CoreLogic, the global provider of property information, analytics, and data-enabled solutions, estimates that across the greater Los Angeles area, nearly 543,000 single- and multifamily homes with a combined reconstruction cost value (RCV) of more than $258 billion are at risk of flash flood damage.
Reconstruction cost value is the overall cost to rebuild a property back to 100%, assuming complete destruction.
It is important to remember, that flash flooding occurs when precipitation rates are greater than the speed at which water drains into the ground surface.
In highly developed regions such as the San Francisco Bay Area and Los Angeles area, water is unable to enter the ground, and because of this, it flows over paved surfaces, which results in flooding roads and sidewalks.
At the same time, in areas that are undeveloped, soil can saturate after prolonged rainfall.
Saturated soil is unable to accommodate additional water, so rainfall pools on the surface and eventually becomes a flash flood.
For the more mountainous regions of California, this can wind up creating mudslides, which can be extremely dangerous.
CoreLogic highlighted the recent flooding that has taken place this month in the state. The company explained that in early February, the US West Coast experienced atmospheric river-related flooding similar to what occurred in the winter and spring of 2023, which has left hundreds of thousands of homes in California at considerable risk of life-threatening flooding.
As of February 5, there had been over 5 inches of rain in a 24-hour period in Los Angeles. Forecasts estimated that parts of the Los Angeles area may receive close to half a year’s worth of rain by Feb. 6. A flash flood warning was in effect for parts of California’s southern and central coastal region, including areas in Los Angeles.
As a result, officials declared a state of emergency in eight California counties, with evacuations taking place in some areas.
As well as experiencing heavy and intense rainfall, weather observation stations in the San Francisco Bay Area recorded hurricane-force wind gusts, which have the potential to cause light to moderate property damage and severe infrastructure disruption, including widespread power outages.
CoreLogic noted that more than 900,000 California power customers experienced outages as the heavy rain and winds battered the state, with the Bay Area and Los Angeles area taking the most damage.