Nothing else matters

Back in 2013, I first wrote about Ravin Boisé, a major residential project being proposed for a forested area in Vaudreuil-Dorion bounded by Upper Alstonvale to the west, Highway 40 to the south and existing developments along Harwood to the north and the east.

I could mourn the loss of another beautiful south-facing woodlot filled with deer, wild turkeys and mature hardwoods, but that’s life in a society that subsidizes fossil fuels and encourages urban sprawl. No, my beef with Ravin Boisé and its 200+ doors is how the developer is proposing to deal with the massive quantities of sewage and runoff directly uphill from the wetland that feeds Viviry Creek and the aquifer that supplies Hudson its drinking water.

At the time, V-D mayor Guy Pilon said Ravin Boisé wouldn’t be allowed to proceed without its own sewage treatment and runoff retention systems.

Earlier this year, work got underway on the project, beginning with an access road from Upper Alstonvale. Last week I biked up to Ravin Boisé to check on progress and ran into someone who said I was welcome to ride down the new road.

Work is well underway on what the developer’s website characterizes as Phase 4. The road into the project is approximately two kilometres long and terminates in a clearing at the bottom of the hill next to Highway 40. The road contractor is installing storm sewers and water lines but there’s no sign of a sewer system and no mention of any sewage treatment facility on the Ravin Boisé website.

I’m waiting for callbacks from Vaudreuil-Dorion’s urban planning department and/or developer Habitations Robert.

The potential for a runoff retention problem is far greater, now that the hillside is being stripped of the trees and undergrowth that used to slow the flow long enough for runoff to percolate into the soil.

The road heads straight downhill, a man-made river directing runoff and meltwater from all those roofs and all those paved driveways directly into the Viviry’s headwaters. Standing there at the bottom of the hill, I could visualize the effects of a torrential downpour, beginning with the Upper Viviry widening into a lake before the volume of water continues down through Hudson.

We’ve already seen what happens to Pine Flats after heavy rains. It turns back into a lake and the Viviry threatens to wash away what’s left of the dam next to Cameron, with potentially catastrophic effects on one of Hudson’s main roads in and out of town.

There are ways to retain and redirect runoff. Our neighbours have a steep driveway up to our street. In winter, there’s a real risk of a vehicle sliding down their hill and crashing into the garage door. So they asked Gord Simpson of S&S Landscaping to come up with a solution.

You’re looking at it here. S&S reshaped and excavated the driveway to include berms that will act as dams to direct runoff to the downhill side. Then they refilled the driveway with layers of gravel, beginning with maybe a foot of coarse stone. Then came more layers of finer gravel that will provide the bed for a type of paver that allows water to penetrate.

If all goes according to plan, the entire driveway becomes a permeable structure that will  drain runoff as quickly as it turns to water. Theoretically, ice can’t build up and all S&S has to do is clear the snow without risking a fast trip downhill.

Back to Ravin Boisé: unless the development includes a common sewage treatment system as well as runoff retention measures, the risk of groundwater contamination with fecal coliform rises exponentially.

Understand this: upstream development poses a significant and growing contamination risk to Hudson’s water supply. As we learned at last month’s special presentation, the only sustainable solution lies in drawing water from the Lake of Two Mountains.

The only way Hudson’s taxpayers can afford the $12-$15M cost is to reach agreement with Hudson’s equally thirsty neighbours — Rigaud, St. Lazare and Vaudreuil-Dorion, home to this and other water-consuming, runoff and sewage-producing developments. If I was Hudson’s mayor, I’d be pushing this file nonstop at the intermunicipal, regional and provincial levels.

Because as you can see, everything is interrelated — sewage treatment, runoff retention, Pine Lake, a new well, development in Hudson and neighbouring municipalities. There’s an argument to be made against spending $1.4M on a new well if there’s the slightest possibility we can come up with a cheaper long-term solution that will bring water to everyone.

Water is and should be at the heart of this election. Without a sustainable water supply, nothing else matters.

Update: I spoke to Vaudreuil-Dorion mayor Guy Pilon Friday afternoon, Oct. 16. He told me the environment ministry demanded that the developer install a tertiary sewage treatment system with sufficient capacity to handle the volume produced by the development when it’s completed.

Pilon said runoff mitigation and retention measures aren’t necessary because the developer is being required to ensure wide setbacks along existing watercourses.

Enough of the forest canopy is being protected to slow runoff and allow it to percolate into the soil, he added. 

Will the outflow from the sewage treatment plant and runoff from the development increase the Viviry’s volume and flow rate downstream through Hudson?

“No, no, no, absolutely not!”