Common use of Alternative C3(a Clause in Contracts

Alternative C3(a. This bridge alternative would require a pier in nearshore waters on the eastern side of Tongass Narrows that could impact bull kelp beds near intertidal Station REV-4. These beds would be expected to reestablish on the lower intertidal rock or concrete structures of the pier. Deep-water piers in mid-channel would develop a rich epifauna. On the western side of Tongass Narrows off the Barge Dock (Station GRV-5), the required piers might be located in an area that currently supports part of the near-continuous eelgrass bed that is interspersed with beds of Laminaria and an area of bull kelp. The offshore causeway that leads south parallel to the airport runway would also shade or require fill in an area with near-continuous eelgrass or kelp beds. Care should be taken, where the route curves around the southern end of the runway, to ensure there is no encroachment into upper intertidal salt marshes and adjacent riparian vegetation, especially along the Government Creek Estuary (GRV-7A). Total marine impact from piers and filling would be approximately 6.3 acres (Table 3-1). Impact on areas of kelp would be substantial (2.79 acres).

Alternative C3(a. This bridge alternative would require a pier in nearshore waters on the eastern side of Tongass Narrows that could impact bull kelp beds near intertidal Station REV-4. These beds would be expected to reestablish on the lower intertidal rock or concrete structures of the pier. Deep-water piers in mid-channel would develop a rich epifauna. On the western side of Tongass Narrows off the Barge Dock (Station GRV-5), the required piers might be located in an area that currently supports part of the near-continuous eelgrass bed that is interspersed with beds of Laminaria and an area of bull kelp. The offshore causeway that leads south parallel to the airport runway would also shade or require fill in an area with near-continuous eelgrass or kelp beds. Care should be taken, where the route makes landfall and curves around the southern end of the runway, to ensure there is no minimize the encroachment into upper intertidal salt marshes and adjacent riparian vegetation, especially along the Government Creek Estuary (GRV-7A). Total marine impact from piers and filling would be approximately 6.3 acres (Table 3-1). Impact on areas of kelp would be substantial (2.79 acres).