By Dave Mason
Lake Temescal is scheduled to reopen to swimming on Saturday, August 12. Lake Temescal has been closed since June 26th due to the presence of blue-green algae (cyanobacteria) toxins.
Quarry Lakes is scheduled to reopen to swimming on Saturday, August 12 as well. Quarry Lakes has been closed since February 8th due to the presence of blue-green algae (cyanobacteria) toxins.
“We are thrilled to be able to reopen the lakes to swimming,” said East Bay Regional Park District Public Information Supervisor Dave Mason. “We’ve been working hard to reduce blue-green algae.”
Recent water quality tests have shown minimal presence of blue-green algae toxins at Lake Temescal and Quarry Lakes causing the District to request approvals from the Alameda County Environmental Health Department to reopened the lakes. The Park District received formal approvals on August 11th.
“We are optimistic Lake Temescal and Quarry Lakes will stay open the rest of the summer and will continue to aggressively work to monitor and maintain water quality,” said Mason. “Safety is our top priority.”
Blue-green algae is a natural organism found in almost all freshwater streams, rivers, and lakes. Under certain conditions, such as increased nutrients, limited water circulation, increased temperatures, and low water levels, it can begin to bloom and, in some cases, release toxins.
Recent treatment efforts at Lake Temescal have been part of a pilot program that will help the Park District develop a long-term strategy for addressing blue-green algae District-wide. The pilot program includes enhanced monitoring at the lake to gain a better understanding of the conditions, sources of nutrients, and changes in the lake post treatment.
Lake Temescal and Quarry lakes will be open to swimming from 11:00 a.m. to 6:00 p.m. daily until August 18 and weekends and holidays after that. Lake Temescal will be open on weekends and holidays until September 17. Quarry Lakes will be open on weekends and holidays until September 4. Both lakes will continue to be open for fishing.
Lake Temescal and Quarry Lakes will be under a “Caution” advisory, which is one step below closure. Most East Bay Regional Park District lakes, even ones that have been open to swimming, have been under “Caution” advisories with robust signage making sure park visitors are informed about blue-green algae. A “Caution” advisory means harmful algae may be present in the water. Caution advisories encouraged visitors to stay away from algae and scum while swimming, not let pets go into or drink the water, and not drink the water or use it for cooking.