Disappearing Rio Grande

We spent Saturday morning in two Piper Cub airplanes looking down at the San Luis Valley.

Erich had a blast as he and pilot Jay Sarason swept over the valley and around the foothills to get the right angle for Erich to shoot photos.  Pilot Bob Johnson would have loved to have taken me as far out as the Great Sand Dunes National Park and I wanted to go. My stomach, however, really wanted me to be on the ground.

Still, what we saw from the air made it obvious there was competition for water. We saw a solar farm and a few towns, but the valley floor is dominated by crop circles.

In a wet year the San Luis Valley will get eight inches of rain a year. It is a desert at 7,000 feet above sea level. If it were not for irrigation, the valley would be mostly brown with a few ribbons of green where the Rio Grande and its tributaries flow.

Thanks to wells, pumps and center pivot irrigation, the valley floor is dotted with more than 2,000 circles where alfalfa, potatoes and wheat flourish.  If you drink Coors, the barley most likely came from one of these 120-acre circles.

With such little rain and a deep aquifer that extends across the entire valley, farmers have almost total control of when and where moisture is applied to their fields. All they have to do is turn on the pump.

The problem is so many farmers have been turning on their pumps that the aquifer is dropping. It has lost more than 100,000 acre-feet every year for the last four years.  Since 1976, it has lost more than one million acre-feet, according to a report prepared for the Rio Grande Conservation District. An acre foot is 325,851 gallons, or enough water to cover an acre with one foot of water.

Instead of feeding water into the Rio Grande, the aquifer is now so low, it is pulling water out.

This threatens Colorado’s ability to meet its obligations to deliver water to New Mexico. It reduces the amount of water available to those who have groundwater rights.  The threat is serious enough that the state engineer has threatened to shut down all of the wells until the aquifer recovers.

The Rio Grande Conservation District is working to create a program taxing farmers. The money from the tax would pay some farmers not to pump.  But there are not many takers so far.  The program cannot pay enough to compete with what farmers can earn growing crops, and by extension, lowering the aquifer.

So, right now, the valley is green, but the river is losing water.

Not as fast as I lost my breakfast, but still, it’s a problem.

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