Regarding California agriculture, and specifically growing the produce and vegetable crops that California supplies the rest of the country. An excellent model

Regarding California agriculture, and specifically growing the produce and vegetable crops that California supplies the rest of the country. An excellent model for urban agriculture, Growing Power of Milwaukee and Chicago, provides such vegetables grown in city greenhouses (lettuce, tomatoes, greens, etc.). They do it year-round in Chicago. Some of the heat comes from compost, worm bins, fish tanks. There are several offshoot businesses (e.g. Eco City Farm here in DC) replicating their model. Growing Power offers training several times a year. So hopefully other places - urban brownfields - will take up some of the agriculture production from California in view of the water problem.