Watershed Restoration

Watershed restoration is a set of tools the County uses to fight against stormwater pollution to help keep our waters clean. These tools include capturing stormwater runoff through green street and stormwater ponds, as well as, physically enhancing stream conditions by constructing aquatic habitat or planting native vegetation. 

Providing stormwater management on existing County facilities is another tool to help reduce impacts to streams. This is important because the County is mandated by the State of Maryland under the NPDES – MS4 Permit  to control stormwater pollution through watershed restoration.

Watershed Restoration Tools

Stream Restoration

The landscape of eroded streams are reshaped using native plants and rocks to mimic natural stream systems.  This will help protect residents where their property crosses or is close by a stream and help promote healthy aquatic habitat in streams.


Stormwater Ponds

Existing stormwater ponds are upgraded by increasing their capacity to trap and reduce stormwater pollution during storms. In other areas where open space is available and stormwater control is inadequate, stormwater ponds are installed to control stormwater runoff.


Green Streets

In neighborhoods where there is a lack of stormwater control and no open space to install large stormwater practices, small stormwater practices are installed in the right-of-way to control and filter stormwater pollution during storm events.


County Facilities

Similar to Green Streets, County Facility projects typically includes installing small stormwater practices as seen in Green Streets projects on properties owned by the County (ie. public schools, libraries, community centers, etc.).


Watershed Restoration Monitoring

Various techniques are used to determine whether a restoration project is successful, partially successful, or did not meet the restoration goals.


Watershed Study and Restoration Project Selection

The County conducts watershed studies for each of the 8 watersheds  in the County. Similar to going to the doctor for an annual check-up, the watershed studies look at the overall health and condition of each watershed and pinpoint where the issues are and how critical it is for repair.

The result is a Watershed Implementation Plan that summarizes the critical areas including the severity of the issue and what is needed for repair. Areas with the most critical condition is given the highest priority and restoration projects would be completed in those areas before moving on to restoring less critical areas. 

Watershed Study Process

Below is a series of steps the County takes when conducting a watershed study.

Image of Watershed Study Process

To download, click on: PDF (4.90MB)

Watershed Restoration Planning Process

The project process is the life-cycle of the County’s watershed restoration projects. From pin-pointing an issue in a watershed study to monitoring the completed project, each project goes through a series of phases which involves the County residents and various regulatory agencies.

Image of Planning guide

To download, click on: PDF (3.32MB)


Alta Vista stream restoration in the Rock Creek watershed (2003 ~ 2011)

Before Construction Before Restoration
During Construction During Construction
After Construction After Construction
After Construction More Time Passing After Construction