The purpose of the mining reservoir project was to rebuild the concrete inlet structure in order to increase the volume capacity of the existing pump house. Due to the complexity of the mine’s internal process, the pump house could not be left without a water source during construction. The pre-project scope included dewatering the existing reservoir, removing deposited silt, and setting up a complex bypass and redundant temporary pumping system capable of supplying 18,000gal/min with day and night remote monitoring. The project scope included installing a cofferdam in the inlet channel to isolate construction from the in-service pump house, cutting back the HPDE liner, demolishing the concrete inlet structure and rebuilding a larger concrete inlet structure. The new inlet structure included pouring 168CY of concrete with HPDE, removable screen and slide gate valve embeds. The project concluded with the installation of a 20’ tall slide gate valve, stainless steel screens and screen rake as well as the structural steel platforms and associated electrical infrastructure.