After being criticized for their lack of preparedness by a county grand jury, Peninsula cities have begun preparing reports on the safety and status of their dams and levees, to be used in the creation of an emergency plan in case of catastrophic failures.
All county cities with dams or levees in their territory are working to turn in emergency action plans by the end of the year, to prepare for flooding or earthquakes in a region that has been called “an act-of-God theme park.”
San Mateo County is bordered by the Pacific Ocean and the San Francisco Bay and contains 19 dams, five of which are considered “high-hazard,” by the California Department of Water Resources’ Safety of Dams Division.
Fifteen health care facilities, 27 schools, 109 city- or county-owned critical facilities and 76 bridges or interchanges lie in county areas at risk for inundation in the event of a dam failure.
Once the reports are gathered by the grand jury, the San Mateo County Office of Emergency Services and Homeland Security will receive the collection and coordinate a countywide emergency plan.
“We need action taken by the end of the year,” said Lt. Murray Randleman. “We can’t obviously replace all the dams and levees right now, so this part is just getting the emergency contacts and plans together.”
On Sept. 4, Foster City approved their report for the grand jury. The Belmont and San Mateo city councils will look at theirs at their Tuesday and Sept. 17 meetings, respectively. Randleman said the county’s Emergency Services Council should have theirs ready by the end of the month.
Belmont has already begun working on the next step of the project, which is to shore up any trouble spots and make sure all water-retention areas are in working condition.
The city’s only dam, at Water Dog Lake, has filled with silt since it was last dredged in the 1960s, according to Public Works Director Ray Davis. While it is not nearing any overflow levels, its total capacity has been reduced by more than one-third. The dredging could cost approximately $1 million, and there may also be reinforcement work needed on the dam.
“We’re not at a level where it’s creating imminent danger of overflow, dams always have a bypass or spillway and no one has ever seen water go over,” Davis said. “We have the dam inspected annually and we’re not aware of any deficiency.”
High-hazard dams in the county
Criteria include potential for lost property or lives, age and size of the dam, as well as other seismic conditions.
» Lower Crystal Springs
» San Andreas
» Spenser Lake
» Notre Dame
» Bear Gulch
– Source: Army Corps of Engineers