To the Editor,
When will the same inundation study be used for Westwood Dam that was done for the Colliery Dam Park dams?
Will Westwood be marked for removal if the inundation model deems it extreme?
Given that it has 2,300,000 cubic metres of water as opposed to both Colliery dams combined at 222,000 cubic metres,(that’s over 10 times the amount of water) it seems highly likely that it would show a greater extreme risk, being up hill from so many homes.
As city staff and the Dam Safety Branch have stated “it is not the condition of the dams in their current state that determines the risk. It is how many people will die if the dams fail instantaneously.”
City staff have said the Westwood spillway would reduce the risk, but if Westwood’s water was lower, it would not have access to the spillway staff mention.
The study also notes Buttertubs Marsh would absorb much of the flood water. But it is a stretch to think Buttertubs could hold more than two million cubic metres of water.
The velocity of the water coming down that hill would be another consideration.
As the inundation model only uses the assumption that all the water is lost instantaneously, it is likely that it would show flooding right into downtown Nanaimo.
So, do we lose Westwood too?
Gwynne Martin
Nanaimo
