Wisconsin’s wetlands serve many important functions, including fish and wildlife habitat, water quality protection, flood storage, and erosion control. . . . Wisconsin has lost more than five million, or approximately half, of its original wetland base since European settlement. Wisconsin’s remaining wetlands are critical to the ecological health of the state. . . .  Wisconsin Act 6, Wisconsin’s isolated wetland protection law, authorizes the Department of Natural Resources to administer the water quality certification program for projects in those isolated wetlands that are currently not protected under the federal Clean Water Act. The DNR also administers Wisconsin’s wetland mitigation program.