California’s reservoirs and rivers are startlingly low, forcing many of the state’s more than 270 hydropower facilities to generate less power.

Lake Oroville, one of the state’s largest reservoirs, made headlines because its water levels have dropped so low the power plant may need to shut down for the first time. While most other hydropower plants aren’t at risk of shutting down, plants that rely on watersheds up and down the state are not able to generate normal amounts of power.