After a number of technical studies, it has been determined that the location of the new Lake Cowichan weir, which will be constructed next to the existing one, has been found to be stable and suitable for the project.
Project manager Leroy Van Wieren said in an update to the Cowichan Valley Regional District that the various public input sessions that have been held over the last few months have shown good support for certain aspects for the design of the weir, such as aesthetics, safety and recreation.
He said an “over-the-weir” walkway is also now incorporated into the design process after receiving input from the public.
“The scope of the [design] project has been expanded to include enhanced communications to ensure the public and waterfront property owners understand the work to be done,” Van Wieren said.
“Due to the specific nature of this program with multiple sponsors, a unique project website has been created for information sharing at www.cowichanlakeweir.ca. [I] have a section on the website called ‘Leroy’s Corner’ to provide updates and address public questions. This web micro site is being well used by the public and has had 11,748 views of the various posts since its inception in June.”
Over a two-year period from 2017 to 2018, a public advisory group developed a water-use plan for Cowichan Lake and the Cowichan River that provides a long-term solution for storing water on the lake in order to maintain sufficient water flows in the river into the future, taking into consideration the climate change projections for the watershed.
The key recommendation of the advisory group was to construct a new weir with an increase of 70 cm of elevation above the existing weir.
The current weir, located at the mouth of Cowichan Lake in the Town of Lake Cowichan, was built in the 1950s to provide industrial water storage for the Catalyst pulp and paper mill in Crofton.
But the weir was not designed to hold the additional and necessary volume of water to sustain the river flows that are now needed, nor does it meet today’s engineering standards required for expansion of storage capacity.
The CVRD is directing the project to replace the weir on behalf of partners Cowichan Tribes, Paper Excellence which owns the Crofton mill, and the Cowichan Watershed Board.
In 2019, senior levels of government announced the weir project would receive $4.08 million over three years from the joint-federal/provincial BC Salmon Restoration and Innovation Fund.
The funding is being used to develop detailed engineering designs and permitting for the new weir, prepare strategies for the removal of the existing weir, and develop Cowichan Lake’s natural boundary in order to conduct an impact assessment associated with an increase to water levels.
Van Wieren said the assessment of the lake’s shoreline, surveys and mapping will be completed by the end of March, and a high-resolution map of the current shoreline attributes, including the natural boundary, will be developed.
“Upcoming work will include an analysis of what future conditions will be after the projected increase due to a new weir and new operating criteria,” he said.
“Future conditions due to climate change will also be evaluated. A set of wave buoys have been installed in the lake and will be used to assess the impact of waves on shoreline characteristics.”
The actual construction of the new weir, whose total cost has yet to be determined, is expected to begin in 2024, and it should take less than a year to complete.
Ian Morrison, the CVRD’s director for Cowichan Lake South/Skutz Falls, said at regional services committee meeting on Feb. 24 that a significant number of property owners on the lake don’t understand the impacts of the new weir on their property.
“In January [each year], atmospheric rivers flow through and water levels in the lake are high, and the weir is eight to 10 feet below the water surface, but many of the property owners still think that adding 70 cm to the height of the weir will flood their properties,” he said.
“Where are we in the educational part of the process so that the property owners can understand that raising the height of the weir will not flood their properties above normal winter water levels?”
Van Wieren said education continues to be a problem, and that’s one of the reasons the website to provide information about the weir project was created.
“Our modelling of lake levels has just begun, and we’ll have an educational package on the website when it is prepared,” he said.
“About a year from now, we will hopefully be out of the pandemic, so we should be able to host open houses and public forums on the project.”