November 9, 2011
The Salinas River Diversion Facility, or Rubber Dam, beat its deadline for repairs fully a day ahead of schedule on October 14, but it never went into operation this fall before its seasonal entitlement ended and the dam went into winter shut-down mode last week.
"Due to a lack of irrigation demand, we did not operate it [since completing the repairs]," says Brent Buche, assistant general manager for the Monterey County Water Resources Agency. The dam is approved for operations only during the dry part of the year, from April 1 through Oct. 31.
Buche said the emergency repairs had to be completed before winter rains could've caused further scour damage to the river bottom. A host of agencies signed off on the process and short timeline, including National Oceanic and Atmospheric Administration fisheries, California Division of Safety of Dams, Central Coast Regional Water Quality Control Board and the California Department of Fish and Game. Investigation and repairs included installing a cofferdam to drain the riverbed at the dam, filling scour damage and eroded areas with concrete and replacing riprap, or large stones, with concrete.
County attorneys are still investigating whether engineers and contractors for the dam, which has operated for two summers, may be liable for the cost of repairs, which totaled $1.16 million. Above, the damaged riprap after the riverbed was drained and before repairs began; photo by Joel Ede. Below, poured concrete fills the scour damage downstream of the dam; photo courtesy MCWRA.