Letters to the Editor

Extreme weather will stress our dams

To the Editor,

Re: Flood signage should be reconsidered, Letters, June 10.

Spectacular flows in the Chase River usually come during a rain-on-snow event. We had two such events in 1996 and 1997. Ninety centimetres of snow fell in a week, followed by 15 centimetres of rain over three days, creating a flow of about 35 cubic metres per second in the Chase River.

At that rate, the water flows over the top of the lower dam. That can erode the vegetation away, then the soil and backfill. That exposes the lower concrete face of the dam, which is then unsupported. This is when the concrete can fail, either catastrophically or with a small crack. If the concrete fails all at once, the people in the floodplain are in dire straits. If it cracks, they would be OK, but they would have to evacuate.

Rain-on-snow events have happened with regular frequency in the past and we don’t know what the future holds. All we know is that the weather is likely to get more extreme.

All provinces have seen extreme weather and extreme flooding. If we were clever, we would learn from those events and take the prudent, risk-averse option and remove the dams. Instead the Colliery Dam Park Preservation Society has chosen to accept the risk of having 220,000 cubic metres of water over the heads of 1,800 people.

Perhaps the flood signage should stay in place.

Charles Thirkill
Nanaimo

We encourage an open exchange of ideas on this story's topic, but we ask you to follow our guidelines for respecting community standards. Personal attacks, inappropriate language, and off-topic comments may be removed, and comment privileges revoked, per our Terms of Use. Please see our FAQ if you have questions or concerns about using Facebook to comment.

You might like ...

Family of hit-and-run victim makes emotional public appeal w/video
 
Australian leader: Siege may have been preventable
 
‘Logically’ if Baybrook goes, so should Filberg
New metal slide installed in Horne Lake caves
 
Part II: Fear Not – There is Help for Children and Youth with Anxiety
 
No firm answers for Jordan River residents
Musician home for the holidays Dec. 21 and 22
 
Painting what she feels, not what she sees
 
Coroner confirms body that of missing senior

Community Events, December 2014

Add an Event


Read the latest eEdition

Browse the print edition page by page, including stories and ads.

Dec 18 edition online now. Browse the archives.