Observations were made relative to the effects of pollution on water quality and water uses in the major problem areas within the basin and the Lake itself. Although some polluting materials are produced in the Lake, practically all wastes originate from land based activities of man. All major tributaries to Lake Erie are grossly polluted at their mouths and many are grossly polluted throughout large portions of their lengths. The rivers are discussed in hydrological sequence beginning with the St. Clair River and following the American shoreline to Niagara Falls. After the rivers, the authors discusses the Lake itself.