Mobilization, preparation of administrative, staging, and work areas, and establishing construction limits • Construction, operation, and maintenance of erosion and sediment control measures in accordance with an approved permit from the NC Department of Environmental Quality • Development and implementation of a control-of-water plan, including design of temporary cofferdams, temporary stream diversion, and dewatering measures consistent with conceptual design approved by NC Dam Safety. The concept includes lowering the reservoir 3.5 feet below normal pool with temporary siphons and the installation of an upstream and downstream temporary cofferdam. • Demolition and removal of the existing spillway structure to the demolition limits shown on the Drawings. • Excavation of soil and rock to the limits on the Drawings. • Installation of sand and stone drainage systems beneath the spillway slab and behind the spillway sidewalls. • Construction of reinforced concrete auxiliary spillway including cutoff walls, labyrinth weir control section, converging chute, and stilling basin. • Installation of sluice gates, ductile iron pipe, and Fiber Reinforced Plastic (FRP) platform for auxiliary spillway outlet works. • Backfill behind new spillway sidewalls and fill placement to level the crest of the existing embankment. • Grading and installation of riprap protection along the outlet channel bank and around the auxiliary spillway entrance. • Installation of other miscellaneous items including FRP ladder, fencing, and instrumentation.
