Erik Wilson is a spray applicator out of Merced, California. He’s well known and respected for his work helping to create the ‘My Job Depends On Ag’ movement. He recently wrote an essay which explains California’s water problem.
He says that people back east may not understand why our farmers are so concerned about improving the water supply here. We get about 12 to 15 inches of rain each year in the the central valley, but much more up in the northern third of the state. That’s why we have the big dams and canals to bring some of that water south.
In the midwest, farmers get an average of 37 inches of rain, or about 3 acre feet per year. That’s enough to grow crops without irrigation. Cities also need 37 inches of rainfall per year to meet their water demand. Yet California’s farmland – and most of its people – are on a desert where 8 tp 12 inches of rain falls each year. Obviously, the water supply must be supplemented.
If a California farmer were to get his full allocation of ditchwater – which seldom happens – he would get the equivalent of 26 inches of annual rainfall. As Erik points out, this shows that California does have enough water for its people and its farms provided it is managed properly and delivery commitments are kept.
Proper water management is critical for other reasons, too. It’s a matter of timing. In California, When it does rain it can be a couple of inches per storm event and sometimes, maybe 15 inches of water in the northern mountains. That can be up to half of what falls in a year coming down in just days, then rushing away in a flood, racing to the ocean. If it wasn’t for dams, most of California’s farmland in the valleys would be flooded for those days and weeks afterward, then dry as a dustbowl all summer.
If we did not manage this water, vast amounts of it would disappear into the Pacific ocean. It’s just gone. Erik says that In the last couple of years something like 80% of the rain and snow that fell on California has flowed away, into the Pacific. If just five per cent of that water had been stored, we’d be able to satisfy every demand.