The recent flash flood disaster along the Guadalupe River in Texas has shone a stark light on the catastrophic impacts of such extreme weather events, a reality that could be mirrored in California’s own low-lying regions when severe storms strike.
As California experiences increasingly erratic weather patterns, the potential for dangerous flooding looms larger, particularly in areas like the Los Angeles region, the Central Valley, and parts of the Central Coast, where heavy downpours can lead to rapid inundation.
In early 2023, a series of intense winter storms swept across California, resulting in tragic outcomes, including the loss of approximately two dozen lives. Victims included individuals unfortunately swept away by rising floodwaters, as well as casualties from rock slides, fallen trees, and vehicular accidents.
Brett Sanders, a professor at UC Irvine whose expertise lies in flooding, emphasized that California shares many traits with Texas that heighten the risk of flash floods.
“We have a lot of the same possibility of flash flooding,” Sanders noted. “Our hilly topography and numerous streams can suddenly unleash vast amounts of water, posing unexpected dangers.”
Historically, California has faced its own share of catastrophic flood events. Memorable incidents include the floods of 1861-62 that submerged Sacramento, the deadly Los Angeles flood of 1934, and the perilous debris flows that followed intense rains in Montecito, Santa Barbara County, in 2018.
The flash floods in Texas painted a grim picture, claiming over 100 lives and leaving others missing, including vulnerable children who were at a summer camp when the waters surged through the area. This event has been labeled a “100-year-flood” by officials due to its unprecedented nature.
Sanders conducted thorough examinations of federal flood hazard maps produced by the Federal Emergency Management Agency (FEMA) in relation to the tragedy. His findings indicated that multiple cabins at the Texas summer camp were situated in a federally designated ‘floodway’ where fast-moving water poses severe risks.
“Floodways are areas where you know the water will be moving really fast, and so you know that’s going to be a really dangerous place to be,” he remarked.
This led Sanders to express concern about awareness regarding flood risks, especially among individuals who were unaware of their perilous situation.
“There were people in harm’s way that didn’t know they were in harm’s way,” he stated, emphasizing a knowledge gap in understanding risks and executing timely responses.
While California is home to numerous structures within flood-hazard zones, it is relatively uncommon for permits to be granted for buildings in floodways. Sanders remarked, “It seems like much more could have been done to increase awareness about the risks of sleeping overnight next to a stream that’s prone to flooding, especially when rainfall was forecast.”
Climate scientist Daniel Swain, from UC Agriculture and Natural Resources, pointed out that the types of storms triggering floods in California differ from the intense thunderstorms that led to Texas’ flooding.
However, Swain cautioned that the severity and rapid onset of flooding could still occur in California, often as a result of multiple winter storms coupled with particularly strong atmospheric rivers.
“Such storms, which roll in from the Pacific Ocean carrying vast quantities of water vapor, would likely impact many watersheds simultaneously, thus heightening concern among officials,” he noted.
Swain also mentioned scenarios where localized thunderstorms could occur alongside larger winter storm systems, which can lead to severe flooding, as seen in the Montecito debris flow incident.
“The extreme storm that produced the Montecito debris flow in 2018 resulted from intense localized downpours,” he explained, highlighting the risks associated with sudden intense rainfall.
Research predicts increased risks of extreme floods in California and beyond largely due to climate change, with warmer air capable of holding greater volumes of water vapor enhancing rainfall magnitude.
Los Angeles County, in particular, is one region with significant flood risks. Kerjon Lee, a spokesman for Los Angeles County Public Works, stated that the county has actively invested in flood protection and stormwater capture initiatives to bolster resilience against climate change impacts.
“We’re using climate projections to develop a robust flood-protection network so communities can survive flooding and other extreme weather events and recover as quickly as possible,” he stated in a recent email.
Furthermore, public awareness initiatives are being prioritized to help residents understand flood risks and motivate them to prepare emergency plans and seek flood insurance.
A 2022 study involving researchers, including Sanders, estimated that a 100-year flood in the Los Angeles Basin could impact up to 874,000 individuals and cause property damage totaling approximately $108 billion.
The research specifically highlighted that Black and low-income communities situated in low-lying areas would suffer disproportionately in such flood scenarios.
Despite California’s established regulatory frameworks to manage flood risks, Sanders acknowledged that campgrounds along rivers and creeks and populations experiencing homelessness are still vulnerable during floods.
“Even in California, you have various flood-prone campgrounds and significant numbers of homeless individuals living along rivers and flood-control channels,” he remarked.
Moreover, motorists who attempt to navigate through swiftly rising floodwaters are frequent victims during such events, with many losing their lives after driving through low crossings that seemed manageable.
“There are numerous reports of vehicles being swept away during floods, and often, individuals lose their lives in the process,” Sanders noted, reiterating the risks faced by Californians.
In summary, as California prepares for potential flooding disasters, the recent events in Texas serve as a crucial reminder of the importance of awareness, planning, and proactive measures to safeguard communities from the consequences of extreme weather.
image source from：latimes
