On March 12th, the winter cofferdam was removed letting water flow freely over the new powerhouse weir and through the newly constructed flow bypass.
Temporary winter cofferdam in place January 2017
Covered intake gates and bypass ready for operation March 2017
Beginning to remove winter cofferdam March 2017
Removal underway March 2017
Final logs being removed March 2017
This summer, the remaining steel from the winter cofferdam will be removed; the weir by the powerhouse will be finished; a retaining wall will be constructed in the downstream area and a general cleanup of the riverbed will occur to remove any pieces of tarping etc. that could not be reached during the high flow times.
Winter cofferdam removed March 2017
Cool black and white March 2017
Logs removed from temporary cofferdam March 2017
There were several months of intensive work to build the main structures of the powerhouse and bypass channel. Some 2000 cubic metres of concrete were poured to create the building and bypass.
Bypass Channel under Construction Feb 2017
Inside Powerhouse Feb 2017
At the peak, there were approximately 90 staff assigned to the project. In additional to Thomas Cavanagh employees, there were a large number of local contractors involved. The build-out went very well despite the cold weather and snow… and more snow.
Formwork in place on a cold day in Feb 2017
Inside powerhouse looking upstream March 2017
Prior to removing the cofferdam, the front of the new powerhouse was waterproofed using a membrane material. Typical stop-logs were inserted into the tailrace, or downstream part of the building. This will keep the powerhouse dry allowing us to continue working through the spring.
Trashrack installation for bypass
Preparatory work for the placement for the various components that make up the hydroelectric generation equipment has begun. The fabrication of this equipment is being done locally by Canadian Hydro Components (CHC) and their subcontractors.
Due to the size of some of the hydroelectric generation pieces, the steel building, roof and glass enclosures will not be erected until all of these are in place. We anticipate that the building will be completed by early fall. Testing of the installed equipment will also occur in the fall.
The downstream American Eel bypass may be in place for this season. A pipe that extends from the front of the powerhouse, under the bypass to a holding container located near the tailrace has been installed. Eels will be attracted by the greater water flow in this area and swim through the pipe and will be trapped in the holding container. Enerdu staff will be monitoring the tank and, should an eel be trapped, it will be photographed, weighed and released downstream of the Brian Gallagher Power Station.
Intake trash racks being installed March 2017
Inside powerhouse approximately 6 metres below the riverbed March 2017
Intake excavation area cleaned and being made ready for flooding March 2017
Installation of eel bypass pipe (green) extends from intake to downstream catchment basin March 2017
The final piece of work to be undertaken this summer is the construction of the weirs located on the Old Town Hall side of the river. More on this in a future report.