High Plains Aquifer pumping is impacting surface water and native fish

High Plains Aquifer via Colorado State University.

From The Denver Post (Bruce Finley):

The agricultural overpumping from thousands of wells continues despite decades of warnings from researchers that the aquifer — also known as the Ogallala, the world’s largest underground body of fresh water — is shrinking.

Even if farmers radically reduced pumping, the latest research finds, the aquifer wouldn’t refill for centuries. Farmers say they cannot handle this on their own.

But there is no agreement among the eight affected states (Colorado, Kansas, Nebraska, New Mexico, Texas, Oklahoma, Wyoming, South Dakota) to try to save the aquifer. And state rules allow total depletion.

Republican River Basin by District

In fact, Colorado officials faced with legal challenges from Kansas over dwindling surface water in the Republican River have found that their best option to comply with a 1942 compact is to take more water out of the aquifer. The state bought wells from farmers during the past decade and has been pumping out 11,500 acre-feet of water a year, enough to satisfy a small city, delivering it through a $60 million, 12-mile pipeline northeast of Wray to artificially resuscitate the river.

The overpumping reflects a pattern, seen worldwide, where people with knowledge that they’re exceeding nature’s limits nevertheless cling to destructive practices that hasten an environmental backlash.

The depletion of the High Plains Aquifer has been happening for decades, according to bulletins U.S. Geological Survey has put out since 1988. Colorado farmers this year pumped groundwater out of 4,000 wells, state records show, siphoning as much as 500 gallons a minute from each well to irrigate roughly 580,000 acres — mostly to grow corn, a water-intensive crop.

The depth where groundwater can be tapped has fallen by as much as 100 feet in eastern Colorado, USGS data show. That means pump motors must work harder to pull up the same amount of water, using more energy — raising costs for farmers. The amount of water siphoned from the aquifer since 1950 to irrigate farm fields across the eight states tops 273 million acre-feet (89 trillion gallons) — about 70 percent of the water in Lake Erie.

On one hand, the industrial center-pivot irrigation techniques perfected after World War II have brought consistency to farming by tapping the “sponge” of saturated sediment that links the aquifer to surface water in streams and rivers. America’s breadbasket produces $35 billion of crops a year. On the other hand, intense irrigation is breaking ecosystems apart.

Overpumping has dried up 358 miles of surface rivers and streams across a 200-square-mile area covering eastern Colorado, western Kansas and Nebraska, according to U.S. Fish and Wildlife-backed researchers from Colorado State University and Kansas State University who published a peer-reviewed report in the Proceedings of the National Academy of Sciences. The researchers also determined that, if farmers keep pumping water at the current pace, another 177 miles of rivers and streams will be lost before 2060…

Disappearing fish species — minnows, suckers, catfish that had evolved to endure periodic droughts — signal to biologists that ecological effects may be reaching a tipping point.

The amount of water held in the aquifer under eastern Colorado decreased by 19.6 million acre-feet — 6.4 trillion gallons — from 1950 until 2015, USGS records show. That’s an average loss of 300,000 acre-feet a year. Between 2011 and 2015, records show, the water available under Colorado in the aquifer decreased by 3.2 million acre-feet — an annual average shrinkage of 800,000 acre-feet. Climate change factors, including rainfall, play into the rate of the drawdown…

They say they’re trying. They’ve reduced the land irrigated in eastern Colorado by 30,000 acres since 2006. They plan to retire another 25,000 acres over the next decade, said Rod Lenz, president of the Republican River Water Conservation District, who for years has advocated use of technology to grow more crops with less water…

Farmer and cattleman Robert Boyd, a leader of the Arikaree Groundwater Management District, said the federal government should intervene to ensure survival of High Plains agriculture…

Kansas Aqueduct route via Circle of Blue

He pointed to proposals to divert water from the Missouri River Basin and move it westward through pipelines across the Great Plains…

But drawing down the aquifer does not violate any law in Colorado. The state engineer’s office monitors well levels and requires permits for wells, limiting the number of acres a farmer can irrigate. But there’s no hard limit on how much water can be pumped…

[Mike] Sullivan and state engineer Kevin Rein emphasized that thousands of acres no longer are irrigated. “And there need to be some more retirements of land to get us into a more balanced situation,” Sullivan said.

They defended Colorado’s practice of pumping more groundwater out of the aquifer, saying this is necessary to comply with the Republican River Compact. Disputes over river flows have risen as far as the U.S. Supreme Court and Colorado’s legal obligations to deliver water to Nebraska and Kansas are clear.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s