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Polluted Runoff: Nonpoint Source (NPS) Pollution

Data, Models, and Other Technical Resources for a Watershed Approach

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National Water Information Center (NWIS) provides access to USGS water-resources data collected at approximately 1.5 million sites in all 50 States, the District of Columbia, and Puerto Rico.

National Water Quality Assessment (NAWQA) Program is a USGS database that can help you answer three questions:
  1. What is the condition of our Nation's streams, rivers, and ground water?
  2. How are these conditions changing over time?
  3. How do natural features and human activities affect these conditions, and where are those effects most pronounced?

National Wetlands Inventory Center: The National Wetlands Inventory (NWI) of the U.S. Fish and Wildlife Service produces information on the characteristics, extent, and status of the nation's wetlands and deepwater habitats. This database is used by federal, state, and local agencies; academic institutions; the U.S. Congress; and the private sector. 

STORET Water Quality Data (WQX): The STORET (short for STOrage and RETrieval) Data Warehouse is a repository for water quality, biological, and physical data and is used by state environmental agencies, EPA and other federal agencies, universities, private citizens, and many others. 

Surf your Watershed - find your watershed using a geographic unit (Zip code, city name, etc) and then enter your geographic information. Once you have found your watershed using those criteria, you will be able to find citizen based groups that are active in your watershed.

Water Quality Reporting Database (ATTAINS): This database displays the most current available information provided by the states in their biennial integrated water quality assessment reports prepared under sections 305(b) and 303(d) of the Clean Water Act.

Water Use Data: The U.S. Geological Survey has put this site together to offer real-time water data, a suspended sediment database, maps, and GIS data for water resources. 

Watershed Assessment, Tracking & Environmental Results (WATERS) is an EPA integrated information system for the nation's surface waters. This framework allows you to access data regarding water quality, permitting, safe drinking water, and nonpoint source pollution.

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Spreadsheet Tool for Estimating Pollutant Load (STEPL) employs simple algorithms to calculate nutrient and sediment loads from different land uses and the load reductions that would result from the implementation of various best management practices (BMPs).

The Region 5 Model is an Excel workbook that provides a gross estimate of sediment and nutrient load reductions from the implementation of agricultural and urban BMPs.

Recovery Potential Screening (RPS) Tool - The RPS provides a systematic approach for comparing watersheds, their condition and how well they may respond to restoration or protection efforts.

The EPA Center for Exposure Assessment Modeling's Surface Water Models page provides access to watershed modeling tools such as:

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Technical Memoranda

These technical memoranda assist organizations conducting watershed projects, particularly those projects that address nonpoint sources of pollution. Many of the lessons learned from the Clean Water Act Section 319 National Nonpoint Source Monitoring Program are incorporated in these publications. 

You may need a PDF reader to view some of the files on this page. See EPA’s About PDF page to learn more.