I’ve become preoccupied the last two or three months with the level of water in California’s reservoirs. If you’re inclined to, here’s where you can join in the fun: The state Department of Water Resources’ California Data Exchange Center. The cliche to describe a collection of information like this is “treasure trove.” For example, here’s one report that I’ve taken to taking a look at just about every morning: The Sacramento/San Joaquin Daily Reservoir Storage Summary. It’s a quick look at about three dozen state’s biggest storage facilities: how much water they’re holding, how many acre feet have flowed in or out in the past day, and–especially interesting–how much water they hold compared both to the average for this date and to the amount held a year ago.
There’s a story in the numbers, though I’m still puzzling out what it is. For instance, the state’s current drought is not a drought everywhere. Although rainfall and the mountain snowpack are generally below average, some reservoirs hold more than average for this time of year and much more than they did a year ago (which was an even worse year, precipitation-wise). But the numbers are just one dimension of a complicated picture. All that water has a lot of work to do. We count on it not just for irrigating the Central Valley farms and bringing drinking and lawn water to the citiies and suburbs, but for providing electricity, too. And in recent decades, the state and federal water managers have even been made conscious of another function the water might perform: preserving wildlife–especially the once-magnificent salmon runs in the Sacramento and San Joaquin watersheds.