About the Watershed

What is the Lower Olentangy Watershed?

A watershed is an area of land over which water runs on its way to a river. Therefore, everything that occurs in a watershed has either a positive or negative effect on the health of its river.

Every watershed combines with other adjacent watersheds to form a basin, and basins combine to form larger watersheds. The Olentangy watershed is part of the Scioto River basin, which drains to the Ohio River. The Ohio River in turn flows into the Mississippi, which makes its way south to the Gulf of Mexico. Therefore, activities that occur here in north-central Ohio have a direct effect on the quality of water in all bodies of water that are downstream. Unhealthy activities in a watershed make for an unhealthy river, just as cleanup projects in one area help to enhance the health of others.

The Olentangy watershed is 32 miles long, and includes about 150 square miles of land situated between the Delaware Dam and the Scioto River. 22 of those miles were designated a State Scenic River in 1973 because of its exceptional water quality.

The watershed includes the City of Delaware, several University campuses including the Ohio State University, and significant portions of Northern Columbus. A large section of Delaware County, the fastest growing area in Ohio, is also part of the watershed. About 250,000 people live in the watershed.

Watershed: The land area that drains to a specific body of surface water such as a stream, river, lake or ocean.

Lower Olentangy River: The 32-mile section of the Olentangy River that begins at the Delaware Dam in Delaware County and runs south to the confluence with the Scioto River in the City of Columbus.