The waters in Clear Lake, the second largest in California, shelter a treacherous occupant — potentially toxic blooms of cyanobacteria. The harmful algal blooms are a threat to public health, recreation, and the local economy.
For the 18 public water systems that draw from the lake the noxious blooms are something else: an operating hazard that is complicating their treatment processes and increasing the cost of providing clean water in one of the state’s poorest counties.
Seven years ago, after the fish died, Sarah Ryan decided she couldn’t wait any longer for help. California was in the depths of its worst drought in the last millennium and its ecosystems were gasping. For Ryan, the fish kill in Clear Lake, the state’s second largest and the centerpiece of Lake County, was the last straw.
Ryan is the environmental director for Big Valley Rancheria. She and others raised alarms for several years about increasingly dire blooms of toxic cyanobacteria.