US's Largest Reservoirs Hit Record-Low Water Levels
The country's largest reservoir, Lake Mead, and the second-largest, Lake Powell, have reached record-low water levels due to climate change, population growth, and over-consumption.
The two largest reservoirs in the US, Lake Mead and Lake Powell, have hit record-low water levels. Located on the Colorado River, these reservoirs provide water for populations across seven US states in the south-western US, with around 40 million people getting some or all of their municipal water from the Colorado River.
## Record Lows
At full capacity, Lakes Mead and Powell can hold a combined 68 cubic kilometers of water - enough to supply all household consumption in the contiguous US for nearly 1.5 years. However, the water level in both reservoirs has been declining for decades. The water level in Lake Mead reached a record low of 317.11 meters on 7 August, while Lake Powell's water level was recorded at a new record-low of 1,072.87 meters on 15 August.
| Reservoir | Full Pool Level | Current Level | | --- | --- | --- | | Lake Mead | 347.60 meters | 317.11 meters | | Lake Powell | 1,127.76 meters | 1,072.87 meters |
The downward trend in both lakes will largely continue until next spring, when the snowpack in the mountains of the Upper Colorado River Basin begins to melt.
## Compounding Factors
The record lows across the two reservoirs are the result of several compounding factors. Since the turn of the 20th century, the amount of water flowing along the Upper Colorado River has declined by about 20%. Research suggests that half of this decline can be attributed to human-induced climate change. The increasing population in the US south-west has also put added pressure on the Colorado River's water supply, with the number of people obtaining some or all of their water from the Colorado system having grown by 15 million (around 60%) since 1992.
Experts attribute the current water crisis to a warming climate and a warming planet, which has led to decreased runoff in the Colorado River Basin. They also point to the slow pace of policy decisions that match the variability of the climate, which has led to the current water crisis.
The US Bureau of Reclamation has released an environmental impact statement on its proposed post-2026 strategy for managing Lakes Powell and Mead. However, experts note that the strategy may not be effective in addressing the current water crisis, as it does not account for the long-term effects of climate change.
