The era of simple solutions is over

Pat Mulroy and Terry Katzer

Sunday, July 6, 2008 | 2:05 a.m.

Last Sunday, Emily Green’s depiction of the Southern Nevada Water Authority’s efforts to secure a future water supply for the Las Vegas Valley covered a lot of terrain. There was significant discussion of the presumed dire environmental consequences that would befall the rural areas if but one gallon of those available waters were to leave.

These presumptions ignore the science of hydrology, the environmental safeguards embedded in state and federal law, and the fundamental principles of Nevada water law that further protect the environment and existing users.

There has been a concerted effort for more than half a century to estimate the water resources in these basins that are available for use. In fact, the Nevada Conservation and Natural Resources Department published a series of water planning reports in the 1970s; one of those reports dealt with water for Southern Nevada and identified several valleys where water was potentially available for export to Las Vegas.

Research efforts include extensive studies by the Desert Research Institute, the Air Force (M-X Missile Program), the U.S. Geological Survey (Great Basin Regional Aquifer System Analysis) and the U.S. Interior Department (Southern Nevada Deep Carbonate Aquifer Study). The U.S. Geological Survey has published many reports in cooperation with the state of Nevada on the hydrology of virtually all of the basins in the state, beginning in the 1940s.

The ground water that can be obtained in these valleys under Nevada water law is considered the perennial yield, or the amount of water replenished each year by precipitation.

To capture this perennial yield, wells must be distributed to tap the ground water uniformly in areas where phreatophytes (deep-rooted plants) obtain the water from a ground-water table, so that the basin returns to a steady-state condition; because ground-water discharge equals the pumping volume, ground-water levels stabilize.

The time required to achieve this new steady state varies from basin to basin depending on many hydrologic factors and may take hundreds of years.

The effect of pumping on the water table is easily monitored and, if unacceptable to the Nevada state engineer, the impact can be mitigated. The ground-water travel time between basins is measured in decades to centuries, ample time to prevent environmental harm.

If need be, well fields can be relocated, pumping can be reduced and artificial recharge of ground water can be accomplished (depending on surface water availability). In short, numerous management options are available to ensure these valleys will not dry up.

However, the bigger issue was not what was said, but rather what was missing.

Nowhere in Ms. Green’s more than 20,000-word series was an alternative described that protects Southern Nevada’s residents if we lose Lake Mead to drought. We are in the eighth year of drought; Lake Mead is down 100 feet and will drop another 6 feet this year.

People who oppose this project generally point to one of two “solutions”: desalinization or growth control. Let’s take the second one first, because virtually everyone in the valley has an opinion about growth.

Economic repercussions aside — and thousands of people have already lost their jobs in the current economic downturn — let’s assume that not another person moves to the Las Vegas Valley. As it stands, 2 million people call Southern Nevada home, and they rely on the Colorado River for 90 percent of their water supply.

If climate scientists are correct and Lake Mead goes dry, there simply won’t be enough water for essential domestic uses, let alone fire protection. No community can conserve enough to survive on only 10 percent of its water supply.

We are not the only ones looking for alternatives. California just declared a state of emergency, and other Western states are scrambling to create secure water supplies. In an era of climate change, no city can afford to rely on a single source.

So what is the solution? Some suggest buying agricultural water from California farmers; but given the dire straits that state is in, California will inevitably take care of its own first. And let us not forget that those farm districts are among the most significant producers of winter fruits and vegetables.

How about desalinization, the favorite silver bullet for project opponents? The Southern Nevada Water Authority is actively working with Arizona and California on projects that will reduce the strain on the Colorado River — including desalinization projects in Yuma, Ariz., and Mexico — but lacking a coastline, Nevada would have to trade with its neighbors for any water acquired from desalinization.

In other words, Nevada would use the purified seawater in exchange for a share of its Colorado River water. This works only if there is sufficient water in Lake Mead to exchange, which is anything but certain.

I challenge the critics to present a viable alternative that can protect our community in the absence of Lake Mead.

Nevada has few surface water resources and must rely on ground water to help meet its needs. Currently, agriculture uses 77 percent of Nevada’s water resources, while cities and towns survive on less than one-quarter of those resources. As an aside, Dean Baker’s ranching operation draws on Nevada’s water but uses it in Utah, enriching that state’s economy. Despite that, there are still ground-water resources that can be safely developed for the benefit of Nevadans.

We are not working to draw on Nevada’s ground-water resources because it is easy or inexpensive; we are doing it because unless the federal government is willing to move large volumes of water over long distances into the Colorado River to make it once again a reliable supply, Southern Nevada must pursue this water.

A renewable water supply is available in east-central Nevada, and it can be used without destroying the environment or the communities in Lincoln and White Pine counties.

To that end, we entered into an agreement with the National Park Service, the U.S. Fish and Wildlife Service, the Bureau of Land Management and the Bureau of Indian Affairs that states they will forever be involved in deciding how much water we pump at any given time, and from where.

At their request, we also agreed to use a hydrologic modeling program (MODFLOW) more common than Timothy Durbin’s proprietary model code — the reason Mr. Durbin’s model was not used.

Few people are left who don’t believe climate change will have profound effects on how we will live in the decades to come. The two most daunting challenges are energy and water; both become more compelling every day in the face of an exploding global population.

Water managers everywhere, particularly in the American Southwest, have come to understand that their communities’ futures depend on cooperation with their neighbors more than ever before. That realization makes Utah’s behavior even more perplexing, given that the Lake Powell pipeline project delivering 130,000 acre-feet annually to St. George will significantly worsen conditions for an already drought-plagued Lake Mead.

We realize this new resource must be used responsibly. In addition to being a moral imperative, our nation’s laws demand that we safeguard existing water users and the environment.

There is no question that this supply is sufficient to protect our community from a catastrophic shortage without harming the environment. It is not an issue of whether water is available, but rather how much can be safely used each year and how it is best managed. At the same time, Southern Nevada must continue to aggressively pursue conservation, which has been vitally important to extending our community’s existing water resources and which will dramatically extend this new supply.

The era of simple solutions is over; the challenges facing the West in the coming decades are daunting. To meet these challenges, attitudes have to change. The future of all of our communities depends on it.

Pat Mulroy is general manager of the Southern Nevada Water Authority. Terry Katzer, a hydrogeologist, was director of the research department for the Las Vegas Valley Water District and is a paid consultant to the Southern Nevada Water Authority.