Okaloosa County BOCC — July 19, 2016 — LGFR application

FY 2017/18 Local Government Funding Request Okaloosa County Inlet Management Project Project Name: East Pass Sediment Impoundment Basin – Design and Permitting Project Description: The project will develop and apply numerous numerical (MIKE) models to evaluate various sediment impoundment basin design alternatives in East Pass to facilitate bypassing of sediment to the adjacent beaches. The project scope includes the alternatives evaluation and the design and permitting (including state and federal permits) of the recommended basin alternative. The project will comply with the Department’s East Pass Inlet Management Implementation Plan (IMIP), specifically the final strategy to investigate availability and feasibility of supplemental inlet sediment excavation outside the federal navigation channels to help mitigate gulf beach erosion that exceeds the bypassing quantities obtained from maintenance of the federal navigation channels County: Okaloosa Range Monuments: NA (Immediately west of R-17) Location: East Pass is located adjacent to Destin, FL, approximately 45 miles east of Pensacola and approximately 50 miles northwest of Panama City. Separating Santa Rosa Island to the west and Moreno Point to the east, East Pass is a structured inlet that provides direct tidal link between the Gulf of Mexico and Choctawhatchee Bay. Project History: The East Pass Federal navigation channel requires frequent maintenance dredging to alleviate shoaling of sediment within the channel. The East Pass Maintenance Dredging is authorized by joint coastal permit number 0288799-001-JC, issued to the U.S. Army Corps of Engineers (USACE) October 2009 and expires October 2019. East Pass navigation channel (maintenance) dredging is also authorized by 0288799-003-JC, which was recently issued to the City of Destin in February 2015 and expires in February 2030. Both permits authorize maintenance dredging within the federal navigation channels that extend from approximately 3,500 ft south of the inlet jetties northward past the US98 Bridge into Choctawhatchee Bay. The permits also authorize maintenance dredging within the Destin Harbor (Old Pass Lagoon) entrance channel. The updated and adopted inlet management plan (2010) reports that the USACE has dredged 2,352,600 cy of material from east pass since 1986. The frequency of dredging ranges between one and three years, with a historic, average annual dredge rate of approximately 98,000 cy/year. Notably, federal and budget constraints have since eliminated Operations and Maintenance dredging operations of non-deepwater ports, removing East Pass and Destin Harbor from the USACE project list. Following Implementation Strategy #4 of the East Pass Inlet Management Implementation Plan (2013), current project aspirations are to design and permit sediment impoundment basins (“sand traps”) to reduce the maintenance dredging frequency of the East Pass federal navigation channels and increase the volume of beach-quality sand available to the Gulf coast beaches. From the Implementation Plan: “Implementation Strategy #4 initiates greater flexibility in the future management of East Pass. Continued Congressional appropriations for the maintenance of the federal navigation project are not guaranteed. Also, a planned channel maintenance dredging project might not even provide a sufficient quantity of sand to balance the sediment budget with adjacent eroding beaches. Additional inlet excavation outside the authorized channels may be warranted. A problem inherent with the existing natural channel alignment is the eastward migration of the channel against the east jetty spur. Between the channel and the west jetty is a developing shoal. The reduced depth and cross-sectional flow area of this shoal within the inlet inhibits tidal flow resulting in an increased flow within the channel. This increased flow has caused scour to depths