Shit Storm: Why won’t SF stop flooding homes with sewage?

It started with the banging.

A few months after Blane Bachelor and Chris Tilton moved into their new home on the corner of Rotteck Street and Cayuga Avenue, just a few blocks down the hill from the Glen Park BART station, they were woken up at 3 a.m. on December 3, 2014, by loud, pounding thuds.

Raoul Cobar and Susan Garduno, who lived around the corner on Cayuga Avenue, heard the banging, too.

Donna Marie Ponferrada, who also lived on Cayuga, didn't hear the banging, but her grandmother and aunt, who lived in a house a few doors down, were startled by the sounds coming from downstairs. They telephoned Ponferrada. Was someone breaking into the house? Were there burglars?

“We were thinking, 'What in the world is that horrible sound?'” Bachelor recalls.

Then they looked outside.

Cobar ran to his front door. Like most of the Mediterranean-style houses on the street, his front door is one story up from street level, at the top of an exterior staircase. It was dark outside and pouring rain. He heard a neighbor calling to him, “Your car, your car.”

“I look outside,” Cobar recalls. “My car is floating across the street.”

Cayuga Avenue was a river. The banging was caused by the lids of the manholes. They kept popping off, says Victoria Sanchez, who lives on that last block of Cayuga, “like champagne corks.” The paved-over creek that gives the little neighborhood of Cayuga its name had taken back the street.

In the morning, the neighbors assessed the damage. The sounds Donna Marie's aunt and grandmother had heard were the contents of their garage — Donna Marie's just-paid-off Ford Explorer and 10 years worth of storage — floating in several feet of water.

Bachelor and Tilton, who had just moved into their house and had yet to unpack completely, were confronted with a garage full of computers and camping equipment covered with a layer of filth.

Cobar had to climb into his basement through the windows. Inside, “it was like you had tipped over a ship,” he says. “Stuff was all over. You couldn't get in a door.”

Worst of all was the smell. “Feces,” Cobar says. “It's feces.”

When Cayuga floods, it doesn't just flood with rainwater rushing over land to fill the quasi-natural basin formed by the residential street meeting the rise of I-280. When Cayuga floods, the underbelly of San Francisco belches: sewage from toilets flushed upstream of this little cul-de-sac flows into basements, garages, and backyards.

After the storm came the cleanup. The city of San Francisco flooded Cayuga again, this time with work crews in Hazmat suits.

“They said, 'Don't worry about anything,'” says Cobar, as he stands in the dusty basement of the house he shares with his fiancee, Garduno. The floors are unfinished plywood, the bottom half of all the walls are gone.

“'We're going to take care of it all. We're going to demo what's here, and we're going to replace it as good or better than it was.'” Cobar knocks on an exposed stud. “Or better.”

Before the flood, this room was finished. The walls were covered with pine wainscotting that Cobar installed himself. There was a tiled kitchen with a working stove in the back. There was a bathroom. Now you can see how high the floodwaters went, because that's how high the demolition crews ripped out the sheetrock.

It's been almost a year since the flood, and the city has not fulfilled its promise. The only good thing, Cobar and Garduno say, is that they can't smell the stink anymore. They are used to the faint whiff of lingering dampness.

The promised cleanup was hampered by a second flood. Eight days later, as residents were still sorting through sodden belongings and preparing to file legal claims, the waters returned. The second major storm last December sent high tides pouring over the Embarcadero, cancelled classes for San Francisco public schools, and unleashed another torrent of floodwater through Cayuga.

To Ponferrada, there was a certain serendipity to the second flood. It couldn't destroy the neighborhood any further — and now, there were witnesses. “The crews and the trucks were here cleaning up. The manhole at the very end of the cul-de-sac was spewing, and I was like, 'Ha! Now you guys are experiencing this firsthand!'”

Garduno was less amused. “After the first one, on December 3, I was telling myself, telling my family, my neighbors: I am not going to be here for another flood,” she says. “Damn it, but a week later we had another one. And I was still here. I shouldn't have opened my mouth.”

Signs of last year's floods are still visible in the neighborhood. People still have sandbags outside their homes. Inside the houses, basements are still gutted. Bachelor and her husband have spent $9,000 installing a trench drain, backvalve, and sump pump in their garage, but the rest of their basement — formerly a one-bedroom apartment — is still bare to the studs. Michael Sanchez, who lives in the basement unit of his mother Victoria's house, has put up some new sheetrock to make his room liveable, but it's still under construction, and he has to keep the windows open because of the damp. Cobar and Garmudo paid to put down a new floor, but they don't have the capital to complete the rest of the work.

Ponferrada's grandmother, 93 years old and suffering from Alzheimer's, had her furnace totalled by the flood. With no money to fix it, Donna Marie and her family members have pitched in to buy a portable electric heater for the winter. “We bought her a lot of robes and an electric blanket,” Ponferrada says.

It's not an ideal situation, but the Ponferradas are struggling to come up with $10,000 to fix the sidewalk — which is caving in due to flood damage — outside her grandmother's house. This work, required by the city of San Francisco, must take precedent over the busted furnace.


It's a nightmare, and for the long-term residents of the neighborhood, a recurring one. This has happened before — in February 2004, a flood of the same magnitude caused similar damage to the neighborhood — and this will happen again.

Cayuga is a known trouble spot for San Francisco's aging sewer system. The San Francisco Public Utilities Commission, which manages the city's sewers, has acknowledged that the coming El Niño winter might lead to more flooding here and at the city's other flood-prone low spot, the area around 17th and Folsom streets in the Mission District.

For Hans Art, who has run an auto repair shop at 17th and Folsom for 36 years, flooding has become a near annual occurrence. Art is used to putting on galoshes and cleaning his property of the sewage-filled stormwater that flows up manholes and drain pipes into his parking lot.

The city has helped some flooded residents get back on their feet. The City Attorney's office has paid out about $2.1 million in claims related to the December flooding, about $373,000 of that to Cayuga residents, and about $1.4 million to residents and businesses around 17th and Folsom. The city also spent about $3.5 million on cleanup and demolition.

But the Ponferradas and many others have had their claims denied. (Of the 57 claims filed by Cayuga residents, 16 were denied and another 10 remain open. Matt Dorsey, spokesman for the City Attorney's office, says that the denial of a claim doesn't mean the city won't ultimately pay, but that it's part of the process that allows a claimant to proceed to litigation.)

Mark W. Epstein, an attorney now representing many Cayuga and 17th and Folsom residents, successfully sued the city over the flooding issue in 2004, and estimates that the city owes his current clients about $5 million in damages. The residents filed a lawsuit against the city, SFPUC, and the Department of Public Works on Aug. 20.

San Francisco's sewers have a flooding problem. The city knows it. The residents who deal with it know it. But there's no indication that one of the richest cities in America is doing anything to stop an inevitable flood of shit from pouring into the homes and businesses of certain residents.

Meanwhile, the winter — and the rain — is coming.

Water flows downhill. You can divert it with a dam, channel it through a gutter, or send it underground into a sewer. But water will flow the way it wants to flow, and it wants to flow downhill.

For San Francisco, a hilly peninsula with peaks and valleys famous for steep grades, hydraulics are complicated by extreme — and early — urbanization.

The city is almost entirely paved over. Almost all the water that falls from the sky will land on a roof or a street. If it lands on a roof, it's routed by gutters into a pipe and down into a sewer. If it lands on a street, it will flow to the side of the road, to a catch basin, and down into a sewer.

Underneath the layer of pavement that covers San Francisco is a network of 1,000 miles of pipe. The pipes follow every street and connect to every home and building. This is the subterranean landscape through which courses the water that San Franciscans use and discard on a daily basis.

Every other city in California (except for a small portion of Sacramento) has separate sewer systems for wastewater — the water that flows from toilets, showers, and sinks — and stormwater. In those cities, the rain water travels from the catch basins and gutters along pipes to an open body of water or river, untouched by any other civic interventions. In San Francisco, the systems are combined. Rainwater is routed into the same pipes that carry raw sewage and runoff from showers and sinks to the city's three wastewater treatment plants.

On a dry day, the result of over 840,000 people flushing the toilets, hogging the shower, and cooking a meal is 65 million gallons of sludgy, stinky water that flows through this network of pipes, following the natural course of gravity, until it reaches a water treatment plant. There, liquid is separated from solids. The water is purified, the waste is cooked, and both are returned to nature (via the ocean, bay, or dumptruck).

On a wet day, the 65 million gallons of wastewater can be joined by hundreds of millions of gallons of stormwater. According to the SFPUC, the total capacity of the system is about 500 million gallons per day. But some storms bring more water than that, or bring too much water, too quickly, overwhelming the pipes' capacity.

“There are times when the whole system is maxed out,” says Jean Walsh, an agency spokeswoman. “That's when we start using the relief valves” — releasing partially treated water into the ocean or bay through a network of discharge gates — “and that's when we start seeing spots in the city start bubbling up.”

17th and Folsom and the Cayuga neighborhood are two of those spots in the city that “bubble up.” Both locations are near the bottom of watersheds — although they are not the lowest points. The pipes at 17th and Folsom receive all the water from Twin Peaks and everywhere in between. After rushing quickly downhill, that water tends to slow and pool at 17th and Folsom before heading further downstream and out toward the bay. For Cayuga, the pipes carry water from Glen Park and the Outer Mission. When it hits Cayuga, the water is forced to wait until it can pass into a too-small sewer under Alemany Boulevard and head further downstream.

When too much water arrives at these locations — and doesn't have room to move farther downstream — it will burst up out of the manholes, catch basins, and drains and spill up onto the street.

Flooding has been a regular occurrence at 17th and Folsom for a century, the SFPUC points out. Before it was a hub for light industry and small businesses, the neighborhood was actually a tidal marsh. Cayuga was a stream bed before it was paved over and houses were built. The construction of the freeway complicated the topography by creating a dam at the end of Cayuga's cul-de-sac.


But the residents of both areas believe that the situation has gotten worse over the years. Art, who opened his auto repair shop at 17th Street and Folsom in 1978, says there was no flooding at all for the first dozen or so years in the neighborhood.

Since the 2004 flood, he says, he's been flooded almost every year.

Art and the other residents involved in the lawsuit believe that the flooding is getting worse because SFPUC keeps doing maintenance work upstream, without doing matching work downstream. Art is a mechanic, and he thinks about things mechanically. “It's Manning's Equation,” he says. “When you increase the size of the pipes upstream, you need to increase the pipes downstream, too.”

Manning's Equation is on the tongues of all the Cayuga residents, who've been taking a crash course in hydraulics to understand why their neighborhood is a seasonal cesspool.

“My friends that are in engineering school all say this is just engineering 101,” says Ponferrada. “It's the Manning's Curve.”

Manning's Equation, a basic concept of hydraulics, is quite complicated to print (V=(k/n)Rh2/3S1/2) but the phenomenon the neighbors describe is simple enough.

When it rains, the water that falls upstream of Cayuga or 17th and Folsom flows into the sewers and then downstream until it reaches the sewage treatment plant.

If there is no room in the pipes upstream, the rainwater will puddle on the streets (usually at intersections) and wait there, on the surface, until it can flow into the sewer pipes and on downstream.

Those upstream puddles can be an inconvenience, both for traffic and for pedestrians, but they limit the volume of water that is flowing toward the low lying areas that are prone to flooding. This puddle water is also comparatively clean, since it has yet to reach the sewers and mix with the water flushed from toilets.

Over the years, the neighbors allege, SFPUC has made improvements around the city to widen the pipes upstream. This means fewer big puddles and fewer small floods around Union Square or on Market Street. But it also means that more water is getting into the sewers more quickly, increasing the likelihood of flooding when that water reaches the low-lying choke points in Cayuga and at 17th and Folsom — and has nowhere to go but up and out into homes and businesses.

And unlike the puddles that occur before the water hits the sewers, the downstream floodwater is unsanitary. “The bottom line is that the city thought they had to put their contracted workers in Hazmat suits” for the cleanup efforts, says Blane Bachelor. “If that's how they're protecting their workers, what does that mean for the people who are living here every day with this?”

Walsh, the SFPUC spokeswoman, dodged the question of whether the agency recognizes that upstream improvements worsen the situation downstream.

“The SFPUC conducts a thorough systemwide analysis of all potential improvements using a highly calibrated hydrologic and hydraulic model,” she wrote in a statement. “The model can identify if any upstream improvements will introduce downstream challenges as well as determine the extent to which downstream capacity constraints could potentially cause challenges upstream.”

Epstein believes that the SFPUC could, if it chose, prevent or alleviate this flooding. When San Francisco's sewer system hits its 500 million gallons per day capacity, the SFPUC can open discharge gates and allow partially treated water to flow into the Pacific or the bay, freeing up room in the city's network of pipes and storage tanks. Discharges from San Francisco's combined sewer system into the ocean and bay are regulated by the Regional Water Quality Control Board, which permits the SFPUC a certain number of overflows per year, but only of partially treated water.

Epstein contends that the SFPUC could, if it chose, take advantage of those floodgates.

“The city knows that when there are fairly significant storms, the system fails. They know the location where it fails,” he says. “The PUC has the choice to open up the floodgates and allow the sewage out. They have the physical ability to let the flow go. They're choosing not to, based on their desire not to pollute the bay and be fined.”

“Given the option of facing fines from the EPA or some unfunded residents,” he says, “they flood the residents.”

Asked whether SFPUC is indeed making this choice, Walsh again hedged. In a statement, she wrote, “Localized flooding is unrelated to how the SFPUC operates the combined sewer system. No urban stormwater system can be designed to handle all stormwater in all storms; there will always be storm events that exceed the capacity of the sewer system. However, the SFPUC strives to support San Francisco residents and businesses in minimizing risk of damage from flooding.”

That's little comfort to Bachelor, who says, “They're putting raw sewage in our homes as a way not to put it in the bay.”

Like the rest of her neighbors, Victoria Sanchez has a collection of flood documents, ready to display for an interested visitor. Blane Bachelor produced a stack of documents from a manila file folder, and displayed videos and pictures on her iPad. Susan Garduno brought out a photo album that included newspaper clippings of major floods and the day Mayor Ed Lee came to visit. Donna Marie Ponferrada has files detailing all her extended family's dealings with the city, including the rejected claims that she had hoped would pay for a new furnace for her grandmother.

Mrs. Sanchez, as she's known up and down the block, brings out an album full of photographs she took during the 2004 flood of semi-submerged cars and a river of angry, brown water — when she was home alone during the day and one of the few witnesses to the six-foot deep inundation. She also shows me her framed wedding photograph, now shredded and warped beyond recognition.


“Everytime I look at my wedding picture, I get disgusted,” she says.

When Mayor Lee visited the neighborhood in the aftermath of last December's flooding, one of the solutions he floated was for the city to buy out the homeowners and knock down the homes. Mrs. Sanchez understands the impulse to flee. “My neighbor sold her house because she couldn't take it anymore. She said, 'Vicky, I've had it.' I say, 'Where am I going to go?' I'm a senior. I got my family here. Where am I going to go? It's hard. I can't start all over again. I'm not young anymore.”

Sanchez attends public meetings with the SFPUC. She stands up and tells her story. She makes noise. She recalls meeting the mayor in the elevator once when she was at City Hall. “I said, 'Good morning, this is Mrs. Sanchez who lives in the Cayuga.' I said, 'Don't forget us.' I asked him, 'Are you going to do anything?' He turned around and said, 'Well, it's going to cost us a lot of money.'”

That is about as straight an answer as anyone asking whether the city is planning to do anything about the flooding can get.

Despite what the mayor told residents and the press last December, buying residents out doesn't seem to be a viable option. While Mrs. Sanchez is hesitant, other residents would go in a heartbeat.

But Tyrone Jue, another spokesperson for the SFPUC, says a buyout plan is complicated, and not just because removing housing units from a city in a housing crunch would be politically toxic. “You can't do an eminent domain process just to minimize the liability of the city for claims,” Jue says. “It would have to be attached to some sort of larger benefit for the sewer system. And many people have lived here for years and may not want to move. So it's not as simple as just buying the land.”

As for actually fixing the problem, well, as the mayor told Sanchez, it would cost a lot of money — a steadily growing amount money which, it seems, the SFPUC is not interested in spending.

Following the 2004 flood, the SFPUC studied the problem at Cayuga. By July 2004, the Department of Public Works' Bureau of Engineering had produced a report identifying the problems with the sewer system in the area and proposing a solution: upgrading the downstream sewer under Alemany Boulevard by constructing over a mile of new auxiliary sewer — vastly increasing the volume of water that could be carried away from Cayuga.

DPW estimated that this would cost $61 million. An alternative plan, basically to construct a giant storage basin and pump station under Rousseau Street, was estimated to cost $7.5 million.

Four years later, documents show that SFPUC was considering another plan. A 2008 document prepared as part of the Sewer System Master Plan recommended two solutions to the flooding: adding an auxiliary sewer on Alemany or building a “diversion tunnel” — called the Cayuga Tunnel — that would head west from the Cayuga area toward the ocean.

DPW recommended this “westward” solution, which it estimated would cost nearly $250 million.

In 2010, the eastward and westward solutions were incorporated into a draft of the Sewer System Master Plan as Appendix X. They had been refined to include either 6,050 feet of relief sewer along Alemany Blvd or nearly five miles of 17- and 14- foot diameter tunnel heading westward to the ocean.

Despite producing these plans, SFPUC is not currently planning to carry them out.

Walsh says of the Alemany auxiliary proposal: “Our analysis shows that adding a second sewer on Alemany may alleviate the flooding at Cayuga but could exacerbate flooding downstream in the Lower Alemany and Bayshore areas. Therefore, the City is not considering adding a second sewer on Alemany at this time.” As for the Appendix X proposals, Walsh says, “Our current evaluation of project options takes into account the ideas in the Sewer System Master Plan and develops them further, with more detailed information regarding performance. We are not currently considering the options described in Appendix X.”

As for 17th and Folsom, Tyrone Jue says that the general idea for alleviating flooding in the area is to construct a “connector tunnel” to increase the sewer capacity. The cost for such a tunnel would be about $200 million, however, and the entire concept is reliant on “another billion dollar project that needs to happen perpendicular to this,” he says.

Whether that $200 million collector tunnel is on SFPUC's to-do list is an open question. Following the 2014 flooding, the SFPUC convened a “multi-disciplinary task force comprised of hydraulic engineers, planners, project managers, and executive leadership” that has “assessed recent and historic rainfall data, conducted extensive hydraulic modeling, and completed technical analyses of both area's sewer system infrastructure,” according to Walsh.

This dream team missed a deadline to present findings in August, and is now promising to share ideas “at community meetings for both neighborhoods planned for this October and November” she says — just in time for the rainy season.

When I spoke to Jue and Walsh at the Southeast Water Treatment Center last month, they were firm on one thing. “All the easy solutions are gone,” Walsh said. SFPUC is vague about what would comprise an “easy” solution, but suggestions from residents — such as raising the level of the sidewalk at 17th and Folsom to create a natural dam for businesses or digging a cistern under the parking lot at the same intersection — have been dismissed.

The SFPUC is about to do major work: The agency is embarking on a 20-year, multi-billion dollar overhaul of its facilities that it calls the Sewer System Improvement Program. The $2.7 billion Phase 1 of the SSIP will include upgrading the city's outdated wastewater treatment plants. But the priorities for SSIP are big picture items like seismic reliability, reducing the number of partially treated discharges into the bay and ocean, and adapting to climate change — not local flooding in a few neighborhoods.


“People are like, 'The rain is coming this winter. When are you going to fix this problem?'” Walsh says. “We're going to try to do our best and that might happen in twenty years…”

“Or sooner,” Jue interrupts. “It's not necessarily twenty years, but the easy solutions just aren't available.”

In the meantime, residents and business owners are largely on their own in preparing for what could be a wet and stormy winter. DPW provides ten free sandbags per resident every winter, an offer met with derision from residents. “Sandbags are a bandaid on a gushing wound,” Blane Bachelor scoffs.

The SFPUC is also encouraging residents to purchase flood insurance and has started a grant program to reimburse property owners for the cost of certain projects — like installing a flood barrier in a doorway or a sewer backflow preventer. Hans Art, the mechanic at 17th and Folsom, says that he worked with the SFPUC for four months to get the grant program up and running, but in the last week, he realized that he won't be able to take advantage of it, thanks to legal fine print that would require him to hold the city harmless and defend the city legally if anyone sues over his project.

According to Walsh, the SFPUC has received nine applications for grants so far, accepted two, and denied one.

“People are getting creative,” Walsh says of the projects property owners are resorting to to protect themselves from sewage. She mentions one man who raised the entire sidewalk fronting his property in order to prevent sewage from flowing in from the street.

That man is Chris Hickey, and his property is at 2140 Folsom, around the corner from Art's auto shop. Hickey shows off the raised sidewalk, as well as the specially sealed garage doors he's put into the property since he bought it three years ago. After Hickey raised the sidewalk, he says, the city wanted to charge him $2,000 a year to inspect the encroachment — a charge he had to go to the Planning Department to get waived.

“You try to fix the problem to protect yourself, and then they come after you,” he says.

Hickey isn't feeling particularly charitable toward the city of San Francisco today. He just received a letter in the mail, informing him that he's responsible for replacing one of the trees that line his portion of the block. What happened to the tree?, I ask.

“It washed away in the flood.”

Californians are used to living on the edge. This is a state where people dig foundations on active fault lines; where homes perch on oceanside cliff tops; where wildfires sweep through the state on a yearly basis; where an earthquake-vulnerable liquefaction zone susceptible to sea level rise is deemed an appropriate place to build hospitals, condominium towers, and a professional basketball arena. We watch movies about the disasters we anticipate, and then head home to the communities we've built in defiance of the disasters we know will one day transpire.

We build anyway. We take the risk.

When you talk to the SFPUC about the flooding at Cayuga or 17th and Folsom, they treat it like any other risk of natural disaster. The homeowners, they say, have to be responsible for their properties — which are at risk of flood. “No one can say to anyone's face that we can design a sewer system that will handle every single storm of every single intensity from now into the future,” says Tyrone Jue.

“The city can't be responsible for every flood,” he adds. “Anything that we're going to do from this point forward has to be considered a partnership. You can't just assume someone else will take care of it for you. No, that's not how anything else works.”

This might make sense if the flooding that residents at Cayuga and 17th and Folsom are experiencing was in fact a completely natural disaster. If those property owners had chosen to build at the equivalent of a quickly eroding oceanfront cliff, few would expect the government to swoop in and buttress their foundations.

But the homes and businesses on 17th and Folsom and Cayuga aren't on the edge of a cliff. Instead, they're in the middle of a convergence of decades of decisions made by municipal engineers, city planners, and politicians.

Gravity might make water flow from Glen Park to Cayuga Avenue, but gravity isn't responsible for that water including an unholy mix of feces, bathwater, urine, restaurant grease, used condoms, and toilet paper. Every single person who flushes a toilet and expects not to have to deal with it later — every single one of us — is responsible for that.

Standing outside of her home of 50 years with her son Michael, Victoria Sanchez says she has little hope that the city will actually fix the problem. She can't even get a city worker to come out and clear the catch basins of leaves, she says, let alone fix the entire sewer system.

And with winter coming, she is fearful for what El Niño will bring.

“They say, oh, it's an act of God,” Mrs. Sanchez says. “No. It's the plumbing. It has nothing to do with God.”

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