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Francis Scott Key Bridge Incident Updates
Watch the Recording of County Executive John A. Olszewski Jr. delivering the Proposed FY25 Budget Message

The Watershed Management and Watershed Monitoring Sections are responsible for the following:

  • National Pollution Discharge Elimination System (NPDES) Municipal Separate Storm Sewer System (MS4) Permit Compliance—Protect water resources from polluted stormwater runoff by coordinating Baltimore County compliance with the NPDES MS4 permit. Track progress on permit requirements, such as the impervious surface restoration for the Chesapeake Bay TMDL. Prepare and issue reports required by law and permit. View the Water Quality Dashboard, which displays waterway monitoring results collected routinely by the Department of Environmental Protection and Sustainability.   
  • Watershed Monitoring—Monitors the living resources, chemical, habitat and erosion condition of Baltimore County's streams and tidal rivers. Data collected includes biology, chemistry, geomorphology, storm drain outfall discharge pipes, bacteria and trash.
  • Watershed Planning—Monitoring data is used to assess watershed conditions and used to develop strategies and plans to protect and restore water quality, including meeting local and Chesapeake Bay  Total Maximum Daily Loads (TMDLs), so Baltimore County can enjoy safe and affordable drinking water, healthy fisheries, safe water recreation and healthy aquatic wildlife.  These strategies go beyond traditional government capital projects and include collaborating with residents, businesses, institutions, community associations, local watershed associations and environmental organizations, and government agencies to prepare and implement plans; as well as engage Baltimore County communities through education, outreach and volunteer activities.

Watershed Planning: Small Watershed Action Plans (SWAPs)

A SWAP is both an assessment of current watershed conditions, as well as a restoration strategy for meeting pollution reduction requirements  Volume one of a SWAP outlines the restoration strategy actions, while volume two summarizes the field and GIS data assessments.

Residents, businesses, institutions, community associations, local watersheds, environmental organizations and government agencies all work collaboratively to build a successful plan. The process is guided by a diverse steering committee, with public meetings and comment periods to generate input from the greater community. The plan involves:

  • Assessing existing conditions within the watershed
  • Identifying potential sources of pollution sources
  • Examining and prioritizing opportunities for environmental restoration and protection
  • Determining potential costs for implementation
  • Outlining a plan, and set measurable goals for actions to reduce pollution

Upon completion of the plan, there are many opportunities for residents and community groups to help implement the recommended actions—in your own yard or on a site nearby. Baltimore County is divided by watershed into 23 Small Watershed Action Plan (SWAP) areas to provide tailor-made plans and strategies for each SWAP. SWAPs have been developed for about half of the planning areas.


View a map of the County's 14 major watersheds, listed below. The Urban Rural Demarcation Line (URDL) separates areas in the County that receive public water and sewer infrastructure from those that rely on private well and septic systems. Watershed areas inside the URDL can accommodate development, including employment, retail and residences, while the areas outside are reserved for agricultural, natural resource protection and low density rural residential development.

Additional Resources

Explore Watersheds

Contact Us

Watershed Management and Monitoring

County Office Building
111 West Chesapeake Avenue
Room 305
Towson, Maryland 21204





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