Here comes the sun–and the aftermath from an extremely wet winter!
Recently, we talked about record breaking amounts of rain in California, floods, and landslides that we’ve already experienced. All that wet weather also brought record amounts of snow and a massive snowpack at 185% of normal. Now that the snow is beginning to melt, things could get even worse.
- The worst flood in California history happened in 1862. Known as ‘The Great Flood,’ it occurred after record rainfall and snow from a series of storms that began on December 9, 1861 and ended with a warm storm on January 17 that melted the snowpack. The runoff added to areas already flooded by rain. Sacramento and Marysville suffered the most damage with areas left underwater for months. Livestock was lost, an immense amount of property was destroyed, and many lost their lives.
- ‘The Christmas Flood’ of 1964 encompassed an area roughly the size of France in Northern California, Oregon, and Idaho. A series of storms—known as atmospheric rivers or pineapple express storms—led to this event. The combination of rain, up to 15 inches in 24 hours, on snow and frozen ground created extreme runoff, erosion, and flooding. The rain-on-snow event killed 47 people, left thousands homeless, and caused more than $540 million (more than $3.9 billion today) worth of damage in those areas.
- The flood of 1997, known as the New Year’s Flood was one of the most devastating floods in California history. The Yosemite Valley flooded for the first time in more than a century. Rivers including the San Joaquin, Sacramento, Feather, Cosumnes, and Tuolumne Rivers overflowed. Loosened soil caused mudslides, road blocks, levee failures, and eight reported deaths. The flooding was the result of a climate condition called La Niña. The region received more than 24 inches of warm rain on an above-normal snowpack and saturated soils that caused the rapid runoff.
- Highway 50, a major route between Sacramento and South Lake Tahoe falls victim to landslides almost every winter. In 1983, the highway closed for 75 days after a landslide. The wet winter of 1997 caused the Mill Creek landslide. Tons of earth gave way closing the road for 27 days, destroying three cabins and flooding two vehicles. Part of Highway 50 in the Sierras is closed again this year after numerous landslides caused part of the road to collapse heavy winter storms.
One of the best things about history is we can learn from it
And it’s telling us that a quickly melting above-normal snowpack on saturated soil creates rapid runoff, widespread flooding, and landslides, so get ready!
As the weather warms up, watch for signs of a landslide
- Keep an eye out for seepage, cracks, or unusual bulges in the ground.
- Look for leaning telephone poles, trees, or fences.
Be aware of potential flood zones
- Do not drive through flowing water or on flooded roadways, “Turn Around, Don’t Drown!”
- Obey safety warnings, road closures, and detour signs.
- Do not stop or park along streams or washes.
View a simulation of what could happen to the Sacramento region of California if the Sierra Mountain peaks were to melt.
Remember, we’ve experienced one of the wettest winters after a nearly six-year dry spell. We’ve seen landslides, flooding, and dam spillway failures throughout the state.
The above evaluations and/or recommendations are for general guidance only and should not be relied upon for legal compliance purposes. They are based solely on the information provided to us and relate only to those conditions specifically discussed. We do not make any warranty, expressed or implied, that your workplace is safe or healthful or that it complies with all laws, regulations or standards.