MOUNTAIN LAKE, MINN. – The corn succumbing to the forks of Brandon Fast’s combine this autumn morning is green. It shouldn’t be. But the floods of June are finally being felt.
“Two years ago, this was 270 bushel an acre,” said Fast, who has farmed since high school in this southwestern Minnesota town of 2,000. “Right now?”
Fast, 46, glances at the colorful numbers rotating on a digital screen hanging inside the cab of his John Deere. “Our average right now is right here at 169″ bushels per acre.
June dumped more than a foot of rain on Cottonwood County. Across South Dakota, Iowa and Minnesota, water spilled from fields, overflowing streams and destroying culverts. A bridge was knocked out a mile from Fast’s farm. Fifty miles east, a dam above Mankato on the Blue Earth River was imperiled, briefly capturing the nation’s attention.
With corn above $4 a bushel, Fast estimates he’ll average a $200-an-acre loss. He farms 700 acres.
It could’ve been worse. Many of his fields are lined with drainage tiles — perforated pipes that drain water from fields to streams. But on this one? “Not a lot of tile in here,” said Fast, shaking his head.
The tiling irrigation system, the same one that saved some of Fast’s corn crop, came under scrutiny as partly to blame for the flooding itself. Even before the floodwaters washing across south central Minnesota highways and basements dried, some observers pointed to the drainage tiles in farm fields across the region for boosting the flood’s destructive power. One researcher, an expert in the region’s hydrology, has estimated tiling was responsible for increasing the peak flow of the Blue Earth River by 20% to 40%.
Over the decades, the piping latticing southern Minnesota’s fertile blue-black clay transformed the region’s fields, including wetlands and sloughs, into expansive agricultural plots. Skeptics say the practice increases sediment erosion and nitrate pollution downstream and, as seen in June, increases the intensity of water sent rushing downstream during a storm.