Posted on January 6, 2025
Jacksonville, Fla. — The U.S. Army Corps of Engineers (USACE), Jacksonville District pursuant to the National Environmental Policy Act (NEPA) issues the Notice of Availability (NOA) of the Supplemental Environmental Assessment (SEA) and Proposed Finding of No Significant Impact (FONSI) for construction of proposed design refinements for the Central Everglades Planning Project (CEPP) North Phase. The specific features of the CEPP Recommended Plan to be implemented in the CEPP North Phase focus on hydropattern restoration in northern Water Conservation Area (WCA) 3A and the backfilling of the Miami Canal that were identified in the 2014 CEPP Final Project Implementation Report and Environmental Impact Statement (PIR/EIS). Construction of the CEPP North Phase will prepare the Everglades system for additional treated water inflows from Lake Okeechobee by providing the conveyance improvements and landscape connectivity necessary to redistribute additional flows to northern WCA 3A. Preliminary hydraulic modeling has found that modifications to CEPP North features are necessary in order to meet the project objectives identified in the 2014 CEPP Final PIR/EIS, including effective and uniformly distributed flow into WCA 3A. The CEPP North SEA and Proposed FONSI address construction of proposed design refinements to the L-4 Levee degrade, a feature of the Recommended Plan in the 2014 CEPP Final PIR/EIS and Chief’s Report.
The Recommended Plan from the 2014 CEPP Final PIR/EIS proposed to degrade approximately 2.9 miles of the southern L-4 Levee west of the S-8 pump station to restore sheet flow and hydropatterns in the northwest corner of WCA 3A. Preliminary hydraulic modeling during Preconstruction, Engineering, and Design (PED) indicated the potential need to modify the L-4 degrade as described in the 2014 CEPP Final PIR/EIS to better address achievement of the project objectives. Hydraulic modeling has revealed the potential need to: (1) expand the existing L-4 Canal to be able to convey the identified flows from the 2014 CEPP Final PIR/EIS of 3,000 cubic feet per second (cfs) to the northwest corner of WCA 3A; and (2) to modify the L-4 degrade to more effectively distribute flow into northwest WCA 3A to achieve rehydration of the downstream marsh consistent with the hydrologic performance described in the 2014 CEPP Final PIR/EIS. Evaluation of higher-resolution topographical datasets and expanded hydrologic modeling revealed that the existing L-4 Canal only had a capacity of approximately 500 cfs, and most of the flow delivered to the L-4 Canal would immediately be discharged into northwestern WCA 3A through the degraded L-4 Levee on the east end of the L-4 Canal adjacent to the Miami Canal with minimum to no flow able to reach the west end adjacent to the L-3 Canal.
To address these concerns, USACE, in partnership with the South Florida Water Management District (SFWMD) evaluated potential engineering design refinements to include variations of degrade geometry, construction of culverts, and/or construction of spreader swales in the L-4 Levee. USACE has prepared a SEA to address environmental considerations related to the construction of the proposed L-4 degrade design refinements along with other reasonable alternatives. We invite the participation of Federal and State agencies, Native American Tribes, local agencies, interested parties and individuals to provide comments and to identify any issues or concerns. Please share this NOA with any interested party.
The SEA, proposed FONSI, and a signed copy of the NOA are available for your review on the Jacksonville District, USACE Environmental Documents website at https://www.saj.usace.army.mil/About/Divisions-Offices/Planning/Environmental-Branch/Environmental-Documents/ . Click the dropdown + next to Multiple Counties and scroll to the bottom row to the link for CEPP North Phase L-4 Canal and Levee Design Refinements.
USACE is requesting that any comments be submitted via email to CESAJ-CEPPNORTH@usace.army.mil within 30 days of the date of this letter. Correspondence may also be sent via mail to the address below, however due to limited staff availability at USACE’s District office, electronic submittal of comments via email is preferred. Questions concerning the proposed action can also be submitted to Mr. Jacob Thompson by phone at 904-232-1893.
Comments may be submitted to:
U.S. Army Corps of Engineers, Jacksonville District
Attn: Jacob Thompson
701 San Marco Boulevard
Jacksonville, FL 32207 or email to CESAJ-CEPPNORTH@usace.army.mil
