By Gagandeep Ghuman
Published: Nov. 5, 2011.
The district plans to spend close to $1 million on addressing dike seepage next summer, but Bill Manson says he has a more cost-effective and permanent solution for dike safety.
Divert the course of the river.
Opening a new channel in the Squamish River across from the Judd Slough will open up new spawning channels and ease the pressure off the Eagle View dike, Manson says.
The new rivulet will cleave through the mountain for a few hundred metres and eventually meet the Squamish River, just above the Mamquam overflow.
A small run-of-the river project can divert water towards the dike, creating an artificial spawning channel.
Manson helped build the dikes in the 1960s, with unflinching support from the then Mayor Pat Brennan.
He says creating a new tributary isn’t as radical as it seems. In fact, it was the main river channel before log jams and sedimentation changed the river’s course causing massive floods until the dike was built.
A few years after the dike was built, Nygard Bros. started digging a cut across from the bottom end of the Judd Slough, but the project was never completed due to lack of money and bureaucratic wrangling from Victoria and Ottawa.
As the district plans to devote some money to the dike next summer, it should seriously consider the proposal to divert the river, he says.
“I think you are winning quite a bit here,” Manson said.
“Brackendale and Mamquam areas will be much safer and we can have healthy spawning channels near the dike,” he said.
Engineer Frank Baumann, however, isn’t as convinced the plan will work.
Baumann said the river has to follow the path of least resistance, and the channel suggested by Manson isn’t.
“You can’t just “open” that old channel because the entire length is filled with sediment, so until the present Eagle Run channel fills with sediment, there is no way the water is going to flow down that old channel,” Baumann said.
“Sure, you could dredge it out- but that would be a monumental job and would only be a temporary fix- eventually, the river will replace any sediment that is dredged out.”
Manson agrees that there is more sediment in the old main channel, but said it can be easily dredged, with an eye on the long term benefit of dike safety.
“We can dig an artificial trench to make sure that river changes course sooner – with several benefits,” he said.
Manson said similar operations had been undertaken in the 1960s in the Cheakamus River.
In the past, the district has spent hundreds of thousands of dollars on the dike, but ignored one of the most critical issues of dike safety: Seepage.
Three reports commissioned by the district after the 2003 floods had warned the district must do work on dike seepage to ensure public safety.
The district revived the 2008 Thurber report which strongly recommended dike seepage remediation.
Finally, the district decided to allot $900,000 to address dike seepage along the Eagle View dike on Government Road.
That project will start next year, the district’s engineer Brian Barnett, said.