SFPUC to 17th and Folsom: Prepare for More Flooding

Almost a year after the area around 17th and Folsom Streets was twice flooded with raw sewage during major rainstorms, the San Francisco Public Utilities Commission has presented the results of the “multi-disciplinary task force” that was convened to come up with solutions to the decades old problem. The upshot: SFPUC is willing to spend a lot of money on a capital improvement project that will take years to carry out but still won't stop the flooding. 

“Part of what we're trying to hammer home is that none of the projects are going to solve the problem,” said Kathryn Howe, SFPUC assistant general manager of infrastructure, at a community meeting for 17th and Folsom residents and business owners last night. 

That's a reality that is “humbling,” said District 11 Supervisor David Campos, who spoke of his growing understanding of the “limitations of what can be done.” 

[jump] As we reported in a cover story earlier this month, 17th and Folsom (as well as the Cayuga area near the Glen Park BART Station) experiences near annual flooding when the city's combined sewage and rainwater system overflows during intense storms. The floods are damaging and unsanitary, and, residents believe they are due as much to design flaws in the system as they are to natural factors.

Proposals to improve the system have been kicking around since 1964, as one meeting attendee pointed out, but the political will (and money) hasn't been there to make it happen. 

That's not the case anymore, according to SFPUC General Manager Harlan Kelly, who spoke at the meeting. “We just felt that we needed to do something, because it was really sad to see it happen two times in a row,” Kelly said to an occasionally frustrated crowd. “This is one of our highest priorities.” 

But the solutions on the table, despite Kelly's statement that, “If we're going to spend a lot of money, I want to solve the problem,” are not going to solve the problem. 

Even after any one of the three projects under consideration is implemented, “The large storms that caused flooding last December would still cause flooding,” Howe said. But, she added, “It would not be as severe.” Howe said that the projects would also make flooding during small and moderate storms less likely. 

The three proposals are as follows:

1. Drill a 17-foot diameter tunnel to connect with a “Channel Tunnel” that is already planned further east. This option would cost $260 million and would be completed by 2024. It would not cause significant disruption to traffic.

2.  Upsize the sewer mains under 17th and 18th Streets and expand the sewer boxes under Treat and Division Streets. This option would provide about the same amount of relief as the tunnel, but it has some drawbacks. Howe said major traffic disruptions — including taking up half the width of Division Street for 12 months — would be necessary for 42 months. This option would cost $200 million and be completed by 2022. 

3. The third option is to dig storage wells in the area. Massive cisterns could potentially be sited under the proposed park at 17th and Folsom (where there is currently a surface parking lot) or in other parts of the area. The problem with storing water — as opposed to increasing the capacity of pipes that convey it toward the sewage treatment plant — is that once the water goes into the tanks, it must be pumped out. So after each storm, SFPUC would have to empty (and sanitize) the holding tanks. SFPUC estimates this plan would cost $110 million (not counting the cost of any real estate it might acquire) and could be completed by 2020. 

The timeline for selecting the project will be slow. Howe expects that SFPUC will choose the best of the three options by 2017. From there, environmental review, bidding, approvals, and construction will take several more years.

With storms expected this winter from El Niño, SFPUC's message for the short-term remains the same: clear catch basins, elevate belongings, get sandbags, buy flood insurance, and make improvements to your property (such as installing backflow valves or flood-proof doors). 

A representative from the city's Department of Building Inspections was on hand to share tips on taking advantage of the city's floodwater management grant program, which will reimburse homeowners for some projects related to protecting their properties from the water. 

SFPUC is also planning to test out some plastic flood barriers on sidewalks at 17th and Folsom. The barriers are filled with water and hug the buildings, preventing water from seeping into buildings. As one resident pointed out, this strategy is basically “a sandbag wall made out of plastic.” 

Several meeting attendees expressed frustration with the limitations of the proposals — and the long timeline. SFPUC also appeared reticent to get into some of the sticky questions of why the sewers are overflowing and why it seems to be getting worse. 

When one attendee asked if it was true that improvements to the sewer system upstream were contributing to problems downstream — a key contention of the residents SF Weekly spoke to for our cover story, Howe and another SFPUC staffer exchanged a look, and were silent. 

These things are “very site specific,” Howe eventually allowed, after another attendee cried out, “Yes, it's true!” 

It seems unlikely that SFPUC will get into that kind of question of fault, given the lawsuit that's pending against it and the city over the 2014 storms. In the meantime, residents are still concerned that SFPUC is not taking full responsibility for the streams of sewage water that are flowing out of its pipes and into their buildings. 

“We're not asking you to protect us from flooding,” said Hans Art, who owns an auto repair shop at 17th and Mission. “We're asking you to fix your sewer system so it won't overflow.”

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