Many Minnesota farmers using groundwater to irrigate their crops have failed to apply for and receive permits that state law requires for high-capacity pumping, Minnesota Public Radio reported on Monday, April 7.
MPR said evidence indicates that more than 200 of the high-capacity irrigation wells drilled between 2008 and 2012 are being used without the required permits. And nearly 200 other wells were used without permits until about the last year.
Under state law, permits, fees and reporting are required for any groundwater use of 10,000 gallons per day or 1 million gallons per year. Irrigation wells routinely pump far more than those amounts.
The MPR report resulted from a year-long investigation that confirmed and expanded on a 2013 Freshwater Society special report titled “Minnesota’s Groundwater: Is our use sustainable?”
The Freshwater report compared two data bases — one from the Health Department listing irrigation, commercial and industrial wells drilled from 2000 through 2010 and one from the Department of Natural Resources listing wells eventually covered by the required use permits — and concluded that nearly 500 wells might be being used without permits.
That was more than one-fourth of the high-capacity wells drilled during that period.
MPR made the same type of comparison over a slightly different period and used a slightly different definition of high-capacity wells likely to require water-use permits. Then MPR took the effort a significant step further: It used satellite imagery to link well locations to images of obvious circles left by center-pivot irrigation systems. Those images can be tracked on the MPR website.
When the Freshwater report was issued last spring, the Department of Natural Resources had already begun an effort to improve its enforcement of the permitting requirement. The Legislature in 2013 gave the DNR new funding to continue and significantly expand the effort.
Read the MPR report and view the mapping. Read the Freshwater report, which reported that agricultural irrigation was the second-largest use of Minnesota groundwater and by far the fastest-growing use.
In 2012, the last year for which pumping totals reported to the DNR are currently available, farmers told the agency they used 106.2 billion gallons for irrigation. That was 36 percent of the 293.7 billion gallons in total reported pumping. Public water systems reported using 143.1 billion gallons, or 49 percent of the total.