Baby salmon reared on Central Valley rice fields grow exceptionally quickly and have a much better chance at surviving the journey to the sea.
The fields are much more productive that the main river channel — they are full of aquatic invertebrates that the young fish fatten up on. Before the dams and levees, the Sacramento River system used to have countless miles of floodplain on which the fish would grow. Now, that only happens on extremely wet years like this one (2016-17).
But with some creative plumbing, we can get baby salmon onto rice fields, which are basically man-made flood plains.
This is an interesting article about Salmon and Rice Fields!