Building off the synergistic relationship that has existed between rice farming and fish rearing for millennia in Southeast Asia, we are attempting a similar relationship in California. Recently, in the Central Valley region of California, we have used rice fields to help conserve declining runs of Chinook Salmon. Here, we synthesize a variety of data sources and ecological studies on the ecological productivity of agricultural floodplains in California. First, we summarize the relationship between historical Chinook Salmon runs and floodplain habitat loss in the region. We find that most natural floodplain habitat has been lost in the Central Valley, with a majority being converted to agriculture, and identify floodplain habitat loss as a primary contributor to significant historical declines in salmon runs. Then, we summarize potential benefits of using rice fields as critical juvenile salmon habitat (rearing areas) and as lateral sources of food subsidies to the larger river ecosystem. We find significantly more growth of zooplankton for salmon growth in off-channel habitat (including rice fields) compared to riverine habitat. Lastly, we use a population model to project benefits of agricultural floodplain access to recruitment of returning adults. We project greater abundances of future adult salmon returns after improved access to and management of agricultural floodplains. High potential exists to develop mutually beneficial reward systems for farms and fish in the Central Valley of California, and potentially other parts of the world.