The need to design a new weir for Cowichan Lake was set in motion when, in response to increasing frequency of critically low summer flows in the Cowichan River, a partnership was formed by the Cowichan Valley Regional District (CVRD), Cowichan Tribes, the Cowichan Watershed Board and Catalyst Paper (a Paper Excellence company) to conduct a Water Use Planning study as per the Province of BC Water Use Plan (WUP) Guidelines.
A Public Advisory Group was formed and, beginning in the Fall of 2017 and finishing in the Spring of 2018, the group developed a Water Use Plan (WUP) for Cowichan Lake and Cowichan River that provides a balanced, long term solution for storing water on Cowichan Lake in order to maintain sufficient water flows in the Cowichan River into the future. The key recommendation of the WUP is to construct a new weir with an increase of 70 cm of elevation above the existing weir.
A condition of this recommendation is that an assessment be done to understand thepotential impacts to Cowichan Lake shoreline due to the additional storage, (go to the Cowichan Lake Shoreline Assessment Project page to learn more about this effort).
Work is currently underway to design a new weir for the Cowichan Lake that will store adequate water for future needs, while reflecting the visual, environmental and recreation goals of the community. Climate change is driving longer, hotter, drier summers, resulting in reduced water levels and flow in the Cowichan River. A new weir would result in maintaining water levels and river flows that will provide enough water to support:
- Fish spawning, habitat, and passage
- Flora and fauna in the Cowichan Estuary
- Recreation on the Cowichan River
- Sport fishing
- Water supply for surrounding community
- Water supply for industrial use
- Wastewater dilution requirements
The development of the new weir design is being funded entirely by the BC Salmon Restoration and Innovation Fund through a grant that was awarded by Fisheries and Oceans Canada to address the following key issues:
- Develop the necessary engineering designs, environmental impact assessments and geotechnical studies, cost estimates and tender documents to allow the partners or others to support a future water license application for a new structure.
- Design the temporary works and the removal of the existing infrastructure to reduce environmental impacts and allow for the potential beneficial reuse of systems components if applicable.
- Provide the necessary information to support future regulatory review.