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  1. Home
  2. Polluted Runoff: Nonpoint Source (NPS) Pollution

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

  • Watershed Approach Overview
  • Planning Resources
  • Technical Resources
  • Funding Resources
  • Capacity-Building Resources
On this page:
  • Data
  • Models
  • Maps
  • Technical memoranda

Data

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. 

Water Quality Data (WQX): The Water Quality Exchange (WQX) is where partners submit water quality data and the  Water Quality Portal is the mechanism to retrieve water monitoring data from EPA.  Water quality, biological, and physical data is used by state environmental agencies, EPA and other federal agencies, universities, private citizens, and many others. 

Hows My  Waterway  - as designed to provide the general public with information about the condition of their local waters based on data that states, federal, tribal, local agencies and others have provided to EPA. 

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.

Models

The Pollutant Load Estimator Tool (PLET) is replacing the Spreadsheet Tool for Estimating Pollutant Loads (STEPL). PLET uses the same underlying formulas as STEPL, but in a more user-friendly web interface. Both tools employ 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).

  • Note as of April 2022,  Spreadsheet Tool for Estimating Pollutant Load (STEPL) and the Region 5 Model have been archived.

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:
  • Better Assessment Science Indicating Point and Nonpoint Sources (BASINS), 
  • Storm Water Management Model (SWMM) and 
  • Water Quality Analysis Simulation Program (WASP).

Maps

  • Mid-Atlantic Nonpoint Source Watershed Implementation Tracking - This map displays state nonpoint source (NPS) management plans, the annual reports of the state nonpoint source work as well as the watershed implementation plans and NPS progress reports for the mid-Atlantic states.  

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. 

  • Technical Memorandum #1 Adjusting for Depreciation of Land Treatment When Planning Watershed Projects (pdf) (2.29 MB, October 2015)
  • Technical Memorandum #2 Relative Applicability of Particle Distribution Measures and Bank Slope Stability in Evaluating NPS Watershed Projects (pdf) (569.29 KB, October 2015)
  • Technical Memorandum #3 Minimum Detectable Change and Power Analysis (pdf) (1.28 MB, October 2015)
  • Technical Memorandum #4 Applying Benthic Macroinvertebrate Multimetric Indexes to Stream Condition Assessments (pdf) (821.4 KB, October 2015)
  • Technical Memorandum #5 Presenting Results (pdf) (2.46 MB, December 2016)

Polluted Runoff: Nonpoint Source (NPS) Pollution

  • Basic Information
  • Types of NPS Pollution
    • Agriculture
    • Abandoned Mine Drainage
    • Forestry
    • Hydromodification and Habitat Alteration
    • Marinas and Boating
    • Highways and Bridges
    • Urban Areas
    • Wetland/Riparian Management
  • Success Stories
  • Using a Watershed Approach
  • Webinars
  • Technical Guidance and Tools
  • Nonpoint Source News-Notes
  • NPSINFO Discussion Forum
  • National NPS Monitoring Program
  • Coastal Zone Act Reauthorization Amendments (CZARA)
  • Grants Reporting and Tracking System (GRTS)
  • 319 Grant program for States and Territories
  • Tribal 319 Grant Program
  • Contacts for NPS Programs
  • Resources for Students and Educators
    • Darby Duck, the Aquatic Crusader
    • Word Search Puzzle
    • What's Wrong with This Picture?
Contact Us about Nonpoint Source Pollution
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on October 28, 2024
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