Massaponax Creek Stream Bank Stabilization
Spotsylvania County, VA

The watershed of Massaponax Creek is experiencing significant development resulting in increased impervious area and increased peak flows.  In addition, an aging sewer line crossing created an unnatural uniform 90-degree flow towards the east bank of Massaponax Creek.   As a result, extreme morphological instability was occurring where the stream bank had moved 30 feet within 3 years. 

Stabilization of the banks of Massaponax Creek was required by USACE.  Spotsylvania County also needed to protect the area of planned sewer line replacement as well as mitigate erosion. 

HSMM designed a cost effective stream bank stabilization based on:  placement of VDOT Class I rip-rap, reduction of the bank slope to 2:1 or less, and planting of black willow (Salix nigra).  

HEC-RAS modeling was applied to predict stream flow velocities at specific locations and total flow volume. 

The project has succeeded in stabilizing the stream bank.  Planted and native volunteer vegetation creates some natural habitat.