For those of you who could attend the July 8th virtual meeting I appreciate your interest, your questions and most importantly spending your valuable time with us on this topic.
It was difficult to capture and hear all the questions and answers from that session so I’ll list them here.
Question: With concern regarding record breaking high water level in Feb 2020, how will future high water levels be affected? Answer: The current and the new weir will continue to be submerged during the high water flood events and do not control the flood levels. There is a downstream natural restriction near the Greendale Trestle that controls the high water lake levels. Therefore future high water levels will be unaffected by the new weir but may be affected by ongoing climate changes.
Question: Will the Canadian Government Data Graph 08HA009 for Cowichan Lake need to be adjusted to reflect the new datum? Answer: We have contacted the Government and they are planning to upgrade all their hydrographs to the new datum.
Question: If channels are excavated, is there a plan to incorporate archeologic studies, especially on the island. Answer: Yes, archeologic studies will be planned during the excavating work.
Question: Is the designed walkway structure earth quake safe? Answer: Yes, the walkway and supporting weir foundation is designed to meet all current earthquake requirements.
Question: Can the recreational paddlers provide input on the portage steps? The proposed design looks less than ideal. Answer: The portage you saw was an example photograph of one that uses steps. The design being considered does not have the haunches on the side you see in the photo. The current design for the portage use 0.5m by 1m wide and 3m long. If you would like to provide feedback there is opportunity.
Question: Will adaptive management be considered with respect to changes to design or features of the design as more information becomes available? Answer: With respect to adaptive management, the new weir design include as lot of flexibility for operations and there is flexibility in how the fishways can be operated.
Question: What improvements are being proposed for the boat lock? What price tag is associated with that? Answer: The only thing that will remain from the boat lock is the current concrete foundation which will need some enhancements to meet earthquake codes. All other components will be replaced with new parts and systems and should operate more quietly. Re-using the existing foundation and upgrading the boat lock is considerably less expensive than removing it and rebuilding altogether.
Question: Will the boat passage be dredged and cleared of logs? Answer: Yes, when the boat lock foundation is refurbished for reuse, the passage will be cleaned up.
Question: If there is a pinch point in the river, would the lake level be reduced to get as much water past before the lake crests the weir? Answer: When the weir is no longer being controlled (end of October) the gates and boat lock are left wide open to allow full flow through the weir. The lake level is then dependent on precipitation events and river pinch points.
Question: Have you received any comments from the downstream First Nation about potential impact to their rights and title interests? Any mitigation to your plans? Answer: As Cowichan Tribes in one of the partners and potentially an owner we are wanting to make sure that all steps are done properly at every stage.
Question: Where are the wind and wave data buoys located? Why were those locations chosen? Answer: One buoy is located in the South Arm near Woodland Shores and the second is located in the North Arm between Whittingham Point and Billy Goat Island. It was difficult to only choose two locations on such a large lake but we thought these locations would ‘catch’ a lot of the wind action and some boat wakes.
Question: If the operations in March would change water levels, the goal of raising the weir, why has that not been a priority in recent years? Answer: The current weir is typically at full storage in March. Analysis is done each spring to determine if early control is viable based on snow pack and weather forecast and lake levels. A higher weir would allow for earlier control of the increased storage.
Question: You reference the 200 year flood line. What year was that established? Answer: 1984. CVRD Document Risk-Assessment-of-Floodplains-and-Coastal-Sea-Level-Rise. Recent analysis also supports this flood line.
Question: I think that your 3 meter swing between low water and high water is a little low. I’m thinking it is more like 15 feet or 5 meters. Although I have never measured it. Answer: The average high water mark over the past 60 years is 164.2m. The low water mark is 161.0m. So a 3.2m difference.
Question: As a WSP objective in the future, can we ensure that there will be maintains connections between cold water refugia and riffle habitat? Presumably the weir can help meet that objective. Answer: Cold water refugia exists in both the river and the lake. The weir will not affect those natural refugia. The new weir fish passages will provide for more opportunity for fish to move back and forth from river and lake, allowing them to better find refugia. Also, by storing more water for release throughout the summer, the minimum flow rate will be achieved more frequently and allow for more fish survival.
Question: Will this video be posted online for review? Answer: Yes it will.