One watershed. 3 states, 6 counties, 9 subwatersheds, 265,000 people, 694,400 acres.


The 694,400 acre St. Joseph River watershed is located in northeast Indiana, northwest Ohio, and south-central Michigan. Indiana occupies 56% of the watershed, while Michigan and Ohio each occupy 22%.

With its headwaters in Hillsdale County, Michigan, the St. Joseph River flows southwest through Williams County, Ohio; Defiance County, Ohio; DeKalb County, Indiana; and Allen County, Indiana, before converging with the St. Mary's River in Fort Wayne, Indiana to form the Maumee River in the Western Lake Erie Basin. Both Noble County and Steuben County in Indiana contribute water to the St. Joseph River, through the Cedar Creek and Fish Creek tributaries.


St. Joseph River and its nine sub-watersheds

St. Joseph River county and urban areas

St. Joseph River as part of Maumee
and Western Lake Erie Watersheds

Land Uses

The watershed is primarily agricultural, with approximately 64% in cropland and 15% in pasture or forage. Woodlands and wetlands are found on 10%, while the remaining 11% consist of urban, farmsteads, airports, golf courses, and other land uses.


The majority of the St. Joseph River Watershed is rural, with a population of approximately 65,000 (excluding Ft. Wayne). Fort Wayne is the largest city in the watershed with over 200,000 residents. Auburn, Indiana is the second largest city and Montpelier, Ohio is the third largest. The population is increasing throughout the watershed, especially in southern DeKalb and Noble Counties and northern Allen County. Small 5-10 acre parcels are numerous in these areas. In all three states, industry is claiming areas along interstate and major state highways.

Soils and Geology 

The topography of the watershed varies from rolling hills in Hillsdale, Williams, Noble, and Steuben Counties to nearly level plains in DeKalb and Allen Counties. The St. Joseph River follows the Fort Wayne moraine and flows past numerous low bluffs and terraces. This indicates that the river was once much wider and deeper. Much of the St. Joseph River bed is composed of sand and gravel deposits. The average slope of the river's bottom is 1.6 feet per mile.

Soils in the watershed were formed from compacted glacial till. The predominate soil textures are silt loam, silty clay loam, and clay loam. Soil associations include Mini-Morley, Morley-Glynwood-Blount, and Blount-Pewamo. Erosion and over-saturation are the major soil limitations.

Water Supply 

The St. Joseph River serves as the drinking water supply for the 200,000 people of Fort Wayne and New Haven. Fort Wayne's Three Rivers Filtration Plant processes 34 million gallons of water daily from the St. Joseph River. The filtration plant also operates two large reservoirs: Cedarville Reservoir in the St. Joseph River and Hurshtown Reservoir. Together these reservoirs store over 1 billion gallons of water.

Attachment    Size
Middle ws map.doc    1.66 MB