Growing threat to Rancho Palos Verdes in Southern California, an idyllic location of 42,000 residents that has been plagued by landslides for decades.
HDN Newsroom
The geology of the area is vulnerable by nature. The soil consists of sandstones and shales that are so weak, so much so that they can even be broken by hand. At the same time, the subsoil is penetrated by water which creates unstable levels where rocks move.
The continuous rainfall of the last two winters, affected by climate change and rising temperatures, has increased soil moisture, aggravating the situation. Jonathan Godt, from the U.S. Geological Survey, points out that the effects of rainfall take months or even years to appear, meaning upcoming landslides could be even more devastating.
The geology of the area, combined with the historically rainy winters of the past two years, has put millions of dollars' worth of luxury homes lying on the brink of cliffs overlooking the Pacific at risk.
The ground is now moving at an alarming rate, causing extensive damage to homes and infrastructure, forcing authorities to issue power cuts and warnings of possible evacuations.
The area of the Palos Verdes peninsula is known for its landslides. It consists of fragile shales and soft sandstones, easily eroded by wind and rain. Its imposing geography, rising almost 450 meters above sea level, makes it extremely vulnerable to weather conditions and erosion by Pacific waves. These natural processes have been enhanced in recent years by heavy rainfall, which creates dangerous conditions as water penetrates the ground and makes it even more unstable.
According to the Washington Post, the consequences of this situation are manifesting themselves in a dramatic way due to the last two winters that brought historic levels of rainfall. Experts say the effects may have started months or even years, but now the situation is escalating as the ground that used to move a few centimeters a year is now moving several meters in a short time. Precipitation has penetrated deep into the soil, accelerating erosion.
Kyle Tourjé, vice president of engineering firm Alpha Structural, says the situation has gotten out of control, pointing out that there are now only two solutions: either a costly and complex intervention by local, state and federal authorities, or the complete abandonment of the most affected areas. Options to stabilize the soil are limited and their implementation is highly uncertain.
The landslides in Rancho Palos Verdes are not a new phenomenon. The area has always had a sensitivity, with known incidents of landslides dating back to the 1950s. The Portuguese Bend area, in the southern part of the peninsula, is an example of an active landslide that has been going on for decades, forcing constant repairs to the road network. However, the crisis now unfolding is more serious than ever and threatens hundreds of homes.
To address the situation, Rancho Palos Verdes received a $23 million grant from the Federal Emergency Management Agency (FEMA) last year. The plan called for trapping water to be pumped underground in the hope of stabilizing the ground. However, the deteriorating situation has raised doubts about the effectiveness of the project, with Tourjé stating that the situation is becoming more worrying every day.
The City Council of Rancho Palos Verdes held an emergency meeting Tuesday to consider measures such as declaring a state of emergency and calling on California Governor Gavin Newsom to also declare a state of emergency for the area. The next few days will be critical as authorities try to protect residents and their properties from further destruction.
