Flooding Study Results Require Action

When heavy rains returned to California last winter after an extensive drought, some Bay Area cities experienced flooding for the first time in many years.  Now, a new study shows that kind of flooding will become chronic in many Bay Area locations in the decades to come.

The Union of Concerned Scientists report provides even more detail on how much climate change will affect specific Bay shoreline cities, and how soon.

As early as 2035, neighborhoods all around the Bay Area–on Bay Farm Island, Alameda, Redwood Shores, Sunnyvale, Alviso, Corte Madera, and Larkspur– would experience flooding 26 times per year or more, and that’s with moderate sea level rise.  By 2060, the number of affected neighborhoods grows to include Oakland, Milpitas, Palo Alto, East Palo Alto, and others along the corridor between San Francisco and Silicon Valley. If the sea level rises faster, that frequency of flooding will occur sooner. Read the full report at http://bit.ly/2vacc5j.

The report raises another problem. The Federal Emergency Management Agency’s maps of flood-prone areas are outdated and don’t reflect sea level rise projections. Those maps determine where property owners can and cannot qualify for federally-subsidized flood insurance, and where communities must construct additional flood protection to retain that insurance.

Outdated maps give communities a false sense of security and lead to uninformed development decisions.  Just ask those homeowners near Coyote Creek in San Jose who were flooded out a few months ago.

The State of California and its agencies, including the Bay Conservation and Development Commission, should be aggressively reducing risks to people and property from climate impacts – that has been explicit in the State’s climate adaptation strategy since 2009.  Pressing FEMA for updated maps should be high on the priority list.

Here’s a report on the UCS study in the San Jose Mercury News, which quotes Save The Bay:

A Feb. 21 photo from a San Jose city worker shows flooding at 1742 Rock Springs Drive. (City of San Jose)
A Feb. 21 photo from a San Jose city worker shows flooding at 1742 Rock Springs Drive. (City of San Jose)

Chronic flooding from rising seas could plague many Bay Area waterfront communities such as East Palo Alto, Alameda and San Mateo within four decades, a nonprofit science group said in a report released Wednesday.

While other studies have predicted inundation of coastal cities, this new study by the Union of Concerned Scientists is the first to put dates on when towns that ring the San Francisco Bay would regularly experience chronic flooding.

Rather than slam shoreline communities with epic floods every few years, rising sea levels threatens to flood streets, yards, parks, homes and businesses in low-lying areas several times a year, the scientists said.

“Cities around the San Francisco Bay will begin to experience more frequent and disruptive flooding in the coming decades and will have to make tough decisions around whether to defend existing homes and businesses or to retreat,” said Erika Spanger-Siegfried, senior analyst in the Climate and Energy Program at UCS and a report author.

Airports and low-income housing in low areas are particularly vulnerable, the study said.

While airports can draw on business income to pay for defenses against rising seas, many poorer neighborhoods are hard pressed to afford bigger seawalls or levees or to move people out of flood-prone areas, said Kristy Dahl, a UCS climate scientist and co-author of the report.

She said the report underscores the need for federal policies to help local communities.

“We shouldn’t have some communities left behind simply because they don’t have the resources of their neighbors,” Dahl said in an Oakland press conference to discuss the study. “A large number of these communities don’t have the resources they truly need to adapt.”

Last year, the federal government announced its first grant to buy and relocate a small town — Isle de Jean Charles, La. — for $48 million after concluding it was not worth trying to save the community in place.

The Union for Concerned Scientists study assessed three scenarios — low, intermediate and high sea-level rise — by the years 2060 and 2100, depending on the pace of emissions and melting rates of polar ice. An interactive series of maps show when inundated communities may reach tipping point, with at least 10 percent of usable land flooded at least 26 times per year.

The study found that:

  • By 2060, in the high sea level rise scenario, parts of many Bay Area communities would face flooding 26 times or more per year, or every other week. Communities with affected neighborhoods include Alameda, Oakland, Palo Alto, East Palo Alto, San Mateo, Burlingame, San Francisco, Corte Madera and Larkspur.
  • By 2100, in the intermediate sea level rise scenario, chronic flooding would affect public infrastructure such as San Francisco International Airport, Oakland International Airport, San Quentin State Prison, Moffett Federal Airfield and the Bay Bridge.
  • By 2100, in the intermediate sea level rise scenario, two Bay Area communities would see more than 10 percent of their land chronically flooded: Alameda and San Mateo.
  • By 2100, in the high sea level rise scenario, more than half of Alameda, about 11 percent of South San Francisco and about 14 percent of Oakland’s land area would be chronically flooded.

“Imagine what it would be like to have your driveway and backyard flooded every every other week on average,” Dahl said, “And you can’t let your kids play in the back yard because it’s flooded.”

The “low scenario” assumes a San Francisco Bay water level rise of around 2 feet by 2100, a carbon emissions decline, and global warming limited to less than two degrees Celsius — in line with the primary goal of the Paris Agreement.

The “intermediate scenario” projects a four-foot water level rise and carbon emissions peaking around mid-century and about four feet of sea level rise globally. In the high scenario, emissions rise through the end of the century and ice melts faster, causing 6.5 feet of sea  level rise.

The group applauded efforts by cities such as San Francisco and Foster City, which already have begun planning where and how to build seawalls and levees. Other regions — such as the cities of Alameda, Hayward and Oakland and Contra Costa, San Mateo, Alameda and Santa Clara  counties — are close behind, identifying potential strategies.

Welcoming the report, David Lewis of the Oakland-based nonprofit Save The Bay said it underscored the need for the Federal Emergency Management Agency to update Bay Area flood maps to reflect new projections. Those flood maps determine where property owners can and cannot qualify for federally-subsidized flood insurance, and where communities must construct additional flood protection to retain that insurance.

He urged the state to press FEMA to update the maps. Congress also must be prodded to provide funding for the updates, he added.

“If maps don’t incorporate projections for sea level rise — and for increased frequency of flooding from extreme storms independent of sea level rise — then communities have a false sense of security, and property values, as well as public and private planning and development decisions, don’t accurately reflect risks,” said Lewis.

“Ask those homeowners near Coyote Creek,” which flooded last winter, he said.


This article was originally published in The Mercury News by Lisa Kreiger and Denis Cuff on 7/12/2017. 

Meeting the Challenge of Sea Level Rise

Too often, we let big and complicated (or just plain uncomfortable) issues linger until it’s too late to change.  Call it what you will – the urge to act like an ostrich and stick your head in the sand rather than deal with problems head-on is something innate in each of us.

Threats to our shoreline communities vary dramatically throughout the region.
Threats to our shoreline communities vary dramatically throughout the region.

And that’s part of why it was so refreshing to see over 400 individuals, agency staffers, local elected officials and scientists come together earlier this week for a wide-ranging set of conversations about the challenge of Sea Level Rise to the Bay Area, and San Mateo County specifically.  Supervisor Dave Pine brought together fellow elected officials (including Congresswoman Jackie Speier and Assemblyman Rich Gordon), scientists, agency heads, and other local leaders on the issue.

Here are some significant takeaways from the morning of talks.  You can learn more about the event and presenters here.

 

We need to start planning now:

Author and Oceanographer John Englander put it best in his talk, we know there will be at least 3 feet of sea level rise throughout the Bay.  We just don’t know – at least not precisely – whether it will take 20 years or 50 years for those projections to become reality.  With that in mind, there’s a strong argument for focusing not on the timeline, but on the level of protection needed to keep our shoreline communities safe, and keep the Bay healthy.  That means we need to start planning now; waiting for more accurate projections will only increase adaptation costs and put more of our shoreline at risk.

 

Different communities have different needs:

As a region, we’re all over the map.  Some counties have built right up to the shoreline, and are facing deep investments in what’s called “hard infrastructure” – the levees and other flood protection that we’re so used to seeing in New Orleans and elsewhere.  But other communities have significant restoration potential (particularly the South and North Bay), where salt ponds and former wetlands can provide incredible benefits to wildlife and communities by buffering against storm surges, which in turn means levees can be smaller and less costly.  There isn’t a one-size-fits-all solution; we will have to be creative in addressing the challenges of sea level rise.

 

Barriers exist, but none are insurmountable:

More than anything else, panelists (and local elected officials) showed that while there are countless barriers that need to be overcome in coming decades, none are insurmountable. And these barriers must be tackled from the local to the federal level.  Panelists from FEMA  discussed necessary changes to mapping and setting rates for flood insurance,  while the Army Corps of Engineers highlighted new challenges to designing and building much of the levee infrastructure. Both called on local pressure from elected officials and residents to change outdated thinking and plan for the future.  Locally, Supervisor Pine and Sam Schuchat, head of the California Coastal Conservancy, highlighted the opportunities presented by a regional funding strategy they are working on as members of the San Francisco Bay Restoration Authority.

 

Adaptation to sea level rise will continue to be a complex issue  filled with significant challenges.  But events like this one in San Mateo are a strong first step in raising the profile of issues like sea level rise, and beginning conversations about how we’re going to address one of the greatest challenges of the coming century.

Weekly Roundup | April 19, 2013

newspaperCheck out this week’s Weekly Roundup for breaking news affecting San Francisco Bay.

Slate 4/19/13
Seven Spectacular Places Saved by the Environmental Movement
The first Earth Day, in 1970, was inspired by anger. The nation was a mess. Four million gallons of oil from a blown offshore well were smearing California beaches. Flames leapt from the surface of Ohio’s Cuyahoga River. Bald eagles, our national symbol, had been winnowed by hunting and chemical pollution to a few hundred breeding pairs in the lower 48 states. It’s no wonder that 20 million people took to the streets.
Read more >>

Tri-City Voice 4/16/13
Beyond Earth Day
Picking up a few empty bottles or planting some trees Earth Day morning has become regular duty for any Bay Area resident with a conscience. The trio below just kept going after “E Day” and shows how average people can make a big difference in our place by the Bay.  Steve Haas started volunteering with Save the Bay about four years ago. Save The Bay is a nonprofit organization dedicated to preserving San Francisco Bay and has been doing it for over 50 years. The management consulting and software development professional retired about two years ago and spends more and more of his free time with Save the Bay and other environmental organizations, getting out once or twice a month to assist projects at Eden Landing in Hayward and other locations on the Peninsula. The projects involve removing invasive plants, planting native species, mulching, and watering. Haas says he enjoys all of these, but especially removing the invasive plants.
Read More>>

San Francisco Bay Guardian Online 4/16/13
Warriors Arena proposal rouses supporters and opponents
Rival teams have formed in the last week to support and oppose the proposed Warriors Arena at Piers 30-32 as the California Legislature considers a new bill to approve the project, a new design is about to be released, and a trio of San Francisco agencies prepares to hold informational hearings.  Fresh off the collapse of two of the city’s biggest development deals, Mayor Ed Lee and his allies are pushing hard to lock in what he hopes will be his “legacy project.” A new group of local business leaders calling itself Warriors on the Waterfront held a rally on the steps of City Hall today, emphasizing the project’s job creation, community partnerships, and revitalization of a dilapidated stretch of waterfront.
Read More>>

San Jose Mercury News 4/13/13
Family of beavers found living in downtown San Jose
A family of beavers has moved into Silicon Valley, taking up residence along the Guadalupe River in the heart of downtown San Jose.  The discovery of the three semiaquatic rodents — famous for their flat tails, brown coats and huge teeth — a few hundred yards from freeways, tall office buildings and the HP Pavilion represents the most high-profile Bay Area sighting since a beaver family settled in Martinez in 2006. The discovery of those beavers sparked national headlines when city leaders at first tried to remove them and then backed down after public outcry.  The appearance of the furry mammals in downtown San Jose is believed to be the first in 150 years.
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San Mateo Daily Journal 4/17/13
San Mateo moves to ban plastic bags, polystyrene
The San Mateo City Council voted unanimously to support a reusable bag ordinance, completing the regional effort in San Mateo County and parts of Santa Clara County to reduce litter.  The amendment to city code promotes the use of reusable bags as an alternative to single-use plastic and paper bags and mirrors a countywide effort.  The City Council also voted Monday night to support the polystyrene ban which will ban the use of polystyrene in restaurants and delicatessens.  Adoption of both ordinances is expected May 6 with implementation beginning June 6 in San Mateo.  San Mateo County, along with many other cities will implement the reusable bag ordinance Earth Day, April 22.
Read More>>

Oroville Mercury-Register 4/15/13
Legal action threatened if Chico adopts plastic bag ban
An attorney for the Save The Plastic Bag Coalition is threatening legal action if the city of Chico moves forward with its proposed ban on plastic bags.  The City Council is set to consider an ordinance Tuesday that would prohibit specified stores from providing single-use plastic carryout bags and require a charge for the provision of single-use recyclable paper bags. The ban is slated to take effect next Jan. 1, after an extensive educational campaign.  Attorney Stephen L. Joseph said the Los Angeles-based Save The Plastic Bag Coalition objects to the ordinance’s adoption without prior preparation and certification of an environmental impact report. In an email to the city, he said the coalition would file a petition in court for writ of mandate if the document is not prepared and request the court invalidate the ordinance.
Read More>>

Marin Independent Journal 4/13/13
Environmental group proposes hybrid levees for Marin, other bayside counties as sea rises
Fortifying the bay’s shoreline with levees fronted by restored tidal marshes is a cheaper, more aesthetic and ecologically sensitive way to protect Marin and other bayside counties from sea level rise, according to a new report by a Bay Area environmental group.  The Bay Institute’s report — the subject of a panel discussion earlier this month in San Francisco — proposes restoring tidal marshes with sediment from local flood control channels and irrigating the marshes with treated wastewater. The plan also calls for “horizontal levees” that are a hybrid of traditional earthen levees and restored marshes. The conclusion was based partly on research done in the lower Corte Madera Creek watershed.
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