Dickson is located on the "Tennessee Valley Divide", which corresponds for some distance with the downtown's Main Street.

The city lakes, formerly a water supply source and the site of an early electrical power plant even before this, are on a Piney River tributary, as was a former city sewer plant, which was closed when a larger water intake was built further down on the Piney.

The West and East Piney rivers flow together near the community of Mount Sinai; this confluence marks the true head of the stream.

The stream flows from this point south-southeast into Hickman County, where it meets the waters of the Duck River a few miles west-northwest of Centerville.

The Piney's major tributary in Hickman County is Mill Creek, a scenic stream which is frequently stocked with trout by the Tennessee Wildlife Resources Agency.