River/Stream: Maquoketa River
Owner: Jones County Conservation Board
Height: 9.5 ft.
Length: 441 ft.
Hazards: usage, visibility
Warning Signs: good
Portage: Portage on river-left (east bank.)
Comments: 2008 flooding severely weakened and undermined the dam. Jones County Conservation is exploring options to modify the dam and water trail. Three options for replacing the dam with structures designed to enhance the riverís natural and recreational attributes are under consideration.
Alternative A, the most expensive at an estimated cost of $2.8 million, entails four stone structures resembling mini-waterfalls. The largest, with a 3-foot drop, would be built at the dam site. Three smaller ones, each with a 1 1/2-foot drop, would be constructed in a 2-mile stretch of river upstream of the dam.
Alternative B (estimated cost: $1.8 million) would consist of the stone structure with the 3-foot drop at the dam site.
Alternative C (estimated cost: $2.3 million) entails replacement of the dam with a rock arch rapids consisting of from six to seven drops, each in the 12- to 18-inch range.