Rising Sea Stage Threatens Stinson Seashore Neighborhoods – CBS San Francisco

SAN RAFAEL (KPIX) – Coastal communities are still grappling with rising sea levels caused by global warming. The US Geological Survey predicts the ocean could rise up to seven feet by 2100 and about 600,000 homes could be at risk of flooding. Many of them are in Marin County.

Sea level rise threatens homes and infrastructure near Stinson Beach. The State Coastal Commission has the final approval authority there and wants to stop the construction of walls and let nature take its course. Residents and the district are pushing back.

“We anticipate that there will be a fire, we anticipate that there will be an earthquake, and we plan to do it. But how much will the ocean really rise? “Asked Mike Matthews, president of the Stinson Beach homeowners association.

Matthews is all too familiar with the threat of sea level rise.

It first took center stage six years ago when property owners in low-lying neighborhoods known as Calles and Sonoma Patio received a letter from the county warning them that a rise in sea levels would affect their ability to Obtaining permits for improvements to their properties.

“A lot of people who loved their beach house and a minute and a half walk to the beach suddenly found that they weren’t going to get permission for anything,” said Matthews.

Any structure within 1,000 feet of the coast called the coastal zone could potentially be affected.

“That means, ‘I can’t sell your house,’ and that means it is depreciating in value, so there was an extreme response,” said Matthews.

The county was pressured by the Coastal Commission to update its local coastal plan, and the commission proposed something called a “managed withdrawal”. That essentially means relocating or abandoning all structures in the coastal zone – in this case the entire city instead of protecting it.

“If you say, ‘well, we’re going to move these houses’ – well where are you going to move them to?” Jack Liebster, County Marin Planning Manager, asked. “These are pretty expensive areas, and where do you get the money for them? That’s … a big question,” added Liebster.

He says a managed retreat could also prevent plans to elevate or protect a low-lying section of Highway 1 near Stinson Beach. “Highway 1 is an icon for the state of California, and it wouldn’t be very good if a piece was missing in the middle of the highway,” Liebster said.

In 2018, Marin County officially proposed a more moderate plan for sea level rise. Liebster says the Coastal Commission sent it back with changes the county refused to accept. The discussions have come to a standstill until now. This year, he says, the district is back at the table with some new ideas.

“One of the things we are considering are nature-based alternatives,” Liebster said. Among other things: Using dredging material from the bottom of the bay to raise the level of the wetland, a project already being carried out in the San Rafael Canal District.

At Stinson Beach there are plans to create a dune system by importing more sand and planting beach grass. That worked well at Lawson’s Landing, a popular campsite at the entrance to Tomales Bay.

“The Lawson family is definitely friends with European Beach Grass,” said Willy Volger, partner at Lawson’s Landing.

He says the beach has actually gotten bigger there over the years, but he knows things can change so a managed retreat could become a necessity.

“The beach is a moving, living thing and we hope that it can grow with us and that we can stay here. But when things don’t work that way, we have more property continuing up the hill, ”said Volger.

Back in Stinson Beach, Seadrift’s exclusive, gated community thought ahead.

“When they could, they got permission to install a very expensive rock wall on the edge of the Seadrift properties on the ocean side,” said Matthews.

Multimillion-dollar homes in Seadrift are built on raised foundations, but the less affluent Calles and Patios neighborhoods of the lowlands remain vulnerable and may soon become unable to protect themselves.

“I wouldn’t want a house down there now,” said Matthews.

He hopes this time around the talks with the state on a local coastal plan will include more compromise, with a focus on shorter 20 years instead of the 100 year plan proposed by the Coastal Commission.

“It is true that you have to look for the worst events in planning, but you want to have a sense that they will actually occur. Let’s see what actually happens and then we get it, ”said Matthews.

The Coastal Commission declined our request for an interview for this story. Two years ago, when we were looking at the same topic in Pacifica, their top expert KPIX announced that there was no time to compromise.

WEB LINKS

KPIX: Homeowners fear losing property due to guidelines to counter sea level rise

Coastal protection: adaptation of sea level rise

Marin County Foundation: Nature-Based Adaptation

San Rafael: Tiscornia Marsh Restoration Project