Comox is taking a big step moving forward with its Northeast Comox Storm Water Management Plan Implementation, as council approved first and second readings at the June 16 council meeting.
Mayor Russ Arnott noted the plan has been a “tremendous work in progress for many years.”
In January, council voted unanimously to proceed with property owners to be granted the right to design and build detention ponds and infiltration galleries for their own properties as the preferred solution for Northeast Comox storm drainage.
The Northeast Comox lands have been a historical flood plain and regularly floods with current stormwater conditions and mitigation. The lands have been unable to develop due to the downstream flooding liabilities the town would incur.
In a presentation to council, Jordan Wall, the town’s chief administrative officer explained the problem with Northeast Comox is that the water wants to drain from west to east, and when the town was first developed, the area was drained and it is very susceptible to flooding.
“This flooding is only going to get worse over time … we’re talking about a very wet area that’s simply going to get wetter.”
He explains if the town allows development that contributes to flooding, there is a large risk that the municipality could be taken to court, and a good chance they would lose an expensive court case.
Earlier this year, Wall explained the downstream area has already been the subject of a lawsuit in the past and landowners have informed the town and its representatives that they are prepared to undertake court action against the town should development in Northeast Comox increase flooding or related damage.
In order to proceed with developing the area, water needs to flow north into the Knight Road Ditch which is owned by the Department of National Defence and regulated by the province. Water then needs to travel along Queen’s Ditch and end up deposited into the ocean with no flooding in the neighbouring Comox Valley Regional District Area B.
“(Water has to flow) at a speed that isn’t going to cause floods when we have a rain event,” he added.
In order to do this, Wall said infrastructure such as infiltration trenches transversing through development needs to be in place to collect additional water travelling over land due to development. He noted it will not take away the character of Comox, and look more like a greenway.
Additionally, dry retention community use ponds would have to be created.
“They’re not going to hold water when it’s not raining,” he explained. “Within 48 hours of a rain event, water will travel from the gravity feed out so that we’re not contributing to downstream flooding.”
The town has made the decision to allow developers to pick the size of the pond relative to servicing the land they have.
Wall said the cost of the system which includes the ponds, related infrastructure and ongoing maintenance will be about 20 per cent of the cost of construction per year, and added while there is still a lot to be worked out, provided a rough estimate of between $1,000 to $2,000 per home per year within the local area service (to be paid by those who are using the system).
He acknowledged the high price of the system with both construction and maintenance costs and added the town is likely going to have to maintain it indefinitely.
A few questions were raised by council, particularly tree retention in the area. Staff will continue to work on the plan and it will return to council prior to final approval.