Almaden Lake, one of the filthiest bodies of water in the Bay Area and possibly the state, is steeped in elemental mercury and polluted by blue-green algae blooms and bacteria from bird droppings.
But how to clean up this community cesspool has raised a fair bit of controversy.
The 32-acre, man-made lake lies under purview of the Santa Clara Valley Water District, which faces pressure from the region and the state to remove the water’s methyl mercury deposits leftover from the now-defunct Almaden Quicksilver Mining operations.
The private gravel quarry began excavating at Los Alamitos Creek in the 1940s, gradually transmogrifying a nearby grazing field into a murky 35-foot-deep lake. San Jose took over the spot in 1982, opening it up as a public park for fishing, swimming and pedal boating. But years of pollution have restricted those uses, rendering the only benefit of the lake aesthetic.
“[The] man-made lake that was once a gravel quarry is actually damaging the ecological structure of the area, serving as a heat barrier to cold-water fish migrating upstream to spawn,” the water district notes on its blog.
You can hear Ngoc Nguyen, the Water District’s engineering unit manager, talk about the history of the lake and some options to clean it up in this CreaTV interview.
The district has presented several options to deal with the lake toxicity, which affects plants, fish and birds:
• Drain the lake’s depth to about 10 feet and split the lake in two, with the Los Alamitos Creek channel as a divider.
• Fill in parts of the lake either east or west of the channel and top with grassy fields (maybe soccer fields).
• Fill in the entire lake to make way for several fields (including soccer fields).
District 10 Councilman Johnny Khamis sent out a survey asking constituents which option they’d prefer. A clear majority of the nearly 700 people who’ve responded so far point to the first choice: filling the lake bottom and restoring the creek.
Members of the Lakeview and Park Almaden homeowners associations circulated a petition that recently gathered 1,500 signatures. The petition urges the Water District to steer clear of completely filling the lake and opt for a scenario that preserves as much water as possible.
The HOAs created a Facebook page and website to update the neighborhood about the Almaden Lake project and advocate against the lake-filling option, fearing it would ding property values and dramatically alter the neighborhood by burying one of its defining attractions.
Another reason the lake’s neighbors cite for keeping the reservoir intact is that state firefighters carry water from it to fight fires in the nearby hills.
“It’s an important part of our neighborhood,” says Lisa Burt, who lives in Lakeview Terrace, a development adjacent to the lake. “This is part of why I moved here.”
District engineers are experimenting with oxygenation—pumping air to the bottom of the lake—at the Stevens Creek and Calero reservoirs in hopes of doing the same at Almaden Lake. The oxygenation experiment should come back with results by December, in time for the district to present the data at a February meeting for the public.
Before that date, the public will get a chance to weigh in again at a September meeting at the Almaden Community Center. The exact date will get posted on the Water District blog, and on signs along Almaden Expressway and Coleman Road.