The Minnesota River near Black Dog is the stretch of the river which flows between sections of Burnsville, Bloomington, and Eagan. The area surrounding this section of the river is part of the Minnesota Valley National Wildlife Refuge and has several lakes, fens, and marshes. Nine Mile Creek flows into this section of the Minnesota River. The Xcel Energy Plant is also located on this stretch of the river, and the Seneca Wastewater Treatment Facility is located just downstream.The Minnesota River at Black Dog, River Mile 8.5 is the main river monitoring station on this stretch of the river. It measures the water quality of the Minnesota River upstream of the Seneca Wastewater Treatment Facility. It additionally is uniquely positioned next to the Xcel Energy Plant, with one cooling effluent pipe entering the river above the water quality monitoring site and one entering below. In 1986, the monitoring station was temporarily located at Minnesota River below Cedar Avenue Bridge, River Mile 7.4 because the regular monitoring station was inaccessible for the year.The Minnesota River is a 332 mile long tributary of the Mississippi River which originates from Big Stone Lake near the border of South Dakota and Minnesota. The watershed of the river covers roughly 17,000 square miles. The geology of the watershed is relatively young compared to other areas of Minnesota, and as a result there is a lot of erosion activity in the Minnesota River and its tributaries. Much of the watershed has been converted into cropland to take advantage of the nutrient rich soil in the region.