Cooley Ranch Culvert Replacement Project
Sonoma County, CA

The Cooley Ranch Culvert Replacement Project consisted of the replacement of a failed undersized 10-foot diameter corrugated metal culvert with an open-bottom, arch-top culvert on Rail Creek at the confluence with Dry Creek, a tributary to Lake Sonoma. EBA Engineering worked closely with the Cooley family and the local Natural Resource Conservation District to provide civil engineering, surveying, and environmental engineering services for the design and permitting of the new culvert.

EBA Engineering’s services included preparation of improvement plans, structural design of the culvert footings and headwalls, regulatory permitting with State and Federal agencies for work within jurisdictional waters, and hydrology and hydraulic analyses to ensure the new culvert was designed to handle a 100-year storm event. The hydrology and hydraulic analyses included research of existing hydrologic information, coordination of back-water flood elevations with the adjacent Dry Creek and Lake Sonoma, and analysis of the effects of scour on the culvert footings. Special consideration was provided in the design of the open-bottom culvert system to minimize the disturbance of sensitive biological habitats and species.

The project was funded in part by the United States Department of Agriculture through the local Natural Resources Conservation District.

Note that we have a video showing the culvert working during a large storm event that would be nice to include somewhere.