TRA-905: ENCOUNTERING RAINBOW MUSSEL, A SPECIES AT RISK, DURING CONSTRUCTION OF A STORMWATER MANAGEMENT FACILITY

Many freshwater mussels in the Ontario-Great Lakes Area are considered Species at Risk (SAR) and these are increasingly influencing planning, implementation, and monitoring of infrastructure projects near watercourses. In 2010, the City of London commissioned an on-line Stormwater Management Facility in the Stoney Creek watershed in the form of an Erosion Control Wetland. Design objectives included: creation of additional water storage in the floodplain, prevent erosion in the downstream watercourse, and reclaim natural heritage features lost during infrastructure development. Erosion and sediment controls were applied during construction; however, storm events in December 2011 washed out a section of bank that had separated Stoney Creek from the active construction site. The washout released streambed sediments and mussels, including the previously unrecorded SAR Rainbow mussel, into the work area. An emergency mussel relocation protocol was developed, through a collaboration between applicable agencies, to relocate the mussels during the winter months. Ultimately, 16 of 70 mussels collected during the winter relocations were SAR. The timing of the bank collapse and mussel relocations provided a unique situation where recapture and growth comparisons could be made between mussels relocated in extreme weather conditions to mussels relocated during optimal handling temperatures. The Stoney Creek project demonstrated construction delays and costs associated with SAR mussel discovery. The project highlights the importance of detailed environmental assessments prior to project planning so appropriate mitigation measures and environmental monitoring requirements are implemented during construction

TRA-904: ROAD MORTALITY HOT SPOTS OF TURTLES: A THREE-YEAR MINISTRY OF TRANSPORTATION STUDY IN BRANT COUNTY, ONTARIO

Road mortality has a significant depressive effect on turtle populations in southern Ontario and mitigation measures to reduce turtle road mortality are therefore increasingly being incorporated into road construction projects in the province. This has included the installation of “ecopassages” beneath roadways which enable turtles and other animals to safely move between habitats. These measures are most effective if they are installed at locations with frequent turtle movement and high road mortality rates. We conducted a detailed multi-seasonal survey of turtle road mortality in order to identify mortality “hot spots” along a 4.85 km stretch of highway in Brant County, Ontario. In total, 122 unique observations of dead turtles of two species (midland painted turtle [Chrysemys picta marginata] and snapping turtle [Chelydra serpentina]) were made. Spatial statistical analysis of mortality data using geographic information system (GIS) software was then used to identify mortality hot spots. These hot spots are being used to determine appropriate locations for installing ecopassages and other mitigation measures to reduce turtle mortality along this stretch of highway

TRA-928: FISH BARRIER MITIGATION OF AN OVERSTEEPENED CULVERT WITHIN SAUGEEN FIRST NATION RESERVE

A deteriorated concrete box culvert conveying a tributary of the Saugeen River under Highway 21 in Ontario had reached the end of its lifespan and was in need of replacement. The tributary supports a diverse range of coldwater fish species such as Rainbow Trout; however, fish passage, particularly upstream migration, has been cut off since the culvert and highway were constructed over seventy-five years ago. Specifically, fish passage has been hindered by shallow sheet flow along the sixty metre flat bottom, excessive velocities associated with the smooth, seven percent gradient, and a perched barrier at the downstream outlet. A key component of the culvert replacement was an effort to improve the overall condition of the tributary’s natural environment, including the promotion of fish passage and migration opportunities. The culvert replacement project undertaken by the Ontario Ministry of Transportation (MTO) and MMM Group, coupled resources with the Saugeen Ojibway Nation (SON) Environment office, Parsons biologists, and Aquafor geomorphologists. The most ecologically sensitive replacement methodology of an open bottom structure was not viable for this project as it would have required a full closure of the Highway for approximately four months. A circular steel pipe culvert installed through tunneling was designed to by-pass and replace the existing concrete box culvert. In an effort to mitigate the current barriers to fish with the new pipe culvert, a prefabricated corrugated steel slip liner with engineered baffle arrangement was integrated into the design. The baffle configuration and geometry was designed by Jason Duguay (Université de Sherbrooke) and Ken Hannaford (Gov. NFLD), and the slip liner construction by the Corrugated Steel Pipe Institute. Construction of the new culvert and slip liner was completed in December, 2015, and a two year monitoring program will be undertaken to assess the effectiveness of barrier mitigation and geomorphic stability of the tributary