General

Here's an article from today's IJ that may be of interest.

Novato landslide repairs to cost $10M, continue through summer

Will Houston

Redwood Boulevard is cracked and buckled after a mudslide near Buck Center Drive in Novato on Wednesday, March 22, 2023. (Alan Dep/Marin Independent Journal)

Nearly two months after a major mudslide destroyed a section of a Highway 101 frontage road near Novato and blocked access to a state park, Caltrans estimates repairs will be completed in

September at a cost of $10 million.

The storm-fueled mudslide on March 21 buckled 100 feet of Redwood Boulevard just north of Novato and threatened two major utility lines serving Marin. The slide also cut off the only access road to Olompali State Historic Park to the north. The park has remained closed since the slide.

Caltrans spokesman Matt O’Donnell said design work to rebuild the road is expected to be completed soon, with construction planned to start around June 10.

“We hope to open everything by September,” O’Donnell said.

While the landslide did have some movement in April, it has since stabilized, according to O’Donnell.

Redwood Boulevard remains closed between Buck Center Drive and San Antonio Road, cutting off access to a bike path just north. Cyclists must make a 17-mile detour.

O’Donnell said plans are in the works to create a shorter detour located closer to the slide area, but crews have no estimate of when the work will be completed.

“They are waiting on PG&E to complete their work so we can build that temporary bike path or work on that alternate detour,” he said.

The location of the slide is also where natural gas and water pipelines that serve tens of thousands of Marin residents are buried. While the mudslide did move and damage Pacific Gas & Electric Co. power poles, it did not damage the two gas lines that serve 93,000 Marin residents. Gas service and electric service have been able to continue without interruption.

The slide also moved, but did not damage, an aqueduct at the

bottom of the hillside that carries Russian River water into Marin County. The aqueduct provides 75% of the water supply for 60,000 residents in the Novato area served by the North Marin Water District and about 25% of the water supply for 191,100 central and southern Marin residents served by the Marin Municipal Water District.

Out of caution, the aqueduct was shut off for nearly a month in case of further slide movement, said Tony Williams, general manager of the North Marin Water District. A break in the aqueduct could cause millions of gallons of water to flood onto the nearby Highway 101.

No damage has been observed after several examinations, Williams said, and the aqueduct has running at full operation since late April.

Without the aqueduct in service, the district had to rely on its only reservoir, Stafford Lake. The lake is typically used as a supplemental water supply during the warm months when water use is at its highest.

If the aqueduct were not in service, the amount of water that could be treated at the Stafford Lake treatment plant would not be able to meet typical demands for this time of year.

Williams said an emergency declaration approved by the district last month gives him the authority to implement emergency water use restrictions should the slide begin to move again.

“We have normal flow but we’re still very cautious and we have this protocol in place between the agencies,” Williams said. “If we see any anomalies we shut it down. But so far so good.”

Olompali State Historic Park is not expected to reopen until the Redwood Boulevard repairs are completed, said California State Parks Deputy District Superintendent Matthew Allen.

“We definitely would like the repairs done as soon as possible and get access to the public for recreation,” Allen said.

Upkeep of the 700-acre park has been able to continue, with staff accessing the park on the bike path to the north. Some employees live in the park.

“One of our concerns was garbage,” Allen said. “We do have several state residences in the park so one of our concerns was garbage and propane delivery. We were able to work that out with the utility companies.”

Some staff were relocated to other nearby state parks, Allen said.

While access to the park is still possible using the bike path, Allen said the park will remain closed. The path is being used to store equipment for construction crews. Additionally, the limited access would pose a safety risk in case of an emergency or medical issue, he said.

“So far people have been respecting the closure and we’re not seeing a lot of people trying to access, so we definitely thank the public for respecting that. We’re hoping to get the park open as soon as we can,” Allen said.