Despite its best efforts, the city will not be able to offer residents and businesses that suffer repeated flooding and sewer overflows a surefire solution. No matter how much money is spent, public utilities managers said at a meeting last night, a really big storm will still overwhelm the city’s sewer system.
“When it’s filled to capacity, no more water can be entered in to the system,” said San Francisco Public Utilities Commission General Manger Harlan Kelly. “Engineers would love to build a bigger system but we’re talking billions of dollars and tearing up the street…We have to work with the system that we have.”
San Francisco’s sewer system, most of which is about 100 years old, can process some 500 million gallons of water on a rainy day. Serious storms can bring down much more and in any big storm, 15th and Wawona streets, Cayuga Avenue at Glen Park, and 17th and Folsom streets are prone to flooding because the overflow works its way down from the city’s watershed to the bay and pool there as a result of the city’s topography, utilities staff explained.
“This issues is one of those that has been very humbling to me,” said Supervisor David Campos in his remarks at the meeting. “There are limitations in what a governing agency can do [against] nature.”
Nevertheless, utilities manager Stephanie Harrison did present three approaches to mitigating the problem. The first would be to construct a $260 million connecting tunnel from 17th and Folsom streets to a bigger, higher-capacity channel tunnel along the city’s eastern edge. That would move more water away from affected areas, easing the bottleneck that forms in the city’s topographic basins. The catch? That bigger channel tunnel also doesn’t exist yet, and would cost some $800 million to build.
Another option, Harrison said, would be to simply widen an existing water pipeline under 17th and Folsom to a 17-foot diameter. Collection boxes and other associated underground infrastructure would also have to be expanded. Unlike a new tunnel, which would simply involve an entry point for tunneling equipment, expanding old infrastructure requires opening up streets, which means traffic snarls, utility interruptions, and higher construction cost – a total of $200 million.
Finally, the city could ask parcel owners for permission to dig out storage tanks under parking lots and other empty spaces to catch some of the stormwater that would otherwise flood the surface. Though it’s the cheapest option in terms of installation, weighing in at just $110 million, staff warned that the tanks would need to be emptied and cleaned of debris after each rainfall.
Putting any of these solutions in place would take between five and nine years, with most timelines for completion ending in 2024. It would take until 2017 for the city to even reach a final decision about which approach to take.
“If we’re going to spend a lot of money, I want to solve a problem” said Harlan Kelly, general manager of the Public Utilities Commission. He and others also cited extensive planning and review processes in place to assure transparency in the use of taxpayer money.
Residents weren’t impressed.
“We are not asking you to protect us from flooding [at the surface],” said one resident. “We are asking you to fix your sewer system so it doesn’t overflow.” He said the pipes under 17th and Folsom, toward the end of the system, simply need to be made proportional to the combined capacity of upstream pipes.
“It’s a little more complicated than that,” said Kelly.
“I don’t think so,” the resident shot back.
“What a joke,” said Blane Bachelor, a Cayuga Avenue resident. “There’s a section of residents in three districts bearing the brunt of the city’s crap.”
Bachelor is one of the core members of Solutions not Sandbags, a group whose mission is to push the Public Utilities Commission toward major sewer improvements rather than short-term fixes.
The latter are in ample supply – the city encourages residents to elevate their buildings, clean their drains, and purchase flood insurance (though residents objected that flood insurance rarely covers sewage back flow, which has damaged several homes). It also offers a program for reimbursing residents who install back flow preventers, flood barriers and other devices.
At Thursday’s meeting, they announced plans to test interlocking modular flood walls around the southwest corner of 17th and Folsom streets, to keep water from flooding off the streets and into the below-grade yards of Hans Art auto shop and Stable Cafe.
“Is that the best they could come up with, the barriers?” asked Lisa Dunseth, who has not fallen victim to flooding but is also growing impatient with the city’s lack of major sewer improvements. She arrived at the meeting with a binder full of documents detailing plans to improve the sewer system under 17tha and Folsom streets – from in 1964.
“In 1964, plans were made to fix the system. Now it’s 2015 and we have sewer flooding and now we’re going to have it streaming down our sidewalks instead,” she said.
Malcolm Davis, who owns the building that houses Stable Cafe and works upstairs, said he had been told that a basin under the 17th and Folsom parking lot that is slated to become a city park had been taken off the table. At Thursday’s meeting, it was brought up again.
“Really, if they lowered that piece of land by four feet, it could stop flooding in the area,” Davis said. “It feels like turning a huge ship.”
@LauraWenus, Thank you for continuing to follow our story. Visit http://www.SolutionsNotSandbags.org for photos, videos, and E-PETITION. And Like/Follow us on Facebook, Instagram, and Twitter. Now it’s our job to get the word out. Please spread the word with everyone you know, online, in person, etc!
The lack of planning for improvements to the sewer infrastructure is appalling.
Folks throughout the City stay up worrying themselves sick during rainstorms and there is no plan to address the issues in any of the neighborhoods affected. This is another variation on “development on the backs of the most vulnerable”.
Thank you Mission Local for covering this important issue. This is an engineering problem; not a “humbling” problem with Mother Nature, topography, or creek beds. We have federal and state regulations which make it illegal to dump untreated sewage into the bay and ocean. Why do our city leaders think it is ok to dump untreated sewage into homes and businesses? Since the 1964 Sewer Bond Measure, administrators with the decision-making power have acted irresponsibly by trying to avoid political or financial liability. They prefer paying lawsuit settlements to responsibly caring for our infrastructure and fixing our sewers. We will all end up paying more in the end. Fix the sewers! SolutionsNotSandbags.org.
Thanks for reporting this critical issue. To clarify my comment above, I was referring to SFPUC general manager Harlan Kelly’s comment in the meeting that leaves in the system are a major factor in the flooding and that residents should be raking out their storm drains. To the contrary, leaves and debris in the system can actually HELP those of us affected by flooding. Why? The mini-floods upstream in the system caused by that debris keep toxic, harmful raw sewage from flowing into our homes downstream. Mr. Kelly’s proposed strategy about the leaves demonstrates a clear lack of engineering expertise, something that thousands of residents like me have suffered from repeatedly thanks to toxic, harmful raw sewage SFPUC’s system keeps dumping into our homes and businesses.
And while I’m pleased to see SFPUC looking at solutions, they have been studying this problem for decades and spending millions of taxpayer dollars doing it. It’s time to stop studying and time to start implementing.
Not fair and not right that the neighborhoods of color have the sewage forced upon them. Look the Bayview waste station. Gets like 90% of the sewage from non residents. We outsource the sewage to these communities. Thankfully Bernie Sanders will fix this sewage injustice pretty soon. Hilary is ok but I do not like how she uses her sex appeal. Should cover up a little bit. No need to show cleavage and stuff bad example for young girl. Please do not vote trump. Bernie good guy.