IN.gov - Skip Navigation

Note: This message is displayed if (1) your browser is not standards-compliant or (2) you have you disabled CSS. Read our Policies for more information.

Nonpoint Source Water Pollution

Nonpoint Source > Watershed Planning > WMP Development Resources WMP Development Resources

A strong watershed management plan (or WMP) is comprehensive without being painfully long, inclusive while remaining focused, and above all strategic to promote functional restoration and long-term protection. Use the Indiana Watershed Planning Guide to lead you through the process of writing a plan. Groups utilizing Section 319 funds to complete a WMP will also need to follow Indiana’s Section 319 Watershed Management Plan Requirements. Groups that wish to apply for 319 funds to implement their plan should also make sure that their WMP meets Indiana’s checklist in order to be eligible for funding. If you need help, IDEM has staff that can answer all types of questions related to watershed planning. As you write your plan, you’ll have a unique opportunity to change attitudes, opinions, and the knowledge people have in your watershed – find out how to gauge your program by reading more on social indicators.

Additional guidance, tools and references from other plans are also listed below.

Stakeholder Involvement

Nonpoint source pollution abatement in Indiana is mostly voluntary; nothing will get done in your watershed unless the people who live in it are involved in your efforts.

Critical Areas

The most important places to restore and protect are known as “critical areas.” Work in these locations should give you the most bang for the buck, both in terms of potential water quality improvements and landowners willing to implement best management practices. Even so, many groups have a hard time narrowing their focus to specific geographical locations. Eagle Cree [PDF] and Big Walnut [DOC] groups have laid out their strategy for prioritizing areas of work in their watersheds; if you are struggling, take a look at what they’ve done. For prioritizing specific land uses (i.e. forested riparian buffers and wetlands), use the tools outlined below:

  • IDNR Riparian Forest Buffer Prioritization Framework:
    • This model prioritizes watershed areas for riparian buffer establishment. Use this tool when riparian buffer establishment is a BMP chosen for implementation. This manual is currently being developed – use the link above to contact Department of Natural Resources staff. A presentation [PDF] about the tool is available via the Indiana Association of Soil and Water Conservation District’s Web site.
  • Wetland Function Assessment [PDF]:
    • Many watershed groups cite wetland restoration as part of the strategy for remediating nonpoint source pollution in their watersheds. This tool provides a framework to prioritize wetlands for restoration, based upon the functions they will provide in the watershed. A lot of GIS is involved.

Goal Setting

Early on, you developed a vision for your watershed. Now is the time to figure out what you need to do to get there. Good goals are SMART: specific, measurable, attainable, relevant, and timely. “Specific” (versus vague) goals tell you some manageable piece of what you want to do (i.e. “reduce nutrients in Mudbug Creek” vs. “clean up the watershed”). You know a goal is measurable if you have a quantity attached to it (e.g. “Reduce total suspended solids to less than 30 mg/L”) Attainable goals are those within your reach. Goals are relevant when they speak to a need required to attain your vision. Finally, goals need to include a timeframe in the not-to-distant future so that you remain motivated to achieve them. For more information on how to set goals, check out Chapter 9 of the U.S. EPA Handbook for Developing Watershed Plans to Restore and Protect Our Waters (Set Goals and Identify Load Reductions) [PDF] and Chapter 6 of the Indiana Watershed Planning Guide (Goal-setting for Success) [PDF].

Action Register

The action register is a table that includes all of the steps you need to take to accomplish your goals. It breaks large goals down into smaller objectives and individual action steps needed to meet those objectives. It includes a timeframe, responsible party, technical assistance needed and cost of the objectives. You can see an example of a good action register in the Big Walnut Creek WMP [DOC]. See the narrative and tables from this WMP for an idea of how to develop your watershed plan action register.

Load Estimate / Modeling:

The U.S. EPA requires watershed management plans to estimate existing loads in the watershed and load reductions necessary to bring the waterbody into compliance with water quality standards and designated uses. A “load” is different than a “concentration.” A concentration tells us how much of a pollutant is in the water and is expressed as mass/volume (e.g. mg/L or CFU/100 mL). A load brings in the dimension of time and measures how much of a pollutant passes by a certain point in a given amount of time. A load might be expressed, for example, in lbs/day. In very simple terms, the load is concentration x flow (discharge). Often, load estimates and reductions are calculated using models. The models listed below are the ones often used in Indiana. However, there is no one-size-fits-all method for calculating loads. Whether you need background information on how to estimate pollutant loads or guidance on selecting the best method for your particular watershed, Chapter 8 U.S. EPA Handbook (Estimate Pollutant Loads) [PDF] is a great place to start.

  • Spreadsheet Tool for Estimating Pollutant Loads (STEPL):
    • STEPL consists of a series of Microsoft Excel worksheets that uses specific watershed characteristics from the user to calculate surface runoff and existing load estimates for nutrients, sediment, and 5-day biochemical oxygen demand (BOD). Users can enter information on Best Management Practices (BMPs) to get load reduction estimates. Detailed instructions, FAQs, and tool downloads are available at this site.
  • Long-Term Hydrologic Impact Assessment (L-THIA):
    • L-THIA, is an online, interactive model designed to help community planners, developers, and citizens quantify the impact of land use change on the quantity and quality of their water. This tool uses the land use and soil characteristics data from the user along with thirty years of precipitation data to determine the average impact that a particular land use change or set of changes will have on both the annual runoff and the average amount of several non-point source pollutants. For those unfamiliar with the hydrologic (water related) impacts of land use change this tool along with the supporting documents will hopefully give the user enough information to start asking questions about land use changes in their area.
  • Online Load Duration Curve:
    • Load Duration Curve Online provides an interactive process to develop duration curves, which identify pollutant loading capacities relative to a target concentration. The program is based on the LOADEST model. The program requires input data for daily mean streamflow (in cfs) and constituent parameter concentration (mg/L, ug/L). Module 5, (Enter Flow and WQ Data for LDC with Surface-runoff and Estimated Loads), can provide estimated individual daily load values (in lbs/day).This program requires a minimum amount of data to work properly and technical assistance to set up. Once you set up the program, you will be able to get duration curves or load estimates in a few seconds. Contact your Watershed Specialist to discuss your data requirements, which program might meet your needs, and for assistance in downloading and running this program.
  • Region 5 Model:
    • This Excel-based model provides spreadsheets to calculate load reductions of sediment, nitrogen and phosphorus from selected agricultural and urban BMPs and bank stabilization. The model is based on the Universal Soil Loss Equation and you will need to input the Rainfall-Runoff Erosivity Factor (R), Soil Erodibility Factor (K), Length-Slope Factor (LS), Cover Management Factor (C), and Support Practice Factor (P).
  • Revised Universal Soil Loss Equation (RUSLE and RUSLE2):
    • These models will help you to determine how much soil erosion was saved by the practices that have been installed in your watershed. Periodically compare the outputs from the models to your sediment goals to update your progress. A tutorial on RUSLE2 is available from the USDA.

General Reference

Who Can Help

  • Agency Responsibility Matrix:
    • The process of watershed management involves activities under the jurisdiction of many state and federal agencies. Use this chart to find out who does what when it comes to watershed planning.