Okaloosa County BOCC — July 19, 2016 — LGFR application — reading text

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 in excess of 50 feet at the jetty spur. Removal of this interior shoal would improve the hydrodynamic conditions between the inlet jetties as well as make available sediment for the adjacent eroding beaches. The concept of dredging interior inlet sediment catch basins or sand traps has been successfully implemented at other inlets in Florida to improve inlet sand transfer. Implementation Strategy #4 would induce the cooperative effort between the department and a local sponsor to conduct the necessary feasibility study and engineering design to facilitate dredging interior inlet shoals.” Finally, the proposed project will provide significant costs savings to the local, state and federal governments by: 1) reducing the frequency of maintenance dredging and, 2) provide a high-quality sand source for future beach restoration events immediately adjacent to existing (permitted) Western Destin beach project area, eliminating the costly need to obtain beach-quality sand from distant, offshore borrow areas. Upcoming Activities:  Norriego Point Stabilization  Utilizing NRDA funds and following the recommendations of the FDEP East Pass IMP Implementation Plan (Strategy #3), the City of Destin is working in close coordination with the State to stabilize critically eroded Norriego Point, which separates Destin harbor from East Pass. The project consists of shoreline stabilization structures and shoreline restoration (sand placement) to provide storm protection to Destin Harbor and reduce maintenance dredging frequency within this area of East Pass. The project will greatly reduce frequency of emergency dredging requirements and allow the USACE and/or City of Destin to place a greater volume of material from channel maintenance dredging events onto adjacent eroding beaches. Use of Requested Program Funds: Funds are requested to accomplish Implementation Strategy #4 of the East Pass Inlet Management Implementation Plan to reduce the maintenance dredging frequency of the East Pass federal navigation channel and increase the volume of sand available to the adjacent gulf coast beaches. Specifically, the County proposes to investigate management solutions that include the implementation of sediment impoundment basins (sand traps), and channel re- alignments/widening. The study will require the collection of current and wave data, literature review, hydrodynamic/wave/sediment transport modeling, and final alternatives analysis. Extensive numerical modeling will assess potential effects of the management alternatives and provide the data to make specific management recommendations for East Pass. Maintenance of the East Pass channel is necessary for public recreational opportunity as well as charter boat captains and commercial fisherman, which provide significant economic benefit to the surrounding area. The proposed study will provide recommendations to reduce East Pass maintenance dredging, thus reducing federal costs, and provide additional sand to adjacent beaches potentially reducing City, County, and State costs.  Local Government Contact: Name Title Email Jim Trifilio Coastal Management Coordinator, jtrifilio@co.okaloosa.fl.us Okaloosa County Tourist Development Council Address 1540 Miracle Strip Parkway SE Phone: (850) 651-7131 Fort Walton Beach, FL 32548 Fax: Mapping- Maps should be provided as attachments. Mapping elements include: □ Project Boundary with Inlet, area of inlet influence and Critically Eroded Shoreline □ Range Monuments Length of Area of Inlet Influence in Feet (As Determined by IMP or SBMP): 20,000 ft Length of area of inlet influence ranges from 6,000-ft to 12,000-ft contingent on selected time period and storm events. These values are in reference to the 1999 (original) and the 2010 (updated) East Pass Inlet Management Plans. The adopted 2013 Inlet Management Implementation Plan cites “the area direct inlet impact was determined to be approximately 10,000 feet to the east and west of East Pass.” Schedule and Budget: (Include estimated phases for 10 years and estimated project costs for 5 years.) Proposed Estimate Project Costs ($1,000’s) Year Description Phase Total Federal State Local Feasibility 0 0 0 0 Alternatives analysis, 2017/ 500 0 250 250 Design & Permitting design, and permitting 2018 Construction Monitoring Feasibility Design & Permitting 2018/ Contract docs & bid 2019 Construction admin Monitoring Feasibility 2019/ Design & Permitting 2020 Construction Basin Construction Monitoring Physical Feasibility 2020/ Design & Permitting 2021 Construction Monitoring Physical  Feasibility 2021/ Design & Permitting 2022 Construction Sand bypassing Monitoring Physical Feasibility 2022/ Design & Permitting 2023 Construction Monitoring Physical Feasibility 2023/ Design & Permitting 2024 Construction Sand bypassing Monitoring Physical Feasibility 2024/ Design & Permitting 2025 Construction Monitoring Physical Feasibility 2025/ Design & Permitting 2026 Construction Sand bypassing Monitoring Physical Feasibility 2026/ Design & Permitting 2027 Construction Monitoring Physical Description of inlet, area of inlet influence, and sediment budget from inlet management plan: Description of Inlet: The East Pass inlet serves as the only connection between the Gulf of Mexico, Destin Harbor and Choctawhatchee Bay. The inlet channel, from the offshore ebb shoat to the bay, is approximately 6,000-ft long. Choctawhatchee bay is approximately 28 miles long and 6 miles wide, and Destin Harbor is approximately 2 miles long and ¼ mile wide. Holiday Isle separates the Harbor from the Gulf of Mexico and Norriego Point separates the Harbor from East Pass. Two rubble mound jetties protect East pass, the west jetty is approximately 3,860 ft and the east jetty is approximately 1,200 ft. The landward end of the east jetty features an approximate 330 ft rubble mound spur jetty that extends into the inlet. The spur jetty is designed to divert flow away from the eastern bank of the inlet and is currently experiencing significant scour near the tip (scour depths extending beyond - 50 ft) due to the eastward channel migration across East Pass. Area of Influence: The East Pass area of inlet influence ranges from 6,000-ft to 12,000-ft contingent on selected time period and storm events. These values are in reference to the 1999 (original) and the 2010 (updated) East Pass Inlet Management Plans. The adopted 2013 Inlet Management Implementation Plan cites “the area direct inlet impact was determined to be approximately 10,000 feet to the east and west of East Pass.” From the adopted 2013 Inlet Management Implementation Plan: “The net accretion (not including fill placement) west of the inlet between V611 and the west jetty (approximately 10,000 feet) has been approximately +6,000 cy/yr [15,000 +