February 12, 2002
Water infusion for Lake Merced
Technology being tested to boost sinking lake levels
by Matthew Verrinder
Staff Reporter
DALY CITY -- Construction begins this week on a pilot program that will test whether or not rainwater can be safely diverted into rapidly sinking Lake Merced.
Known as a storm water interceptor, the $706,400 apparatus is hoped to collect rainwater from around Lake Merced, remove unwanted sediment and divert the treated water into the lake.
Hydrologists have long noted the sinking water levels at San Francisco's only lake, bordering San Mateo County. They have stressed the importance of restoring the lake.
"It used to be one of the finest urban fisheries in the United States, now it's a disaster," said Mark Bergstrom, executive director of the conservation group, California Trout. He noted increased mortality rates among trout, bass and catfish.
The lake is also a back-up water source for San Francisco's fire department.
The announcement that two cities have a plan in place to replenish ailing Lake Merced comes just four months after a landmark meeting between Daly City, the San Francisco Public Utilities Commission, and representatives from the Olympic, San Francisco and Lake Merced golf clubs, all parties involved in the lake's restoration.
At their first meeting on Oct. 25, the parties announced a three-fold plan to not only restore the lake, but protect the Westside Aquifer which is the source of 43 percent of Daly City's drinking water.
In addition to storm water diversion, the plan calls for a $6.5 million recycled water facility and joint conservation measures taken by Daly City and San Francisco.
Still, some Lake Merced interest groups are criticizing both cities for failing to protect local water sources. Critics remain dissatisfied that only the storm water portion of the agreement has seen any progress.
"[The interceptor] is important, but it's only one piece to solving what is becoming a well-known future water shortage for San Francisco and the surrounding communities," said Dick Allen, co-chair of the Lake Merced Task Force.
Allen noted that construction has yet to begin on the $6.5 million water treatment facility that will irrigate the golf courses and lessen their reliance on the over-drained aquifer.
"If we don't get much rain, we won't get much to divert [with the interceptor] into the lake. But the pumpers will continue to pump," Allen said. "We need to control what we can."
Daly City and golf course lawyers failed to meet a dec. 17 contract deadline that would outline how to get recycled water out to the three golf clubs.
Other Lake Merced interest group members echoed Allen's concern about the overall problem.
"There are at least three legs to the stool, for helping the lake and the aquifer.," echoed Jerry Cadagan of the Committee to Save Lake Merced. "[The pilot interceptor program] is very important, but it's just one leg."
Patrick Sweetland, Daly City's director of water and wastewater, remains positive about the storm water interceptor's impact.
During a healthy rainy season, the equipment will have the ability to raise Lake Merced's water levels six to eight inches. "It's definitely worth pursuing," Sweetland said.
Daly City is trying to get the pilot interceptor built by the middle of February. If it works successfully, storm water facilities would be expanded during the next few years.
