49th and Fulton Stream Restoration, Stream/Culvert Investigation and Design

Coastal Resources, Inc. (CRI) conducted a geomorphic assessment, topographic site survey. and restoration design of a perennial stream located at the intersection of 49th Street and Fulton Street in Northwest Washington, DC. The stream restoration involved designing a transition from the existing stream invert to the recently replaced culvert. A 36” culvert was replaced with a 48” culvert under 49th Street to convey the stream under the road. The new culvert inlet is much lower than the previous culvert inlet which caused a steep headcut into the existing stream bottom that was actively eroding.  

CRI performed a topographical survey using a total station and traverse points to create a 3D surface for existing conditions. CRI performed a hydrology study to determine the design discharge for the project. Hydraulic calculations were performed to size the rock and determine the slope for the rock weirs.

The proposed design includes three rock weirs to safely convey the stream to the 48” culvert.  The weirs are at two-foot elevation spacings with pools in between. Imbricated sill rocks with imbricated footer rocks will be used on the downstream side of each weir to provide structure. The upstream stream corridor appears to be very healthy and is on National Park Service (NPS) property and therefore will not be disturbed. This design will transition the flow down from the healthy upstream forest to the 48” culvert while keeping impacts to the forest (and NPS land) at a minimum. The Class II Riprap for the rock weirs is sized to withstand the allowable velocity predicted from the hydraulic variables. The weirs will be built on a geotextile lining. The rock weirs will help convey flow through a steep slope in a stable manner.

Around the rock weirs and pools, shrubs and herbaceous plants are proposed to stabilize banks and create an aesthetically pleasing site and biodegradable erosion control matting will be placed along the banks in the flow area to prevent erosion while plantings are establishing.

CRI produced construction plans, specifications and estimate for this project along with a design report. CRI presented the design alternatives to the DDOT and DOEE and other stakeholders. CRI also assisted with permit preparation from various agencies. The project is currently on hold awaiting DOEE permits and construction funding.


Washington, DC


District Department of Transportation – Infrastructure Project Management Division (IPMD)

Key Services:

  • Geomorphic Assessment
  • Topographic Site Survey
  • Stream Restoration Design
  • Permitting Support