Can Rancho Palos Verdes stop homes from sliding toward the ocean? A new study might find out

The city of Rancho Palos Verdes is embarking on a comprehensive study to look at how stormwater flows into the landslide complex that has been slowly ripping homes apart — and if that water can be redirected elsewhere.

The decision on Tuesday to go forward with the study comes as the city continues to grapple with unprecedented land movement that has led to around 20 homes being red tagged and dozens more damaged. The landslide has also been buckling roads, driveways and other infrastructure, prompting gas and electricity shut offs.

Read more: Rancho Palos Verdes homes continue to slide into the ocean, but the destruction could have been avoided

“ For the last 40 years, we've been basically taking water out of our basement by need to survive. And in different versions of that, we've had different levels of success, mostly tied to how much rainfall,” said Councilmember Stephen Perestam at Tuesday’s meeting. “For the first time, we're actually gonna take this step. We're gonna go look at the whole move, what's causing us to keep shoveling out the water out of our basement.”

The Portuguese Bend area of the city has been plagued by land movement for decades. The land in the area is made up of bentonite clay and when water collects in the ground there, the clay becomes slippery, causing the land to slip and slide.

What will the study entail

The study will create a model of regional rainfall patterns and map out how the water collects in the landslide area. The model will also determine drainage options and if stormwater can be re-routed elsewhere where it will do less damage. The study will also use projections for rainfall in the future.

The study will aim to determine how groundwater flows within the landslide complex. This will help the city strategically place wells that pump water out of the ground.

While it seems as if California is always struggling with drought conditions, the reality is the city saw above average rainfall in 2022 and 2023.

 ”While we know the water comes downhill, we don't know where it's coming from, the velocity it's coming, the distribution of where it's coming from, how much is groundwater. It rains a lot, trillions of gallons,” said Perestam. “All that's going to be really a better understanding of that coming out of this study.”

How much will the study cost 

Rancho Palos Verdes taxpayers could be on the hook for the $1.2 million study. The City Council was told Tuesday that 70% of the cost could potentially be covered by a FEMA grant. But, the city will still have to front the costs, with FEMA potentially reimbursing the money after an audit.

Why it matters

The heavy rains of 2023-24 led to land movement that slowly ripped apart buildings and homes, prompting gas and power shutoffs and constant repairs to the main thoroughfare through the landslide complex.

Responding to the destruction has been a huge financial drain on the city, which spent $48 million on the landslide complex from October 2022 until June of this year. The city has allocated another $18.6 million to spend toward repairs and shoring up the land movement for this fiscal year.

For context, the entire city budget is around $40 million annually.

How to keep tabs on the Rancho Palos Verdes city council

The Rancho Palos Verdes city council meets on the first and third Tuesdays of the month. Meetings start at 7 p.m.

Here’s how you can follow along:

• Attend in person: The board meets at Fred Hesse Community Park, 29301 Hawthorne Blvd., McTaggart Hall, Rancho Palos Verdes
• Listen to the meeting via phone: Call (866) 590-5055. Access code: 4138489
• Watch the live broadcast
• Here’s how to submit a comment or contact the council.

To submit a comment, you can attend in person, dial in or submit a comment via email to response@ocgov.com.