Jump to main content or area navigation.

Contact Us

Water: Survey of the Nation's Rivers & Streams

National Rivers and Streams Assessment

U.S. rivers & streams were sampled for biological condition: over half are rated poor.

Nutrient pollution is widespread: 40% of river & stream miles have high levels of phosphorus, and 27% have high levels of nitrogen.

Compared to a 2004 stream survey, 7% fewer stream miles are in good biological condition.

Aquatic life in rivers & streams is more likely to be stressed when phosphorus and nitrogen levels are high.

Nearly a tenth of U.S. river & stream miles have high levels of potentially harmful bacteria.

The National Rivers and Streams Assessment (NRSA) 2008-2009 Draft Report (PDF) has been released for public comment. Comments must be emailed to nrsa-hq@epa.gov by 11:59 p.m. May 9, 2013. A fact sheet is available for a summary of the findings.

Archived webcast on the findings of the NRSA 2008-2009.

The 2013 field season for the NRSA 2013-2014 is complete. Training will begin for the 2014 sampling season in April 2014.


EPA and its state, tribal, federal and other partners have completed the report highlighting the work on the first survey of the nation's rivers and streams (National Rivers and Streams Assessment, NRSA 2008-2009). This survey combines an assessment of the nation's rivers with the second national survey of small wadeable streams (Wadeable Streams Assessment (WSA)). Planning is also underway for the next survey of the nation's rivers and streams (NRSA 2013-2014).

This survey uses a random sampling design to provide regional and national estimates of the condition of rivers and streams. States and tribes use consistent sampling and analytical procedures to ensure that results can be compared across the country and over time. The NRSA is one of a series of surveys being implemented to periodically generate statistically-valid and environmentally relevant reports on the condition of the nation's water resources. These collaborative assessments are also intended to improve monitoring across jurisdictional boundaries and to enhance the ability of states and tribes to assess and manage water quality.

Fact Sheet (2 pp, 464K, About PDF) on the findings of the NRSA.

Visit our Monitoring and Assessing Water Quality page for more information on other water quality reports developed by EPA.

2008-2009 NRSA

 All Data (ZIP) (9.6M)

 Benthics Condition Data (CSV) (295K) Metadata (TXT) (3K) 
 Benthics Count Data (CSV) (7.4M) Metadata (TXT) (1K)
Benthics Metrics Data (CSV) (1.2K) Metadata (TXT) ( 9K)
 Benthics Taxonomy Data (CSV) (148K) Metadata (TXT) (2K)
 Enterococci Condition Data (CSV) (704K) Metadata (CSV) (10K)
 Fish Condition Data (CSV) (440K) Metadata (TXT) (5K)
 Fish Count Data (CSV) (3.0MB) Metadata (TXT) (2K)
 Fish Metrics Data (CSV) (1.4MB) Metadata (TXT) (13K)
 Fish Taxonomy Data (CSV) (56K) Metadata (TXT) (2K)
 Fish Tissue Mercury Data (CSV) (105K) Metadata (PDF)(96K)
 Physical Habitat Condition Data (CSV) (220K) Metadata (TXT) (2K)
 Physical Habitat Low (selected metrics) Data (CSV) (1.4MB) Metadata (TXT) (11K)
 Physical Habitat Med (metrics) Data (CSV) (3.4MB) Metadata (TXT) (23K)
 Site Information Data (CSV) (449K) Metadata (TXT) (2K)
 Water Chemistry Data (CSV) (438K) Metadata (TXT) (2K)
 Water Chemistry Condition Data (CSV) (200K) Metadata (TXT) (1K)
 Water Chemistry QA Codes (CSV) (2K)
 Water Chemistry Alert Qualifiers (CSV) (7K)

2004 WSA

 Retrieving Wadeable Streams Assessment Data

The initial planning for the NRSA 2013-2014 has begun. Current tasks include: site reconnaissance and evaluation, indicator selection, field form development, reference site selection, and manual development.


April 30-May 4, 2012: 8th National Water Quality Monitoring ConferenceExit EPA Disclaimer (NWQMC) in Portland, OR

Many NARS related presentations and workshops were offered at this conference, see conference website for proceedings. 

April 10-11, 2007: 8th Annual Environmental Assessment and Monitoring (EMAP) Symposium in Washington, DC

A half-day session at this EMAP symposium focused on the next steps in developing the National Rivers and Streams Assessment. This meeting was co-sponsored by EPA and the Council of State Governments Exit EPA Disclaimer (CSG).  Key issues and topics discussed included: lessons learned from the WSA; comparability of sampling methods; reference conditions; taxonomic QA across labs; and future steps in planning and designing the survey.

January 10-12, 2007: National Rivers and Streams Assessment Planning Meeting in San Antonio, TX

A meeting co-sponsored by EPA and the Council of State Governments (CSG) was held at the Marriott Riverwalk in San Antonio, TX. The meeting provided an initial opportunity to discuss the broad goals of the survey, and to provide input on the survey design, indicator selection and interpretation, sampling methods and opportunities to leverage the survey to support state, tribal and other monitoring programs and objectives. Speakers included representatives from EPA, U.S. Geological Survey, and several states. The feedback and recommendations provided at the meeting will contribute to the survey design and selection of sample locations.

Jump to main content.