(KRON) — Lake Anza at Tilden Regional Park in Berkeley is closed for swimming due to weeds in the lake that are overgrown, parks and recreation officials said.

The closure, which started on Thursday, is to prevent swimmers from getting entangled in the weeds and hindering their ability to see in the water.

In addition to the lake closure, there are signs posted advising the public of blue-green algae present in the lake. It is unknown when the lake will reopen for swimming.