John L. Riley in his book…

John L. Riley in his book The Once and Future Great Lakes Country concludes his ecological history simply by writing "Nature never repeats itself".

It is unlikely that dumping fill into flooded quarries will restore agricultural land, but it might create a new wetland. Who knows. Hydro geology is an imperfect science and the part of Caledon in question is so riddled with extraction holes and imperfectly understood groundwater systems that remediation proposals are little better than crap shoots.

Perhaps the Province should experiment with what Beavers might be able to accomplish - but of course you'd have to plant Alder, Birch and other preferred provender for them first.