year design life with construction completion in 2035. Applying these parameters results in a projected sea-level rise of approximately 0.92 feet in 2040 and 2.17 feet in 2060. An additional 2-foot allowance per FDOT's resilience planning criteria, has been incorporated into the hydraulic and elevation design of the Preferred Alternative to ensure long-term resiliency. A SLIP study was conducted in March 2026 and submitted to FDEP. A copy of the SLIP study is available in the project file.

5.4.15 Water Quality

A Water Quality Impact Evaluation (WQIE) Checklist, Form No. 650-050-37, was prepared for this project. The WQIE focuses on surface water and groundwater. The surface water evaluation identified and documented water quality issues to produce designs that comply with the goals of the Clean Water Act (CWA), as amended.

Water Quality Treatment: The alternative SMFs have been evaluated to provide treatment for the entire project limit in accordance with the following State standards based on the ERP Applicant's Handbook Volume I. For the impaired basins, BMP Trains was used to show a total of 80% nitrogen and 80% phosphorus removal for the proposed project due to the impairment of waterbodies. A higher rate of nutrient removal of 95% on nitrogen and phosphorus will be evaluated for the Interim Condition in the future phase to accommodate the encroachment of OFW's boundaries at the watershed downstream end.

Water Body Identification (WBID) waterbodies that are verified impaired include 1848A, 4848D1, and 1848D2. A Total maximum daily load (TMDL) plan is not required for any of the previously mentioned WBIDs.

Water Quantity: SWFWMD has water quantity criteria for open basins that must be satisfied.

• Southwest Florida Water Management District – The District's design storm event for construction activity is the 25-year/24-hour storm for open basins (40D-40, F.A.C.). It will be necessary to demonstrate that the post-development peak discharge from the design storm does not exceed the pre-development peak discharge for the same storm event for open basins.

Water quality regulatory requirements apply to this project and water quality and stormwater issues will be mitigated with the design requirements of the regulatory agencies.

5.4.16 Hydrology and Floodplains

For the Floodplain impacts for Interim Improvements impact 0.013 acer foot (ac-ft) of floodplains and compensates those impacts with 0.017 ac-ft of compensation. For the Preferred Alternative 0.675 ac-ft of floodplain impact and 1.123 ac-ft of compensation are provided. Nine cross drains (CD) were evaluated throughout the corridor; CD-1 will be replaced with a 3' × 6' box culvert, CD-

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