WINTER 2019 AVENUES 29 REHABILITATION PROFILE occurring on the expan- sion lands that resulted in a remnant quarry of about 0.6 hectares in size and about three to four metres deep,” says Sisco. “This former quarry site was being used by snakes as an over- wintering site… as there were rock fractures where the snakes could enter. The site was part of a local Eramosa Scarp feature which retains moisture during the winter months, which is critical for snake survival.”  Since the former quarry and hibernacula were situated within what will eventually be Extraction Phase 3 of the expansion lands, current quarry owner Waterford Sand & Gravel requested permission from the Ontario Ministry of Natural Resources and Forestry (MNRF) to create an extensive program to monitor the microclimate of the existing site and then design alternate off- site hibernacula on additional lands abutting to the west. “Waterford retained herpetologist ecolo- gists who specialized in snakes to undertake extensive monitoring of both the existing hibernaculum as well as the candidate site, which is located 500 metres away,” says Sisco. “After significant monitoring of the existing conditions and the candidate alter- nate site, it was confirmed that the condi- tions could be replicated.”  Once construction of the new hibernacula is completed, fencing and other means will be used to discourage snakes from returning to their existing site and encourage them toward the new one. The new site will then be monitored for several years to determine if it’s successful and if snakes are indeed hibernating there.  “Construction of hiber- nacula is not new, but historically, the success rate is fairly low,” notes Sisco.  “However, the local MNRF biology staff and Waterford S&G’s herpetologist together have exten- sive research and practical experience and were able to design a structure at a site the mirrors the existing site’s conditions. They are confident of a high success rate.” HISTORY The existing quarry has a long history. It started operation in 1947, when Quigley Construction extracted materials used to build portions of the Queen Elizabeth Way (QEW). In 1984, when Waterford bought the site, there was no extraction activity. The entire quarry was full of water and it took two years to de-water at a controlled rate. Then in the late 1980s, Waterford started extracting dolos- tone to produce a range of granular and premium clear products. Around that time, they also began progressive rehabilitation, which involved placing backfill at the south and east walls. Waterford also started importing clean fill and topsoil onto the existing quarry floor. This fill and soil will create an interim agricultural rehabilitation along with some natural features that will contribute to the green space over the next 30 to 40 years as extraction of the expansion lands occurs. The final use of the existing quarry and expansion lands, however, will be an 80-hectare lake. The commercial- grade quarry stone that is extracted