FYI, most of the Central Valley was actually seasonal marshlands and swamps before it was settled, and the vast majority of that area has enough water to survive several more years of drought before cutting of water completely. Westlands was a dry wasteland up until the feds decided to "develop" the area in the 1950's, and they are 100% dependent on water allocations from the federal government to keep their land from turning back into a desert.
There's plenty of water, but the problem here is water rights. The primary water rights holders to all of the rivers in California are the irrigation districts that border them. Cities like SF have junior water rights after those districts. Court orders have given environmental protection water rights just below the cities. Contracted sales by those top level irrigation districts have rights just below the fish and birds. And the feds? The federal government comes in dead last in the water rights, only getting to take its water needs from whatever is left over from the other users. When supplies get tight, they get nothing at all...and districts like Westlands get nothing.
But here's something to consider. The white area in the map outlines the irrigated farmland throughout the Central Valley. The colored spot shows the small portion of that land dependent on federal water. When you hear that Central Valley farmers are going belly-up because federal water is being cut off, remember two things: 1) The vast majority of farms here aren't dependent on federal water at all. 2) While most of the valley farms are still owned by families, Westlands mostly a collection of industrial corporate farms. Very few people live there, and those who do are mostly employees of the companies. Heck, if you look it up on Google Earth, you'll see that the area even LOOKS different...where the rest of the valley is a collection of smaller farms and orchards, Westlands is a massive grid of enormous industrial agriculture.
