Remembering the Great Flood that Put Northern California Under 30 Feet of Water

If you take a look at Northern California on a map, it will show a large valley right down the middle of it. This vast valley, which many of us live in, was shaped over thousands of years of flooding through the middle of the state. In fact, most of our vast waterways drain into a small outlet in the San Francisco Bay, making Northern California very prone to flooding.

The history of the region has seen a lot of flooding, but among all the massive floods Northern California has seen, there was none more powerful or destructive as the Great Flood of 1862.

The Great Flood of 1862 was the largest ever recorded in Oregon, Nevada and California’s history. The flooding occurred from December of 1861 until January of 1862, drowning the state in water and leaving much of the Northern Valley unlivable until the summer months of 1862. The flood created a lake down the center of the state that was 300 miles long and 20 miles wide. It’s estimated that thousands of people were killed in Northern California during the event.

It all started late 1861, when NorCal experienced an unusually wet winter with heavy snow in the mountains and rain in the valley. In November of that year, the snowpack was unseasonably large and the valley floor was saturated with rainwater. That was just the start.

By early December, the Native American tribes, who had lived in the area for 10,000 years, saw the early warning signs and left the region for higher ground. The European settlers, who insisted on building their cities along rivers for transportation and drinking water, would experience tremendous devastation.

On December 9th, a warm atmospheric river, or “Pineapple Express,” hit the region with a fury. The warm, tropical rain melted and flushed down the lower snowpack, running down into the watershed and carrying all the way into Sacramento. It would be the first of four warm storms through the next six weeks that would completely flood the valley.

In the northernmost region of the state, the flood was disastrous. Fort Ter-Waw, an army base near the mouth of the Klamath River, was completely destroyed. Entire forests were brought down and any semblance of settlement in the North Valley was delivered extreme destruction, eventually sitting under large amounts of water.

In Weaverville, John Carr described the catastrophe of the storm:

“The water in the river… seemed like some mighty uncontrollable monster of destruction broken away from its bonds, rushing uncontrollably on, and everywhere carrying ruin and destruction in its course. From the head settlement to the mouth of the Trinity River, for a distance of one hundred and fifty miles, everything was swept to destruction. Not a bridge was left, or a mining-wheel or a sluce-box. In forty-eight hours the valley of the Trinity was left desolate. The county never recovered from that disastrous flood.”

Another atmospheric river came on December 23rd and lasted for four days. During that Christmas season is when infrastructure began to fail and the flooding reached epic proportions.

The foothills of the Sierra Nevada were seeing tremendous flooding activity during this time. The American River near Auburn rose 35 feet and some of the small mining towns were completely submerged. On the Stanislaus River near Knight’s Ferry, two major bridges washed down the river and anything within 40 miles was completely destroyed.

Then between January 9th and 17th of 1862, two more warm storms came in to Northern California to finish the job. During this stretch of flooding, no place was more damaged than the city of Sacramento.

As the massive waves of water ran down the Sacramento and American Rivers, converging in downtown Sacramento, the city went completely underwater. Water was flowing into the city from two different directions, putting some areas under 30 feet of water. Most of the houses in the area were destroyed.

Leland Stanford was just elected governor in November and his inauguration day was during the storm on January 10th. As the story goes, the governor-elect rowed a boat through the streets of Sacramento to the State Capitol, where he was inaugurated. Shorty after, the legislature moved the the state government to San Francisco for months until the flooding subsided.

At the time, Sacramento had a levee at the junction of the Sacramento and American Rivers. When the floodwaters entered the area from higher ground in the east, the levee acted like a dam, holding the water in the city. Eventually a chain-gang was sent to break open the levee, and when it finally broke, the water level in the city dropped around six feet.

The Sacramento River had widened significantly all the way up the valley during this time. John Carr wrote about his riverboat trip up the river during the peak of the flood:

“I was a passenger on the old steamer Gem, from Sacramento to Red Bluff. The only way the pilot could tell where the channel of the river was, was by the cottonwood trees on each side of the river. The boat had to stop several times and take men out of the tops of trees and off the roofs of houses. In our trip up the river we met property of every description floating down – dead horses and cattle, sheep, hogs, houses, haystacks, household furniture, and everything imaginable was on its way for the ocean. Arriving at Red Bluff, there was water everywhere as far as the eye could reach, and what few bridges there had been in the country were all swept away.”

The floodwater remained throughout California until later in the summer of 1862. Here is a hypothetical illustration of how the floodwater sat in California:

William Brewer of the California Division of Mines and Geology wrote during the event:

“Nearly every house and farm over this immense region is gone. America has never seen such desolation by a flood.”

The U.S. Geological Survey have hypothesized that these mega-floods come to California about once every 200 years, meaning we are due for one in the next 50 years. That future mega-flood could cause up to $1 trillion in damage and have a death toll in the tens of thousands. It would exceed anything we’ve seen in U.S. history.

Today, officials are taking steps to ensure a flood of such proportions doesn’t cause the same financial hit and death toll as it did in 1861. They have even named the future catastrophe ARkstrom.

We can learn a lot from the Great Flood of 1862. The next California mega-flood is a terrifying concept – it’s not a question of if but when.