The Project includes ongoing operation of Dry Dock 4 and maintenance dredging over a 10-year period. The purpose of the Project is to continue to provide a ship repair and dismantling facility at the Mare Island Dry Docks. Up to 24 evolutions (i.e., filling the dry dock with water from Mare Island Strait, opening the caisson, allowing a ship to enter or exit the dock, and then draining the dock and performing fish rescue and relocation activities) will be performed in Dry Dock 4 each year. Additionally, up to 40,000 cubic yards of sediment will be removed from an approximately 3.89-acre area in the Mare Island Strait each year via a mechanical (i.e., clamshell) dredger.
The Project is expected to result in incidental take of up to 909 individuals of longfin smelt (Spirinchus thaleichthys), and a smaller number of Delta smelt (Hypomesus transpacificus), Winter-run Chinook salmon (Oncorhynchus tshawytscha), and Spring-run Chinook salmon (Oncorhynchus tshawytscha). Longfin smelt and Spring-run Chinook salmon are designated as threatened species under CESA. Delta smelt and Winter-run Chinook salmon are designated as an endangered species under CESA. The ITP referenced above as issued by CDFW authorizes incidental take of species listed under CESA that may occur as a result of Project implementation.