Las Vegas, Nevada’s most populated city with 2.2 million habitants in its metropolitan area, is known for its hotels and casinos. Situated in the middle of a desert, the city has a total area of 350 km2, of which only 0.03% is water (United States Census Bureau 2010). Las Vegas’s largest source of water is the Colorado River, which is primarily withdrawn from the Lake Mead, and furnishes about 90% of its total water consumption (SNWA).
The Lake Mead was created in 1931 with the construction of the Hoover Dam. Today, it constitutes the United States’ largest water reservoir in terms of volume (26MAF or 32 km3 at full capacity). Water leaving Lake Mead goes to three states and Mexico (Holdren and Turner 2011).
The 1922 Colorado River Compact allocated 15 million acre-feet of water among seven US states, but more water rights were allocated than actually exists in a normal year (Karamanos 2010). Nevada has the right to use 300,000 acre-feet of water per year. Las Vegas takes 450,000 acre-feet yearly because it gets credits for treated wastewater it returns to Mead (SNWA).
All of the following information is drawn from Lasserre’s article “Water in Las Vegas: coping with scarcity, financial and cultural constraints”:
The explosive population growth since the 70s in Las Vegas have resulted in an increase in water demand for domestic but also economic use. Additionally, there has been a 22-year megadrought in the region due to climate change. Rising temperatures combined with the fast population growth explain why Lake Mead’s surface has dropped drastically over the past few decades. According to the NASA Earth Observatory, the reservoir is at its lowest levels since 1930s, at 35% of capacity.
As the Colorado River Compact is still in effect, Nevada has to cope with its acquired rights from the past, which turns out to be quite challenging. Lasserre explains that since the beginning of the 1950s, conservation policies have been encouraged due to the fast depletion of groundwater, the high costs of diversion infrastructures and the limited amount of available water. He points out that these policies led to a declining per capita water use: between 2002 and 2012, annual water use dropped by 110 million m3 (89TAF).** Most people believe that it is the fountains, golf courses, casinos and hotels that are responsible for most of the city’s water use, however, this is just an illusion. Most of Las Vegas’ water goes into residential use, both in and outdoor. In 2013, residential demand was responsible for 60% of the total water used in Las Vegas whilst the tourism industry is very water efficient (Lasserre 2015).
The Southern Nevada Water Authority, a government agency in charge of Southern Nevada’s water management, has started to implement some measures to face this water shortage. These measures include scheduled watering days for residential landscaping and the implementation of xeriscapes, which is the process of gardening with less need for water (National Geographic). Although measures to reduce water consumption reduced residential water use by over 30% since the 2002 drought, its overall water consumption has increased by 1.2 billion gallons between 2011 and 2014 (Lustgarten 2015).
* Please help my Water Scarcity students by commenting on unclear analysis, alternative perspectives, better data sources, or maybe just saying something nice 🙂
** Note from DZ: It’s unclear if this drop has left “more water” in Mead or been diverted to other uses in NV. Hopefully Elise can clarify.