Environmental Services

Watershed Management



What is a watershed?

A watershed consists of a water body such as a stream, river, lake, or estuary and all of the land surface that drains to that water body. All of the rain that falls on Arlington County eventually drains to the Potomac River (except the water that is taken up by plants). View a map of Arlington's watersheds.  Arlington's 26 square miles are a small part of the 64,000 square mile Chesapeake Bay watershed.

What is watershed management? 

Watershed management is the effort to protect streams, rivers, lakes, and estuaries by focusing on activities on the land area that drains to a body of water.  Watershed management includes land use planning, regulation of development, control of water pollution, stream buffer protection and stream restoration, and outreach and education. These programs consider all sources of pollution in a watershed, including spills and leaks, factories, and stormwater runoff from urban and agricultural areas. In an urban area like Arlington, with very few industrial facilities, stormwater is the main source of pollution to local streams.  Watershed management is closely related to Stormwater Management. The major point source discharger in Arlington is the Water Pollution Control Plant.

Condition of County Streams 

Streams are an important natural and recreational resource in Arlington.  However, development in Arlington has significantly impacted the nearly 30 miles of perennial streams in the County.  Most of the buildings and roads in Arlington County were built prior to regulations requiring stormwater be slowed down or treated, so runoff from these areas flows uncontrolled to County streams. This is one of the key watershed management challenges facing Arlington County and its citizens today. Existing development has much greater impact on streams than new development or redevelopment.

Given the impacts of development on stream described above, it is not surprising that a County wide stream inventory conducted in 1999 that most County streams were in fair condition, with some severely degraded stream reaches. No County streams were evaluated to be in excellent condition. The inventory found 40 locations with active streambank erosion and 70 locations where riparian buffers are in poor condition. Litter is a pervasive problem in streams because storm sewers are very efficient litter delivery systems. There is also evidence of recurring spills and leaks that adversely affect water quality.

Also, bacteria levels in Four Mile Run, like most urban streams, routinely exceed water quality standards considered safe for primary contact recreation (swimming). 

Read more about water quality monitoring results in Arlington County streams from the volunteer stream monitoring program. 

Watershed Management Goals


Arlington has developed a comprehensive watershed management program to protect and restore local streams and to help protect downstream water quality in the Potomac River and Chesapeake Bay. The goals of this program are:

  • Address the requirements of all of the regulatory and regional programs to protect water quality. 
  • Minimize the effects of stormwater runoff, especially from existing development, on local streams and buffers, which provide habitat to a variety of wildlife.
  • Do Arlington’s part to protect the Chesapeake Bay. 

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Watershed Management Programs 

The County has developed watershed management strategies to address the impacts of development on streams and water quality. In addition, the County is currently updating the Stormwater Master Plan.

Short term strategies:

•        Implement urban housekeeping ‘best practices’ (e.g., street sweeping, catch basin cleaning, storm sewer inspections, and pollution prevention).

•        Restore stream corridors to address stream bank and channel erosion, infrastructure impacts and improve stream habitat and ecology.

•        Maintain and upgrade stormwater infrastructure.

•        Outreach and education programs.

•        Effective and targeted monitoring programs that leverage volunteer and other (e.g., state/federal) resources.

Longer term strategies:

•        Identify opportunities for retrofits to the landscape and storm sewer system to reduce stormwater pollution.

•        Require on-site stormwater controls for new development.

•        Maintain and upgrade stormwater infrastructure.

Please contact Jason Papacosma at (703) 228-3613 for more information about Arlington's Watershed Programs.

Last Modified: December 04, 2013
2100 Clarendon Blvd. Arlington, VA 22201 Tel: 703-228-3000 TTY: 703-228-4611