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Defending San Francisco, from Breakers to Bay - By tom-molanphy - October 5, 2017 - SF Weekly
SF Weekly

Defending San Francisco, from Breakers to Bay

(Photo: Jessica Christian)

The reports out of New Orleans in 2005 were grim. Katrina’s epic storm surge was rising so fast that some residents, certain they would be washed away, taped their driver’s licenses to their bodies to ensure their corpses could be identified.

The 2017 Atlantic hurricane season has continued Katrina’s legacy of destruction. Although the cold waters of the eastern Pacific can’t churn up quite the same fury that the Atlantic can — hot water contains more energy, and thus it can spew out massive storms — it doesn’t mean San Francisco is safe from the rising waters. The National Research Council has forecasted average tides in the Bay Area to rise from 3 to more than 5 feet by 2100, so experts from breakers to Bay are wondering: where will all that water go?

Ocean Beach’s surf has pounded the ill-placed Great Highway for generations. It’s part of Mother Nature’s timeless leverage against humanity: She’s been designing her system for billions of years, and she can go billions more — with or without us.

Instead of outmuscling, outsmarting or waiting out Mother Nature, the Ocean Beach Master Plan, created by by the San Francisco Bay Area Planning and Urban Research Association, is a comprehensive plan to respond to severe erosion issues on the 3.5-mile stretch of beach between the Cliff House and Fort Funston.

Spaced out over a 40-year period, it offers a dramatic solution: Give way to the pounding waves and make some room for the original ecosystem.

“Ocean Beach is one of the places already exposed to coastal hazards, and luckily, some adaptation strategies have already been done,” Benjamin Grant, the urban design policy director of SPUR, tells SF Weekly.

Although this stretch of Ocean Beach has hung on through a combination of closures, riprap (piles of rock), and dump trucks regularly hauling sand back and forth, rising temperatures pack storms with more water and more energy, which means the winter storms that batter Ocean Beach will most likely become stronger. And the rocks, sand, and dump trucks come with drawbacks.

“The boulders cover the beach up and are unsafe to cross,” Grant says. “They scour out the sand when they send waves back out and can create problems in places that don’t have the boulders.”

All things being equal, the safest solution would be to give back a large part of the Sunset to the Pacific Ocean. But not only would a few Sunset residents, fishermen, surfers, and threatened bird species on Ocean Beach have a problem with this, all of San Francisco needs an integral piece of infrastructure tucked between the Pacific Ocean and the San Francisco Zoo: the $200 million, 12-acre Oceanside Treatment Plant that handles about a fifth of San Francisco’s wastewater.

“Before the Clean Water Act, raw sewage would be poured into the ocean,” Grant says, adding that the plant “is a huge investment that needs to be protected.”

The compromise? Managed retreat, which basically means both giving into the ocean’s power but also building against it. In 2018, the first phase of the Ocean Beach Master Plan will begin closing the Great Highway south of Sloat Boulevard, and replace this section with a coastal trail.

Grant concedes that planning for global warming is more complicated than most planning. Although there is a consensus that sea level rise will occur, calculations vary on how much, which means projections of what should be done are equally uncertain.

“The farther out you go, the more the models fall apart,” he says. “But we’re lucky here in San Francisco that we don’t have to contend with climate denial.”

The arguments about what to do in San Francisco center around what is the best science — not what is science.

On the other side of the city, Elaine Forbes, executive director of the Port of San Francisco, deals with the rising tide of the San Francisco Bay.

“My job is very different in terms of where I can do a managed retreat, or just manage the water,” she says.

As hard as it is to manage the forces near Ocean Beach, the line between the bay and the billion-dollar infrastructure of transportation, housing, and commerce downtown is even more rigid: a 3-mile, 100-year old seawall from Fisherman’s Wharf to AT&T Park.

“The seawall is where managed retreat does not work at all,” Forbes says.

While housing took over the Sunset’s natural ecosystem of dunes in the early 1900s, the takeover on the city’s eastern side was dramatic and decisive: The bay was filled, and nearly 500 acres of land were reclaimed from the water.

“We have a dual threat from rising water and seismic vulnerability since the seawall sits on mud,” Forbes says. “And the soil will liquefy [during an earthquake] and push the seawall bayward, which we have evidence actually happened in 1906. We need to strengthen soil under this seawall.”

In addition to being in mud, the seawall is damaged in places, and an initial estimate for a seismic retrofit came in at around $2 billion.

Those who have been on the Embarcadero during the King Tides, when the waves rise over the sea wall, have had a preview of what could be a more frequent event by 2100.

“We have very low-lying areas,” Forbes says. “In the area of Pier 14, we already have flooding in the Embarcadero. Disaster-prone communities are always racing against the clock. Anyone living in coastal communities knows things have changed. The hubris in not reacting to what can be seen is quite stunning.”

Unlike Grant and Forbes, who are under pressure to devise a plan that satisfies multiple interests, Patrick Barnard of the United States Geological Survey focuses on understanding what’s going on with sea level rise. And he sees clear problems with Houston’s city planning.

“Houston has a lot of oil and gas and groundwater pumped out, so the center of Houston has sunk about 10 feet,” Barnard says. “They also paved over all of the wetlands with very little consideration for flood routing, which made them even more exposed.”

hese are lessons that can be useful for the Bay Area. For example, San Jose subsided about 12 feet since the first half of the 20th century, so the city curbed groundwater pumping rates over the last 50 years. And salt pond restoration helps extend the South Bay, which creates an alternate route for rising water.

Barnard emphasizes that not only water but sand and earth have natural movements that must also be taken into account when planning. “These beaches need to migrate naturally. … Otherwise, the beach will be pushed between the ocean and wall, and basically drown.”

Although the power and value of water is universally recognized, Barnard notes that sand is the second-most used natural resource behind water. And when sand is taken out of a natural system — a practice done in the bay to help make concrete — that natural buffer for storms is eliminated.

“The combination of sediment practices (such as dredging and mining) limits the amount [of sand] that gets out to the coast,” Barnard says.

In addition to stronger winter storms causing erosion on Ocean Beach and rising tides flooding from the bay, scientists like Barnard point to a third front: Rising temperatures mean Mother

Nature’s perfectly designed water-storage system of snowpack in the Sierras will see less snow and more rain, as well as by earlier melts — which means even more water for the Bay Area to deal with.

“We’re probably going to look something like New Orleans, eventually,” Barnard says. “We’re pretty dug in. Google and Facebook are in very low areas, so we’ll need to spend lots on flood protections. It looks like we will do a lot more defending and less retreating.”