The 1862 flooding event in California dumped an equivalent of 10 feet (3.0 m) of precipitation in California, in the form of rain and snow, over a period of 43 days

This according to Native American verbal histories happens periodically every 150 to 300 years. So, because it has been over 150 years now since this event this could theoretically happen any year now?

Because it is now 162 years since the last event.

However, what I would do is not buy land within about 20 miles of the Sacramento River because eventually Sacramento (the city) will be under 6 feet of water again for 6 months or a year. However, it might be possible to boat between high Rise buildings now that are over 1 story tall too. (even though the first floors of everything near the Sacramento River will be underwater. So, if you own land within 20 miles of the Sacramento River make sure you have a 2nd story on your home or be high enough in altitude to survive something like this. Also, you might want a flat bottom boat with a fan like they have in Florida for water levels of 6 feet deep or under. or any kind of boat that doesn't draw very much water that you paddle or row or have a motor on even a kayak. Because if this happens that kayak might save your life and your families lives.

I suppose you could build a treehouse on your land if you are near the Sacramento River too. The STeam boat Gem picked up many men in 1862 out of trees heading north as you will read about if you click on this information here: 

•  

  The Great Flood of 1862 was the largest recorded natural disaster in the history of California, Oregon, and Nevada, caused by 43 consecutive days of atmospheric river storms from December 1861 to January 1862. [1, 2, 3]

  
  

 

begin partial quote from "The Great Flood of 1862" from Wikipedia:

Lithograph of K Street in the city of Sacramento, California, during the Great Flood of 1862
Date	December 1861 – January 1862
Location	Washington, Oregon, Nevada, California, Idaho, Arizona, New Mexico, Utah, Baja California, Sonora, Mexico
Deaths	>4,000[1]
Property damage	$100 million (1861 USD)[2] $3.117 billion (2021 USD)

The Great Flood of 1862 was the largest flood in the recorded history of California, Oregon, and Nevada, inundating the Western United States and portions of British Columbia and Mexico. It was preceded by weeks of continuous rains and snows that began in Oregon in November 1861 and continued into January 1862. This was followed by a record amount of rain from January 9–12, and contributed to a flood that extended from the Columbia River southward in western Oregon, and through California to San Diego, as well as extending as far inland as the Washington Territory (now Idaho), the Utah Territory (now Nevada and Utah), and the western New Mexico Territory (now Arizona).

The event dumped an equivalent of 10 feet (3.0 m) of precipitation in California, in the form of rain and snow, over a period of 43 days.^[3][4] Immense snowfalls in the mountains of far western North America caused more flooding in Idaho, Arizona, New Mexico, as well as in Baja California and Sonora, Mexico the following spring and summer, as the snow melted.