Yolo Bypass West Levee Culvert Replacement Project, CIP 20-06

CIP 20-06

Phase:  Design

Anticipated Completion Spring 2022

Project Description

The entire City’s storm drainage system empties to the Yolo Bypass through the Outfall Channel and culverts through the Yolo Bypass West Levee (YBWL). The existing culverts were constructed around 1971 and consist of three 48-inch diameter corrugated metal pipes with flap gates on the discharge end.  Capacity of these existing culverts does not meet current County and City storm conveyance standards. Some of the existing metal pipes have corroded and need replacement to maintain levee stability, as well. Furthermore, storm drainage flows have increased significantly since 1971 due to development within the City and, as a result, even more additional capacity is needed through the culverts crossing the YBWL. 

The project generally includes excavation and replacement of the YBWL after removal of the metal culverts and installation of five 72-inch diameter concrete culverts.  The culvert improvements include sluice gates and positive closure devices to protect lands west of the YBWL from high water in the Yolo Bypass (including the City of Woodland and Conaway Ranch).  The work includes significant dewatering and environmental mitigation because the existing culverts are several feet underwater on both sides of the YBWL.  Environmental permitting work is expected to take between 1 and 2 years with permits required from several agencies.