Places > Tarnans Branch Stream Restoration

Tarnans Branch Stream Restoration


Project Type
Nutrient Bank
Maryland | Anne Arundel County
Project Size
Wetland: 4.54-acre AC Streams: 4,421 LF LF
Nutrient Reduction (TMDL), Stormwater Management & Water Quality


Kristen Keene

M: 443.613.4492

In 2020, RES completed stream restoration design and construction services along Tarnans Branch in Anne Arundel County, MD. This project was submitted as part of the 2017 Maryland State Highway Administration (SHA) Full Delivery Stream Restoration Services RFP, to help meet SHA’s total daily maximum load (TMDL) requirements.  

The project required the restoration and stabilization of 4,421 LF of a degraded and unstable stream channel as well as the restoration of a 4.54-acre wetland floodplain. This project was designed utilizing a hybrid of natural channel design and floodplain reconnection approach. Beneficial outcomes of this project included greater stability within the stream channel and stream banks, floodplain accessibility, and habitat and biodiversity recruitment post-construction. RES’ work on this project included property owner recruitment and buy-in during site selection evaluation, design, permitting, and construction.  

The Tarnans Branch watershed continues to develop rapidly with yearly increases in the overall impervious area upstream of this site; the implementation of the RES approach will result in the reduction of 659 pounds of phosphorus, 1,431 pounds of nitrogen, and 38 tons of sediment per year for this watershed. 

This project required close coordination with several interested project participants and entities including the property owner, SHA, Anne Arundel County, Maryland Department of the Environment (MDE), the US Army Corps of Engineers (USACE), and various subcontractors and suppliers. RES’ coordination and logistics among the project participants allowed for the successful and on-time delivery of this work.