Threat of hillside crashing into Point Richmond homes may not be over for months
RICHMOND – Tuesday brought another day of rain and more concerns over debris flows and mudslides.
There are a number of areas that have already been impacted, including the hillside above Seaview Drive in Point Richmond, where back in January a total of 15 homes were evacuated due to threats of a slide.
Experts say the danger for some communities might not be over for months.
"That's another one over there," said Mary Lou Clarke, pointing to the plastic drainage pipes right outside her front door.
Clarke lives directly across from a damaged area of hillside in Point Richmond now covered by huge sheets of plastic held down by strings of sand bags.
"It's not doing too bad in this storm," she told KPIX as she looks out over the plastic covered slope.
Clarke and her husband Lance have lived in their home on Seaview Drive since 2008, but were forced to evacuate for 24 days at the beginning of January after massive cracks appeared at the top of the hillside, a possible warning sign of a dangerous slide.
"The tension at the beginning was really tough. But as it wore on and nothing happened and nothing happened, it was a relief. We were pleased that they actually did that work," said Clarke.
The land owners hired contractors to cover the hillside with tarps and install temporary drainage systems to prevent more water from soaking into the ground, all to reduce the risk of a future slide.
In other places around the Bay, the ground is still moving.
"That tells you that there's elevated soil moisture that could lead to an instability," said Jeremy Lancaster, a geologist with the California Department of Conservation.
Lancaster said the risks of debris flows and shallow slides are highest during and immediately after strong storms, but the risk of deeper landslides can last for weeks or even months.
"It takes a long time for the water to percolate through the soil down to the rock, 50 to 100 feet down into the hillslope, but we've seen deep-seated landslides occurring, sometimes a couple months after the last rainfall," he said.
For Point Richmond residents like Clarke, the threat of a mudslide still looms large.
"We really didn't want to leave," she said, looking out her back door of a view of the Richmond marina.
There is still a significant amount of stabilization work that needs to happen here in Point Richmond. While the tarps and pipes offer a temporary solution, the permanent fix can't begin until the rain ends. Engineers said they're confident the area is stable, for now.
