A fire hydrant was knocked over about 6 a.m. Wednesday morning at 45th Street and Highland Avenue in Manhattan Beach, forcing a stream of water downhill toward the beach.

City fire crews experienced difficulty getting to the shut-off valve, which meant that the water ran for nearly an hour, City Manager Dave Carmany said in an email.

"The runoff went down 45th Street but did not cause any damage to homes downstream," he said.

The city initially reported "significant" beach erosion. But Public Works Director Jim Arndt said later that water from the downed hydrant gushed into a storm drain that empties onto the beach, taking off a top lip of sand near the ocean. He likened the incident to a major rain event and said no structures were damaged.

The city received calls concerning "cloudy" water afterward, and advised residents "to run their water until it shows clean."

Arndt said officials do not know who knocked out the hydrant.

- Kristin S. Agostoni