Watering the West is not the Midwest's problem

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The water shortage gripping the U.S. Southwest is a tragedy of untempered greed mixed with inexplicable denial, which has left desert cities scrambling to find water to sustain explosive growth that they've long been told is simply not sustainable.

Today, decades of drought aggravated by climate change in the Colorado River basin has pushed two major supply reservoirs — Lake Powell at Page, Ariz., and Lake Mead near Las Vegas — to record lows, nearing levels where hydro plants on dams cannot generate electricity needed by 10 million people.

Lake Powell is approaching "dead pool" where no water could pass downstream, periodically drying the Colorado through the Grand Canyon and further depleting Lake Mead.

Implications of all this go well beyond the Southwest. Minnesota and the Midwest are in a bull's-eye as the urgent hunt for water casts increasing interest toward the Mississippi River and the Great Lakes to augment the Colorado's flow.

By various estimates, water importation to the West would require 85-foot diameter pipes and colossal amounts of energy to move water uphill over very long distances, costing upward of $100 billion, encountering a slew of complexities and surely triggering social and political turmoil.

Arizona recently put up $1.2 billion to seek alternative water sources, including Midwest pipelines. In the U.S. Senate, the seven Colorado-basin states are forming a caucus to ensure their outsized interests are protected.

Basin states cannot agree among themselves on how to curtail water use. The largest single user, California, opposes any cutbacks, relying on senior rights granted under a hodgepodge of laws dating back to the 1800s when gold miners and ranchers protected water claims with six-shooters and fists.

California's opt-out means basin reallocation likely will go to the federal government. It would be a formidable task of appeasing states and powerful water interests represented by armies of lawyers.

The present-day chaos is rooted in the 1922 Colorado River Compact where basin states agreed to water allocations that, it turns out, were based on gross over-calculation of how much water would be annually available.

In 1969, more accurate water forecasts came from tree-ring scientists who revealed a history of prolonged droughts, and accurately said the Colorado wouldn't have nearly enough flow to satisfy all legal users under the earlier agreement.

More and more demand for less and less water.

Agriculture has priority to 80% of allocated water, which raises common-sense questions about flooding deserts to raise crops. Worse, growers have turned to high-profit, water-intensive crops like tree nuts and fruits, alfalfa and even giant feedlots for milk and meat.

With California claiming senior rights, the parched Southwest faces daunting challenges and few options, including desalinization to make potable water from briny seas, importation, or conservation and recycling, in any combination.

So there doubtless will be ongoing interest in piping Midwest water. Minnesota and other states, and Canada, signed the Great Lakes Compact in 2008 that prohibits interbasin water diversion. That would be difficult to overcome.

Mississippi diversion is marginally more likely. But a 2012 federal study said it would take 30 years to plan and build, assuming favorable environmental review and somehow obtaining the hundreds of state and local permits that would be required.