Climate Change Puts Colorado River At Risk

One hundred years after politicians ignored warnings that even the majestic Colorado River could not sustain all the demands on its water from seven different states, policy-makers are still ignoring the science—a path that is particularly unwise in a climate emergency, Grist reports.

Currently providing water for 40 million people in New Mexico, Arizona, Nevada, California, Utah, Wyoming, and Colorado, the Colorado River is “shrinking as the planet heats up, reducing the snowpack that feeds the river and causing more water to evaporate as the river snakes its way from the Rocky Mountains to the Gulf of California.”

But even in the absence of the climate emergency, the waterway would likely still be struggling because “back in 1922, when states originally divvied up water from the river, they grossly overestimated the amount of water flowing through it.”

That basic math error “set in motion a series of decisions that led to the shortages today,” which have led to the seven states turning to the reserves of Lake Mead and “overdrawing 1.2 million acre feet of water annually—enough to quench the thirst of a couple of million households for a year.”

The practice has a long history, and not for lack of data. Six years before the Colorado River Compact was signed, explains Grist, a young hydrologist with the U.S. Geological Survey, Eugene Clyde LaRue, “concluded that the Colorado River’s supplies were ‘not sufficient to irrigate all the irrigable lands lying within the basin.’” LaRue’s conclusions were backed by other hydrologists at the time, but “alas, their warnings were not heeded.”

Over the years, the fallout from demanding too much of the Colorado has traditionally been blamed on poor data. But good data was buried, or at least repeatedly ignored, according to a new book by water experts John Fleck and Eric Kuhn titled Science be Dammed: How Ignoring Inconvenient Science Drained the Colorado River.

Fleck and Kuhn told Grist the transcripts of LaRue’s 1925 congressional testimony, which stated the problem at hand in clear layperson’s terms, proved that his listeners chose to “willfully ignore” his warnings and those of other expert witnesses.

“The short-term incentives were always to pretend that there was more water, so everybody could build the stuff they wanted to—dams, canals, cities, and farms,” Fleck said. “Everyone knew, if they were being realistic, that the problems would fall on future generations.”

To this day, Kuhn said the pressure on municipalities to declare themselves flush with water, and the lack of a process to keep from overusing whatever water is actually there, hampers progress.

He also pointed to the combative stance of policy-makers who, abiding by traditional game theory, regularly overstate their demands when negotiating water access—thereby routinely ignoring data that show a drop in municipal demand. Citing both Las Vegas and Denver, Kuhn told Grist that “we’re much, much more efficient in how we use water, and that has yet to get into the culture of the basin.”

The system has done no better at factoring in the problem of climate change. While planners are getting much better at modeling climate risks to the water system, said Fleck, water users often have trouble taking in the reality that while their needs are declining, so is the supply, thanks to drought and other fallout from the climate emergency.

What is needed, he said, is collaboration, and a concern for the future. “If, alternatively, we cling to the old water allocation rules that were written a century ago, and everybody digs in their heels and says, ‘Yeah, but I need all that water,’ then the whole thing could blow up, and it would be a catastrophe in the West.”