A sign warns of high bacteria levels at San Pedro's Cabrillo Beach,… (Allen J. Schaben / Los Angeles…)
Water quality at Los Angeles County beaches has worsened over the last year in a decline that may be linked to heavy rainfall, according to an annual report by the environmental group Heal the Bay.
Only 76% of county beaches earned an A or a B in the annual beach report card released Wednesday, down from 79% the year before. Water quality statewide dipped by 2% but remained "very good to excellent," with 88% beaches earning A or B grades.
Some of the county's most chronically polluted beaches saw the gains made in recent years slip away. Poor water quality at historically dirty beaches in Malibu, Avalon and Long Beach helped drag down the overall grades for both the county and state.
Heavier than normal rainfall may have played a part in the sagging ratings because it increased the amount of polluted runoff making its way to the coastline through conduits such as the L.A. River, Malibu Creek and Topanga Creek.
Heal the Bay President Mark Gold said the decline, which comes after several years of rising water quality grades shows there still hasn't been enough progress in reducing urban runoff. But the fact that rains didn't push water quality figures down even more, he said, is an indication that beaches are starting to do better.
"We had a very wet year statewide, so the fact that the grades were pretty similar to years past is actually a good thing," he said. "I fully would expect if we get back to normal rainfall that we'll have water quality improvements."
One of the few success stories highlighted by Heal the Bay was a dramatic turnaround at the popular beach south of the Santa Monica Pier, which earned an A after years of ranking among the state's worst.
The report gives hundreds of California beaches letter grades based on state-mandated tests that probe the water for bacteria. A high bacteria count means the beach water is likely to harbor pathogens that can sicken swimmers with ear infections, skin rashes and stomach illnesses.
Eight beaches in L.A. County received year-round Fs. Four of them — Avalon Beach on Santa Catalina Island, Cabrillo Beach in San Pedro, Topanga State Beach and Colorado Lagoon in Long Beach — made the list of "Beach Bummers," the 10 most polluted beaches in California.
Some of the most disappointing marks went to Long Beach, which sits at the mouth of the L.A. River and saw its summer beach water quality grades plummet after three years of improvement. Only one-third of the city's beaches received an A or a B for the year from April 2010 to March 2011, the period covered in the report.
Twenty-one percent of California beaches scored perfect A-plus grades. Beaches in San Diego, Orange and Ventura counties on the whole had outstanding water quality despite some notable exceptions, such as Poche Beach in San Clemente and Doheny State Beach in Dana Point.
Beach water testing also continues to be threatened by a lack of state funding, the report noted.
The state Water Board tapped bond money last year to extend monitoring through 2011, but how it will be paid for after that is uncertain.