Little Miami River - Hydrography

Hydrography

The Little Miami River is a tributary of the Ohio River. It is part of a watershed that drains a 1,757 square miles (4,550 km2) area in 11 southwestern Ohio counties: Clark, Montgomery, Madison, Greene, Warren, Butler, Clinton, Clermont, Brown, and Highland. The river discharges on average 1,737 cubic feet per second (49.2 m3/s) into the Ohio River. An average of 1,280 cubic feet per second (36 m3/s) flow through the river proper; after heavy rains, the river flow may rise to 84,100 cubic feet per second (2,380 m3/s).

Tributaries of the Little Miami include Sugar Creek, the East Fork Little Miami, North Fork, Todd's Fork, Duck Creek, Caesar Creek, Massie Creek, and Turtle Creek. The river's main tributary, the East Fork of the Little Miami, was dammed in 1977 by the United States Army Corps of Engineers to create Harsha Lake, located in East Fork State Park. Similarly, in 1973, the Army Corps dammed Caesar Creek to create Caesar Creek Lake, located in Caesar Creek State Park.

The river's headwaters, considered part of the North Fork, are located about 5 miles (8.0 km) from South Charleston in Clark County, near Plattsburgh. The river empties into the Ohio River at California, a neighborhood of Cincinnati in Hamilton County. Between the headwaters and the mouth, there is a 705-foot (215 m) decrease in elevation.