By Ron Knecht
I recently penned a Nevada water white paper for Fred Simon, MD, running for Nevada Governor. Here are highlights.
Colorado River annual flows are over-allocated among seven states, and reservoir storage in Lakes Powell and Mead is shrinking. Hence, water allocations under the 1922 Colorado River Compact may be renegotiated or litigated in coming years. Nevada needs to aggressively protect its interests in the Colorado River waters that supply 90 percent of Clark County’s needs.
More interstate water rights have been allocated by the “Law of the River” (rules, regulations and laws, including the Compact, governing the Colorado River) than there is real water on a reliable, continuous basis to satisfy them. Fortunately, not all those water rights are currently in continuous use, especially in the Upper Colorado Basin, leaving some margin, which is rapidly diminishing with population growth and new development.
The Compact and a treaty with Mexico have allocated 16.5-million allocated acre-feet. The problem is that tree-ring analyses suggest that the actual yearly flow over the last 1,200 years has been 14.6-million acre-feet. And we’re currently in a long-term drought.
Fortunately, Lakes Mead and Powell reservoirs can hold a combined 56-million acre-feet. But diversions and increased evaporation due to a Colorado River Basin drought since 2000 have reduced water levels in them to less than half their capacity. And Upper Basin states, especially Colorado, Utah and Wyoming, are beginning to use more of their allocations.
The Southern Nevada Water Authority (SNWA) has asked the Legislature to outlaw water-guzzling ornamental grass that people almost never walk on (“non-functional turf” in road medians, housing developments and office parks). This unprecedented measure would reduce annual water use by 15 percent, allowing for some growth while remaining below use limits dictated by the Law of the River or falling Lake Mead water levels.
These savings would buy time to develop new conservation measures, perhaps greater Colorado River allocations, and even restoration of Lake Mead water storage to historic levels.
Clark County’s bedroom communities have embraced conservation measures, including aggressive monitoring of sprinklers and leaky irrigation systems. Since 2003, SNWA has prohibited developers from planting green front lawns in new subdivisions. It also offers owners of existing properties very generous rebates up to $3 per square foot to tear out sod.
But 2020 was among our driest years in history, when Las Vegas suffered a record 240 days without measurable rainfall. Although a ban on ornamental grass may draw resistance from master-planned communities, officials believe homebuyers from wetter regions now accept such limitations.