In 2005, the California Department of Water Resources, Division of Safety of Dams
(DSOD) instituted a seepage threshold of 30 cubic feet per second (cfs) for Lake Fordyce Dam. Seepage at Lake Fordyce Dam exceeded the threshold in November 2011. Accordingly, in 2012 DSOD required PG&E to submit a plan and schedule to mitigate the seepage. The Project is intended to bring Lake Fordyce Dam into compliance with DSOD’s seepage threshold.
The Project includes placing an impermeable membrane liner on the dam’s upstream face to cutoff seepage through the embankment and construct a new concrete plinth and grout curtain at the upstream toe of the dam. To implement these dam improvements, Lake Fordyce Road would be improved to allow construction equipment access. Additionally, a cofferdam would be constructed in Lake Fordyce to
create a dry work area on the upstream face of the dam. The Project is scheduled to occur from April to October each year for three consecutive years. The cofferdam may be removed in the fourth year of construction due to weather conditions in the third construction year. During Project construction, minimum flow releases of 5 cfs into Fordyce Creek would continue to be met.
This is to advise that the State Water Resources Control Board (Lead Agency) has, based on the record before it, approved the above described project on October 30, 2020, and has made the following determinations regarding the above described project.