Writing this post in suburban Cincinnati, I am surrounded by the buzzing of sprinklers and lawnmowers under the summer sun. Every yard has its carpet of grass, requiring regular watering and constant cutting. In suburban Las Vegas, however, things are undoubtedly much quieter; the city has banned the planting of new turf in the front yards of single-family homes and the common areas of apartment buildings.
Vegas’s restrictions have emerged from concerns over the growing problem of water in the American Southwest. Nearly all of the region’s water resources come from the Colorado River, which stretches from its headwaters in the Rocky Mountains to the Gulf of California. Since the establishment of the Colorado River Compact in 1922, a series of regulations colloquially known as the “Law of the River” have allotted water to each of the seven states in the Colorado River Basin, controlled by a complex system of dams and canals. Yet as global climate change continues to increase the likelihood of drought conditions in the region, water supplies may not be able to meet the rates specified by the law.
The problems caused by lack of water are tied into other areas of the Southwest’s prosperity, from agriculture to electricity. For example, Arizona farmers use 77 percent of the state’s water resources, nearly all of it piped in along irrigation systems from the Colorado. The majority of agricultural water in the region is used to grow hay for animal feed, even though this crop provides the least value per acre-foot of water. The river’s flow is directly tied to the ability of massive hydroelectric projects like the Hoover Dam to produce power, but other electric producers depend on the river for cooling. Geothermal and coal plants are concerned that droughts could put them out of production, causing power outages across the Southwest.
In light of these large-scale issues, reducing the water used for lawns and gardens may seem like a drop in the bucket, but when applied over the entire region, the savings become quite significant. Over the past ten years, Las Vegas’s program has reduced water use by over 9 billion gallons, and Los Angeles is sponsoring a lawn rebate scheme estimated to save 47 million gallons yearly. Monetary incentives have encouraged many homeowners to practice xeriscaping, the replacement of lawns with “regionally appropriate plants” that can tolerate low water conditions. Cacti and succulents are a far cry from the green fields one expects in the suburbs, but they may play a crucial role in ensuring that the Southwest’s thirst is met in the coming years.