Re: City greenlights major flood mitigation project to the tune of $11.5 million.
The feds will throw in $5.4 million, the city has $2.5 million in its land development reserve fund and the remaining $3.56 million would have to be borrowed. Why?
Google 'C.P.G. River Road upgrade' and scroll down to the YouTube video.
In my opinion the sub-drain system should have been installed on the south side of the road with the lead walls on the north side running across the road southwards into the sub-drain system.
Also, the lead walls should have had valves to shut them off in case of a major flood. As it is, the sub drain system is too small in the case of a major flood.
The talk is of installing above- and below-ground walls in the walkway path. Rebuilding the pathway is where the extra $3.5 million comes in. What's more, no one uses that path during a flood.
What they should have done on the north side of the river road and up tight to the edge of the road is drive a standard PZC-18 sheet piling into the ground.
These sheet pilings are 40 feet long and 50 inches wide.
Around 3.3 kilometres of sheet pilings adds up to 2,600 pieces at $3,000 each for a total of $7.8 million. And they work.
Our land development reserve and federal money adds up to $7.9 million and we wouldn't have had to borrow anything with $100,000 to spare.
And I bet if they shopped around they could get a deal on 2,600 pieces of sheet piling.
When I say that sheet piling works, ask the people that use it to build coffer dams in the river when they are building piers for a bridge. (Twinning the Simon Fraser Bridge comes to mind.)
They drive the piles (in the shape of a rectangle) into the river bed, throw in a few pumps to pump out the water, then they get down into the river bed and do their thing.
But we are stuck because the sub drain system is where it is and to move it to the south side of the road would be another waste of money.
So, all we could do is drive the sheet panels a few feet north of the existing sub drain system and let it take care of the seepage. It's too small to handle a big flood.
Eugene Fetterly,
Prince George
