As of Monday, the National Oceanic and Atmospheric Administration’s forecast for this year’s expected water supplies in the Colorado River is at 59% of average. That’s not good news.

If that prediction proves true, this will be one of the driest water years since Lake Powell was constructed nearly 60 years ago. The volume of water stored in Lake Powell each year is affected by three primary factors: the amount of water flowing into the reservoir after ‘Upper Basin‘ water users have extracted water for their use, minus water released from the reservoir to support Lower Basin water users, and minus evaporation from the reservoir itself. Lake Powell will lose – by my estimation — about 22 feet of water this year, or about 2.1 million acre-feet of storage.

At that point, the reservoir will be 60% empty.