National Dam Inspection Program. Dutch Fork Dam (NDI ID Number PA-490), Ohio River Basin, Dutch Fork, Washington County, Pennsylvania. Phase I Inspection Report.

摘要

The Dutch Fork Dam consists of an earth embankment approximately 460 feet long with a maximum height of 42 feet from the downstream toe and a crest width of 12 feet. The flood discharge facilities for the dam consist of a combined primary and emergency spillway located on the left abutment (looking downstream). The spillway structures of the dam consist of a concrete overflow section, a trapezoidal concrete-lined spillway discharge channel which terminates in a concrete-lined plunge pool at the toe level of the dam near the left abutment. The overflow structure of the spillway is an 89-foot-long concrete weir, trapezoidal in cross section, located at an elevation approximately 10 feet below the dam crest. The outlet works consist of a reinforced concrete box culvert and a control tower located at the center of the embankment. The conduit is equipped with trask rack devices on the upstream end with a stilling basin at the discharge end. The flow through the conduit is controlled by stop logs located in the control tower. The stop logs divide the control tower into inflow and outflow chambers. The stop logs in the control tower extend from the invert elevation of the box culvert to the normal pool elevation. The flow entering into the intake chamber of the control tower through the upstream portion of the outlet conduit rises to the normal pool elevation, spills over the stop logs into the outflow chamber, which in turn discharges into the downstream portion of the outlet conduit. The lake can be drawn down below the normal pool elevation by removing the stop logs. The control tower is not equipped with any mechanical device for removing the stop logs. This outlet system constitutes the emergency drawdown facility for the dam. (Author)