Summary
Work includes removal of existing low level drawdown system and installation of new reinforced concrete stop log guide walls including new sill and slots for new stop logs, and installation of a new low level drawdown system including new gate thimble, concrete overlay, and concrete operating platform. Leakage reduction items include installation of PZC-18 metal sheet piling along the specified corridor and backfilling the area between sheet piling and upstream face of the dam. On the downstream face perform masonry joint repairs, masonry stone replacement, and tree removal to support leakage reduction. To improve site safety along the concrete walkway, remove and replace existing pipe handrail with OSHA and IBC-compliant handrail system with safety gate at the new gate operator. Existing siphon pipe is to be extended upstream of the sheet piling and existing water line along the walkway handrail for reinstallation or to be replaced in-kind. Demolition Work shall include full or partial demolition of the following existing structures: pipe handrail along the walkway, existing gate, stem, operator, and components. Localized chipping/demolition of the concrete slab near reported near the bottom of the existing gate may be required to accommodate installation of the new low level drawdown system. Work shall also include site safety, maintenance of traffic, water control, site security, and site cleanup.