Watershed Planning


The watershed planning process can be lengthy and includes things like stream monitoring, understanding and analyzing data, using Geographic Information System (GIS) mapping tools, examining watershed impacts such as erosion and impervious (hard) surfaces like rooftops and roadways in order to solve complex problems. The planning process involves many key steps such as:

  • Identifying the watershed to assess
  • Collecting data
  • Data analysis and prioritization
  • Drafting the watershed assessment
  • Finalizing and publishing the watershed assessment
  • Developing an implementation plan
  • Hosting and receiving feedback through public meetings at various stages

Using the best science and technology available, staff can utilize tools and data to determine watershed goals, collaborate and share information with the public and various regulatory agencies. Establishing plans that lead to actionable and measurable outcomes that provide benefits beyond clean water is the goal of the watershed planning process.


Watershed Studies/Assessment

Watershed Assessment and plannning Staff document stream health concerns and analyze data to develop watershed assessments used to make improvements in water quality. 

Watershed Assessment and plannning

Project Selection

Watershed Project Selection Project selection is performed after a watershed assessment is completed. Sites are carefully selected, then projects are ground-truthed, designed and constructed.

The project selection process is very involved and includes many facets in order to prioritize projects once a watershed assessment and plan has been completed. From pin-pointing an issue in a watershed assessment to determining a project’s suitability and equity ranking, to establish specific project goals, objectives and co-benefits, each project goes through a rigorous analysis. Each project goes through a series of phases which involves feedback from County residents and various regulatory agencies. Finally, a completed project must also be monitored over time to determine if the long-term goals have been sustained.

Suitability and Equity Mapping Tools

Equity mapping The County has suitability and equity mapping tools to cross reference that projects are planned in the most suitable and equitable locations for water quality improvements and our diverse populace.

Clean Water Montgomery and the watershed restoration division’s primary goal is to improve the County’s stream health and water quality for all communities. With a county as diverse as Montgomery, strong partnerships are required to make this happen. By fostering these partnerships and creating new ones, the division can evaluate our planning, design and construction processes to address innovation and equity.

MS4 Permit Program

For most urban areas like Montgomery County, what goes into our storm drains (stormwater) eventually ends up in our local streams. These streams are part of larger systems that flow into major rivers like the Potomac River and, ultimately, the Chesapeake Bay. Since water doesn't recognize county or state boundaries, the federal government takes charge of regulating everything that enters storm drain systems.

To carry out this regulation, the federal government entrusts the state of Maryland through the Maryland Department of the Environment (MDE) with the authority to manage stormwater leading to our storm drains and streams. They do this through a program called the Municipal Separate Storm Sewer System Permit Program, or MS4 Permit Program for short, which they issue to municipalities.

The main objective of the MS4 Permit Program is to reduce stormwater pollution across the United States and preserve the health of our waters. Montgomery County receives its own MS4 Permit from MDE, which requires the County to meet specific water quality standards. This permit is renewed every five years.

Montgomery County's MS4 Permit authorizes them to prohibit pollutants from entering stormwater and to prevent unauthorized discharges. They must also work on restoring streams with poor water quality by achieving required pollutant reduction and implementing other actions to safeguard water quality. The county uses stormwater best management practices to capture, slow down, and treat runoff effectively.

To ensure compliance with the MS4 Permit, the Department of Environmental Protection is leading a collaborative effort involving multiple departments and agencies. Together, they strive to meet the requirements and protect the health of our local waterways and beyond.

Read more about the Maryland MS4 Permitting program >>

Stormwater Management Data for Sediment Control Permits

The Maryland Department of the Environment (MDE) requires Montgomery County to document information for each stormwater best management practice (BMP) for the County’s Municipal Separate Storm Sewer System (MS4) Permit.

As such, Effective July 1, 2024, Montgomery County will collect stormwater management (SWM) data for each new sediment control permit that requires stormwater management in order to meet MDE requirements and for SWM BMP tracking purposes.

Learn how to submit stormwater management data for sediment control permits >>