Water levels in Lake Mead and Lake Powell, two of the nation’s largest reservoirs, have sunk to levels not seen since the 1930s, threatening not only tourism along their shores but also water supplies for a several western states and parts of Mexico.
Lake Powell, created by the 1960s-built Glen Canyon Dam and Lake Mead, impounded by the 1930s-era Hoover Dam, are both on the Colorado River. The system supplies water to areas from Denver to Tucson in seven states; 70% is used for agricultural irrigation. The two dams also rely on water flow to produce electric power.
The continuing drought of the past few years has reduced water levels in Lake Powell to 51% of capacity, and of Lake Mead to 39%. Aside from the downstream effects, the drop has devastated businesses along the shores that support watersports and houseboats; in many cases the launch points for watercraft are now steep cliffs away from the water.
For the tourism and sports businesses, plans are underway to modify access points or build new ones, but for the long-term users of the water, the picture is different: It’s simply not possible to increase how much water is available from the sky. Instead, efforts are focused on finding more efficient ways to use the water for crops, and eliminating unnecessary uses, including extensive urban lawn-watering.
Image: Hoover Dam and Lake Mead; the white cliffs above the dam had been covered by water before the drought.
UPDATE August 16
Water levels in Lake Mead have now dropped to a point where Federal officials have declared a first-ever water shortage for areas downstream that depend on it for water as well as hydroelectric power. Over 40 million people in seven states are in the affected area.
Tanya Trujillo, Assistant Secretary of Interior for water and science told a press briefing that “We are seeing the effects of climate change in the Colorado River basin through extended drought, extreme temperatures, expansive wildfires, and in some places, flooding and landslides. And now is the time to take action to respond to them.”
Flow in the Colorado River has declined for a number of years, but a shortage has been averted by cities and states reducing their usage, but even the lower level now cannot be sustained.