Downtown flood shows why San Diego is scrambling to replace crumbling water pipelines – The San Diego Union-Tribune

A water main that ruptured Sunday, spewing untold gallons of water into downtown San Diego, is part of an antiquated system of pipes long overdue for replacement.

The underground pipe — which created a large sinkhole at 11th Avenue and A Street — is 76 years old and made of cast iron, city officials said Monday. A second pipe that also burst Sunday, flooding north bound Interstate 5, was made of reinforced concrete.

Following a string of ruptures in recent years, the city has been steadily replacing its cast-iron water pipes, some of which are more than 100 years old, with more durable tubes made of polyvinyl chloride, better known as PVC. The city has replaced roughly 180 miles of pipeline since 2013.

“We’ll continue to do our best to switch out the oldest pipes, the cast-iron pipes that we know fail with regularity,” said Mayor Todd Gloria at a press event Monday where construction crews worked on the broken pipe.

A car drives down a flooded Tenth Ave. after a water main broke at A Street and Eleventh Avenue.

A car drives down a flooded Tenth Ave. after a water main broke at A Street and Eleventh Avenue, a block away from City College on Sunday, Nov. 21, 2021 in San Diego, CA.

(K.C. Alfred/The San Diego Union-Tribune)

The city has roughly 55 miles of cast-iron pipeline remaining, and officials estimate the last sections will be upgraded by 2025.

The city experienced 33 water main breaks in 2020, down from a high of 131 in 2010. The city has averaged nearly 80 major ruptures a year over the last decade.

Those incidents include a pipe that broke near Idaho Street and Polk Avenue in 2018, flooding homes and businesses in North Park, as well as a series of ruptures in Mission Valley the previous year that opened a sinkhole on I-5, leaving hundreds of motorists stranded for over an hour.

Gloria said he supports investing in aging pipes but also has concerns about adding to the already high cost of water in San Diego. The city is bracing for water rates to climb sharply as it continues to build out its wastewater recycling program, known as Pure Water.

“This stuff is not free,” he said Monday. “It’s always a balancing act. I worry a lot about what it takes to live in this city.”

The water main broke around 3:30 p.m. on Sunday, flooding the streets and at least one nearby business. The city turned off the water around 6:45 p.m. to prevent further damage.

Many residents lost running water in their homes, including Andrew Hoffman, who lives on Cortez Hill.

“I’m on a group text with my neighbors, and all of a sudden, everybody’s like, ‘I lost water,’” said the 59-year-old.

The city gave out bottled water and posted water wagons in the area.

“It’s an issue of, ‘Is the infrastructure keeping up?’ I don’t know who’s in charge, but it’s pretty evident it’s not,” said Hoffman while filling up a plastic jug from one of the wagons near the construction site on Monday.

Running water was restored to most downtown homes and businesses around 7 p.m., according to the city. Some residents reported regaining access to water as early as 4 p.m. It’s not clear exactly how many people were impacted.

A boil water notice was issued to nine addresses, including: 545 Laurel St., 1210 11th Ave., 1280 12th Ave., 1011 and 1110 A St., as well as 2302, 2350, 2395 and 2402 Sixth Ave.

Shortly after the city turned off water to the ruptured pipe in downtown, the second water main burst near state Route 163 and I-5.

That break did not impact any water customers, officials said. However, it did flood the northbound lanes of I-5 in downtown, which remained closed as of Monday evening.

Officials said an investigation will be conducted to determine the exact cause of the breaks and whether they were connected.