The Souris River is an international stream which originates in the Province of Saskatchewan, Canada. The river flows southward from Canada into North Dakota and then, after making a large horseshoe bend, flows northward into the Canadian Province of Manitoba. Water uses in the United States affect both the quality and quantity of water released to Canada. Since the Basin's water supply is not adequate to meet the needs of all potential water uses, conflicts exist over priority of water use. Large variations in annual runoff compound these water use conflicts. Waste sources include untreated and inadequately treated municipal and industrial wastes, agricultural wastes, urban runoff, rural runoff, and several large wildlife refuges. The primary objectives of the report are to: Assess the impact of municipal and industrial waste discharges on water quality; Define water quality conditions in the wildlife refuge areas; and Provide background data on inorganic constituents in the river system as a basis for evaluating the water quality effects of the Garrison Diversion Irrigation Project.