Irrigation is responsible for about 40 percent of global food production but most agriculture in the Great Lakes Basin has been rain-fed and, historically, irrigation has played a marginal role. This chapter investigates irrigation and irrigation-related water conflicts in the Basin in the context of the changing climate. It presents a case study of the most significant irrigation-based conflict in the Great Lakes Basin to date: the battle over the Mud Creek Irrigation District in Michigan. Michigan is, by far, the largest irrigator in the Basin. In most years, it withdraws more irrigation water than all the other states and provinces combined. Wisconsin has one of the Basin's irrigation hotspots, located southwest of Green Bay, where irrigation is used to grow corn, soybeans, potatoes, and other vegetables. For most states and provinces, the Mud Creek conflict highlighted some glaring weaknesses in the Great Lakes Charter and prompted new efforts by governors and premiers to create stronger intergovernmental water governance institutions.