For the InstructorThese student materials complement the Water Science and Society Instructor Materials. If you would like your students to have access to the student materials, we suggest you either point them at the Student Version which omits the framing pages with information designed for faculty (and this box). Or you can download these pages in several formats that you can include in your course website or local Learning Managment System. Learn more about using, modifying, and sharing InTeGrate teaching materials.
As you have read about in The Big Thirst: Dolphins in the Desert, Las Vegas has been aggressive in water conservation efforts. Part of these efforts focus on simple reductions in household water use through education, regulation (i.e. watering restrictions), and incentivized removal of water-intensive landscaping. The city has also implemented GPS technology and pressure and acoustic sensors to monitor leaks in their pipelines to limit leaks and thus maintain high efficiency. As a result of these efforts, per capita water use in Las Vegas has decreased substantially over the past 20 years or so, from over 340 gallons per day to less than 200 gallons (a 40% reduction!) (Figure 12). The SNWA has set a conservation target of 199 gallons per day fro 2035. As a result, Southern Nevada's total annual water use dropped by almost 90000 acre-feet (30 billion gallons) from 2002 to 2012, even as its population grew by 400,000.
Additionally, as noted above, Las Vegas treats wastewater for re-use, especially for applications that (a) don't require high-quality water, like watering golf courses and parks; and (b) are consumptive. Re-use, incentivized by lower pricing, effectively allows the same water to be used twice, thus making the modest allotment of Colorado River water go further. Indeed, although Southern Nevada's gross withdrawals from Lake Mead are almost 600,000 acre-feet per year (Figure 9), this is offset by return of treated water to the Lake such that net withdrawals (consumptive use) remains at the 300,000 acre-feet limit.
Source: SNWA water conservation plan, 2014-2018.