Lagoon Valley Watershed Stabilization

Vacaville, CA

City of Vacaville
Fall/Winter 2004

Hanford ARC contracted with the City of Vacaville for repair and stabilization of the Lagoon Valley Watershed designed by LSA Associates. The work addressed substantial erosion on four ephemeral stream reaches which were contributing sediment to Lagoon Valley Lake. LSA included a number of experimental stream bioengineering techniques to address specific erosion sites, as well as entire channel reaches. Each reach required the construction of temporary access roads to relatively remote sites, with steep slopes and difficult access.

Applications included rock grade stabilization and vortex weirs, bioretaining walls, live check dams, live cuttings, slope grading and channel recontouring. LSA, and the City of Vacaville worked closely with Hanford ARC to field fit these treatments, and Hanford ARC provided operators experienced with field-fitting and interpretation of plans based on field instruction.

Approximately 3000 willow poles were harvested and utilized for the biotechnical retaining walls and willow planting. Hanford crews cleared and prepared for planting 45,000 square feet of the watershed removing exotic trees and debris.

After structure installation, the areas were hydroseeded, mulched and planted with woody and herbaceous plants. Three stream trail crossings were added along trails including bridges and articulating concrete blocks for both trail users and to stabilize the crossings for cattle grazing.