Overview To

Watershed Assessment:

Tools For Local Stakeholders

United States

Environmental Protection

Agency

EPA 832-B-01-004

September 2001

Office of Water Washington, DC
Overview To Watershed Assessment:

Tools For Local Stakeholders

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U.S. Environmental Protection Agency

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EPA 832-B-01-004

September 2001
Table of Contents

Preface .......................................................................................i

Foreword....................................................................................ii

Introduction ............................................................................... 1

Watershed Framework

Definition Of Assessment

Coordinating Data

Purpose Of The Assessment

The Watershed Parntership

Purpose Of The Guide

Roles And Responsibilities ....................................................... 5

Federal Government Agencies

States/Tribes

Local Governments

Permitted Dischargers

Drinking Water Utilities

Other Interested Parties

Developing A Watershed Assessment Plan ...........................11

Establish Assessment Goals And Objectives

Establish Baseline And Conduct Preliminary Assessment

Electronic Data and Geographic Information System

Data Analysis

Identify Data Management and Analysis Procedures

Identify Process For Periodic Evaluation

Tables

Table 1 Potential Roles And Responsibilities For

 Watershed Assessments .............................................................. 10

Table 2 Summary Of Data Typically Utilized For

Watershed Assessments ............................................................... 21

Appendices

Appendix A Generic Scope For Watershed Assessment

Appendix B Reports And Documents

Appendix C Electronic Resources

Appendix D Mapping And GIS Resources

Appendix E Training Opportunities

Appendix F Important Contacts

iii
1

Introduction

The Watershed Framework

The Watershed Management Framework is being used increasingly to improve

the receiving water quality of the nation’s rivers and streams and the uses of its

waterways. Using the watershed unit, rather than governmental boundaries as

has been the case, provides for comprehensive, sensible water resource decisions

and strategies, and addresses more effectively the full range of stakeholder

concerns.

The “watershed approach” has long

originated at the local watershed level,

because of its practicality in problem

solving among people, jurisdictions,

and industries sharing a water resource.

Now this approach is receiving a great

deal of focus in the United States

associated with the United States

Environmental Protection Agency’s

(EPA) more formal development of the

watershed approach. With rivers

frequently serving as jurisdictional

boundaries, water management concerns are best handled at the watershed, rather

than jurisdictional, level. Working at the watershed level appropriately involves

those most knowledgeable about the specifics of the river and its watershed: the

interested governments, industries, citizens, and a full range of other interested

stakeholders.

Various catalysts might lend impetus to the formation of a watershed

organization: a single or compound water pollution issue, accelerated growth, or

the proposal of a large industry or other project. The partnership formed by the

watershed organization provides for one of the most critical elements to address

water management: coordination of data from varying sources on a different

geographic basis—the watershed.
2

Overview To Watershed Assessment

The watershed approach fosters the coordinated implementation of programs to

control point source discharges, reduce polluted runoff, and protect drinking

water sources and other sensitive natural resources such as wetlands. A watershed

approach also highlights cost-effective opportunities to go beyond reducing

chemical pollutant concentration, and instead to think about ways to enhance the

overall health of the aquatic ecosystem and preserve biodiversity. The watershed

approach also fosters greater interest from the public and provides a foundation

for partnerships among federal, state, tribal, and local public and private

watershed stakeholders.

Definition Of Assessment

The assessment phase is one of the first elements of effective water resources

management. This document provides a set of “tools” to support these

watershed-level frameworks to conduct the assessment phase. Assessment refers to

a focused or comprehensive overview of key conditions and trends representing a

baseline status. The assessment generates recommendations for management

alternatives, a comprehensive plan, and a means of implementation.

In the case of water quality, it is essential for the assessment to include all available

monitoring data. However, while the term ‘assessment’ can mean water quality

monitoring, an environmental assessment report for a watershed should include

all related material, especially land uses, soils and topography. The assessment

should coordinate all relevant datasets and maps, which must be analyzed,

organized and displayed so as to be most useful to later interpretation and

management.

This effort requires intimate knowledge of the environmental conditions in the

watershed, and will rely on the mix of agencies and institutions that must play a

part in achieving coordinated and comprehensive solutions to today’s complex

pollution problems. Federal agencies can provide technical and, in some cases,

financial assistance to facilitate watershed management. State and tribal leadership

can bring all levels of government, the private sector and the public together to

make the watershed approach work. But a watershed-up level approach reflects

those most interested and affected in the watershed, who are best able to identify

relevant data and interpret it in the context of the specific watershed.

Watershed assessment focuses on the overall watershed management program. It

is critical in identifying pollutants of concern and the relative role of point and

nonpoint pollutant sources, strategizing pollution prevention and control

measures, and tracking progress and making adjustments towards meeting

watershed goals and objectives.
3

Coordinating Data

Federal water quality monitoring and assessments are important aspects of many

EPA programs authorized under the Clean Water Act, including the National

Pollution Discharge Elimination System (NPDES), §106 State/Tribal Water

Quality Program Management grants, § 305(b) Water Quality Inventory reports,

and §300j-13 Source Water Protection under the Safe Drinking Water Act. The

United States Geological Survey (USGS) also conducts instream chemical

monitoring through its National Ambient Water Quality Assessment (NAWQA).

However, due to the different program objectives, results from these programs are

typically difficult to compare. Watershed-based assessment provides an excellent

opportunity for coordinating information from existing and new federal

programs.

At the state and local levels, information about pollution sources and impacts in a

receiving water is collected and maintained by different organizations and

agencies with little or no communication among them. For example, point source

monitoring data may be maintained by the permit compliance branch of a state

regulatory agency, biological monitoring data may be maintained by the fisheries

division of the same state regulatory agency, and storm water outfall monitoring

data may be gathered by the municipality. Sharing of collected, watershedspecific data among local and regional decision makers maximizes its usefulness

and allows targeting of limited local dollars to collect any monitoring data

necessary to fill in the gaps.

Watershed assessments do not necessarily require extensive additional resources if

existing efforts are expanded to include a data coordination role. A useful

watershed assessment report can be generated through better organization of

existing information, supplemented with changes in existing monitoring

procedures where necessary. The preliminary data review will identify if any

additional water quality sampling, monitoring, and assessment is necessary to

develop management strategies.

Purpose Of The Assessment

A watershed-based assessment provides a comprehensive evaluation of conditions

and trends in the entire watershed. Watershed-based analysis can then be used to

address the following objectives:

1. Characterize conditions and trends in water quality and watershed health;

2. Determine causes of existing and future water quality and watershed health

problems;

Introduction
4

Overview To Watershed Assessment

3. Aid in the development, prioritization, and implementation of an overall

watershed management program to prevent or correct the identified

problems;

4. Establish a baseline and assess progress of overall watershed management

activities or effectiveness of pollution prevention and control practices;

5. Support documentation of compliance with permit conditions and/or water

quality standards and criteria;

6. Increase ecological and stakeholder benefits with minimal additional effort;

7. Provide data to calibrate and verify watershed/water body models;

8. Educate and inform the public; and

9. Refine the existing monitoring program.

The Watershed Partnership

Watershed partnerships should include all affected governments, and can be most

effective through inclusion of representatives of municipal utilities, industries,

business groups (such as the local Chamber of Commerce) and conservation

advocacy organizations. Through such partnerships, resources are shared, roles are

clarified, and cost effective practical solutions are put in place. As a result, a better

informed and more involved constituency can make a commitment to lasting

environmental improvements in their own community. While the goals,

resources, and characteristics of the partnership will vary from watershed to

watershed, this document outlines the typical roles and responsibilities of key

watershed stakeholders and the strengths each brings to the partnership.

Purpose Of The Guide

This document describes the key steps to develop and implement watershed

assessment plans. The term watershed assessment used here includes a variety of

data collection, mapping and water sampling methods to characterize the

environmental health of a watershed (see Table 1, page 10, for examples).

This document provides essential tools for local watershed stakeholders in overall

assessment principles and structure. The second half is the Resources section,

which contains essential reference material that will support the organization in

proven techniques, so as to get a rapid start on devising the plan. The References

section includes Web sites and electronic mapping (GIS) file availability, as well as

extensive sources for paper map products fundamental to understanding a

watershed. The Web-based version of this document is an electronic “portal” to

all types of necessary material for an individual watershed assessment.
5

Roles and Responsibilities

Watershed assessment is inherently intergovernmental and interjurisdictional,

because watershed boundaries do not correspond to political boundaries.

Initiating a watershed assessment presumes a watershed coordinating group (or

task force, commission, etc.) reflecting the appropriate balance of stakeholder

concerns in the watershed. A coordinated assessment effort should encourage all

stakeholders to become involved in the planning and implementation process,

with the representatives of the stakeholders joining to form a watershed-based

assessment team. Ensuring the appropriate participation of these various

stakeholders at the outset will make efficient use of resources and avoid later

obstacles.

The coordinator or coordinating group will serve as a central information

repository, a QA/QC coordinator, and a general organizational contact. The

group will establish goals and objectives, provide access to necessary data, and

manage the scope and coordination of analysis. Stakeholders can provide data,

scientific expertise, manpower, and even financial backing for assessment efforts.

See Table 1 for a suggested responsibilities matrix.

Specifically, the coordinating group should have the ability and resources to

perform the following tasks:

• Establish the Watershed Assessment Plan goals and objectives;

• Provide existing data and access to information that will aid in implementing

the assessment strategy;

• Provide technical oversight and scientific expertise reflecting their

responsibilities;

• Maintain appropriate contact with elected officials and appointed boards;

and

• Develop funding options.
6

Overview To Watershed Assessment

Federal Government Agencies

U.S. EPA can provide assistance through guidance, training, technology transfer,

database assistance (e.g., STORET, BASINS, etc.) and by providing information

from special projects in

the watershed such as

TMDL development.

Access to extensive

information can be

accessed via EPA’s “Surf

Your Watershed”

program. EPA

developed this Internet

capability to facilitate information sharing by watershed, county, or other

geographic unit. “Surf Your Watershed” (at URL http://www.epa.gov/surf)

allows users to access information on a watershed level, including data such as

ambient water conditions, water column chemistry, biological integrity, bottom

sediment characteristics, instream designated uses or impairments or special

protection areas, instream flow data, point source discharge data (e.g., compliance

monitoring data), and watershed land use data. The site’s Index of Watershed

Indicators compiles information on the condition and vulnerability of watersheds

in the United States. Fifteen indicators, including assessed waters which meet

designated uses, fish consumption advisories, and contaminated sediments, are

combined into an overall index score for every watershed in the nation. The

Index also allows users to learn more about other organizations in their watershed.

Watershed managers at the state and local level may access EPA’s STORET

(STOrage and RETrieval) data system (at URL http://www.epa.gov/owow/

STORET). Available in PC or LAN version, STORET is a national system that

can store virtually all types of water quality and biological data, and allows for data

sharing among organizations. To aid in data sharing, a specific set of quality

control measures is required for any data entered into the system.

Another important database available from EPA’s Office of Water is the Better

Assessment Science Integrating Point and Nonpoint Sources (BASINS)

geographic information system (GIS) application. BASINS includes some of the

data and modeling tools required for planning level evaluation and modeling of

watersheds. This system assists federal and state agencies in performing large-scale

assessments of watersheds, identifying and prioritizing pollution sources and

issues, evaluating impacts on water quality, developing total maximum daily loads

(TMDLs), and predicting the effects of management scenarios. BASINS’

databases and tools are directly integrated within an ArcView GIS environment.
7

(Users should be alert to the importance of checking for updates via BASIN’s

Web site to obtain current data.)

In the case of an interstate watershed assessment, a federal agency such as an EPA

Regional Office can assist in facilitating proposal development among

stakeholders. Finally, where the State/Tribe is not the permitting authority, U.S.

EPA is responsible for approving all proposals affecting regulatory requirements.

States/Tribes

Due to the State’s role in setting water quality standards and permit limitations, it

is important that the State be involved to the greatest extent possible. The State

can act as a lead coordinator, a partner, or as a technical resource to the local

watershed group. (Some Native American Tribes hold certain environmental

regulatory powers parallel to those of the State on Tribal lands, under PL638, and

must be included in any watershed organization linked with those lands.)

North Carolina is a good example of the State acting as a lead coordinator. North

Carolina has developed a plan where the State conducts comprehensive monitoring

of waterways in all major

watersheds on a five-year rotating

basis. Where programs such as

this exist, local watershed

monitoring organizations can

provide valuable assistance in

expanding the State program.

This is achieved by increasing the

number of monitoring sites, or

expanding the number of

parameters to be monitored.

Where local organizations

participate in established State

programs, these organizations

should work closely with the

State to ensure the new programs

support the overall State effort.

In contrast, North Dakota and

Nevada are examples of limited

Statewide watershed assessment

programs coordinated and

implemented locally. While

EPA and the State/Tribe are

Roles and Responsibilities
8

Overview To Watershed Assessment

available to provide technical guidance, the assessment programs are tailored to

meet local resources, designated use goals, and local watershed management plans,

if they exist. Another advantage of a locally driven assessment program is that

those actually residing in or around the watershed are actively involved and

therefore, more likely to support the assessment results. Finally, by maintaining a

locally driven assessment plan, the assessment goals can better be linked to the

overall goals of the local watershed management plan. Even with the organization

and actual assessment being conducted by the local watershed team, it is

important that EPA or the State/Tribe continue to provide guidance on

assessment techniques and program design to ensure compatibility with federal

and State water protection programs.

Finally, there are programs where both the State and local watershed organizations

have played leading or supporting roles in leading the assessment effort. The

State of Maryland, for example, has acted as lead agency in protecting major

waterways, such as the Chesapeake Bay and major tributaries. The regional

organization the Metropolitan Washington Council of Governments, has served

to provide technical assistance and to coordinate intergovernmental activities in

the Anacostia Watershed, with key involvement of the federal government

because of the extensive federal lands. The conservation-oriented Audubon

Naturalist Society, and area county governments have been the catalysts in

volunteer monitoring of the headwaters of local streams and of the Anacostia

River.

Local Governments

Local governments are critical to the assessment of watershed conditions because

of their unique land use authority, and their understanding of pollutants of

concern, local impacts, and historical and projected land use changes. Their land

use authority is key in providing information on environmental requirements in

the process of land development, and in developing potential strategies, like

requiring storm water quality BMPs for new development. They are sources of

information on environmental problem areas, BMP locations, community

interests, and local initiatives. In addition, local governments may play a major

role in monitoring subwatersheds and areas that go beyond those covered by the

State. Local governments are good sources for current and future land use

information. Many localities have GIS databases including forecasts for housing

and employment, which forecasts will be much more accurate than assuming full

build-out according to zoning and the comprehensive plan.

Watershed-based initiatives are often initiated by local governments, frequently to

protect a drinking water supply. For example, in Northern Virginia, local

governments with lands draining to the Occoquan Reservoir formed a Policy
9

Board to serve as a forum for discussion of changes and strategies within the basin.

The Occoquan Basin Policy Board funds a technical assistance committee to

examine nonpoint source control strategies (staffed by the Northern Virginia

Planning District Commission) and retains an independent university-based

monitoring lab. Significantly, the Policy Board includes not only the local

governments and their water and wastewater utilities, but the Soil and Water

Conservation Districts and citizen appointees.

Permitted Dischargers

Dischargers will have experience in point source and ambient water quality

sampling techniques, as well as quality assurance and quality control procedures.

Dischargers can also be a valuable resource in assessing existing ecosystem

conditions because they are likely to be familiar with local habitat and water use.

Finally, permitted dischargers can provide financial resources for instream

monitoring (water column, aquatic biota, etc.) If approved by the regulating

authority , an offset may be provided of limited reductions in currently required

effluent monitoring, as guided by EPA Burden Reduction Guidance.

Drinking Water Utilities

Utilities and agencies charged with providing and monitoring drinking water

have a strong interest and scientific expertise in watershed monitoring and

management. Source water monitoring is essential to the “multi-barrier” approach

to treatment of surface water. The multi-barrier approach uses source water

protection as one of three techniques to assure drinking water quality. Utilities

monitor drinking water intakes and often monitor at upstream stations. These

assessment resources could be joined with others in the watershed for a more

comprehensive picture of the contaminants of most concern for both drinking

water and primary contact (swimming).

Other Interested Parties

Other stakeholders may represent key affected industries, environmental advocacy

groups, and expert resources. In forming the watershed organization, the

following constituencies should be identified and considered for inclusion:

• Environmental groups;

• Agricultural organizations such as the Soil Water Conservation districts or

Farmers Cooperatives;

• Local businesses and business groups such as the Chamber of Commerce;

• Universities and research scientists; and

• Civic groups and concerned citizens.

Roles and Responsibilities
10

Overview To Watershed Assessment

Such stakeholders can contribute to the success of a watershed-based assessment

program through their expertise, knowledge of local conditions, and involvement

in the watershed. Volunteer monitoring programs can provide high quality data

that is valuable in conducting a watershed assessment (See References entries on

Volunteer Monitoring). Volunteers can receive technical training for monitoring,

which covers sampling techniques and reliable quality assurance/quality control

(QA/QC) measures.

Table 1. Potential Roles and Responsibilities

for Watershed Assessments

Local

Regional

Federal

State

Permitted Dischargers

Drinking Water Utilities

Citizens

Office

 Task

Coordinate Assessment Plan

Provide data sourcesProvide technical assistance in datacollection and samplingAnalyze watershed dataAuthorize changes in end-of-pipemonitoringConduct periodic evaluations ofassessment planManage and evaluate unifiedwatershed data

X X X X X

X X

X X

X X

X

X

X

X

X

X X X

X

X X

X

X

X

X

X

X

X

X
11

Developing A Watershed Assessment Plan

There is no single, correct method for developing a watershed assessment plan.

The process will be different for each watershed due to differences in critical

challenges, natural resources, watershed conditions and trends, and relative

impacts of various pollutant sources, all of which drive watershed goals and

objectives. A generic Watershed Assessment outline is provided in Appendix A,

but each assessment plan must be designed specifically for each watershed.

The process for developing a watershed assessment plan is outlined below. More

information on each element of the process is presented below.

Establish Assessment Goals And Objectives

Before developing a watershed assessment plan, watershed stakeholders should

agree on the purpose of the assessment effort, as guided by the established goals of

the overall watershed program. Setting watershed assessment goals and objectives

helps stakeholders understand the benefits and limitations of watershed
12

Overview To Watershed Assessment

assessment activities. Implementing a multi-focused assessment will help achieve a

successful and dynamic program.

In particular, watershed stakeholders should address the following questions in

setting watershed assessment goals and objectives:

• Where are the known environmental problem areas and pollutants of concern?

• What are the major sources of impairment? Or is this a relatively unimpaired

basin?

• What data/information is needed? By whom?

• What sources of information exist? What are the apparent gaps?

• What intensity of additional field monitoring, if any (water quality, biota, etc.)

is required to meet the goals of a watershed management/protection plan?

• How will the assessment and management program be sustained over time?

What will be the availability of future resources?

• Who is responsible for what? What regulatory authorities affect the plan and

its findings?

The goals and objectives of any watershed assessment plan must be clearly

defined. Yet the needs for assessment data will change over time as human

activity, pollution controls, or watershed management activities are implemented.

Periodic review of the watershed assessment plan goals, objectives and protocols

will ensure that the data collected is timely and relevant.

The generic scope for a Watershed Assessment at Appendix A can be focused

toward potential impacts of anticipated activities, as well as on pristine areas to be

protected. A comprehensive document will include a complete geographic grid.

Establish Baseline And Conduct Preliminary Assessment

Definition Of A Baseline

The next step in the development of an assessment plan is to establish a baseline

of conditions within the watershed. A baseline is a “snapshot” of environmental

and other relevant conditions at a point in time which will serve as a point of

reference for management strategy priorities, and for future changes in the

watershed. Watershed data collected prior to the implementation of proposed

pollution controls and other management activities can be used to establish a

baseline for determining the success of the overall watershed management plan,

and to adjust the plan as time passes.
13

Data Coordination By Watershed Boundaries

Data coordination is one of the most useful tasks of the entire watershed

assessment. Extensive regulatory requirements and local concerns demand that an

enormous amount of data is collected under various programs—but rarely is this

data organized by watershed. Indeed, the challenge of carving out datasets

relevant to the watershed, and coordinating the data in comparable terms, may be

one of the biggest efforts undertaken by the watershed organization, but the

results will provide an unprecedented view of the watershed.

The organization and availability of data and maps can depend on the boundaries

that delineate a community’s watershed. Watersheds are organized by hydrologic

units which are classified into four levels: regions, sub-regions, accounting units,

and cataloging units. Each hydrologic unit is identified by a unique hydrologic

unit code (HUC) consisting of two to eight digits based on the four levels of

classification in the hydrologic unit system. Hydrologic units and codes for

specific communities can be accessed electronically or through government

agencies.

It is important to recognize that assessment activities include a broad range of

existing data and information. Table 2 at the end of this section provides a

summary of types of data that may be useful in watershed assessments. To reduce

costs, watershed stakeholders should maximize the use of these existing resources

and minimize duplication of monitoring and data collection efforts.

Developing A Watershed Assessment Plan
14

Overview To Watershed Assessment

Many agencies are also good sources of historical information and data trends.

Baseline analysis should include data records over a period of years, to assess areas

of improvement or decline and trends in pollution sources (e.g., conversion of

forested land to urban).

Readily accessible sources include a combination of federal, state and local data

sources, such as:

• Existing assessments of water bodies (§ 305(b) reports)

• Impaired waters (§303(d) list)

• NPDES permit monitoring data

• Safe drinking water permits

• USGS topographic, hydrological and water quality sampling data

• Land use (existing actual land use via aerial photos; zoning and comprehensive

plans; and land cover related to resource industries such as forestry and

agriculture)

• Population and employment growth trends

• Soils (especially erodibility index) and subsurface geology

• Biological resources; rare, threatened, and endangered species

In addition, agencies such as the U.S. Army Corps of Engineers, the U.S. Fish

and Wildlife Service, the U.S. Census, and state departments of fish and game

maintain important background information (e.g., population growth, wetlands

status, general land use trends). Statistical documents are also maintained in

county, state and federal court houses. Local colleges and universities with

departments pertaining to the physical environment often have abundant

resources. Academic credentials of university staff can assist the watershed

organization, and can be a low-cost research aid if the research goals of the

watershed organization are reconciled with those of the academic institution. In

addition, assessment data collected from similar watersheds should also be

considered. For example, data associated with the Nationwide Urban Runoff

Program (NURP) of the 1980’s may be useful in predicting storm water

pollutant loads from specific land uses. Likewise, accepted performance

efficiency data for pollution controls from credible sources may substitute for

duplicative monitoring of individual pollution controls.

Stakeholders should, therefore, invest significant time in the identification of

existing sources of data before any additional monitoring is undertaken. A

thorough effort at this stage can help identify data gaps and prevent duplication
15

Developing A Watershed Assessment Plan

of efforts and may also result in

the identification of additional

stakeholders.

Other useful resources (see

Appendix D) are large-scale aerial

photos, remote sensing data,

satellite images, and historical

photos. A rectified electronic base

map with locational (preferably

latitude/longitude) information is

essential for proper integration of

data by watershed, as well as for

spatial analysis systems such as

GIS.

Electronic Data And

Geographic Information

Systems (GIS)

The advent of the Internet and

more powerful desktop

computers offers an

unprecedented resource for the

watershed organization. Much of

the data outlined above may be available electronically, and most government

agencies maintain World Wide Web sites to provide easy access and assurance of

current data. Ease of use, and widespread availability of computers with access

to the Internet, means that electronic access is a tool within the reach of even the

smallest watershed organization, in technical difficulty and affordability.

The use of GIS mapping resources, such as the USGS at the federal level, as well

as state and regional GIS agencies, does not presume that the watershed

organization possesses GIS software or trained personnel. Many of these

mapping resources provide paper maps, and can sometimes produce specific

combinations of data “layers” custom printed (and provided electronically) by

some agencies. Most importantly, the advent of GIS has meant faster, cheaper,

and more informative map creation—with provision for spatial analysis—by the

agencies responsible for mapping. But the GIS tool is most appropriately used

when spatial data is both analyzed and displayed electronically, for coordination

and conversion of data by watershed.
16

Overview To Watershed Assessment

Data Analysis

Once the baseline data set has been organized, the next step is to examine,

analyze, and evaluate the data to determine watershed conditions. Stakeholders

should use existing data to identify: areas not meeting water quality standards,

areas showing other signs of impairment, significant water resources for

protection, and likely or potential sources of impairment. The combination and

organization of data should aid stakeholders in screening for priority areas for

additional watershed assessment activities, and for targeting pollution control

implementation.

Methods For Additional Field Data Collection

The analysis of the baseline dataset may determine that additional data and

information is needed to better characterize watershed conditions and to meet the

goals and objectives of the watershed assessment plan. With the objectives of the

assessment plan clearly understood, specific details such as what parameters to

monitor, monitoring station locations, and monitoring frequency can be

developed (see References). In particular, data on biota is not typically collected

on a systematic basis under the various Clean Water Act requirements, but rather

by the U.S. Fish and Wildlife Service, and by State fisheries agencies. Similarly,

most Clean Water Act requirements place an emphasis on ambient, or dry

weather, water quality. Communities subject to the storm water rule (Municipal

Separate Storm Sewer, or MS4) may already be conducting some wet weather

monitoring.

The watershed organization can play a key role if it is determined that the desired

additional monitoring data can be supported at the appropriate technical level.

Assistance that can be provided by the coordinating body members includes:

• Identify data inadequacies

• Develop assessment strategies, such as coordinating volunteer monitoring

programs with appropriate Quality Assurance\Quality Control (QA/QC)

• Collect comparable data, conduct sampling, analyze samples, and assess habitat

conditions

• Interpret and evaluate monitoring results

• When appropriate, advise the permitting authority on possible substitutions of

ambient monitoring for effluent discharge monitoring (in accordance with EPA

Burden Reduction Guidance)

A field data collection plan must be prepared and possibly approved by reviewing

authorities (see Appendices B and C). As in the original data collection effort, the

types of field data collection, monitoring and sampling activities to be included in

a watershed assessment should be determined using the assessment goals and

objectives identified earlier in the process.
17

Developing A Watershed Assessment Plan

Water quality or biota field data collection methods must address how, where,

when, and by whom samples should be taken (and who will pay the costs). EPA

has established protocols for Quality Assurance\Quality Control (QA\QC) for all

sampling and analysis. The data collection plan should also address safety

measures.

For example, to accurately document the impact of wet weather flows,

monitoring and sampling strategies must reflect the unique characteristics of wet

weather flows, including the altered flow regimes and storm event pollutant

loadings which vary with watershed land cover conditions. Therefore, the

baseline assessment should be designed to provide the necessary information

about land cover and point sources to assess the relative contributions of pollutant

sources. General information on water quality impairment can be used to

determine the right mix of monitoring, in consultation with the state offices

responsible for this monitoring. Table 2 at the end of this section provides a

summary of the different types of

monitoring.

Selecting the appropriate

parameters to sample is one of the

core decisions in developing a

watershed monitoring plan. The

plan should include a range of

physical, biological, and chemical

parameters to ensure that

sampling will provide an accurate

picture of the ecosystem. The

goals and objectives of the

assessment plan (e.g., baseline

characterization, problem

identification, monitoring

compliance) will help determine

parameters to use.

Recognizing that monitoring

needs to encompass wet weather

impacts allows for a wide variety

of sampling parameters from

which to choose. The

parameters can be grouped as

physical (e.g., flow hydrology, precipitation, channel morphology, turbidity),

water quality (e.g., dissolved oxygen, BOD/COD, suspended solids, temperature,

pH, conductivity, nutrients), health of the aquatic community (e.g., fish, macro

invertebrates, aquatic habitats, sediment deposits), health of the terrestrial
18

Overview To Watershed Assessment

community (e.g., waterfowl, reptiles, stream bank erosion, riparian habitat),

aesthetics (e.g., trash, floatables, oil), human health (e.g., toxics, bacteria, metals),

and indirect parameters (e.g., beach closures, fish advisories). Successful

monitoring programs will combine biological and physical as well as chemical

parameters to measure impacts of pollution, locate pollution sources, and track

changes over time.

Generally, monitoring sites are selected using one of two approaches: probabilistic

or tiered. Probabilistic approaches use a limited number of random samples to

estimate trends within a larger

geographic area. The use of

random samples minimizes bias in

sampling site location, and

therefore, a greater representation is

achieved. In watersheds where

little is known about environmental

conditions, probabilistic

monitoring may be a good place to

start. Several States are using this

approach to broaden their

knowledge of watersheds. For

watersheds where more

information exists about

conditions, a tiered approach may

be more useful in creating a base

program to track long- term trends,

target monitoring in specific

regions for management purposes,

and establish a random or spot

check to identify unrecognized

problem areas.

Sampling frequency will vary from watershed to watershed depending on the

goals and objectives of the monitoring plan. When considering frequency, it is

important to consider that sampling should be conducted during both dry and

wet weather for a true watershed assessment. For wet weather monitoring, the

number of sampling events per year should be sufficient to address seasonal

variability, and must also provide an adequate number of observations for

statistical analysis of the wet weather water quality impacts. The watershed

assessment plan should also establish a minimum targeted rainfall event as well as

a minimum antecedent dry period between rainfall events. In addition, the

watershed monitoring plan must address implementation issues such as record

keeping and reporting, scheduling, financial resources, and ongoing staff

responsibility.
19

Developing A Watershed Assessment Plan

Quality assurance/quality control (QA/QC) procedures are essential to any

watershed monitoring plan. They help assure data accuracy, continuity, and

defensibility. Traditional QA/QC procedures such as documenting sample times,

locations, and clarifying confounding factors are essential to ensure accurate data.

Testing and certifying samplers for each type of sampling (e.g., different levels of

certification ranging from debris identification to measuring vegetative overhang

to subspecies macroinvertebrate identification), can help ensure the data is

accurate. Standard operating procedures also ensure that the appropriate

parameters are measured by approved methods.

Identify Data Management And Analysis Procedures

The watershed assessment plan should address data management including type

of data base, methods for data analysis, quality assurance and quality control

methods, modeling strategy (if appropriate), and how the data will be used to

support the overall goals and objectives.

When developing a comprehensive watershed assessment plan, it is important

that collected data be useful beyond the network of sampling stations. By

ensuring compatible collection methods, comparable detection limits, uniform

analytical methods, and common/compatible storage software, will increase the

value of collected data for planning purposes, to enable comparisons to other

watersheds, and also potentially for compliance purposes. Due to the statistical

complexities of comparing different data, the statistical level of confidence at

which the program objectives are achieved should be defined during the

development of the monitoring program. While these issues will likely be

encountered when acquiring information from outside agencies, using compatible

monitoring protocols within the watershed can avoid these pitfalls as the

watershed assessment progress.

Identify Process For Periodic Evaluation

Periodic review of the watershed assessment plan is essential to evaluate whether

the plan is meeting its intended goals and objectives, and to effectively target

monitoring resources. It also helps evaluate whether Best Management Practices

or other wet weather controls are helping to meet the goals and objectives of the

watershed management plan, such as improved water quality, species diversity, or

wildlife habitat. Data needs may change over time, and periodic review can help

identify targets for revising monitoring frequencies or locations.

In addition to reviewing watershed assessment data, periodic review includes

review of monitoring and sampling protocols. Periodic review can help determine
20

Overview To Watershed Assessment

which monitoring sites need continued base monitoring, which are targets for

spot monitoring, and which should be targeted monitoring locations. Each

monitoring point should be reviewed to determine whether parameters, sampling

frequency, location and analytical procedures continue lead to data that meets the

proposed goals objectives. Reviews should focus on measurable quantities, such as

number of samples planned/analyzed, data confidence scores, or water quality in

areas where BMPs have been implemented. As the watershed assessment

progresses, monitoring sites may be covered by each of these monitoring methods,

new locations can be determined, and results of the assessment can evaluated. If

any component of the assessment does not meet overall goals and objectives, the

component should be revised, and reviewed again.
21

Developing a Watershed Assessment Plan

Table 2. Summary of Data Typically Utilized for Watershed Assessments

Data Type Description Typical Assessment Frequency

Base flowWater quality

water quality sampling during non-stormconditions

temperature, pH, conductivity, nutrients, bacteria, totalsuspended solids, turbidity, dissolved oxygen and alkalinity

Typical Parameters

periodic (monthly)

Storm flowWater quality

water quality sampling during and while a stream isaffected by a storm event

temperature, pH, conductivity, nutrients, bacteria, totalsuspended solids, additional parameters can included metals,hydrocarbons, and pesticides

continuous (by event; 15-minute intervalsor flow-weighted)

Aquatic biota primarily aquatic fauna populations, including

numbers, species diversity, and distribution

macro-invertebrates and fish infrequent (seasonal to every three years)

Physical habitat physical condition of a stream channel and its ability

to support aquatic biota

wetted perimeter, bank stability, condition of substrate,sinousity bank condition, riparian area, embeddedness andlarge woody debris

infrequent (every three years)

Sediment contaminants in stream and river sediment particle size distribution, metals, PCBs, and pesticides

infrequent (every three years)

Ground water flow ground water systems in connection with surface

water bodies, indlucing unconfined aquifers,recharge, and discharge areas for regional confinedaquifers; flow in these systems does not necesarilymimic surface topography

ground water levels, referred to as head infrequent (seasonal to every few years)

Access to

Existing

Data

highlow to moderate

low to moderate

low to moderatelow to moderate

moderate to highData Type

Developing A Watershed Assessment Plan
22

Overview To Watershed Assessment Description Typical Assessment Frequency Access to Existing Data water quality of the ground water systems described above pH, conductivity, nutrients, pesticides, metals, bacteria Typical Parameters infrequent (seasonal to every few years) moderate to high maps, remote sensing data, and surveys of land use/ land cover existing and projected changes in land use and land cover levels of imperviousness infrequent (every five years) moderate to high can include rainfall, rain on snow, duration, intensity, and quantity continuous (by event; 15-minute intervals or intensity-driven) moderate to high subsurface geologic conditions such as karst or carbonate substrate system; depth to groundwater contour and slope map by percent slope

conducted in support of an approved discharge permit facility-specific, depends in part on the type of facility, size of

operations, and the receiving stream

regular (bi-monthly) high

public wells and surface water intakes point data with drainage infrequent

areas served by sewer and septic land area; linked to imperviousness; potential for septic

pollution depending on density and soils

five years

comparisons of upstream/downstream, before/after, or inflow/outflow

land use, channel condition (see stream structure andphysical habitat) and water quality (see storm flow waterquality)

infrequent (by event) moderate

conducted by trained volunteers, civicorganizations, and school classes

physical stream condition, water quality, aquatic biota periodic (monthly) low to high

Data Type

Ground waterqualityLand covercharacteristicsPrecipitationGeologyTopographyLocation ofpermitteddischarges andend-of-pipe waterWater intakesSevered andancyroid areasBMP performancemonitoringVolunteer streammonitoring

Table 2. Summary of Data Typically Utilized for Watershed Assessments (Cont.)
23

Appendix A

Generic Scope for Watershed Assessment

SECTION 1 - GOALS AND OBJECTIVES OF THE WATERSHED

ASSESSMENT

1.1 Background

1.2 Purpose Of And Need For Action

1.3 Presenting Issues

1.4 Location Of The Watershed

1.5 Scope Of The Environmental Assessment Process

1.6 Organization Of This Environmental Assessment

SECTION 2 - AFFECTED ENVIRONMENT

2.1 Location, Activities and Uses, And History Of The Watershed

2.2 Topography And Drainage

2.3 Soils

2.4 Geology

2.5 Water Resources

2.5.1 Surface Water

2.5.1.1 Hydrology And Flow Regime

By Stream Order

2.5.1.2 Surface Water Quality -

Ambient (Dry Weather)

2.5.1.3 Surface Water Quality -

Wet Weather (Storm Water)

2.5.1.4 Uses

2.5.2 Groundwater

2.5.2.1 Abundance And Depth To Groundwater

2.5.2.2 Uses

2.5.3 Floodplains
24

Overview To Watershed Assessment

2.6 Climate, Precipitation, And Air Quality

2.7 Biological Resources

2.7.1 Vegetation

2.7.2 Terrestrial Wildlife

2.7.3 Aquatic Biota

2.7.4 Threatened and Endangered Species

2.7.5 Wetlands

2.7.6 Designated Resource Preservation Areas

2.7.7 Forest and Wildlife Corridor

2.8 Cultural And Historic Resources

2.9 Land Use

2.9.1 Actual Existing Land Use

2.9.2 Planned Land Use

(Zoning and Comprehensive Plan)

2.10 Transportation

2.11 Aesthetics

SECTION 3 - REGULATORY AND PERMIT REQUIREMENTS

3.1 Relevant Federal, State, And Local Statutes, Regulations, And Guidelines

3.2 Permit Requirements

SECTION 4 - IDENTIFIED NEED FOR ADDITIONAL MONITORING DATA

SECTION 5 - REFERENCES

5.1 Literature Cited

5.2 Persons and Agencies Consulted

5.3 List of Preparers
25

LIST OF TABLES

Table 2.1 Soil Series and Attributes

Table 2.2 Surface Water Quality Data - Chemical

Table 2.3 Surface Water Quality Data - Biological

Table 2.4 Summary of Local Climatological Data

Table 3.3 Summary Of Land Use Categories

Table 4.1 Summary Of Environmental Trends

LIST OF FIGURES and MAPS

Figure 1-1 Area Location, XXX Watershed

Figure 1-2 Beaverdam Creek Reservoir

Figure 2-1 Sunrise Nuclear Power Plant

Figure 3-1 Topography And Soils In Watershed

Figure 3-2 Surface Water And Floodplain In Watershed

Figure 3-3 Wetlands And Resources Protection Areas

In Watershed

Figure 3-4 Land Use In Watershed

Figure 3-5 Recreational Uses In Watershed

APPENDICES

Appendix A Generic Environmental Assessment Scope

(Outline)

Appendix B Reports And Documents.

Appendix C Electronic Resources

Appendix D Mapping and GIS Resources

Appendix E Training Opportunities

Appendix F Important Contacts

Appendix A
26

Overview To Watershed Assessment

Notes