L. Richard Billups woke up Christmas morning to find his 2000 Chevrolet Corvette ruined.
An overnight storm caused a flood of brown stormwater and sewage out front Billups' home on Ashton Avenue, where he has lived for about 50 years in San Francisco's Ingleside Terraces. The flood destroyed his car’s electrical systems, monitors, carpet and seats.
“The insurance company said the cost would be more than the car is worth as far as market value is concerned,” he said. “That's the price to them. It meant a lot more to me.”
Video footage provided to The Ingleside Light by a neighbor shows the brown water rushing from Ocean Avenue onto Ashton Avenue around 2:43 a.m. on Dec. 25, overrunning gutters and pooling on sidewalks and yards.
In the span of minutes the sewage and stormwater flooded Ashton Avenue.
The incident was the latest in a series of combined stormwater-sewage floods that residents say the city has repeatedly failed to address. With the 1,100-unit Balboa Reservoir project underway and a seven-story mixed-use development proposed nearby, neighbors are demanding upgrades to an undersized sewer under Ocean Avenue before increased wastewater from additional residents adds further strain to a sewage system they say has been inadequate for years.
William Walraven, an Ashton Avenue resident, said he has dealt with many similar floods over the years, and the harm is real. Walraven said he fears the problem will worsen as climate change brings more extreme rainfall to the region.
“These are very disruptive. They damage and ruin living spaces and personal property.”
“We experienced firsthand the adage shit goes downhill, and I have the toilet paper in my backyard to prove it,” he said. “These are very disruptive. They damage and ruin living spaces and personal property.”
The Christmas Day flooding prompted 20 Ingleside Terraces residents to voice their growing concerns. In a letter sent Jan. 12 to state and local government officials obtained by The Ingleside Light, the residents said the flooding demonstrated the sewer system is unable to handle current demands. They said adding new development to the corridor without fixing the underlying infrastructure would make a bad situation worse.
“Given the Ocean Avenue sewer's documented history of surcharging during moderate rainfall, and its inability to manage overland flow even after pipe enlargement and high-capacity catch basin upgrades, any additional load risks increasing the frequency and severity of backups and overland flooding within this constrained sewer system,” the letter stated.
The residents want regulators to monitor the San Francisco Public Utilities Commission’s handling of sewage discharges in the neighborhood.
The commission’s staff attributes the flooding to the storm's intensity, saying rain gauges recorded between 0.39 and 0.54 inches of rain within 15 minutes.
“When very intense storms occur over a short period of time, ponding can occur,” SFPUC spokesperson Nancy Crowley said.
San Francisco is the only Californian city, apart from older sections of downtown Sacramento, served by a combined sewer system that handles both sewage and stormwater in a single set of pipes. When that combined flow increases beyond capacity or hits a bottleneck, sewage backs up onto neighborhood streets.
Greg Braswell, a retired hydraulic engineer who spent 22 years with the city's Department of Public Works, said a mixture of stormwater and sewage traveling downhill toward Ocean Avenue hits a constriction near the Ingleside Library. When the pipe cannot handle the volume, sewage backs up out of the manhole and flows down the avenue's gutters before spreading onto the flatter grade of Ashton Avenue and pooling on Urbano Drive.
“About half of it is water that could not get into the sewers, and about half of it is likely to be sewage coming out of the manholes by the library,” he said.
The SFPUC countered that steps have been taken to ensure the Balboa Reservoir development does not worsen flooding on Ocean Avenue.
“The project includes requirements for the developer to install large stormwater storage pipes and weirs that will temporarily store and convey the increased stormwater flows from the project,” Crowley said. “These requirements were crafted specifically with Ocean Avenue sewer capacity in mind.”
Braswell is skeptical that the additional storage will be enough. He said the stormwater requirements do not address the sewage that the new development will add.
“Although they are going to try to slow down the stormwater coming from those new homes, they're not going to slow down the sewage coming out of the toilets,” he said. “It's the sewage that the folks were complaining about, not the rainwater.”
The San Francisco Public Utilities Commission is investing $634 million in sewage and stormwater improvements across three areas of the city. But the spending wasn't the utility's own decision.
A 2021 order from the California Regional Water Quality Control Board determined the city’s collection systems “cannot convey or contain all wastewater and stormwater” during heavy storms.
“The SFPUC offers excuses and explanations, free sandbags and the nightmare of paperwork and litigation for the victims. When will they offer a real solution?”
Solutions Not Sandbags, a group that has advocated for sewer improvements since 2014, said the same storm that caused the overflow along Ashton Avenue also led to the flooding of at least eight homes along Cayuga Avenue.
“After all these many years, sewer-flooding is still happening on Cayuga Avenue,” the group wrote in a February statement. “The SFPUC offers excuses and explanations, free sandbags and the nightmare of paperwork and litigation for the victims. When will they offer a real solution?”
Ingleside Terraces was not included in the 2021 order issued by regulators.
Braswell, who has advised Solutions Not Sandbags on technical matters, said the neighborhood's exclusion from the order came down to a lack of documented evidence.
For now, the neighbors will have to continue their advocacy.
The Office of District 11 Supervisor Chyanne Chen declined to comment on the Ocean Avenue and Cayuga Avenue Christmas Day flooding. Staff with the Office of District 7 Supervisor Myrna Melgar said they have been in contact with SFPUC about the matter to obtain more information.
Billups, whose Corvette was ruined, believes the flooding was preventable.
“The city should have addressed this the first time it happened,” Billups said. “Obviously, they didn't do anything about it because now it has happened again.”
Alex Mullaney contributed reporting.
