This project is located on Mendums Pond in Rockingham County, New Hampshire, and is being performed for the New Hampshire Department of Environmental Services (“Owner/Engineer”). The intent of the project is to rehabilitate the existing dam to meet current dam safety regulations and includes: 1. Phased construction and phased diversion of water, including installation and removal of temporary cofferdams, temporary bypass piping, and temporary pumped diversion facilities. 2. Select demolition of existing outlet works features. 3. Extension of the existing outlet works conduit and construction of the new concrete impact basin at the downstream end of the conduit. 4. Construction of concrete seepage collection well and HDPE drain pipes. 5. Construction of riprap outlet channel downstream of the concrete impact basin. 6. Construction of downstream earth buttresses for the left and right dam embankment sections, including installation of toe drains, weir boxes, coarse drainfill, fine drainfill, and medium drainfill. 7. Installation of a new stop log and trash rack guide at the intake structure. 8. Instrumentation for weir boxes and existing piezometers. 9. Modifications to the existing toe drain.
