source
control workshop, and stormwater/urban nonpoint source con-
trol fact sheets.
Within each EPA Region, appropriate efforts are coordinated
by the Nonpoint Source Coordinator. Contact your regional coor-
dinator for information on nonpoint source management ac-
tivities in your State, and for publications such as this handbook.
Comments or questions concerning this handbook should be for-
warded to Tom Davenport of my staff.
DALE S. BRYSON
Director, Water Division
U.S. Environmental Protection Agency
Region V
230 S. Dearborn Street
Chicago, Illinois 60604
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Contents
Foreword i
Introduction 1
Effects of Land Development 3
What Do We Do Now? 5
Developing an Information and
Education Program 9
Implementing the Information and
Education Program 13
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Introduction
Precipitation provides the essential replenishment of our water
supplies, but when that precipitation is viewed as stormwater
runoff, it becomes an unwanted nuisance. We have created highly effi-
cient methods for getting stormwater runoff away from our streets and
into nearby rivers, lakes, or wetlands. Unfortunately, our efficiency car-
ries a very high cost: we have
degraded water quality;
damaged or destroyed many of our natural wetlands;
increased flooding;
significantly reduced natural ground water levels.
We now know that good stormwater management programs can
preserve water quality and control water quantities in developed and
urban areas. What remains then is to inform and educate the public and
local governing bodies.
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The Problem
"Stormwater" (runoff) is the surface and ground water that results from
precipitation. In developed areas, urban stormwater is the major com-
ponent of sewer and stream flows. As an area becomes more developed,
the maximum rate and volume of runoff rise; the amounts of pollutants
carried in the water increase accordingly. This is caused in part by chan-
ges to surface drainage patterns, growing numbers of impervious areas
(e.g., streets, roofs, parking lots), and more human and vehicle traffic.
Human activities add pesticides, fertilizers, animal waste, oil, grease,
heavy metals, and other potential pollutants to stormwaters. The end
result may be flooding, erosion, and water quality deterioration.
"Stormwater management" refers to the development of effective
programs and policies designed to:
preserve or enhance the quality and control the quantities of
stormwater runoff;
reduce land loss caused by erosion and prevent flooding;
increase water availability; and
provide funding sources.
Nature's Way
In the absence of human development, normal stormwater runoff is col-
lected and recycled by the environment. Plants and organic materials,
combined with small animal and insect burrows, give soil an open,
spongelike structure. That natural structure quickly absorbs and holds
stormwater runoffreducing the rate of runoff and recharging ground
water.
Environmental health depends (in part) on:
receiving runoff that has been reduced in quantity to allow for
sufficient absorption and storage in natural wetlands;
receiving enough runoff to maintain ground water levels; and
receiving runoff enhanced in quality after flowing through
undisturbed vegetation and soils.
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Effects of Land
Development
Increased Stormwater Runoff
Land development alters the balance between stormwater runoff and
natural absorption areas. If the soil is compacted or paved, less water
can infiltrate and the total quantity of runoff increases: more water runs
off the land and at a much faster rate.
Loss of Ground Water and Increased
Flooding
The cumulative effect of paving, filling, and compacting the soil over
extensive areas can be enormous. Streams experience more rapid flows
and accentuated fluctuations in volume; banks erode as the channel
changes its contours to accommodate the increased velocity and
amounts. Peak flooding may double, yet because the replacement of
ground water has been blocked, streams may cease to flow during dry
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periods. Lowered ground water levels stress fragile plant systems and
severely disrupt all of the downstream environments that depend on a
flow of freshwaterwetlands, floodplains, and estuaries.
Erosion and Sedimentation
Land development seriously accelerates erosion. Erosion on a construc-
tion site may be as great as 40,000 times that of undeveloped land. The
greater velocity and turbulence resulting from erosion, in turn, increase
the water's ability to erode and transport sediment. When the water
slows and the solids settle, the resulting sedimentation begins a pattern
of treacherous biological destruction:
sediment clogs the gills of fish, blocks the light transmission,
and increases water temperatures;
sediment fills channels, lakes, and reservoirs, thereby
decreasing their use; and
sediment serves as a major transport mechanism for other
pollutants.
Urban Contaminants
Increased runoff carries all of the contaminants associated with urban
land uses:
settled air pollutants, including lead from automobile exhausts;
food, wash water, and cigarette butts discarded on the street;
rubbish or used crankcase oil dumped into stormwater drains;
and
road deicing salts, lawn care products, and other chemicals.
The runoff from a typical American city during the first hour of a
storm may carry many more pollutants than that same city's untreated
sewage would during the same period. Runoff flushes these impurities
into receiving waters. When natural filters such as soils, wetlands, or
vegetated areas are bypassed or destroyed, the impact can be over-
whelming.
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What Do We Do Now?
Historic Attitudes
Finding ways to remove stormwater from urban or developed areas as
quickly as possible has been the customary goal of stormwater manage-
ment. In the past, excess water flowed through drainage systems to the
nearest stream, river, or lake. That approach proved to be short-sighted,
however, because ultimately it degraded water quality, significantly in-
creased downstream flooding, destroyed plant and animal ecosystems,
and lowered ground water levels.
The waters that drain off urban streets, construction sites, farms, and
other developed areas following a rainstorm carry contaminants into
our streams, rivers, lakes, and seas. Officials of the U.S. Environmental
Protection Agency estimate that 50 percent or more of this Nation's
water pollution is waste picked up from urban and rural lands by rain-
fall, which then reaches ground and surface waters through runoff and
seepagenot through a pipe or other direct source of pollution.
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New Ideas About Stormwater
The emerging philosophy of stormwater management emphasizes con-
trolling stormwater where it falls and incorporates both structural and
vegetative measures to detain and "treat" the water. An effective
stormwater management program addresses specific needs regarding
quantity and quality of stormwater runoff by requiring new develop-
ment projects to:
prevent any increase in the current peak amounts of runoff;
not allow any increase in the velocity of the runoff;
maintain the current volumes in rivers, streams, lakes, and
ground water supplies; and
provide for improving water quality to the highest degree
possible with currently available technology.
Appropriate on-site control measures for new development can
reduce flash flooding and associated drainage costs, enhance runoff
water quality, and thereby protect general water supplies from non-
point source pollution.
Specific Stormwater Management Methods
There are five basic components of stormwater management systems:
1. Conveyance System
Solid conduit pipes and catch basins designed to carry the flow
from major storms (e.g., those that can be expected to occur every
10 or 25 yearsor more) allow only a lateral flow: water usually is
not intended to permeate such structures, and therefore does not
seep into the ground. However, conveyance systems can be
designed to facilitate both quantity and quality control:
conduits and catch basins can be porous or perforated to
allow water to infiltrate the ground;
roadways and driveways (also conveyance structures) can
be constructed using pervious pavement that also permits
infiltration; and
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channels (sometimes called "pen" channels) can be built
into the land where underground conduits are not
necessary, thus permitting infiltration, evaporation, and
reaeration of runoff.
It is crucial that the conveyance system design include struc-
tures to collect the "first flush" of runoffthe initial surge caused by
the stormand allow it to infiltrate into the ground.
2. Detention/Sedimentation System
Detention/sedimentation basins collect and store runoff, releasing
it slowly. In most cases, total runoff volume increases, the first flush
storms decreases, and a minor flow is maintained between storms.
This type of system usually consists of a large detention basin built
at the lowest part of a managed site, which handles all of the site
runoff. The surface-to-volume ratio is usually low, and outlet con-
trol simply ensures the ability to control the maximum runoff
generated by a storm.
It is possible to accomplish detention and sedimentation with
several smaller detention pools and appropriate use of landscaping
and grading. This can increase the area-to-detention volume ratio,
infiltration, and evapotranspiration (natural water loss from
evaporation and plant transpiration), and lead to quantity and
quality improvements.
3. Infiltration System
Infiltration systems allow water to soak into the ground, or
"recharge" the ground water. This system permits better main-
tenance of ground water levels and total runoff, decreases peak
runoff, and helps improve water quality.
Infiltration systems ensure that new development will not
change total runoff volume. The capacity of the soil to accept water
and the time required for it to seep into the ground will determine
the size of this system. It is feasible to incorporate this type of sys-
tem into conveyance structures and detention basins, to develop as
either an above- or below-ground system, or to build either on a
small local scale or as part of an overall development approach.
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4. Wetlands Renovation
Wetlands provide several valuable functions, of which quality res-
toration is one of the most important. New and existing wetlands
can control and moderate flooding, improve water quality, and
lower maintenance costs. New wetlands can be created at compara-
tively low cost.
Wetlands systems intercept and slow stormwater runoff, reduce
sharp peaks of stormwater runoff, reduce stream velocity, and pro-
vide storage areas for the runoff. The complex, inherent interactions
that take place within a wetland naturally reduce and cleanse pol-
lutants.
Plans for detention or infiltration structures can incorporate
wetland renovation concepts. However, it is important to use addi-
tional stormwater management systems in areas of intensive
development. The structure and function of natural wetlands can
be seriously and adversely altered by excessive inundation or in-
ferior water quality.
5. Water Harvesting
Water harvesting is the process of collecting runoff for on-site use. It
can be as simple as intercepting water and directing it to a holding
area for use by plants or as complex as storage-automated irrigation
systems. This approach offers water conservation benefits: the later
use of harvested water to irrigate on-site dramatically reduces the
peak demand for water during dry periods. Water harvesting
works well in conjunction with detention, infiltration, wetland
renovation, and conveyance systems.
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Developing an
Information and
Education Program
Regulatory Authority
Local governments generally hold the authority to promulgate land use
regulations, leaving the primary responsibility for stormwater manage-
ment in the hands of county and municipal officials.
An essential first step in upgrading a community's stormwater
management policies and programs is the development of a com-
prehensive information and education (I&E) program for the general
public. The strength of such a program usually determines whether a
community will cooperate or remain indifferent. Typically, the most
successful I&E programs are those that originate at the local level. The
successful I&E program must create an enthusiastic response within the
community and result in the concerted efforts of concerned citizens and
their elected representatives to produce an improved stormwater
management program.
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Creating an Advisory Committee
The first step in developing a comprehensive I&E program is to con-
vene an advisory committee comprised of dedicated individuals from
the community (e.g., educators, scientists, homeowners, planners, local
officials). Select committee members for their ability to contribute to the
processes of defining program objectives, setting realistic goals, and
developing and implementing the program. Good management and
negotiation skills are very important during the planning, develop-
ment, and implementation stages.
Early in the process the committee should assess each member's
level of commitment to the project, and what each can contribute in
time and ability. Consider:
person hours available
the mix of skills committee members offer
the special expertise of committee members
individual committee members' visibility or sphere of
influence in the community.
This information will enhance the committee's ability to plan and
manage the I&E program.
Gathering Information
Thorough knowledge of the current stormwater management policies
and their effects, feasible alternatives, related costs, and the benefits of
upgrading management policies is essential. Research might include:
historic programs and current management policies
land use plans
local zoning ordinances
recent water quality data
drainage patterns and hydrology
known or perceived sources of pollution
currently planned development (residential, office, and streets
and roads)
population projections.
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A variety of local, State, and Federal agencies and organizations
have already gathered much of this information. The agencies that may
be able to provide specific data include:
Regional Planning Commission
Soil Conservation Service
Agricultural Conservation and Stabilization Service
State natural resource, conservation, or water quality agencies
County zoning administrators
Local experts and technicians
U.S. Environmental Protection Agency regional office.
Defining Goals and Developing a Workplan
The development of short- and long-term goals makes I&E programs
more manageable, and prevents the committee from losing sight of
overall objectives by directing too much attention to making speeches
and writing pamphlets. Prepare realistic goals; do not expect results to
come quickly. A workplan is an important tool to focus committee ef-
forts and evaluate progress. It should set a course for the program by
ranking activities and helping the committee see that goals are achieved
in a timely manner.
It is important to evaluate continuously whether or not the commit-
tee is achieving its objectives. If it is not, it may be necessary to review
the objectives or re-evaluate the techniques chosen to get the message
out, the message itself, the audience, or the media selected for that
audience.
Where to Get Help
A number of agencies and organizations at the local, State, and national
level are ready and able to assist with technical questions. To avoid
wasting precious resources, see if needed materials already exist, or if it
is necessary to develop additional materials to address the specific
needs of a community. It may not be necessary to look beyond the com-
munity for help: local educators, technical experts, or retired profes-
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sionals with public speaking, writing, fundraising, or management ex-
perience may offer the right mix of skills needed to develop and dis-
seminate I&E materials.
Funding Options
What do you need to get the job done? What will it cost? Will it fit
within the projected budget? Community groups have devised a
variety of methods for raising money to implement stormwater
management by sponsoring such activities as:
festivals
dances
bake sales
flea markets
raffles
solicitation of individual contributions
contributions from local businesses and industry
taxes (or tax benefits)
grants from foundations and governments.
Begin the fundraising campaign early while research and planning
activities are underway.
Know the Audience
The secret to any successful information campaign is to know and un-
derstand the audience. Before developing the I&E program, find out as
much as possible about who the listeners are, then adapt the message to
their characteristics, attitudes, and values.
A number of controversial issues may arise during any I&E project.
It is often possible to defuse a potentially volatile situation by knowing
the probable reaction of an audience before something becomes an
issue.
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Implementing the
Information and
Education Program
Evaluate the Message
The way this issue is presented is as important as the issue itself. Con-
sider:
Timeliness: do the community stormwater management needs re-
quire urgent attention or are they of lower priority than other issues?
Degree of controversy: will this subject alienate or divide particular
groups? Will it create greater disputes?
General appeal: does the committee's approach to this issue fit the
audience? Will it be appropriate to their attitudes, beliefs, and con-
cerns?
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Emotional impact: might the question of stormwater management
anger or antagonize the specific people the committee intends to
reach? Is it possible to present it in a way that evokes support, good
will, and involvement?
Clarity: is the stated need clear, concise, and effective?
Accuracy: does the committee have all the facts? Have the facts been
double-checked for accuracy?
Developing Information Programs
Consider carefully the structure and content of any efforts to inform.
Remember, the audience needs to understand several issues (e.g., con-
servation, water pollution, available options, budget requirements),
and it may be necessary to address each separately. It may be helpful to
focus special attention on informing and educating specific groups that
will be directly affected by different program choices.
Getting the Message Out
Make the most of all opportunities to increase awareness and stimulate
interest. Many free or relatively inexpensive mechanisms exist for get-
ting the word out. When matching information goals with the ap-
propriate media, consider the following options:
press releases, magazine and newspaper articles
radio and television talk shows
local celebrity television appearances
television news programs
public service announcements
professional and educational newsletters
printed materials (e.g., pamphlets, brochures)
public notices
paid advertisements
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community events
participation and involvement awards
public meetings, conferences, symposia, workshops, and local
club meetings.
A Word to the Wise
Use facts, not emotions.
Do not assume anything about the audience.
Know and understand all the issues.
Do not shy away from difficult issues.
Be sensitive to needs of all community members.
Be flexible and open to change.
Expect a few failures before achieving success.
Do not give up until the message has been received and
understood.
And you will know when it has been received and understood. The
questions and the comments at public meetings and in the media will
begin to focus on the "how," not the "why" of stormwater management.
The response may be subtle at first, but eventually it will materialize
into a community commitment to protecting water quality.
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U.S. Environmental Protection Agency
Regton 5, Library (PL-12J)
77 west Jacfcsoit Bpufevard, 12th floor
rL §0604-3590
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Sources of Infotniation Used;
Protect Your Lake by Controlling Stoirawater Runoff From New
Development, Waterworks, Winter 1989, Volume 5, Number 1.
Putting Stormwater to Maximum Use, Lake Line, May 1989,
Robert W. Kortmann, Ecosystem Consulting Service, Inc.
Stormwater Runoff Control: A Model Ordinance For Meeting
Local Water Quality Management Needs, Natural Resources
Journal, Vol. 20, October 1980, Frank E Maloney, Richard G,
Hamann, and Bram D. E, Canter (University of Florida Law
Center).
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