Greenwater River Engineered Logjam and Road Removal

Herrera assisted the South Puget Sound Salmon Enhancement Group with field surveys, hydraulic modeling, engineering design, construction cost estimating, and construction inspection support services for a large-scale habitat restoration project in the Greenwater River near the town of Greenwater, Washington. The project includes several engineered logjams (ELJs) along three miles of the Greenwater River to rehabilitate instream aquatic habitat and riparian habitat, re-introduce functional wood to the system, increase side-channel and floodplain connectivity, and convert a plane-bed, boulder-cobble channel to a complex pool-riffle channel with greater variability in bed texture. In addition to achieving these goals of habitat rehabilitation, the ELJ structures were designed to trap mobile woody debris and sediment to create self-sustaining habitat. The project also included removing approximately one mile of Forest Service road No. 70 that acted as a levee, confining and disconnecting the Greenwater River from its floodplain.

Project Details