The Metropolitan Water District (MWD) which serves parts of Riverside and San Bernardino Counties has issued a warning for Skinner Reservoir, also known as Lake Skinner. The lake is in western Riverside County, northeast of Temecula. Officials report they detected, and are treating, a cyanobacteria (blue-green algae) bloom at Lake Skinner that is producing cyanotoxins, which in high concentrations can be harmful to humans and animals. They further stressed this is not a drinking water issue as water is not currently being delivered from the reservoir. The CDC warns humans who drink or swim in water that contains high concentrations of cyanobacteria or cyanobacterial toxins may experience gastroenteritis, skin irritation, and allergic responses. MWD Press Office Manager Rebecca Kimitch advised the agency will treat the lake with copper sulfate on Thursday, June 6 which should address the bloom. In the meantime, however MWD has posted warning signs at the lake, primarily aimed at fishermen. They are advised to throw away the guts of fish they catch and clean fillets with tap or bottled water before cooking and avoid using lake water for cooking (boiling the water does not make it safe). Swimming is never allowed at Lake Skinner. In addition, all are advised to prohibit pets from drinking the lake water or swimming in the lake. Blooms like this are generally a seasonal problem that occur in warm months and are visible as large areas of green water.