A water man break Monday, Aug. 23, 2021, caused Codornices Creek in Berkeley to have a milky hue. Credit: Tracey Taylor

After months of drought, Codornices Creek has thinned, in some places slowing to a trickle. But on Monday, it briefly flowed anew, when a corroded water main broke and runoff flooded the stream bed. 

The water main break occurred at 2:20 a.m. on the 2900 block of Shasta Street in Berkeley, according to East Bay Municipal Utilities District representative Andrea Pook. An hour later, water to the main was severely reduced. Dechlorinating tablets were added to runoff to prevent the treated drinking water from poisoning fish or other wildlife. 

After the leak, some residents noticed a milky-white color in the creek. Susan Schwartz, president of the Friends of Five Creeks, attributed the creek’s appearance to the area’s fine clay soils being disturbed by the sudden influx of water.

Schwartz said the ongoing drought has drastically affected Codornices Creek. “Several people who have lived on the creek for many years say they’ve never seen it so low,” she said. In some places of the creek, monitoring groups have found no water flowing above ground. 

Schwartz sees a silver lining in the main break for the creek plants, languishing from drought, that received a sorely needed subsidy of water. “Under the circumstances, it may have been the best thing that could have happened,” she said. 

Pook confirmed that, according to EBMUD scientists, most of the leak’s runoff “did not make it to the Bay” and was instead “absorbed by super dry soils.”

An EBMUD report listed corrosion as the primary cause of the leak. That doesn’t surprise Schwartz, who said aging infrastructure throughout the Bay Area has led to frequent leaks. “Oakland, Berkeley, San Francisco — all these cities have hundred-year-old pipes,” said Schwartz. Given the current drought, and the likelihood of future severe droughts, she sees replacing those pipes and curbing water loss as a priority.

The East Bay’s frequent seismic activity makes damage to pipes even more common. Much of Berkeley, including Codornices Creek, is intersected by the Hayward Fault system. Small shifts along that fault can easily rupture brittle cast iron pipes. 

Pook said that utility scientists are also investigating whether the drought could be making water mains more susceptible to rupture as parched soils pull away from pipes.

She added that EBMUD has reduced the amount of water lost to leaks and other waste in recent years. In 2017, the utility lost about 54 gallons per day per connection; last year, it lost 40. She attributes the change to a robust leak detection program and an accelerated pace of replacing aging pipes. 

“It’s a never-ending process,” said Pook of replacing the aging infrastructure. “It’s like repainting the Golden Gate Bridge.”