Santa Clara Valley Water District officials are anticipating an Aug. 27 shutdown for recreational boating at Anderson Lake as water from the reservoir continues to be drained and used for the county’s main source of drinking water.
“With the algae bloom in San Luis (Reservoir), we have had to switch to Anderson earlier than we had expected and that has lowered the water level in the reservoir,” wrote Colleen Valles of the SCVWD’s public information office in her Aug. 6 announcement. “We expect to continue drawing water from Anderson, and in a couple of weeks, that will likely lower the water level too much to continue to allow the launching of boats.”
The boating season regularly runs from April 15 through Oct. 14. Last year, Anderson was closed for boating in mid-August due to low water levels. If the water level reaches about 40,000 acre feet, then boats can’t be safely launched.
As of Aug. 8, Anderson is at 51.3 percent capacity or 46,358.5 acre feet.
An acre foot covers an acre of land 1 foot deep—enough water to supply two families of five for a year.
Santa Clara County Parks and Recreation, which manages recreation on and around water district facilities like Anderson, has notified boaters that boating at Anderson will be suspended on Aug. 27, when the water level is expected to be below the boat launch, Valles added.
Coyote Reservoir, which is connected to Anderson, was closed to boating in July after water levels decreased below the boat launch. That water was also being used to replace affected San Luis Reservoir water, according to Valles.
This summer, SCVWD was treating water from the delta as its main source for the county’s drinking water until late June-early July when “an earthy, musty odor” was detected due to the presence of algae in the water. A byproduct of the algae called geosmin was causing the smell. Despite the smell, the water remains safe to drink.
“The water district takes water quality and water supply issues seriously. As you can see, we routinely need to strike a balance between the two, and in this case, that means the unfortunate early closure of certain reservoirs to boating,” Valles wrote. “We will continue to work toward providing water of the highest quality to the community we serve.”
Water officials switched from the delta to San Luis Reservoir but found the same algae issue in that source, according to Valles. Then, they decided to tap Anderson water July 6.
“While this is unfortunate, it’s important to remember that the primary purpose of Anderson is to provide clean, safe water to Santa Clara County. The water district’s mission is to ensure the quality and delivery of that water.”
Anderson, the largest reservoir in the county, is also in line for a $200 million dam retrofitting project that will cease any water activities during construction. That project is scheduled to begin in Spring 2017 with an estimated completion date between November and December 2020.
Because of seismic restrictions imposed by state regulators, the lake can only be filled to a about two-thirds of its maximum capacity.
