In Part Two, we will discuss the recent catastrophic mudslides in southern California, what caused these mudslides, and what can be done to minimize them in the future. We will also talk about erosion control products and the role they play in both prevention and revitalization in wildfire-damaged regions.
When the Rain Falls and the Land Slides
On the early morning of January 9th, just over a month after the Thomas Wildfire in southern California first raged burning a record-breaking 281,000 acres, a pounding rain began in Santa Barbara and Ventura Counties. The storm poured rain with such intensity that it dropped almost an inch of rain in 15 minutes—4 times the amount of rain needed to trigger debris flow. The rain in the area very rarely falls this fast and this heavy. Within 24 hours, a devastating 5 inches of rain would accumulate in the region.
Rain would be a blessing during a fire or in the middle of a drought. But right after a wildfire has just destroyed an area’s forests and vegetation, rain is a disaster. Hardened earth in a fire-ravaged area does not absorb water the way it normally would. So instead when the rain fell, it slid effortlessly down the mountains , hills and slopes like a theme-park water slide. On its way down, it took with it fallen and burned debris, sludgy sediment, loosened rocks, continuing and building velocity until reaching the southern California cities of Montecito and Carpinteria.
Once there, it pummeled the small communities with mud and debris, surprising the residents with its sudden force and destruction. “It looked like a World War I battlefield,” said Bill Brown, the Santa Barbara County sheriff. “It was literally a carpet of mud and debris everywhere with huge boulders, rocks, downed trees, power lines, wrecked cars—lots of obstacles and challenges for rescue personnel to get to homes, let alone get people out of them.”
By the time the mudslides were over 20 people had died, hundreds more rescued and over 100 homes were destroyed.
While the mudslides are over for now, unfortunately, the flooding risk in the fire-ravaged Thomas Fire area is just beginning. According to FEMA, flooding can be a problem for up to five years following a wildfire, until natural vegetation has time to take root again and regrow.
What Can You Do?
So what can be done in the meantime to prevent further mudslides if you are in a flood-risk region near a fire-devastated area?
Control of the soil is a crucial first step in prevention of mudslides after a wildfire.
To determine this on a broader scale, a U.S. Forest Service Burned Area Emergency Response (BAER) assessment team evaluates the watershed conditions in forests burned by wildfire. Because time is precious, the assessments often begin even before the wildfire is completely contained. The BAER team produces a post-fire report describing immediate emergency measures to reduce flooding risks and debris flow threats arising from the wildfire’s destruction.
Steps Toward a Safer Future
The mudslides that affected southern California were tragic and a perfect storm of events—combining the largest wildfire in California’s history with unusually heavy rains. Erosion Control products can mitigate potential flooding in the future, saving the forest and the communities below.
Join us for the third and final installment on our wildfire series. In the next post we will discuss how wildfires negatively affect water quality in communities and how it can be treated and prevented. We will demonstrate several methods of filtration and proper best management practices.
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