The Lower Otay Reservoir spilled over its dam Tuesday for the first time in six years because of Monday’s heavy rainfall, the city of San Diego reported Tuesday, while a Lake Poway spill-over might begin by Wednesday morning.
The reservoir crested and began to spill into the Otay River Valley, but no downstream danger was anticipated, city spokeswoman Alma Rife told City News Service.
“The reservoir serves as a terminal reservoir for a significant-sized watershed, imported water aqueducts and a source of local water for the Otay Drinking Water Treatment Plant,” Rife said. “For these reasons, the reservoir intentionally operates at a higher capacity level than many of the other city reservoirs which are used primarily for storage and rely on local rain and snow runoff.”
According to city records, the reservoir can hold nearly 49,849 acre- feet of water, and on Monday was reported to have been at more than 93 percent of capacity.
The National Weather Service recorded more than 2-3 inches of rain Monday in the South Bay area.
Rife said no other city-operated dams were spilling over. The only others even close to capacity in Monday’s observations were Lake Murray at almost 88 percent, and Miramar at nearly 85 percent.
In the North County, however, the city of Poway announced that Lake Poway was nearly full and could begin spilling over by Wednesday morning. However, the rate of inflow to the body of water had slowed throughout the day, so the spillover level might not be reached, city officials said.
Poway city officials said the dam was inspected and is structurally sound. They said they’ve been trying to reduce the lake’s level with diversions into the drinking water system.
If the lake spills over, the water is expected to run into a canyon north of the dam, through the Blue Sky Ecological Reserve, along a creek adjacent to the Maderas Golf Course and ultimately into Lake Hodges. The reserve and hiking trails near the lake have been closed as a precaution, according to the city.
The last time Lake Poway overflowed was 20 years ago, and there were no injuries and no property damage, city officials said.
—City News Service
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