Forty million people depend on the Colorado River for drinking water. But water shortages in the river are already common. And the problem is going to get worse as the climate changes.

That’s not just because we’re going to see changing precipitation patterns. It’s also going to get warmer. And warmer temperatures can exacerbate droughts, especially when they happen in spring.

The headwaters of the Colorado River are fed by snowpack, and a warm spell in spring can make that snow melt too early. When it does, it evaporates or gets absorbed by soil. As a result, when summertime comes, less is available for runoff into the river.

Connie Woodhouse of the University of Arizona says this situation is already happening. Weather records show that springtime temperatures in the west are increasing, and scientists expect the trend to continue.

Woodhouse: “We’re moving toward these warmer drought conditions that are having more of an impact on stream flow.”

So for the farmers who depend on the river for irrigation, and the communities that rely on it for drinking water, warmer and drier conditions pose a real and immediate threat.

Reporting credit: Sarah Kennedy/ChavoBart Digital Media.

Photo: Colorado River.