10:51 am
Wed July 24, 2013

Can Intensive Farming Coexist with Healthy Lakes and Streams?

The Central Sands region boasts some of Wisconsin’s most productive farm fields, but evidence is growing that keeping them irrigated comes at the expense of nearby streams and lakes.

Wisconsin scientists are monitoring the situation, including the Little Plover. It’s a small river in Portage County but coveted because of its native brook trout.

George Kraft arrived on the scene 24 years ago, to direct the groundwater center at UW-Stevens Point. He calls the area, a hydrogeologist’s dream.

On the eastern edge are moraines from the Ice Age; to the west, flats reach out to the Wisconsin River.

“We also have many headwater streams, trout streams, cold water eco systems and 80 some lakes – prized for many things – county parks, cottages, wildlife, fishing,” Kraft says.

Farmers also prize the flats. Potato and vegetable growers cultivate bumper yields from the sandy soil, by drawing up groundwater to irrigate the fields.

“Since 2000 there’s been a large expansion in high capacity wells, dominantly for agriculture,” Kraft says.

.....bringing the count up to 3,000 high capacity wells; that in a year’s time pump up 78 billion gallons of water.

Kraft says he dove into the “quantity issue” a decade ago, when his phone didn’t stop ringing. People living on Central Sands lakes wanted to know why their water levels were dipping. They suspected irrigation, but he admits he was skeptical.

“ Because we know that there are natural ups and downs. You know could this be explained just by what we see naturally,” Kraft says.

However, as Kraft began investigating low lake and stream levels across the Sands, they did not correlate with weather conditions – they weren’t that dry. So he dug deeper....

“That’s when we started dusting off old reports and found it was predicted 30 or 40 years ago,” Kraft says.

In 1971, the U.S. Geological Survey published a dense document. It’s titled, “Effects of Irrigation on Streamflow in the Central Sand Plain of Wisconsin” and is replete with charts and graphs.

“You know, we do a lot these things very short term on a computer now. They had to do them with pencils and slide rules, when groundwater pumping and irrigation was in its infancy. These really smart guys said, geez if we don’t get ahead on the management of this resource, we’re going to see these lakes dry up and these headwater streams dry up, and indeed, we didn’t manage the resource. We continued pumping more and more water, more wells, and we have the situation they predicted,” Kraft says.

Kraft and other scientists have tweaked computer models; and students have mucked around waterways and collected current day data. He says levels in some Central Sands’ lakes are down five to seven feet.

The Little Plover River has become the poster child for the region’s dilemma.

“It’s going on seven years, eight years that the Little Plover River dried up and they haven’t grasped the science just yet,” Kraft says.

Kraft was one of the scientists who sat around a table Tuesday, as the DNR talked about developing a multiagency approach to maintaining healthy water levels. Although Kraft welcomes drawing fellow hydrologists into the research pool, he’d like to turn the conversation to...

“....what would a different agricultural system look like that would be sustainable with the lakes and streams. How much water could we pump and still have a lake that fish will live in,” Kraft says.

While the DNR grapples with the health of the Little Plover River, a group called Friends of the Central Sands is challenging high capacity well permits the DNR granted to a large dairy operation within the region. The parties will head back to court later this summer.