Background: water property rights in the West follow the “first in time, first in use” rights structure, which is very different from the riparian rights (your water rights adjoin your property line) typical in the East. Southern California’s cities are at the end of that time-chain of property right settlement, which was not a big deal as long as there was enough Colorado River water to go around. But with population growth in Phoenix and other Southwest cities, they are starting to exercise their “first in time, first in use” water rights, which means that Southern California cities are facing potentially serious water shortages. A deal between farmers and cities for farmers to sell water recently fell through, as described in news articles here, here, and here.
According to this story, the parties may renew talks this coming weekend, in the hopes of reaching an agreement in the three weeks before the federal government enforces the decreased Colorado River water flow to California.