National Program for Inspection of Non-Federal Dams. Papermill Pond Dam (CT 00471), Thames River Basin, Sprague, Connecticut. Phase I Inspection Report

Papermill Pond Dam is a 573 ft. long composite rubble masonry, concrete, and earth embankment dam consisting of a 124.5 ft. long gravity masonry overflow section, and 84 ft. long earth embankment to the right of the overflow section and a 365 ft. long earth embankment to the left of the overflow section. About 160 ft. of the upstream face of the left embankment is paved with concrete. It is a run-of-the-river dam which is used for storing process water for a paper mill located upstream on the left bank of the river. In the left embankment there is an intake which controlled flows through a conduit to a turbine facility in a mill building located immediately downstream of the dam. The turbine has been abandoned and the mill building is in the process of being razed. The spillway for the dam is equipped with 2.3 ft. high permanent wooden flashboards. The dam is judged to be in generally good condition, but is rated as in fair condition owing to the absence of a dewatering facility. There is brush growth on both embankments. Mortar is missing from the joints of the rubble masonry section of the spillway. There is a crack in the concrete apron on the left embankment and the construction joints of the apron have opened up. Minor erosion has taken place on the downstream slope of the left embankment. The spillway can pass 7,750 cfs or about 72 percent of the routed test flood outflow without overtopping the right embankment.