The Cutting Edge

Prior appropriation rights presume that water is scarce, transportable commodity not tied to the land. When water is treated in this fashion it may be mortgaged, sold, transported out of the watershed, and historically in the western U.S., subject to violent disputes.

The water wars of the nineteenth century are well behind us. But there are stark choices to be made in the west. And the recent drought in the southeast sees some locations receiving three feet of rain a year while other receive only a tenth that amount.

Normally soggy Atlanta, with three to five inches of rain monthly and an annual average of fifty inches over the last thirty years, became the metropolitan poster child for water conservation in 2007 when rainfall plummeted to less than thirty two inches. Watering bans were discussed in the state assembly, housing developers and landscapers thronged the statehouse, the governor held a public prayer ceremony, and the Senators began talking about the unfairness of the border between Georgia and Tennessee. Almost two centuries ago the state of Georgia refused a surveyor's request to replace his antiquated equipment and the result has left the border between the two states a mile south of its intended location, neatly cutting Georgia off from the waters of the Tennessee River.

Atlanta's reservoir, Lake Lanier, is a unique and solvable portion of the problem. Most bodies of water have a fifty to one watershed to lake surface area, but the giant 38,000 acre Lanier drains an area of just over half a million acres, a ratio of only fourteen to one. Atlanta resident and environmental science text author Dr. Karen Arms reveals an underlying issue. "We get plenty of rain, we just do a poor job of keeping it." According to Arms, a concerted effort at building impoundments in places that currently drain freely would do much to take the stress off the city.

Las Vegas is at the opposite end of the spectrum with an average annual rainfall of just three and a half inches. The city's primary water supply is Lake Mead, the impoundment behind the Hoover Dam, but the level is down almost a hundred feet since Pat Mulroy started in her position as General Manager of the Las Vegas Valley Water District twenty years ago. The lake showed remarkable stability in its level, filling in during the three years from 1936 to 1939. It remaining at that level until 2000 with the notable exception of the major ten –year drop from 1964 to 1974 that coincides with the filling of Lake Powell. Mulroy does a fascinating dance of planning, negotiation, and regional diplomacy in order to keep water flowing to the city of Las Vegas. But her job has grown harder each and every year this decade and soon she may run out of options.

The drought that began in 2000 may not be a drought at all, but instead a climate change event. The west has gone from wet to dry and back again many, many times since humans first camped at New Mexico's Blackwater Draw nearly fourteen thousand years ago. As a nation we had the good luck to begin building in the west in earnest during a historically very wet time, with seven states signing the Colorado Compact governing water use in 1922. Today the luxury of relatively easy water may be gone and with it come hard choices.

Both cities have curtailed lawn irrigation and Las Vegas has gone to its characteristic extreme, uprooting nearly three square miles of lawns and banning the use of turf in landscaping new construction. Atlanta may recover; each tropical storm is watched anxiously, but a direct hit on the well inland city brings only a few downed trees along with a much needed reservoir refill. Las Vegas faces a need to build a new intake in Lake Mead as projected water levels will be below their current connection in 2010. Even with the new construction, Nevada must wrestle with the six other states that participate in the management of the shrinking Colorado, and they labor under a historic disparity, qualifying for just 2 percent of the river's total annual flow of fifteen million acre feet.

Cities will have to confront a new epoch in their demand, conservancy and utilization of a changing and often shrinking resource: water.

Cutting Edge Sci-Tech writer Neal Rauhauser is a member of the Stranded Wind Initiative and can be found at www.strandedwind.org.