california flooding 1862
© California Historical SocietySacramento under water, circa 1862.
There's been a lot of talk about weather records being broken this winter, but it was only January's epic snowfall totals that have made it into the record books so far. In January 2017, the Central Sierra Snow Lab (CSSL) near Donner Pass and many Tahoe Sierra resorts set new monthly snowfall tallies ranging from 20 to 25 feet.

But the current seasonal snowfall total of about 42 feet at the CSSL means we still have a long way to go to reach Top 10 status at Donner Pass, let alone exceed the 68 feet that fell in 1938. We are, however, closing in on the wettest year in the precipitation category, currently holding at third place behind 1982 and 1995, the first- and second-ranked water years since 1871. Remember, precipitation is rain and the water content of snow combined.

The signature weather pattern of this winter has been a seemingly relentless series of atmospheric rivers that transported huge volumes of water vapor from the Pacific Ocean into the West Coast. At CSSL, resident scientist Randall Osterhuber has measured about 100 inches of precipitation so far — the annual average is 55 inches — but warmer temperatures due to the subtropical origin of many of the storms has limited snowfall totals at elevations below 7,000 feet.

There have been plenty of weather-related issues across the West this winter, but even if this year manages to exceed the all-time precipitation record of 112 inches measured in 1982, it won't compare to 1861-62, the most devastating winter in California history. The predominant weather characteristic in 1862 was also an onslaught of powerful atmospheric rivers, but significantly more intense. The mega-flood that they caused took thousands of lives and destroyed 25 percent of the state's economy. The devastation forced California into bankruptcy.

In November 1861, steady rain fell day after day and Sacramento Valley ranchers started reporting cattle losses due to flooded grazing lands and cold temperatures. In early December, a series of powerful storms overwhelmed the state from north to south with snow, ice and rain. Soon newspapers throughout the Sacramento and San Joaquin valleys were posting headlines about people drowning and hundreds of cattle being swept away.

One editor stated:
"For the past two weeks King Storm has prevailed in the North State. Nearly all bridges north of Red Bluff are washed out and no mail has been received from Yreka in over a week. Loomis Ward of Tehama lost 700 cattle by December 9. When the levee at Sacramento broke, the water was 10 feet deep in places. One hundred Chinamen were drowned on the Yuba River."
The months of December and January were remarkable for exceptional rainfall that generated widespread inundation in the Sacramento and San Joaquin valleys. Communication was lost when telegraph poles and wires disappeared under water 30 feet deep. Witnesses reported that by the third week of January, "The Sacramento and San Joaquin valleys were transformed into a broad inland sea stretching from the foothills of the Sierra to the Coast Range, somewhat similar in extent and shape to Lake Michigan." The Alta California newspaper described the flooded area as "extending from Tehama, 80 miles north of Marysville, to a point in the San Joaquin at least 50 miles south of Stockton, forming a lake 20 miles wide by some 250 miles long." Sacramento remained swamped by floodwater for six months.

Geology professor William Brewer, who was working on a geological survey of California at the time, reported that the great Central Valley was "a district of 5,000 or 6,000 square miles" where nearly every house and farm was obliterated. He stated that the delta region had become an inland sea: "The water ice cold and muddy — that the winds created high waves which beat the farmhouses into pieces." Household furniture such as chairs, sofas, tables and beds floated among the carcasses of drowned animals. Brewer estimated that 200,000 cattle died.

Rainfall amounts in California reached biblical proportions. Between Nov. 11, 1861, and Jan. 14, 1862, 6 feet of rain fell near Sonora in Tuolumne County. By February another 30 inches of rain added to the total, followed by still more storms that battered the Golden State.

By the end of January 1862, rainfall in Sacramento was approaching 40 inches, nearly double what the city averages in a year. Residents of Los Angeles endured 28 consecutive days of rain in a season that totaled 66 inches, more than 400 percent of normal. San Francisco was slammed with nearly 30 inches in 30 days — a rainfall event so severe that climatologists have determined that its statistical likelihood of return at once every 37,000 years.

William S. Jewett took a steamer from San Francisco to Sacramento during the flood and gave an eyewitness account:
"The dreadful flood completely drowned Sacramento, the capital of our State. I found the town lying about from three to fifteen feet under water — some of the wooden houses had sailed off down the river and others floated into the middle of the streets in all manner of positions."
Whole communities were swept away and the loss of people and livestock was staggering. Edwin Waite described conditions in the Sacramento Valley:
"In some places we saw sheep on scaffolds but a few inches above the surface of the water, where they have been for weeks, fed occasionally by means of boats. The loss is not so much in the destruction of property as confidence. The people of the lowlands have lost all confidence in the large valleys as places for permanent homes."
California's legislature convening in Sacramento also lost its confidence and escaped to San Francisco. Newly elected Governor Leland Stanford was forced to travel to his own inauguration ceremony by rowboat.

The onshore flow of moist Pacific air translated into heavy precipitation with fluctuating snow levels in the mountains. Nearly 42 inches of precipitation were recorded at Grass Valley in November and December alone. Some locations picked up 11 inches of rain in just 24 hours. Nevada City in the lower foothills reported 115 inches of precipitation by March. Many locations in the Sierra foothills endured between 8 to 10 feet of rain that season.

Sedimentary evidence indicates that floods of this magnitude occur on average every two centuries in California. It's been 155 years since the last mega-flood and, just like with earthquakes, the clock is ticking.
About the author

Tahoe historian Mark McLaughlin is a nationally published author and professional speaker. His award-winning books are available at local stores or at thestormking.com. You may reach him at mark@thestormking.com. Check out his blog at tahoenuggets.com or read more at TheTahoeWeekly.com.