LOS ANGELES — Los Angeles County sanitation officials blamed the intense rain from this week's storms for overloading the regional wastewater system, leading to numerous sewage spills that led to the closure of beaches which are in place Friday in San Pedro and Long Beach.

County and Long Beach officials announced that as much as 8 million gallons of sewage had spilled into the Dominguez Channel during the storms, leading to a closure of Cabrillo Beach in San Pedro and all open coastline in Long Beach.

The Los Angeles County Sanitation Districts, which manages the countywide sewage system for 5.4 million people, issued a statement Thursday insisting that the system has "performed well during previous heavy rains," but the record-setting storm that battered the region this week severely over- taxed the system.

Sanitation officials said floodwater entered the sewer system through manholes, causing "temporary overloads to sewers that resulted in sewage overflowing onto streets at 10 locations."

The county agency noted that its largest sewage treatment plant, Warren Water Resource Facility in Carson, typically treats 250 million gallons of sewage per day, but on Tuesday, it was inundated with 560 million gallons, "with more than half of the flow coming from the stormwater inflow."

"Our goal is to have zero sewer overflows and we are disappointed that the recent overflows occurred," Robert Ferrante, general manager of the Sanitation Districts, said in a statement. "In the aftermath of this huge storm, we will redouble our efforts in working with our member cities and the county to minimize rain getting into the sewer system. We've recently invested $11 million in flow sensors throughout the system and will be analyzing that data to determine where the problem areas are so that we can prioritize our efforts."

Sanitation officials insisted that none of the overflows occurred due to aging infrastructure or poor maintenance.

"In fact, the district's pumping plants and treatment plants remained online during the storms and treated record amounts of flow," according to the agency. "The recent storms are unprecedented. Los Angeles County experienced record setting rain over much of the Los Angeles Basin, sometimes at high intensity. The region's extensive storm drains and sewers simply could not keep up with the amount of water."

Updated Los Angeles County beach closure information is available by calling 800-525-5662 or online at publichealth.lacounty.gov/beach/. Long Beach recreational beach water quality information is available at 562-570-4199 or longbeach.gov/beachwaterquality.

In addition to the sewage-related closures, county health officials have issued a separate warning that will be in place through the weekend urging people to avoid contact with ocean water, particularly near discharging storm drains and creeks, due to bacteria carried to the coast by storm runoff.