Hydropower out of whack thanks to record heat and precipitation

In California, hydropower output is expected to double this year. But in the hydro-dependent Northwest, abnormal heat could cause it to shrink by 19%.

By Julian Spector  . 

dam and reservoir
A view down the spillway of the Shasta Dam into the Sacramento River in Shasta Lake, California (Michael Macor/The San Francisco Chronicle via Getty Images)