The Politics Over Water in a Drier Future
Lake Mead is the country’s biggest reservoir of water. Think of it as the savings account for the entire Southwest. Right now, that savings account is nearly overdrawn.
For generations, we’ve been using too much of the Colorado River, the 300-foot-wide ribbon of water that carved the Grand Canyon, supplies Lake Mead, and serves as the main water source for much of the American West.
The river sustains one in eight Americans — about 40 million people — and millions of acres of farmland. In the next 40 years, the region is expected to add at least 10 million more people, as the region’s rainfall becomes more erratic.
An especially dismal snowpack this past winter has forced a long-simmering dispute over water rights to the fore, one that splits people living above and below Lake Mead.
It’s a Messy, Confusing Situation, so Here’s an Overview of What’s at Stake
Users of Colorado River water below Lake Mead include the cities of Phoenix, Los Angeles, Las Vegas. The people in the lower basin exist partly at the mercy of what happens in the upper basin, an area encompassing the snow capped peaks of Wyoming, Utah, Colorado, and northern New Mexico, the source region of the river.
Snow pack in the Rockies has been dwindling, and there’s no physical way for upper basin users to store the water they depend on. There are no big reservoirs in the Rockies.
States in the upper basin sent a strongly worded letter to one of the river’s biggest users, the Central Arizona Water Conservation District, or CAWCD, which supplies water to Tucson and Phoenix. This letter accuses the utility of manipulating the complex system that governs Lake Mead in order to get more water. The Arizona utility denied the charges.
The Central Arizona Water Conservation District operates the Central Arizona Project, 336 miles of canals, tunnels and pipelines that deliver Colorado River water to cities, irrigation districts and tribal nations.
The Whole Thing Feels Like the Beginnings of a Water War
Over-reliance on the Colorado River has helped pave the way for rapid population growth across the region, from Southern California to Denver, which may now, ironically, begin to pose a threat to those same cities.
The latest official projections from the U.S. Bureau of Reclamation, the federal agency that manages the Colorado River system, shows that Lake Mead is likely to dip below the critical threshold of 1,075 feet above sea level late next year (2019). That could trigger the first official “call on the river” — a legally-mandated cutback for certain users aimed at avoiding an all-out free-for-all.
When Lake Mead dips below 1,075 feet, Phoenix may find itself in a position where it stops building new subdivisions, the state’s agricultural economy comes crashing to a permanent halt, and a fit of well-drilling begins to deplete the local groundwater.
This is not just a Phoenix problem as it impacts any locality looking to tap into this water supply.
The low snow pack in the upper basin states means that inflows into Lake Mead will be just 43 percent of normal this year, raising the stakes for conservation programs throughout the West. In the midst of long-running drought, 2017 was the most successful year for water conservation in decades — which is evidence that when there’s less water around, people can make things work.