This is an archived article that was published on sltrib.com in 2011, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.

Recent editorials in The Salt Lake Tribune focusing on the Southern Nevada Water Authority's request to use a portion of Nevada's unused, unallocated groundwater supply have served as reminders that science is sometimes subjugated by emotion and rhetoric.

Given this, it seems appropriate to take a moment and rationally evaluate the facts associated with Nevada's in-state groundwater project.

What is consistently mischaracterized by project opponents as a "water grab" is in fact nothing of the sort. Activists' claims that there is no excess water available for export are simply false. The reality is that Nevada's state engineer has quantified a supply of renewable groundwater within Nevada that is both unallocated and unused.

As the public agency tasked with providing a reliable water supply for 2 million residents and Nevada's economic engine, the SNWA has applied for the right to use a portion of that water. As a permitee, the SNWA would be subject to the same rules that apply to all other water users; in fact, the environmental safeguards associated with this project are both numerous and comprehensive.

Lake Mead and Lake Powell benefited from a strong snowpack in the Rocky Mountains this past winter, bringing Colorado River users back from the brink of declared shortages. At the same time, Southern Nevada's economy — which has been ravaged by the recession — is only now beginning to show signs of recovery.

Given these factors, some have questioned why the SNWA is continuing with the permitting process, which ultimately would make it possible to draw upon groundwater from five basins in east-central Nevada — one of which is shared with the state of Utah. The answer is simple: security.

A decade of drought has taught us that relying on one source of supply is unwise. Despite all the dams that have been built and the agreements that have been put in place, weather patterns that bring extended periods of severe drought are a reality. As the agency whose responsibility it is to assure a reliable water supply 50 years into the future, we have to anticipate these droughts in our long-range planning.

The only thing that provides that needed security is a supply not connected to the Colorado River. Some have suggested ocean desalting, an option that we have been evaluating with neighboring states for years and believe will be a part of our resource portfolio in the future.

Unfortunately, Nevada has no ocean-front property, and being able to exchange desalinated water for Colorado River water is all but impossible when the river is in drought, which is precisely when the supply would be needed.

Under healthy river conditions, desalination can be used to increase our available supply through an exchange for Colorado River water. However, when deliveries are curtailed during drought, any desalting facilities that can be built by our neighbor California will undoubtedly be used to protect the 20 million inhabitants of Southern California, who will be as affected by shortages as our state's residents.

While financing the in-state groundwater project will require an investment by the community — a recent analysis indicated that, under severe economic conditions where no other revenue sources are available, the typical customer could pay up to $30 per month extra to support the project's construction by the year 2025 — that investment pales in comparison to the risk associated with not having a reliable water supply. Additionally, even if this comes to pass, Las Vegas' water rates will remain comparable with other Western cities.

Southern Nevada can no longer afford to rely on Lake Mead for 90 percent of its water supply. Cities like San Francisco, Denver, San Diego, Los Angeles, Albuquerque, Phoenix, Tucson — and yes, Salt Lake City — would not exist as they do today had they not secured the community's water supply by bringing water in from other areas.

Although Southern Nevada is suffering through the consequences of the national recession, it can and will recover; but only if businesses and a flourishing tourist trade can rely on a secure water supply no matter how dire drought conditions become.

Water security is not a luxury — it is an absolute necessity in this, America's driest city.

Patricia Mulroy is general manager of the Southern Nevada Water Authority.