The south beach of Shadow Cliffs Lake closed Wednesday afternoon due to an extremely high E. coli bacteria measurement, according to the East Bay Regional Park District website.
Alameda County Environmental Health Department recommended the closure, stated the website.
According to EBRPD water management Supervisor Hal MacLean, the district sampled water Thursday afternoon and results should be ready by noon Friday.
Water samples will be taken daily until it is safe to reopen, which the district says should be in the next several days.
"Shadow Cliffs' water usually gets higher (E. coli) readings in the summer," said MacLean. "But the south beach's level spiked really high."
MacLean added that some of the contributions to the high readings could be the low water level, as well as not watering the lawn.
"We haven't been watering the lawn to conserve water," he said. "So instead of the geese congregating on the lawn, they're congregating on the beach."
The EBRPD website has provided the public with a rating system of the water quality.
The north beach, left of the lifeguard chair, is currently open with a "Yellow Light" water quality rating -- which means there is an increased health risk for swimming and wading, and bacteria results do not meet State Health Standards.
Sheryl Chance wasn't aware of the high readings of E. coli Thursday afternoon when she took her grandchildren to swim at the north beach. With no hesitation, she quickly told her grandchildren they couldn't swim.
"It's bacteria," she said. "I don't want them swimming in it. I wouldn't swim in it."
The daily maximum of the State's water quality bacteria level is 235. As of Tuesday, south beach's bacteria level was 24000 and north beach 680.