[Carry_Okie]

The great deluge was not in 1861, but in January of 1862 when there was over 24" of rain in Sacramento, compared to the usual 2-4". When the rain is warm, it melts the accumulated snow and the mess is horrific. Yet the mining of the Gold Rush had raised the river bottoms as well. So the 24" floods in the highest points of the Sacramento Valley in 1862 were due to a combination of factors less likely today because of dams and admittedly aging and inadequate flood control projects. See the link in post 52.

Rains like this at this time of the year are far less of a threat because the snowpack has not yet accumulated.

[SierraWasp]

Plus, the American River watershed is very wide spread with three forks all three of which are very steep and short compared to typical rivers around the world. The surge, even with multiple hydro-electric dams come up really fast and that is why it's still such a threat to Sacramento's and the Bay Delta's levees.

In the control room at Folsom Dam you can see the schematic for the whole watershed and notice the Auburn Dam above Folsom that was stopped by liberals when it was 2/3rds completed in 1977. It's now just a monument to stupidity of militant activist EnvironMentalists!!!

Carry_Okie's comment on the timing is precisely correct because it really isn't a true "Pineapple Express" until there's a massive snow pack being drenched with a warm river of rain falling on that Sierra Cement, making it race to the bottom...