Project Detail

Stone Mill Road Bridge


GM2 Associates, Inc. was responsible for conducting a Rare Species Survey and Habitat Assessment in the Fenton River for the proposed replacement of the Stone Mill Road Bridge (77-231) in Mansfield, Connecticut. This study was part of the design and construction inspection responsibilities of GM2 for the town of Mansfield. Connecticut DEP’s Natural Diversity Database indicated that the wood turtle (Glyptemys insculpta), a state-listed Species of Special Concern, had been documented in this area of the Fenton River. The objectives of the survey and habitat assessment were to document the presence of wood turtles and to describe habitat suitability which would help with environmental permitting and planning for bridge construction. Gm2’s Biologist (Biodrawversity) searched for wood turtles and noted habitat features within the adjacent to the Fenton River along a 1,000 meter reach, including 500 meters upstream and downstream of the bridge.

The entire survey area contained suitable habitat for wood turtles. This midsized, relatively shallow portion of the Renton River is similar to many brooks in New England where this species is found. One individual was found during a full day survey but potential habitat occurs throughout the study reach and it is likely that more individuals occur in this area.
GM2 provided the following recommendations for avoiding injury or mortality during the construction phase:
1. During the active turtle season (April through November), a qualified turtle monitor should search all work areas for turtles and relocate turtles to a suitable area outside of the work zone. Surveys should be conducted in any areas where turtles may occur and where construction activities might harm them, including land underwater, banks, and vegetated areas within 200 feet of the stream.
2. Barrier Fencing should be installed to intercept migrating turtles before reaching the work area, thereby reducing the potential for mortality or injury from construction activity. The turtle monitor should be present when the fencing is installed to make sure turtles are outside of the work area, and to advise placement so that the fencing is the most effective.
3. The turtle monitor should present a training session to instruct construction crews, project foreman, and site engineers to recognize wood turtles, explain protection measures that are used, and how to notify the turtle monitor or DEP if turtles are encountered or injured during construction. A laminated photo of species description, with contact information, should be posted at the job site.