Las Vegas Water
Las Vegas is located In the Mojave desert. The Colorado River and local groundwater are the two primary resources that provide the Valley with its water needs. About 90 percent of the water supply is provided by the Colorado River which is renewed by rain and snowmelt from the Rocky Mountains.
The river serves about 40 million people in California, Colorado, Arizona, Utah, Wyoming, New Mexico, Nevada and parts of Mexico. Nevada is allocated, the smallest amount at 2%.
The additional 10 percent of Southern Nevada's water supply comes from groundwater that is pumped from an aquifer beneath the city, which is fed by rain and snowmelt from mountains surrounding Valley.
Lake Mead, the largest reservoir in the United States, was designed to hold 28,945,000 acre-feet of water (about 9.5 trillion gallons). It is drawn from Rocky Mountain snowmelt and runoff via Lake Powell to the North.
But the lake has dropped more than 150 feet since 2000 when it was almost full, to 25% full by 2022, mostly due to reduced precipitation and higher temperatures in the Las Vegas Valley.
A particularly precipitous year in 2023 increased the Lake Mead level by two feet to 33% full. This amounts to 480 billion additional gallons. 40 million Las Vegas visitors consume approximately 28 billion gallons per year while the 2.3 million locals total about 84 billion, so the additional rainfall represents over four years additional capacity.
Water used outdoors cannot be captured, treated and used again, however.
To address this, the Las Vegas region enacted laws requiring only three days per week outdoor watering in the fall and one day per week in winter, along with natural foliage replacement incentives.
PLANNING FOR THE FUTURE
In response to the low levels, the Las Vegas Valley Water Authority installed a low level pumping station and third intake pipe so that if water levels were to lower further, Southern Nevada would remain able to draw water from the reservoir and deliver it downstream. Fortunately, a particularly precipitous 2022 winter increased levels by 24 feet up to 1/3 full, negating immediate need to use the system.
In 2023, the Colorado river operated under ‘Tier 2’ water restrictions that reduced Nevada’s allotment by 8%. 2024 will bring a ‘Tier 1’ consumption allotment requiring an additional 7% reduction.
These reductions do not encumber Southern Nevada, however, as it is one of the most water secure communities on the river and one of the few places on the planet that recycles all indoor water. All unused water empties into the sewer system that is transported to a wastewater treatment facility. Because 40% of all consumption is used indoors and 99 percent of that is recycled and returned to Lake Mead, total water consumption in the valley has diminished by 30% since 2000 (despite population having grown by approximately 750,000 over that period).
Further, the state also approved investment of up to $700 million toward a $3 billion project in Southern California that would allocate Nevada up to 30% of the water from that plant.
Future changes in farming practices along the Colorado River, where about 75% of water usage is for agriculture will be addressed. The Bureau of Reclamation discussed paying farmers to leave their fields unplanted to allow the water that would’ve been used to irrigate crops to stay in the Colorado River.
Desalination of seawater also has been considered as part of an overall strategy but is costly. The desalination plant in San Diego cost $1 billion but meets just over 10% of the water needs for those 3.3 million people.
Including groundwater, Lake Mead and assets in other states, Las Vegas also has about 12 years’ worth of water stored (345,000 acre-feet) in a groundwater system accessible by wells.
An environmental review will be undertaken in 2025 and is expected to add about 3% additional to Southern Nevada’s annual water supply.