The Ottawa River, also known as Ottawa Creek, is a short river, approximately 20 miles (32 km) long[1] (or about 48 miles (77 km)[1] if Tenmile Creek, the longest tributary, is included), in northwest Ohio and southeast Michigan in the United States.

[2] It drains an area on the Ohio-Michigan border along the eastern and northern fringes of the city of Toledo, goes through Ottawa Hills, and empties directly into Lake Erie.

It crosses the Michigan state line for its final 1 mile (1.6 km), entering Little Maumee Bay on Lake Erie.

The water quality assessment of the lower section of the Ottawa River found many chemicals in the water with a hazard quotient greater than 1 (from highest to lowest concentration): lead, aluminum, PCBs, manganese, iron, DDT, thallium, selenium, chromium, nickel, cadmium, cyanide, and zinc.

[5] The poor water quality results primarily from the river's form and structure, since it has a slow flow, and, secondly, from urban runoff and discharge from landfills and sewers.