Vanishing Waters - a Google Map Mystery

Last summer as I was driving to the St-André Golf course I wasn't in a rush so I decided to drive using alternate routes. As I drove near St-Hermas, I remember the old quarry that we used to go to dive (more like jump) from the cliff into the deep water of the quarry. Technically, it was trespassing and the police (QPP at the time) regularly would try to scare people into coming back. They has no parking signs for a mile around it and made it hard to park anywhere near the 'pit'. As I drove there last summer at least 40 years had past since I actually went for a dip. I had heard that they had filled it up to make sure no one would visit it again. I believe there had been a few fatal accidents there as the cliff were quite high and the water quite deep. The thing that struck me was that there was no sign of the quarry ever being there. The no parking signs were gone. No physical signs of it ever being there. It seemed to have completely disappeared making me think that maybe it had never existed but I clearly remember my first time jumping off the 40 foot cliff and hitting the water. I certainly remember that it took me an eternity to finally make the plunge with a lot of egging on by my pals.

When I got home that night, I decided to search Google maps to see where a place that was vivid in my memory has disappeared. What it so long ago that it was on another road and that why I could find it anymore. To my surprise, as I zoomed into the area, there it was, exactly where I remembered. It was on the road from St-Hermas to St-André, Chemin de las Rivière Rouge Sud. At the bottom of the map, there was another water 'feature'. See below.

After seeing this, I thought that a satellite view would show me more. It did, by showing less. Both water 'features' were gone on the satellite. See below:

The bottom one remains a mystery and if the road leading to it is not a private road I might have a mission for next summer. But as you see, in the zoomed maps below, the 'pit' is now history and why it is still showing up on Google and Bing maps although it's been filled in for decades remains a mystery.

WAIT! As I superimposed the terrain and satellite zoomed images (below) I may have solved one of the mysteries. I remember the quarry to be more round than the odd shape of the water in the map. The arrow points to where I believe the swimming hole used to be. The superimposed blue area we see on the map is probably a swampy area that does sometimes fill with water. Mystery Solved!
The only mystery left now is the Supermarket in the middle of the farmers field. Maybe I will buy some sausages the next time I am in the area.

UPDATE!. I received some history of the quarry and the area from Guy Francoeur. The reason it was there is that it was dug to build the Carillion Dam and it was filled in the 90's. The blue area was the quarry and was used as a landfill dump by Lachute.