Lake Powell, the second largest human-made reservoir (水库) in the US, has lost nearly 7% of its potential storage capacity since it (build) in 1963.
In addition to water (lose) due to years of drought, the US Geological Survey found, Lake Powell (face) an average annual loss in storage capacity of about 33, 270 acre-feet per year between 1963 and 2018. That's enough water (fill) the Reflecting Pool on the National Mall about 1, 600 times.
The capacity of the reservoir is becoming smaller because of sediments (沉淀物) (flow) in from the Colorado and San Juan rivers. Those sediments settle at the bottom of the reservoir decrease the total amount of water that the reservoir can hold. It's bad news for a region has already faced water shortages and extreme wildfires due to the drought.
Lake Powell is important reservoir in the Colorado River Basin. Both Lake Powell and nearby Lake Mead, the nation's largest reservoir, are drying up an alarming rate. In August, the government declared a water shortage on the Colorado River for the first time after
Lake Mead's water level decreased to a record low, leading to cuts in water consumption for the (state) in the Southwest that began in January.
