Alabama Department of Conservation and Natural Resources Alabama-Mississippi Sea Grant Mobile Bay National Estuary Program U.S. Army Corps of Engineers, Mobile District Ms. Jenny Jacobson Mr. Justin McDonald Delta Roundtable Five Rivers Delta Center June 17, 2015
Vision Statement A vibrant coastal Alabama with a healthy and resilient economy, environment, and social foundation Goals Reduce vulnerabilities by providing a roadmap that increases the economic, environmental, and social resiliency of coastal Alabama for current and future generations
- Inclusive and comprehensive constituent input process - Builds off prior planning efforts - Forward thinking that is sensitive to current needs - Shared vision and ownership of the Alabama Coastal Comprehensive Plan
- State and Federal Agencies - Elected Officials - South Mobile County - Resource Dependent -Commercial & Recreational Fisheries - Environmental - Businesses - Transportation - Tourism - Academic - West & North Mobile County - North, West, & South Baldwin County - Community Organizations
Dr. Susan I. Rees U.S. Army Corps of Engineers, Mobile District 109 St. Joseph Street Mobile, Alabama 36602 251-694-4141 Phone 251-690-2704 Fax Susan.I.Rees@usace.army.mil Email Ms. Jenny Jacobson U.S. Army Corps of Engineers, Mobile District 109 St. Joseph Street Mobile, Alabama 36602 251-690-2724 Phone 251-690-2727 Fax Jennifer.L.Jacobson@usace.army.mil Email
Mobile Bay Sediment Management Strategy ------ Regional Sediment Approach
Mobile Bay Interagency Working Group (IWG) Alabama State Port Authority (ASPA) USACE, Mobile District Engineering, Research, and Development Center (ERDC) Alabama Dept. of Environmental Management (ADEM) Alabama Dept. of Conservation and Natural Resources (ADCNR), State Lands Division ADCNR, Marine Resources Division (MRD) Geological Survey of Alabama (GSA) U.S. Fish and Wildlife Service (FWS) National Marine Fisheries Service (NMFS), Habitat Conservation Division Mobile Bay National Estuary Program (NEP) Dauphin Island Sea Lab (DISL) The Nature Conservancy (TNC) Mobile County Environmental Department
Beneficial Use Opportunities Brookley Hole - Short term Tidal marsh creation in upper Mobile Bay - Long term In-bay disposal - Long term
Beneficial Use of Dredged Material to Fill Borrow Pit (Brookley Hole) Borrow source for creation of Brookley Air Field Hypoxic conditions degrade ecological productivity 1.2 MCY of fill from upper Mobile Bay Channel Fill Options - Fill to some level of productivity - Fill to surrounding grade - Emergent feature w/ marsh Leveraging other research programs (DOER) - Conducted baseline characterizations - Continued post-fill monitoring Monitoring to determine level of restoration Initial fill completed September 2012 Monitoring Results - No evidence of hypoxia/anoxia - Increase in fish usage - Increase in benthic diversity and abundance IWG recommended continued placement - Summer 2014 dredging cycle - Additional 750,000 cy placed
Establishment of Long Term Beneficial Use Site in Upper Mobile Bay Potential Long Term Beneficial Use Site in Upper Mobile Bay Low Priority 700 Acres Medium Priority 780 Acres High Priority 1,200 Acres IWG plan and implement semi-contained, large scale open water disposal area (tidal marsh) in upper Mobile Bay Builds on requests of ASPA to partner in implementation of more effective sediment management associated with maintaining Mobile Harbor Develop feasibility level Beneficial Use design ASPA will take lead on the design, NEPA coordination, and permitting actions Activities completed - Hydrographic survey of the upper Bay - SAV survey - Cultural resources survey Geotechnical surveys next step BU sites as refined and prioritized from the April 12 Meeting 14
Mobile Bay Channel Open Water Thin-Layer Disposal Summer of 2012 Exercised emergency action in permit Placed 9 MCY in pre-established historic open water disposal areas Disposal Areas 1-3, 10,11 and 13 Utilized hydraulic cutterhead dredge Thin-layer disposal techniques Used as demonstration to monitor and model behavior Answers questions as to the fate of the sediment once placed
Thin-layer Monitoring and Modeling Conclusions Approximately 35% of the sediment that erodes from the designated disposal areas is transported and deposits in the navigation channel. The remaining 65% is widely dispersed throughout the bay by wind-, river-, and tide-driven currents. The dredged material placed in thin-layers is less erodible (~ 45%) than native sediment. Sediment becomes remobilized into Bay s natural sediment system (Not transported along the bottom) Based on these results - IWG recommended USACE pursue modification of Mobile Harbor WQC to include a long term open-bay thin-layer disposal option - WQC modified in June 2014-850,000 cy placed in open-bay sites
Sand Island Section 406 Oil Spill Mitigation Created an emergent island in a manner that will begin a reestablishment of the original Sand Island. In addition to oil mitigation, action would provide opportunity towards accelerating the return of sediment into the local system Increased disposal capacity in the SIBUA consistent with established regional sediment management implementation principles and goals.
Mobile Harbor Expansion
Dr. Susan I. Rees U.S. Army Corps of Engineers, Mobile District 109 St. Joseph Street Mobile, Alabama 36602 251-694-4141 Phone 251-690-2704 Fax Susan.I.Rees@usace.army.mil Email Ms. Jenny Jacobson U.S. Army Corps of Engineers, Mobile District 109 St. Joseph Street Mobile, Alabama 36602 251-690-2724 Phone 251-690-2727 Fax Jennifer.L.Jacobson@usace.army.mil Email