_______________________________________ FINAL ENVIRONMENTAL ASSESSMENT CHESAPEAKE BAY OYSTER RECOVERY, PIANKATANK RIVER, VIRGINIA _______________________________________ Prepared by: U.S. Army Corps of Engineers Norfolk District Planning and Policy Branch Environmental Analysis March 2016 EXECUTIVE SUMMARY The purpose of this document is to analyze the environmental impacts of the project identified as Chesapeake Bay Oyster Recovery, Piankatank River, Virginia. This restoration project is located in the lower Piankatank River at its confluence with the Chesapeake Bay. As a component of the U.S. Army Corps of Engineers Chesapeake Bay Oyster Restoration program, this project is authorized by Section 704(b) of the Water Resources Development Act (WRDA) of 1986, as amended. The ultimate goal of the program is to restore abundant, self-sustaining oyster populations in the Chesapeake Bay and its tributaries. The objective of this project is to construct new reef habitat and rehabilitate existing reef habitat in the Piankatank River to closely resemble natural conditions, in terms of structure and function, in a technically and economically sound manner. The project area is located in Middlesex and Mathews counties at the mouth of the Piankatank River where it discharges into the Chesapeake Bay proper. The Piankatank River is a medium-sized river located south of the Rappahannock River and north of the York River in the Middle Peninsula region of the Commonwealth of Virginia. The entire project area occurs on subaqueous land owned by the Commonwealth of Virginia and managed by the Virginia Marine Resources Commission (VMRC). The project will consist of the construction of approximately 200 acres of new oyster reef habitat in the Piankatank River between approximately 6-12 feet Mean Low Low Water (MLLW). The reef habitat would be constructed using artificial substrate materials, or a combination of the alternative substrate and shell. Alternative substrate materials used to construct the new oyster reef habitat may include stone, crushed concrete, recycled concrete, shaped concrete structures such as reef ball® type structures, pyramids, modules, and “castles,” and other materials of opportunity. Reefs would be built to an elevation of approximately one foot above existing bottom. As the non-federal sponsor, VMRC, has constructed an estimated 25 acres of new reef habitat and will rehabilitate up to approximately 30 additional acres of existing seed and sanctuary reef habitat through reshelling in the Piankatank River. An Adaptive Management and Monitoring Plan (Appendix A) describes how the results of project-specific monitoring would be used to adaptively manage the project to achieve established goals and objectives. Construction of the project will include temporary, minor impacts to air quality, water quality, the aquatic community, recreation, navigation and the level of noise experienced within the project area. It is predicted that these negative impacts will end once construction has been completed and most environmental parameters within the project area will return to pre- construction conditions. Construction of the project will result in a permanent change from soft-bottom benthic communities to reef structures; this will result in negative impacts to some sessile benthic species. However, the long-term impacts resulting from the project are predicted to be largely beneficial. The reef structures will increase habitat heterogeneity and species diversity, as well as increase the amount of reef habitat within the river. The new reef habitat will increase productivity of the system and create new habitat for prey species, such as crustaceans, mollusks, worms and fish. Hard reef structures will provide shelter and protection for many species of fish and other motile invertebrates. Other positive long-term impacts include enhancement of water quality resulting from increased oyster (and other filter feeding) populations which will have a beneficial impact on all organisms of the Piankatank River and the Chesapeake Bay. This project will be an important step in restoration of the Piankatank River, and is a significant contributor to the achievement of the goals set forth by the Chesapeake Bay 2014 Agreement to “Restore native oyster habitat and populations in 10 tributaries by 2025 and ensure their protection.” The Piankatank River is designated as a Priority tributary for restoration by the Chesapeake Bay Program’s Sustainable Fisheries Goal Implementation Team (GIT). This project also fulfills the directives of Executive Order 13508, Chesapeake Bay Protection and Restoration, signed by President Obama in 2009. ii iii iv FINAL ENVIRONMENTAL ASSESSMENT CHESAPEAKE BAY OYSTER RECOVERY, PIANKATANK RIVER, VIRGINIA TABLE OF CONTENTS 1.0 Project Purpose And Need ...................................................................................................................... 1 1.1 Agency Goal Or Objective ................................................................................................................. 1 1.2 Project Authority ................................................................................................................................ 2 1.3 Project Name ....................................................................................................................................... 2 1.4 Project Location .................................................................................................................................. 2 1.3.1. Restoration Site Selection Methodology..................................................................................... 4 1.4 Related Environmental Documents..................................................................................................... 6 2.0 Alternatives ............................................................................................................................................. 6 2.1 Description Of Alternatives ................................................................................................................ 6 2.1.1 Alternative A ............................................................................................................................... 6 2.1.2 Alternative B ............................................................................................................................... 7 2.1.3 Alternative C ............................................................................................................................... 8 2.1.4 Alternative D .............................................................................................................................. 9 2.2 Issues And Basis Of Choice ................................................................................................................ 9 2.3 Alternatives Eliminated From Detailed Evaluation ............................................................................ 9 2.4 Preferred Alternative ......................................................................................................................... 10 2.5 Monitoring And Adaptive Management ........................................................................................... 11 2.6 Comparison Of Alternatives ............................................................................................................. 11 3.0 Affected Environment ........................................................................................................................... 17 3.1 General Environmental Effects ......................................................................................................... 17 3.1.1 Physical Setting ......................................................................................................................... 17 3.1.2 Hydrology ................................................................................................................................. 17 3.1.3 Water Quality ............................................................................................................................ 18 3.1.4 Climate Change ......................................................................................................................... 20 3.2 Environmental Resources ................................................................................................................. 21 3.2.1 Wildlife Resources .................................................................................................................... 21 3.2.1.1 Benthic Community ...................................................................................................... 21 3.2.1.2 Fish ............................................................................................................................... 22 3.2.1.3 Rare, Threatened and Endangered Species ................................................................... 22 3.2.1.4 Invasive Species............................................................................................................ 26 3.2.2 Habitat Resources ..................................................................................................................... 26 3.2.2.1 Oyster Resources .......................................................................................................... 26 3.2.2.2 Essential Fish Habitat ................................................................................................... 29 3.2.2.3 Submerged Aquatic