John Metcalfe was CityLab’s Bay Area bureau chief, covering climate change and the science of cities.
NASA highlights Lake Shasta’s year-long progress from a virtual dust bowl to a healthy basin.
Last December, any swimmer attempting to blindly jump into Lake Shasta—the biggest reservoir in California—would tumble, Homer Simpson cliff-jump style, down a barren, bruising drop. Water levels in the lake had fallen to more than 100 feet below their historic averages but, thanks to recent rains, they’re doing remarkably better today.
Evidence comes from a series of NASA images made with USGS Landsat data, documenting a year in Shasta’s journey from dusty decrepitude to water-plump health. They begin on April 13, 2015, when the lake surface was at a low 995 feet, exposing hundreds of miles of new, tan-colored beach:
The situation worsened by November 23. Levels had plummeted to 914 feet—not as bad as their lowest point in the ‘70s of 836 feet, but still fairly awful news for folks who depend on Shasta for drinking water and farming:
Now zoom ahead to March 30, when storms riding on the back of El Niño flooded the lake to 1,048 feet, or 109 percent of its historic height for that date:
Despite this heartening comeback, California is still suffering from drought conditions. Many of its southern reservoirs remain diminished, and there’s the persistent problem of agricultural operations sucking up all the groundwater. The Weather Underground’s Bob Henson writes:
[A]s of March 17, agricultural users in California are projected to receive 30% of water requested from the State Water Project supply this year. This compares to 20% in 2015 and 0% in 2014. Despite the improvement, we can expect many farmers and ranchers to continue drawing from California’s largely unregulated groundwater, a practice that has led to subsidence so dramatic—up to 2 inches per month in some areas—that it is detectable by NASA satellites.