Dewatering Activities
Where appropriate to protect giant garter snake, aquatic habitat for the giant garter snake will be dewatered prior to ground disturbance in waterways and remain dewatered and absent of aquatic prey for 48 hours prior to the initiation of construction activities. This approach may be most appropriate where habitats to be dewatered are relatively small compared to adjacent habitats or where the work areas will be isolated within coffer dams. If complete dewatering is not possible, the water feature will be thoroughly inspected by a Qualified Biologist prior to the commencement of construction. If snakes are found, the USFWS-Approved Biologist will proceed as indicated in the previous measures. Engineering controls will be instituted as appropriate to prevent snakes from being entrained by the suction of large pumps used in dewatering. Such controls may include installation of a wire cage to create an area of separation between the water body and the intake. A Qualified Biologist will be present during the initial dewatering activities and will periodically inspect the waterway to confirm that it remains dry and incapable of supporting aquatic giant garter snake prey. If, during project planning, complete dewatering is not anticipated to be possible or appropriate (e.g., would cause more harm than working in the wet), the Project Proponent may propose alternate measures for USFWS review and approval when submitting the ESA Section 7(a)(2) Review Form. At minimum, in the absence of dewatering, the water feature will be thoroughly inspected by a Qualified Biologist prior to the commencement of construction. If snakes are found, the USFWS-Approved Biologist will proceed as indicated in the previous measures.