Much of the central Sacramento valley is floodplain which can be, and has been, more of an inland sea or lake during wet winters than a valley.
Before flood control was put in, Sacramento itself was subject to major inundations, though the last of these was in the 1950s as I recall.
During early settler / Indian times, substantially the entire central valley would flood. It's a watershed in which a 300-400 mile long, 50-100 mile wide region drains, all of it flowing out ultimately through the Golden Gate. Water can and does pile up there.
And that's the region where rice is typically grown.
Contrast this with southern California -- the arid southern part of the Sacramento / San Joaquin Valley near Bakersfield is pretty dry, but cross the Tehachapi Mountains to the south and you're in the Mohave desert. That region still gets water, via the California Aqueduct and state water project, and is also home to much agriculture, including alfalfa and cotton cultivation, which demands a lot of water.
Before flood control was put in, Sacramento itself was subject to major inundations, though the last of these was in the 1950s as I recall.
During early settler / Indian times, substantially the entire central valley would flood. It's a watershed in which a 300-400 mile long, 50-100 mile wide region drains, all of it flowing out ultimately through the Golden Gate. Water can and does pile up there.
And that's the region where rice is typically grown.
Contrast this with southern California -- the arid southern part of the Sacramento / San Joaquin Valley near Bakersfield is pretty dry, but cross the Tehachapi Mountains to the south and you're in the Mohave desert. That region still gets water, via the California Aqueduct and state water project, and is also home to much agriculture, including alfalfa and cotton cultivation, which demands a lot of water.