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A flood next time?

On the 20th anniversary of the 1998 flood, changes to end San Francisquito Creek's threat are making progress

A sunny day of summer-like weather on Friday seemed worlds away from the historic rain event of 1998 that inundated parts of Palo Alto, Menlo Park and East Palo Alto. But on the 20th anniversary of the Feb. 2-3 floods, residents in all three cities said they still vividly recall the devastation, and they fear a flood of that magnitude could strike again.

San Francisquito Creek flowed over more than 11,000 acres, flooded 1,100 homes and caused the evacuation of 500 people. In less populated times, for eons it nurtured the floodplain, bringing silt from the mountains and organic material to build areas that would become fertile grasslands that supported wildlife and built soil on an alluvial fan.

But creeks on their own do not adapt to people and their demands upon the land. In the last 150 years the San Francisquito has been dammed, concreted and sculpted to fit human needs. A burgeoning population has replaced the spongy soil and vegetation that absorbed runoff with concrete and asphalt, which has increased rapid runoff into the channel, hydrologists say.

Thus primed, in heavy rain events the creek has overflowed at least 13 times since 1910, with peak floods in 1955, 1958, 1967, 1982 and 1998, according to a 2006 report by the San Francisquito Creek Joint Powers Authority. The creek overtopped its banks again in 2012 and 2017, damaging property and, in 2013, damaging the dirt levee abutting an East Palo Alto neighborhood, which if breached could have taken lives. That flooding created a state of emergency in East Palo Alto, requiring emergency repairs to the levee.

But the 1998 flood was the greatest in the creek's history, with waters rushing at a record 7,100 cubic feet per second, authorities said. The 1998 flood caused a documented $28 million in damage in the three cities, according to the U.S. Army Corps of Engineers. A U.S. Army Corps of Engineers report in 2000 estimated a 100-year flood event could cause $800 million in damages to 3,785 homes and businesses in Palo Alto alone. Given the increase in the area's population and astronomical rise in property values, the cost of another flood could be exponentially higher.

Two decades after the great flood, San Francisquito Creek is still a threat, and for the last 20 years frustrated residents have asked why. The slow pace of fixing the problem provokes anger at public meetings, with residents threatening lawsuits if the creek floods again.

Flood-reduction work has been fraught with as many twists and turns as the unpredictable creek.

A night that no one has forgotten

Palo Alto resident Tom Rindfleisch still vividly describes the damage the 1998 flood did to his neighborhood.

"At 2 or 3 a.m. there was 1 to 2 feet of water in our yard. It came within a half inch of coming in the house. The whole cul-de-sac was a sheet of water one foot deep. One neighbor has a basement, and it filled with water," said Rindfleisch, who lives across from Eleanor Pardee Park.

On Center Street near Dana Avenue, water rose four to six feet into people’s yards, drenching personal belongings and furniture.

"After the flood was over, on Center the street was lined with ruined furniture and bedding," he said.

In East Palo Alto, Dennis and Louella Parker’s home was flooded by water and mud after the creek overtopped the nearby levee and inundated their neighborhood.

"There was very little knowledge of the creek and the flood potential," Dennis Parker said. The couple had moved into their home in 1960, five years after the previous big flood of 1955. "When the flood came in 1998, someone with a bull horn drove through the streets ordering everyone to evacuate. My wife had not made any preparations, and panicked when she saw the intersections flooding at both ends of the block. She had no idea what to do. Her daughter told her to just grab and change of clothes, a pillow, and hygiene products, and they headed out of town," he said.

The Parkers were again forced from their home in December 2012 when the creek overtopped and damaged the levee. Dennis Parker, who was watching the water level rise on the online creek monitor, saw the water was so high that the monitor was no longer functioning. The couple evacuated to the Red Cross shelter at East Palo Alto City Hall. People were coming in with their pant legs soaked to their knees.

Menlo Park resident Jim Wiley was one of the lucky ones.

"My wife and I live in a house five feet from the creek. Even though we are five feet from the creek bank, our house is not in a flood zone. Palo Alto, Menlo Park and East Palo Alto are built on an alluvial fan and San Francisquito creek is a "perched" creek, therefore the creek banks are the highest point for miles around," he said in an email.

"Our major loss from the flood of 1998, like many others in Menlo Park, was from fast moving flow that induced severe creek bank erosion. The creek bank right at our house was armored by a previous owner after losing about 10 or 20 feet of this property in the flood of 1955. However, just upstream of our house, erosion almost undermined Woodland Avenue and the City of Menlo Park placed rip-rap (big) boulders on the creek bank in the days after the flood to stop further erosion of Woodland Avenue. Downstream of our house, we lost several feet of our property to erosion,” he said.

Wiley said that many Palo Alto residents have focused attention on the Pope-Chaucer Bridge.

"But my observations the night of the flood and the day after show that it’s not just the Pope-Chaucer Bridge that caused flooding. There were major flood breakouts upstream of the Pope-Chaucer Bridge, at the Middlefield Bridge, and below the Pope-Chaucer Bridge just upstream, and just downstream of the University Avenue Bridge. In that area, most Palo Alto residents have brick walls between their property and the creek, so the University Avenue Bridge breakouts only flooded East Palo Alto," he said.

Wiley and his wife walked all along the creek. They saw areas where the San Francisquito broke out of its banks.

"Many, many cars parked in below grade parking garages on East O’Keefe Street (in East Palo Alto) were destroyed by this flooding," he said.

The next morning they saw where a major sheet of water had overtopped the creek above the Pope-Chaucer Bridge around Hale Street and Seneca Street.

"This breakout appears to have contributed the majority of the flood water than flowed through the streets of Crescent Park and Duveneck/St. Francis and ended up pooling in the lowest-lying areas of Palo Alto with further flow to the Bay blocked by the elevated Highway 101. The floodwater that was not able to pass through the Middlefield Bridge had to take a longer path, starting by rushing down Byron Street in Palo Alto, then through the streets, and it also ended up in the lowlands near Greer Park. The park is only a few feet above sea level. The houses where the pooling occurred, around the Greer Park, Oregon Expressway and Embarcadero interchange were built on land that was salt marshes a few decades earlier," he said.

Getting a handle on the problem

The San Francisquito runs through two counties and multiple cities as well as Stanford University. Of all of the watersheds that flow into the southern part of San Francisco Bay, the San Francisquito Creek watershed it the only one that has continuously supported a run of steelhead trout, listed as a federal Endangered Species Act threatened species, according to the San Francisquito Creek Joint Powers Authority. Multiple government agencies must sign off on any modifications to the creek, including to structures that cross it.

In 1993, the Watershed Council (later the San Francisquito Creek Watershed Council) began taking special care of the creek, raising public awareness of its value, preserving the creek’s natural condition with plantings and monitoring of the creek’s conditions. Palo Alto resident Trish Mulvey, a convening member of the Watershed Council since its inception, said the San Francisquito is "the most inter-jurisdictionally complex watershed in the Bay Area."

How to preserve the creek’s natural flow and address flooding is a complex issue, but the 1998 flood was a wakeup call.

"The flood event was the trigger for implementing a Watershed Council recommendation to form what became the San Francisquito Creek Joint Powers Authority and bring together elected representatives from the three cities and two flood agencies in the lower watershed, along with participants from Stanford and the Watershed Council to work together on shared interests," she said in an email.

East Palo Alto, Palo Alto, Menlo Park, the San Mateo County Flood Control District and the Santa Clara Valley Water District formed the Joint Powers Authority in 1999, with San Francisquito Creek Watershed Council and Stanford University as associate members.

The Joint Powers Authority was tasked with finding ways to facilitate bank stabilization, channel clearing, creek maintenance and flood protection, including finding funding for long-term flood protection.

In June 2000, the agency initiated an urgent project to restore the levees constructed in 1958 downstream of Highway 101 to their original elevations to help decrease the overbanking. That work was completed in 2002, according to the agency. The authority worked on other impact studies and developed models for understanding sediments from Searsville Dam.

In 2002, things were looking up as the House Committee on Transportation and Infrastructure in the U.S. Congress passed a resolution requesting the Secretary of the Army conduct a study of the watershed to determine if flood-damage reduction and stormwater retention was feasible. An initial draft report in 2005 found positively for potential federal funding.

But the big money never came through. Federal funding to continue an Army Corps of Engineers study was nixed in 2006 by the Bush administration after it diverted $7 million for the study to the Department of Homeland Security anti-terrorism effort.

The JPA soldiered on by securing funding from its member agencies, particularly from especially from voter approval of the Santa Clara Valley Water District’s ballot measure for “Safe Clean Water and Natural Flood Protection,” which was supplemented by grant funding for the downstream project.

Rindfleisch, a computer engineer and director emeritus at Stanford University School of Medicine's Lane Library, and Stephen Monismith, a professor of civil and environmental engineering, set about in 2003 to study the creek after years of inertia, he said.

"Nobody knew why the creek overflowed," he recalled. The initial ideas they proposed in 2009 became the basis for some of the current creek modifications, he said.

But even as the project was getting off the ground, it hit regulatory snags. When the first phase of the plan was submitted to the state Regional Water Quality Control Board in August 2012, the agency delayed the project with demands and minutiae that lasted for nearly two years. Local officials and citizens hammered on the board to stop the delays.

Finally moving forward

In August 2016 after finally securing the regulatory permits from all state, local and federal agencies, the first of two projects, the San Francisco Bay to Highway 101 project, broke ground in East Palo Alto.

Rindfleisch credited Len Materman, the Joint Powers Authority's current executive director, with getting the project off the ground. "I think Len has navigated the straights and shoals of what needs to be done," he said. "Things are really poised to happen."

The project has focused on looking at and eliminating pinch points where water flows have been restricted. For the most part, they are man-made.

The $41.35 million project's first phase, the Bay to U.S. Highway 101 segment, will protect 5,700 homes and businesses in East Palo Alto, East Menlo Park and Palo Alto from a high-water flow that includes an extreme high tide with more than two feet of sea-level rise -- a so-called 100-year flood event. The work is adding new flood and retaining walls near private property in East Palo Alto, reinforcing damaged parts of the levee on the east side, widening the creek by building a new levee through the golf course and excavating decades of sediment.

A California Department of Transportation (Caltrans) bridge-replacement project over the creek and Highway 101 has added new culverts and an additional fourth culvert under the highway to accommodate additional water. Prior to the replacement, the channel flow capacity was less than half of what is needed to accommodate a 100-year storm event, according to the JPA. Caltrans agreed in 2009 to improve the floodwater capacity of the bridge structure to match the JPA's downstream improvements. The JPA is designing and constructing the widened inlet from the creek at the upstream side of West Bayshore Road, and the outlet from the bridge at the downstream face of East Bayshore Road.

Materman said that residents are already receiving protections because of the modifications.

"Even with the fourth culvert not yet opened, the three new ones functionally can pass more water than the old bridge," he said. He added that it is now "impossible" for the areas near the Highway 101 Bridge and near the floodwalls to flood.

Downstream work on a flood wall near Daphne Way in East Palo Alto is about 85 percent completed and will protect homes and businesses on both sides of the creek east of the highway, some of which flooded in 2012. Crews are currently constructing a new levee along the Palo Alto Golf Course and restoring the Faber Marsh north of the creek.

Work on new levees from Daphne Way in East Palo Alto to Palo Alto's Geng Road past the Friendship Bridge is paused until June and still leaves some neighborhoods in East Palo Alto vulnerable, he said. Work near the baylands can only be done when the threatened Ridgeway’s rail, an elusive bird that lives in the marshes, isn’t nesting, which is another slowdown the project has faced.

In Palo Alto, a large, 300-foot-long concrete structure is being removed, along with some areas with sacked concrete. The structures will be replaced with other hard material further back into the creek, widening the channel and using much less concrete. In the neighborhood on the west side between Newell Road and Manhattan Avenue in East Palo Alto about a quarter mile upstream from University Avenue, the creek is being widened, which should help protect the very vulnerable area, which saw significant flooding of homes and apartments in 2012 and 1998.

The JPA will not be addressing the Newell Bridge replacement at Woodland Avenue, which connects Palo Alto and East Palo Alto. That project is being undertaken by Palo Alto, Materman said. But the JPA has provided the city with data on how much water would flow under the bridge as a result of the upstream project at Pope-Chaucer so that the Newell construction can be adequate. The City of Palo Alto is scheduled to release its Draft Environmental Impact Report for the Newell project in the next several months, Materman said.

The next steps

With the lower creek construction nearing completion, the JPA has turned its attention toward the second project phase: Upstream of Hwy. 101 Project, an area from the west side of the freeway to Middlefield Road. The agency has held a number of public meetings, the latest in October 2017, which included a tour of the project site. About 16 alternatives based on public comment came out of those meetings, which included everything from removing the Pope-Chaucer Bridge to raising it above grade and adding a culvert under Palo Alto Avenue.

Materman said that some of the alternatives are infeasible, but staff has looked at all of them and is narrowing the list down. In the next few months, the JPA expects to publish its Draft Environmental Impact Report, which will be open for public comment. More public meetings would be held, he said.

With any luck, he hopes the project would begin construction in 2020 or 2021 at the latest. The project would take two construction seasons to complete, probably finishing in 2022, he said.

But those hopeful goals are based on when the project can get regulatory approval from the multiple agencies involved: the San Francisco Regional Water Quality Control Board and state and federal agencies such as California Department of Fish and Wildlife and the U.S. Fish and Wildlife Service.

Stanford University's Searsville Dam could complicate matters. The dam is facing possible demolition or other expensive mitigation efforts due to a lawsuit filed by environmental groups Our Children’s Earth Foundation and Ecological Rights Foundation over water retention, which is impeding the passage of threatened steelhead trout that use the creek for spawning. The university is under a court order to come up with a way to mitigate the lost creek flow caused by the dam.

The university, along with multiple regulatory agencies and the JPA, including an advisory group, sought alternatives that would not compromise the fish and other sensitive species, yet could allow for increasing water and silt loads down the creek. Increased silt load could be a sticking point.

In its April 2015 Searsville Alternatives Study Recommendations, which was developed by a steering committee including input from the Water Quality Control Board, the university proposed two alternatives to removing the dam: allowing it to completely silt up (it is already 10 percent from reaching that capacity) and letting the water flow over the top, adding fish ladders to assist the steelhead; or boring a hole into the bottom of the dam, which would add a valve that would regulate the water coming from the creek on the far side of the dam during high-rain events to prevent downstream flooding. But the report also noted that both options would increase silt load down the creek. The dam has trapped sediment since 1892 -- 126 years worth. The fine particles are expected to wash out to San Francisco Bay, carried by the increased water flow. But coarser material could collect in the creek, narrowing its banks and raising the water levels, the report noted.

Enter the Regional Quality Control Board, which in a Jan. 18 letter to Materman made clear it wants the JPA to address the Searsville-induced sediment in its Draft Environmental Impact Report.

That letter, and circulation of it, sparked multiple concerns from residents affected by the downstream flooding that having to mitigate for Stanford's theoretical future sediment loads could push the JPA's Phase 2 project back many years.

But Materman said this week that the JPA plans to demonstrate that the downstream project won’t increase the deposit of that would move naturally from Searsville. The project would mitigate any impacts if it does increase sediment.

The Water Board wanted to link changes to Searsville four years ago when JPA sought a permit for the flood project's first phase from the bay to Highway 101. At that time, the JPA argued that if Stanford modifies the dam the university would be responsible for addressing the impacts of their project. Stanford has said it recognizes its responsibility in writing, he said.

The JPA's project would alter less than 4 percent of the creek between Searsville and the bay, he said. Replacing the Pope-Chaucer Bridge, if that occurs, and removing other constrictions downstream would be minimal work that would remove impediments and would allow speeding water to carry much of the sediment from Searsville out to the bay, he said.

"The object of the project is to achieve meaningful flood protection that can be achieved near terms -- at least to protect to the flood of record of 1998," he said. The Water Board's letter isn't delaying the JPA's plan to release the draft EIR in 2018, he said. "We are doing early designs of the project."

Materman said he is also hopeful that, given these same issues came up during the first phase of the project the JPA can work through them with the Water Board.

"Since we got the downstream project permitted our relationship with the board is much better," he said. He noted that board members attended the October public meetings, which "shows they are truly engaged," he said.

Materman said he has met with Stanford for years about Searsville. On Feb. 1, he again met with Stanford officials regarding a long list of information the JPA has been seeking to evaluate the sediment. He outlined the JPA's needs in a Jan. 8 letter to the university. Stanford has provided some documents, but not all.

He said the JPA is doing everything it can to ensure the project isn't slowed down by the flow of documents from the university.

Rindfleisch said it is likely to be decades before corrections at the creek's upper source at Searsville Dam will be addressed. Residents and creek watchdogs who experienced the 1998 flood said they have waited far too long already, and they can’t see the point of waiting to do the lower creek work until Stanford figures out what to do with Searsville.

"Twenty years is a long time to sit with that (threat) sitting over our heads," Rindfleisch said.

As manager of the Crescent Park Neighborhood Association's email list, he said every winter when there are heavy rains he gets calls from people who worry about flooding.

"People just live with this constant harassment of the creek," he said. The Searsville project "is probably a $100 million project and it is subject to regulations. ... We're talking about a 10- to 20-year effort. We cannot stand for that. We have had a half-dozen really close calls at Pope-Chaucer in the last five years or so."

Comments

Like this comment
Posted by Harold Schapelhouman, Fire Chief
a resident of Menlo Park: Stanford Weekend Acres
on Feb 4, 2018 at 11:19 am

From the Menlo Park Fire District:

That was a busy night and week starting with two Swift Water Rescues from homes along Alpine Road in the Stanford Weekend Acres neighborhood and then a man trapped in a car almost completely submerged on the 1900 Block of University Avenue (Wiskey Gulch) and finally hundreds of people moved out of Apartment Buildings by using our Ladder Trucks (Quint’s) along West Bayshore in East Palo Alto where the water was chest height in places.

Cars in apartment complexes along East Okeefe in below grade garages were completely submerged and the levee failed along the Mosley Tract just north of the Dumbarton Bridge flooding along Bayfront Expressway and threatening its closure. A small building was washed off its foundation and pinned against a tree 2655 Alpine Road (Weekend Acres). Highway 101 was Closed due to flooding, standing water, mud and abandoned vehicles between University and Embarcadero because the new freeway sound walls and continuous concrete center divider had created a levee condition trapping the water coming from the overbanking of San Francisquito Creek.

The creek bank erosion, damage, under pinning of trees and power poles was most severe behind homes along Bay Laurel, Oak Avenue, and San Mateo Drive. The old candle shop at Allied Arts was partially hanging over the edge of the creek bank. Woodland between Pope and Laurel had major Creek bank damage and erosion. Woodland Avenue in general between Willow and West Bayshore had bank damage throughout. Up on Walsh Road along the Atherton Channel various bridges were damaged and Sharon Heights had a number of small mud slides and sluffing.

By the time the sun came out that next morning the Fire District had run Some 300 emergency calls. Unfortunately one fire truck was completely out of service because the electronics had been destroyed by water submersion, another was damaged after it had to be pulled out of a drainage ditch, one command vehicle was damaged when a power line fell on it and another had the antennas ripped off due to low hanging tree branches. Three of seven fire stations had minor roof leaks but the good news was no fire personnel were injured, despite some close calls performing water rescues and responding to emergencies under darkness and adverse weather conditions all night long.

Subsequent flooding events have not been as severe and much has improved sine the creation of the Creek JPA but the understanding that the areas below a bowled mountain range that spans an area from Palo Alto to Woodside that then funnels water down to a bay that can also simultaneously experience high tides should always provide a cautionary history that requires vigilance, planning, preparedness and readiness when ever it starts to rain, regardless of the improvements being made.


2 people like this
Posted by Peter Carpenter
a resident of Atherton: Lindenwood
on Feb 4, 2018 at 11:52 am

Peter Carpenter is a registered user.

Sue - Superb reporting - Thank you!


Like this comment
Posted by whatever
a resident of Menlo Park: Central Menlo Park
on Feb 4, 2018 at 12:47 pm

Excellent article. However I had heard that one of the floods in the 1950s was the largest having flooded large sections of MP west of ECR?


2 people like this
Posted by Peter Carpenter
a resident of Atherton: Lindenwood
on Feb 4, 2018 at 2:48 pm

Peter Carpenter is a registered user.

The real flood threat comes from the Bay not from the foothills. Over the next few decades a large portion of the Eastern side of Menlo Park, Palo Alto and East Palo Alto) will be below sea level and an even larger portion will be subjected to significant seasonal flooding. There has been no planning for this hazard and significant efforts need to be
made now to mitigate those flood hazards, to provide for a real time warning system that does not rely on cell phones or the internet and to provide well thought out neighborhood evacuation plans for all of the potentially impacted areas AND for the adjacent areas which will, of necessity, serve as evacuation sites (whether planned for or not).

Reference: The Water Will Come: Rising Seas, Sinking Cities, and the Remaking of the Civilized World
by Jeff Goodell


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