Croydon Creek and Calvin Park Tributary Stream Restoration

In Progress

Aerial map showing creek restoration work areas, access points, landmarks, residential areas, and labeled trails through a wooded park setting.

The Croydon Creek and Calvin Park Tributary Stream Restoration project consists of approximately 4,000 linear feet of stream within the City of Rockville’s Civic Center Park property, and includes portions of Croydon Creek, Calvin Park Tributary, and two unnamed tributary streams that flow into Croydon Creek from the north. The project was recommended for restoration in the Rock Creek Watershed Assessment Management Plan because the streams have areas of unstable meander bends and severe bed and bank erosion, which are contributing high sediment loads into Rock Creek.

The majority of the streams within the project area are moderately to severely entrenched with several areas of tight meander bends and vertical, unstable banks. In Croydon Creek, bed and bank erosion has created an over-widened stream channel and area of excessive sediment deposition.

The project will provide ecological enhancement and support the requirements of the National Pollutant Discharge Elimination System (NPDES) Municipal Separate Storm Sewer System (MS4) permit issued to the city by the Maryland Department of the Environment (MDE) and assist the city in meeting pollutant load reductions associated with the Chesapeake Bay Total Maximum Daily Load (TMDL).

The restoration project also includes wetland enhancement and creation, riparian buffer improvements, and trail improvements using practices and materials to minimize maintenance burdens. The design will also avoid and protect trees to the fullest extent possible.

The goals of the stream restoration are to:

Use natural stream channel design techniques to reduce stream bed and bank erosion.
Improve stream bedform diversity (riffles and pools).
Reduce sediment and nutrient loads.
Promote greater floodplain connectivity.
Enhance riparian and in-stream habitat.

Before Photos

A concrete wall spans a small creek with trees and vegetation on both sides.

A small creek runs through a forested area with exposed soil banks, rocks, and trees reflected in the water.

A narrow stream runs alongside an eroded embankment with fallen tree branches crossing above and across the water, surrounded by grass and trees.

Two people stand on the bank of a forested stream, near a pile of branches and debris, with trees and water in the foreground.

Exposed tree roots along an eroded riverbank with water at the base and vegetation above.

A shallow creek flows through a wooded area with green grass and trees on both sides under daylight.

A shallow creek with rocks runs through a wooded area with bare trees and patches of green vegetation along its banks.

A shallow stream runs through a forest with fallen branches and leafless trees, and a red object is visible in the water.

Project Budget

Cost of Design: $570,000
Cost of Construction: $5,246,400 (of which $2,000,000 is funded with a grant from Maryland’s
Chesapeake and Atlantic Coastal Bays Trust Fund).