Rancho Palos Verdes dealing with landslide 'twice as deep' as what had been modeled, geologist says

RANCHO PALOS VERDES, Calif. (KABC) -- The city of Rancho Palos Verdes is dealing with more land movement from a larger slide plane than what was previously reported, the city's geologist said.

"What we've now confirmed with about 10 borings on the site, at least in the Portuguese Bend area, is that there is a landslide that's almost twice as deep as what had been modeled," said geologist Mike Phipps.

On Tuesday, the city council held a meeting to address the issues and discuss next steps.

"They're finding that there is a second slip plane that's actually lower that's moving the entire landslide complex," said Mayor John Cruikshank.

Phipps said the rate of the land movement overall has leveled off, but it's still moving 3.5-4.5 feet per month. He compared it to a car going from accelerating on a freeway to cruising.

"If you look at all the data as a whole, the landslide, as a whole, has actually decelerated 1%," said Phipps. "But there are areas, some areas have accelerated up to 13% and some areas have decelerated up to 13%. But overall, it's a 1% deceleration."

According to the city's website, generally, movement on the north and west ends of the landslide complex is slowing down, while movement at the south end continues to accelerate.

The absence of rain over the past three months has temporarily slowed the movement, but Phipps said time is of the essence.

In July, 135 homes had their gas service cut off as a result of the movement, forcing homeowners to reassess their plans.

"Most of them are actually staying in their homes, trying to ride this out, literally," said Cruikshank. "Trying to find ways to convert from what they once used, gas to heat water and their food, to now using electricity or propane."

Since spring 2023, the city has seen a significant increase in movement that has resulted in roadway damage and the red-tagging of two homes that were damaged severely enough to be dangerous to inhabit.

The land movement has also caused water and gas distribution pipes to break, displaced sanitary sewer collection pipes and made utility poles lean. On Oct. 3, 2023, the Rancho Palos Verdes City Council declared a local state of emergency, which was renewed on May 8.

So what's being done to slow down the movement?

"Underneath the base of the landslide, there's tremendous water pressure in the fracture space of all the rocks pushing up on the landslide," said Phipps. "So the idea is to try to relieve some of that pressure. If it works here, we can employ it elsewhere and hopefully try to slow this thing down."

Earlier this month, Cruikshank asked Elon Musk to help homeowners in the landslide area affected by the gas shutoffs and potential electricity shutoffs.

"Given Tesla's advancements in solar technology and energy storage solutions, we see a potential partnership to equip these homes with solar panels and Powerwall batteries," read a letter sent to Musk. "This initiative would not only provide these residents with immediate relief, but also demonstrate the viability of clean energy solutions in a real-world scenario, further solidifying Tesla's role as a leader in the green energy revolution."

Cruikshank said he would be meeting with the Tesla energy team as well as other energy storage companies later this week.

He's also exploring additional methods to help stop the land movement. Residents can get updates on the landslide and the city's efforts here.

City News Service contributed to this report.