City of Wilmington – Edgars Hoopes Reservoir

Installation of a silt barrier and temporary mechanical pipe plug in 120-feet of water at the upstream face of the dam.  The silt barrier consisted of a 25ft x 21 ft x 35 ft arched steel structure with support bracing.  The silt barrier was installed at the bottom of the dam to encompass the existing blow-off structure.  The installation involved the removal of sediment utilizing a 300hp hydraulic submersible sludge pump, anchor bolting and placement of sandbags.  An engineered mechanical pipe plug was installed into the existing 36-inch pipe to provide a water-tight seal to facilitate the installation of a new gate valve.  Sediment debris was removed from the interior of the blow-off pipe to a distance of 85 linear feet.   Two decompression chambers were used during the project.

Project Gallery