The drought that gripped Minnesota in the summer of 2021 was one of the worst on record. Day after day a blazing sun shriveled leaves, dried up waterfalls and turned ponds to puddles. In a state known for its 10,000 lakes, many people could do little except hope for rain. But big farmers had another option. They cranked up their powerful irrigation wells, drenching their fields with so much water that they collectively pumped at least 6.1 billion gallons more groundwater than allowed under state permits. Nearly a third of the overuse happened on land affiliated with one company, R.D. Offutt Farms.