There are two low head dams on the Swatara Creek. They are both operated by water companies for the purpose of drawing water from the creek for public water supply use.
These dams, often call “drowning machines”, are dangerous to boaters. A person or boat can be trapped in the hydraulics that occur as the water flows over the dam (see below). It is very difficult to escape the churning water and the the person can be trapped underwater against the dam. Avoid these dams!
The Lebanon Water Authority operates the dam just north of Jonestown. To avoid the dam, exit the creek at the Lickdale Access in Swatara State Park and reenter at Jonestown. If you choose to float this sections of creek, portage is on the left of the dam.
The dam in Hershey is operated by PA American Water Company. To avoid this dam, exit the creek at the Boathouse Road access. Enter at Union Deposit or Swatara Creek Park.
There are other dams within the Swatara Watershed, but not on the main creek.
The Seigrist Dam and reservoir, operated by the Lebanon Water Authority, is supplied by Fishing Creek and is the source of drinking water for Lebanon City.