Nassau 

Guard 

Gate 

Replacement 

on 

Trent 

Severn 

Waterway

Project Description

• The Nassau Guard Gate involved the construction of Earth Dams on the east and west side of the historically significant Trent-Severn Canal, and the construction of a Concrete Structure within the canal complete with Steel Sector Gates and associated electromechanical components. The Guard Gate would be used in the case of a major flooding event and would redirect water upstream to the Otonabee River, protecting the homes, businesses, and critical infrastructure adjacent to the canal. The Work also included the construction of a flow bypass system, and installation of a new watermain. The bypass system, consisting of a 1200mm diameter HIPRESCON pipe, cast-in-place Inlet and Outlet Structures, and an electrically-powered slide gate, would allow for the gates to be preventatively closed in the winter time, enabling an ecological flow to maintain familiar levels in the canal, and help protect important wetlands, fish habitat and fish spawning grounds.
• The Scope of Work included excavation, grading, diving operations, cofferdams, dewatering, rock grouting, rock anchors, structural concrete and complex formwork, structural steel fabrication and erection, electrical works, mechanical works, watermains, bypass pipes, culverts, environmental protection measures, and landscaping

Requirements

• Phase 1 (January – March, 2018): Clearing and Grubbing, Canal Dredging and removal of weathered rock to maintain deep navigational clearance, Cofferdam installation, and Excavation of West Bank within Cofferdam Work Area
• Phase 2 (April – November, 2018) : Installation of Watermain across East and West Bank, Construction of Earth Dams, Construction of By-Pass Pipe and By-Pass Inlet and Outlet Structures, and Construction of the West Side of Concrete Structure for the Guard Gate.
• Phase 3 (November 2018 – March 2019) : Cofferdam Installation, Watermain Installation Across the Canal, Construction of East Side of Concrete Structure for Guard Gate, Concrete Apron on the Canal Bed, Stop Sills, Sector Gate Embedded Parts (Gate Sill, Pintles, Vertical Sealing Path), Sector Gate Installation, Electrical Works,
• Phase 4 (April 2019 – May 2019): Gate Commissioning, Landscaping