3_-_SCDHEC_Guide_to_Developing_Watershed_Plans_2022.pdf

South Carolina Department of Health and Environmental Control

2022 Guide to Developing Watershed Plans

Purpose

This guide has been created to assist developers of watershed plans in South Carolina. It serves as an overview of the watershed planning process, including helpful tips and links to resources. For a more in-depth discussion of specific plan elements, the US Environmental Protection Agency (EPA) has created a comprehensive handbook for watershed plan creation. In addition to reviewing this guide, organizations are encouraged to contact their Watershed Manager for help and feedback while developing watershed plans.

The Need for Watershed Plans

Local knowledge and planning are needed to improve and protect the quality of water in our streams, rivers, lakes, and estuaries. A watershed plan helps accurately identify pollutants and pollution sources so that appropriate and effective solutions can be recommended and implemented. While there is an increased realization in South Carolina of the importance of watershed plans in addressing local water quality issues, there are many parts of the state in need of watershed plans.

Effectively improving water quality requires addressing the entire watershed holistically - including identifying all water quality concerns and their potential sources. A watershed plan is a roadmap for communities to systematically define and address water quality problems and areas for protection within a given watershed. Successful watershed planning includes active participation from stakeholders, analysis of the specific causes and sources of water quality problems, identification of measurable water quality goals, and implementation of specific actions needed to solve those problems. Watersheds with approved nine-element plans are eligible for Clean Water Act Section 319 grant funding to reduce or prevent nonpoint source pollution. See Section 8 below on funding assistance for more information.

The overall goal of the completed watershed plan is to provide recommendations to address known water quality impairments and develop a thorough plan for implementation of those recommendations. While data analysis is an important aspect of watershed planning, most of the efforts and resources should be spent on the interpretation of data for implementation rather than data analysis. Refer to the SC Watershed Atlas to identify impaired waters in your chosen watershed.

The Nine Required Elements

There are a minimum of nine required elements outlined by EPA to be included in a watershed plan.

While there may be several additional elements and sections you may choose to include in your watershed plan, these nine elements must be included in a watershed plan to be eligible for Section 319 grant funding.

The nine required elements are:

a. Identify causes of impairment and pollutant sources

b. Estimate the load reductions expected from management measures

c. Describe management measures to be implemented

d. Estimate technical and financial assistance needed

e. Include informational and educational components

f. Create a schedule for implementation of management measures

g. Develop interim measurable milestones https://www.epa.gov/sites/production/files/2015-09/documents/2008_04_18_nps_watershed_handbook_handbook-2.pdf https://scdhec.gov/environment/your-water-coast/watersheds-program/watersheds-program-contacts https://gis.dhec.sc.gov/watersheds/

h. Determine criteria to measure success

i. Create a monitoring plan

Writing the Plan

EPA’s nine elements are only minimum requirements as there are several other critical components to be included in a thorough watershed plan. A watershed plan should include each of the following sections and it is recommended that the plan follow this outline.

1. General Watershed Overview

Watershed plans are generally developed for one to four 12-digit Hydrologic Unit Codes (HUCs). An overview of the watershed should include the HUCs included in the project location, hydrology, geology, climate, land use and land cover, discharges, projected growth and population, source water intakes, number of drinking water customers, and a demonstration of local interest in protection and restoration.

2. Watershed Analysis

A watershed analysis should include water classification and standards, designated uses, water quality impairments impacting source water, the use or watershed function affected by the impairments, and Total Maximum Daily Loads (TMDLs), if applicable. South Carolina designates four uses for fresh and salt waters: aquatic life (AL), recreation (REC), fish consumption (FISH), and shellfish harvesting (SHELLFISH). Other uses that could be affected by water quality impairments include drinking water supply and wastewater treatment. Impairments are important because they indicate that a waterbody currently does not meet state water quality standards based on the intended use of the waterbody. Refer to the following water quality data and impairment status. A clear objective statement should be included in the watershed plan.

• Water Classification and Standards

• SC 303(d) list of impaired waters

• SC Watershed Atlas

• Approved TMDLs

• TMDL Attainment Status

3. Element A: Pollutant Source Identification

After locating impairments, it is important to identify causes of the impairment and potential sources of pollutants which can later be targeted for improvements. Causes are what specifically leads to an impairment (sediment, nutrients, fecal matter). Potential sources of bacteria may include livestock in streams, pet waste, failing septic systems, and sewer pipe overflows which would cause human health risks, shellfish bed closures and increased drinking water costs.

Once the impairments, causes, and sources of those impairments are identified for the watershed, the plan should establish targets or goals for the watershed. These goals can be used to create milestones and criteria to measure success. Typically, the goal of a watershed plan is to improve an indicator so that it meets state water quality standards, leads to a removal from the 303(d) list, and/or allows for a particular use. For example, the goal may be to lower bacteria levels in a creek so that it is safe for recreational use.

https://scdhec.gov/BOW/water-regulations-standards/water-regulations-standards-water-classification-standards https://scdhec.gov/BOW/water-regulations-standards/water-regulations-standards-water-classification-standards https://scdhec.gov/bow/south-carolina-303d-list-impaired-waters-tmdls https://gis.dhec.sc.gov/watersheds/ https://scdhec.gov/environment/your-water-coast/approved-tmdls https://scdhec.gov/environment/your-water-coast/approved-tmdls https://scdhec.gov/sites/default/files/media/document/tmdl_08sites.pdf

It may be useful to compile an initial list of impairments, causes, sources, and impacts on waterbody in a table, such as in the example below.

Impairment Causes Potential Sources Waterbody Impacts

Phosphorus Excess nutrients Livestock in streams, excess fertilizer, failing septic systems

Recreational and human health risks, algal blooms, taste/odor issues, increased drinking water treatment costs

Turbidity Sediment Construction activities, cropland, increased impervious cover

Decreased aquatic life populations, decreased oxygen and light, increased water temperature

Bacteria Fecal matter Pet waste, wildlife, failing septic systems, livestock in streams

Human health risks, shellfish bed closures, increased drinking water treatment costs

Element A: Considerations

Are sources of pollution identified, mapped, and described?

Are causes identified?

Are loads from identified sources quantified?

Are sources broken-down by subwatershed, if applicable?

Are data sources, estimates and assumptions sufficient, cited, and verifiable?

Are existing data gaps identified? Is there a plan to address data gaps?

4. Element B: Load Reductions

Load reductions provide a snapshot of the impact a project will have on reducing pollution in a watershed.

Watershed plans should include the current pollutant loading in the watershed and the acceptable loading required to meet water quality standards. If a TMDL calculation has been established for a pollutant in the watershed, it will include the quantifiable amount of pollution that must be reduced in a watershed to meet water quality standards.

In addition, each management measure should be accompanied by estimated pollutant load reductions expected from each measure. These reductions can then be compared to the total amount of pollution that needs to be eliminated from the watershed.

Load reductions are typically estimated by using standard literature values or by running a model. There are many studies that report the amount of pollutants that certain practices either contribute (ex. cattle, pet waste, or failing septic systems) or reduce (ex. rain gardens, wetlands, or riparian buffers). These standard numbers can then be applied to any watershed based on the number of people, livestock, or practices in that watershed.

The best estimates usually come from studies conducted locally or regionally. When possible, use data from studies that have been conducted in South Carolina, in nearby states, or in areas with similar soils and/or land-use. When using literature values, remember to cite data sources so that readers will understand the assumptions and limitations behind the data used to develop the plan. Beyond literature values, several tools are also available to determine pollutant loadings and reductions:

• Pollutant Load Estimation Tool This modified spreadsheet tool calculates the amount of nutrients, biological oxygen demand, and sediment generation in a watershed based on land use, soils, and management practices. It also estimates load reductions for specific management practices.

• Schueler Simple Method to Calculate Urban Stormwater Loads The appendix presents data and methodologies for using the simple method to estimate pollutant load from a site or drainage area.

• Region 5 Model This Excel workbook provides a gross estimate of sediment and nutrient load reductions from the implementation of agricultural and urban BMPs

• Revised Universal Soil Loss Equation 2 (RUSLE2) This model predicts average annual erosion or soil loss based on local climate, topography, soils, and land use.

Element B: Considerations

Will expected load reductions ensure water quality standards and other plan goals are met?

Are expected load reductions linked to pollution sources identified in Element A?

Is the complexity of modeling appropriate for the watershed characteristics, the scale and complexity?

of the impairment and the available water quality data?

Are the estimates, assumptions and data used in the analysis explained, cited and verifiable?

5. Element C: Management Measures

A watershed plan should describe the management measures needed to achieve the goals discussed in the previous sections. These measures can include Best Management Practices (BMPs) that are recommended for implementation in a watershed plan. Measures and practices can control pollutant loads to waterways by:

• Reducing the availability of pollutants (ex. fixing a failing septic system)

• Slowing the transport of the pollutant to the waterbody (ex. detention pond)

• Treating the pollutant before it reaches the waterbody (ex. riparian buffer)

Measures can be structural, on-the-ground practices that reduce pollutant loads before they reach nearby waterways (ex. building a fence to keep cattle out of a stream) or nonstructural, which are practices that focus on behavior change to address a pollutant at its source (ex. educating homeowners on picking up pet waste). Educational management measures can be described separately as part of a larger education and outreach program.

https://www.epa.gov/nps/plet https://scdhec.gov/sites/default/files/media/document/Schueler%20Simple%20Method%20to%20Calculate%20Urban%20Stormwater%20Loads.pdf https://www.epa.gov/nps/spreadsheet-tool-estimating-pollutant-loads-stepl-and-region-5-model#R5%20Model https://www.ars.usda.gov/southeast-area/oxford-ms/national-sedimentation-laboratory/watershed-physical-processes-research/research/rusle2/revised-universal-soil-loss-equation-2-overview-of-rusle2/

Be sure to list all potential structural measures that could be implemented. In addition to determining the type of management measures needed, thorough plans will also include the identification of target areas for management practice installation. Certain areas of the watershed may be prioritized to protect valued resources, take advantage of stakeholder cooperation, or reduce costs. For example, management measures could be concentrated on property closest to the stream of interest, near monitoring stations with the most standards violations, or around heavily used recreation areas. Watershed plans should include maps that display the project area, priority parcels, and other watershed information.

Recommended locations for BMPs are also highly recommended.

Another crucial component of structural BMP implementation is maintenance as the function of structural BMPs is only as good as its maintenance. A plan should acknowledge and state that all structural BMPs will have a maintenance plan enforced by the responsible party.

There are numerous resources on BMP design. A few examples are listed below:

• National Resources Conservation Service (NRCS) Practice Standards

Contact your local NRCS office for assistance with design and installation.

• International Stormwater BMP Database

This database contains over 700 BMP studies, performance analysis results, tools for use in BMP performance studies, monitoring guidance, and other study-related publications.

• DHEC Stormwater Best Management Practice Handbook

This manual includes practices for erosion and sediment control, runoff control, and low impact development.

• National Menu of Stormwater Best Management Practices

This searchable database includes education, construction, post-construction, and pollution prevention measures.

• Best Management Practices for Georgia Agriculture

This manual provides descriptions, effectiveness, and relative cost of BMPs that are understood to protect surface water quality in Georgia.

• Quick Reference Guide for Best Management Practices

This guide provides BMP examples and their functionality in a watershed model and was developed by the Chesapeake Bay Program.

• Agricultural BMP Handbook for Minnesota

This handbook includes definitions, effectiveness based on scientific literature, and economic considerations for many BMPs.

Element C: Considerations

Does the plan describe BMPs that will address the causes of pollution identified in Element A? Have critical and priority areas been identified?

Is the rationale given for the selection of BMPs?

Are BMPs applicable to the pollutant causes and sources? Are they feasible?

Are the BMPs linked to load reductions identified in Element B?

Continue on next page >> https://www.nrcs.usda.gov/resources/guides-and-instructions/conservation-practice-standards https://www.nrcs.usda.gov/resources/guides-and-instructions/conservation-practice-standards http://www.bmpdatabase.org/ http://www.scdhec.gov/Environment/WaterQuality/Stormwater/BMPHandbook/ https://www.epa.gov/npdes/national-menu-best-management-practices-bmps-stormwater https://www.epa.gov/npdes/national-menu-best-management-practices-bmps-stormwater https://gaswcc.georgia.gov/agricultural-conservation-programs/best-management-practices-georgia-agriculture https://www.chesapeakebay.net/documents/BMP-Guide_Full.pdf https://wrl.mnpals.net/islandora/object/WRLrepository%3A2955/datastream/PDF/view

Have BMPs been mapped?

In selecting and siting the BMPs, are the estimates, assumptions and data used technically sound?

6. Climate Change Considerations

Understanding how climate change may impact a watershed is an important aspect of any watershed plan. Climate change in South Carolina could result in higher stream temperatures and more intense watershed disturbances such as more frequent and intense flooding, tropical storm events, higher stream flows, rising sea levels, increased erosion rate, displacement of coastal wetlands, more frequent and larger wildfires, and tidal mixing. Such changes would likely cause increased levels of pathogens, nutrients, and dissolved oxygen in waterbodies. These changes could harm not only humans but also native aquatic life populations such as macroinvertebrates and fish.

Watershed plans should assess and prescribe BMPs that determine what local needs may be and incorporate adaptation planning aspects to ensure proposed BMPs take more intense watershed disturbances and their impacts into consideration. Identified BMPs should also address not only pollutants and their sources (historic or present) but also take into consideration the impacts of more intense watershed disturbances. All watershed plans should include a water protection component, such as conservation easements and climate change adaptations. See the DHEC Watershed Plan Grants page for resources regarding climate considerations for watershed planning.

7. Environmental Justice (EJ) Considerations

Watershed planning should acknowledge and consider environmental justice in its recommended efforts.

Disadvantage Communities (DACs) should be prioritized when considering locations for implementation and funding recipients. Authors should ensure that the environmental concerns and needs of DACs, specifically related to NPS pollution, are considered and addressed. This could include prioritizing DACs, offering sliding scale payment options, combining multiple funding options, and many other efforts. EPA provides several resources on environmental justice resources on their webpage.

• EJ in SC EPA provides EJ efforts and strategies in Region 4 as well as regional contacts for EJ.

• EJ Learning Center This one-stop training portal of online resources is intended to build the capacity of EPA’s partners to advance environmental justice. These resources offer a broad range of knowledge on topics relevant to the practice of environmental justice.

• EJScreen Tool This environmental justice mapping and screening tool was developed to better protect public health and environmental needs. It is based on nationally consistent data and an approach that combines environmental and demographic indicators in maps and reports.

• EJ Funding EPA provides an extensive list of grants, technical assistance, and funding opportunities available to DACs.

• EJ Outreach EPA provides initiatives to foster outreach and engagement related to EJ efforts.

https://scdhec.gov/environment/your-water-coast/watersheds-program/watershed-based-plan-development-grants https://www.epa.gov/environmentaljustice https://www.epa.gov/environmentaljustice/environmental-justice-your-community#region4 https://www.epa.gov/environmentaljustice/environmental-justice-your-community#region4 https://www.epa.gov/environmentaljustice/environmental-justice-learning-center https://www.epa.gov/ejscreen https://www.epa.gov/environmentaljustice/environmental-justice-grants-funding-and-technical-assistance https://www.epa.gov/environmentaljustice/community-outreach-and-engagement

8. Element D: Financial and Technical Assistance

Financial and technical assistance are critical to implementing a watershed plan. Cost estimates for management measures including salaries, regulatory fees, supplies, equipment, and contractual work should be established during the planning process. Knowing generally how much a plan will cost to implement makes applying for funding quicker and easier.

Sources of financial assistance to implement management measures can include:

• Section 319 grants for nonpoint source implementation projects

• SC Clean Water State Revolving Fund

• USDA’s Environmental Quality Incentives Program and Conservation Reserve Programs

• Local government stormwater fees and capital improvement funds

• Federal grants

• In-kind donations of labor, equipment, supplies or cash

It is also important to consider what kind of technical assistance will be needed to implement the watershed plan. For example, specific expertise may be needed for best management practice design, siting, and implementation, as well as developing monitoring or outreach programs.

Element D: Considerations

Are sources of needed technical assistance included?

Does the plan describe the anticipated involvement of assisting organizations or volunteers?

Are cost estimates included? Are they reasonable?

Does the cost estimate include all planning and implementation costs?

Are potential funding sources listed?

Is there an estimated contribution from each funding source?

9. Element E: Education and Outreach

In the planning stages, it is important to engage community members in identifying water quality problems and solutions and to solicit partners for executing the plan. Education and outreach are also an important component of a watershed plan. Outreach can be viewed as a nonstructural best management practice in which the goal is to change behaviors that contribute to water quality problems. For example, a watershed plan may recommend educating residents and visitors about picking up pet waste so that it does not run off into nearby streams.

Effective outreach aimed at changing behavior typically follows these five steps:

1. Identify the problem. In watershed plans, this is usually the pollutant of concern the plan is targeting.

2. Set goals. This includes the overall vision or outcome of an outreach campaign.

3. Identify undesirable behaviors contributing to the problem. Outline what people are doing that needs to be changed.

https://scdhec.gov/environment/your-water-coast/watersheds-program/section-319-nonpoint-source-implementation-grants http://www.scdhec.gov/HomeAndEnvironment/BusinessesandCommunities-GoGreen/EnvironmentalGrantsandLoans/StateRevolvingFund/ https://www.nrcs.usda.gov/programs-initiatives/eqip-environmental-quality-incentives https://www.nrcs.usda.gov/programs-initiatives/eqip-environmental-quality-incentives https://www.epa.gov/nps/funding-resources-watershed-protection-and-restoration

4. Identify appropriate behaviors to reduce contributions to the problem. Outline what people in the watershed should be doing.

5. Get to know your audience. Find out who specifically is doing the undesirable behavior to teach them good practices.

This process should be repeated for each target audience, based on what behavior should be encouraged or changed. It often takes multiple outreach efforts before people will adopt a new practice. Having partners who know people in the watershed is therefore essential to establishing those relationships needed to encourage adoption of management measures. EPA’s Watershed Academy page has more information and resources on education and outreach.

Element E: Considerations

Does the plan identify relevant stakeholders?

Are there sustainable mechanisms to keep the public informed about the plan and its implementation?

Does the plan include methods to engage stakeholders and landowners in participation and implementation?

Do education measures affect behavior change?

Does the education process prepare stakeholders for BMP operation and maintenance after implementation is complete?

Was there active and diverse public participation in the plan’s development?

10. Elements F and G: Implementation Timeline and Milestones

Watershed plans should include the milestones or measurable tasks necessary to implement the plan, understanding that goals and milestones may change over time. Groups should prioritize goals and tasks and assign a time frame to each. Milestones should include details such as considering funding options, obtaining permits, or engineered designs, and project implementation tasks. Milestones are measurable, incremental actions toward reaching a water quality improvement goal while the implementation schedule is the overall timeline for aspects of implementation.

Elements F and G: Considerations

Does the schedule include a logical sequence of implementation actions needed to meet plan goals?

Is the schedule appropriate based on the complexity of the impairment and size of the watershed?

Are identified milestones measurable and attainable?

Does the plan identify incremental milestones with anticipated completion time-frames?

Does the plan include progress evaluations and possible adjustments, or revisions as needed?

Are the milestones linked to the schedule in Element F?

https://www.epa.gov/watershedacademy

Below is an example of a milestones and implementation table.

BMP Milestones Timeline

Year

1 2 3

Pursue Funding Sources Work with partners to consider funding options

Apply for funding

Land Protection Prioritize parcels for protection

Send targeted mailings to priority landowners

Pursue conservation easements on prioritized parcels

Septic Tank Repair or Replacement

Send targeted mailings to homeowners and septic contractors

Provide educational materials, workshops, and presentations

Replace 50% of all failing septic systems

Livestock BMPs Prioritize parcels

Conduct outreach to landowners

Install exclusion fencing

Install alternate water sources

Stream Restoration Identify priority areas

Identify and obtain necessary permits

Channel grading and stabilization

Install native vegetation for buffer

Host educational workshop

11. Element H: Evaluation Criteria

All watershed plans should include a way to track plan progress and determine if plan goals are being met or if they need revision. Criteria should be established for each management measure as well as for the overall success of the watershed plan. Evaluation criteria should be measurable and quantifiable. For example, a plan might include tracking the number of management practices installed, or the percentage of samples meeting water quality standards. A plan could also include criteria that compares response rates before and after an educational campaign.

Element H: Considerations

Are criteria measurable and quantifiable?

Do the criteria effectively measure progress toward load reduction goals?

Are target achievement timeframes identified?

Does the plan include a process to determine if anticipated reductions are met?

12. Element I: Monitoring

As water quality improvements are the ultimate goal of watershed plans, it is critical to outline the type of monitoring necessary to measure this goal. Watershed plans will include DHEC monitoring information, however plans should outline an ideal monitoring strategy which may go above and beyond DHEC monitoring. This section should reflect what type of monitoring a group believes is necessary to fully identify and measure progress towards water quality goals as well as acknowledge any monitoring that is currently being conducted.

As with other plan elements, visuals are useful for strategically assessing monitoring needs in a watershed. Watershed plans should include a map with the key waterbodies, existing monitoring stations, and potential monitoring locations to clearly communicate the monitoring strategy.Some resources for monitoring data in South Carolina include:

• DHEC Surface Water Monitoring Program

• USGS Water Data

• Volunteer Monitoring programs including SC Adopt-a-Stream

• Universities

• Municipalities including those with MS4 programs

• Water Utilities

In addition, for groups interested in establishing new monitoring sites, DHEC has created Regulatory Data and Quality Assurance Guidance which may be useful in thinking about the best monitoring approach.

Element I: Considerations

Does the plan describe how monitoring will be used to evaluate the effectiveness (in reducing loads to the waterbody) of the implementation efforts?

Will the monitoring plan effectively measure the evaluation criteria identified in Element H?

Are the monitoring methods, including parameters, number of sites and frequency of sampling, appropriate and adequate?

Will the monitoring method link the load reductions from implementation to improvements in the waterbody?

http://www.scdhec.gov/HomeAndEnvironment/Water/MeasuresSurface/ https://www.usgs.gov/mission-areas/water-resources/data-tools https://scaas.app.clemson.edu/home.php https://scdhec.gov/stormwater-municipal-storm-sewer-systems-ms4s/municipal-separate-storm-sewer-systems-ms4s https://scdhec.gov/stormwater-municipal-storm-sewer-systems-ms4s/municipal-separate-storm-sewer-systems-ms4s https://scdhec.gov/sites/default/files/docs/HomeAndEnvironment/Docs/fw_agency.pdf https://scdhec.gov/sites/default/files/docs/HomeAndEnvironment/Docs/fw_agency.pdf https://scdhec.gov/sites/default/files/docs/HomeAndEnvironment/Docs/fw_agency.pdf

Putting It All Together

The final draft version of your watershed plan will be submitted to DHEC Nonpoint Source Staff for review.

Changes, corrections, and suggestions may be made by DHEC staff to be completed before the plan is approved. Once a plan has been approved, it will be published on the DHEC webpage and the SC Watershed Atlas.

Watershed plans should be revisited periodically to include additional components, changing conditions, data, and goals, or revised to cover additional HUCs or BMPs. A watershed plan provides an excellent opportunity to educate community members about key water quality issues and get them involved in restoration activities.

Important Notes to Remember:

• The overall goal of a watershed plan is to provide a plan for implementation of the recommendations made in the plan to address known water quality impairments

• Only discuss pollutants that are addressed by recommendations made in your watershed plan

• Proofread the watershed plan for grammar, spelling, and formatting before submitting for review

• Provide a draft plan to stakeholders for review before submitting to DHEC

• Submit the full draft to DHEC for approval only after it has been thoroughly reviewed by all authors and direct participants

• Focus on sources of pollution and measures to reduce them rather than crunching data

• DHEC staff, including the NPS coordinator and Watershed Managers, are available for technical support and guidance throughout this process – please do not hesitate to contact us.

https://gis.dhec.sc.gov/watersheds/ https://gis.dhec.sc.gov/watersheds/ https://scdhec.gov/environment/your-water-coast/watersheds-program/watersheds-program-contacts