Posted on May 13, 2024
The U.S. Army Corps of Engineers, Jacksonville District, is preparing a National Environmental Policy Act (NEPA) assessment to support design refinements being considered in the Central Everglades Planning Project (CEPP) North Phase Validation Study. The purpose of the CEPP North Phase Validation Study is to confirm project components, construction sequencing, and project dependencies as described in the 2014 CEPP Final Project Implementation Report and Environmental Impact Statement (PIR/EIS) and Chief’s Report. In addition, the Validation Study will also validate that the proposed design refinements are necessary for the CEPP North project components to function as originally intended and determine if the refinements require additional NEPA. The 2014 CEPP Final PIR/EIS is available at https://usace.contentdm.oclc.org/utils/getfile/collection/p16021coll7/id/16154.
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 PIR/EIS. The map, which can be viewed with the signed document at the link below, shows these features are located within northern WCA 3A, and along the boundary between the L-4, L-5, and L-6 levees and the Everglades Agricultural Area (EAA). Please note that the CEPP North features depicted on the map are not shown to scale. Features to be implemented in the CEPP North Phase also include modifications to the S-8 pump station complex, including S-8A and the connector canal extending from the Miami Canal (south of the existing S-8 pump station) to the L-4 Canal. 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.
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) has 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. The L-4 design refinements require an addition NEPA analysis to determine effects on the human environment, while other design refinements included in the Validation Study analysis were determined to be within the scope of the 2014 CEPP Final PIR/EIS.
To address these concerns, the Corps, in partnership with the South Florida Water Management District (SFWMD) is evaluating potential engineering design refinements to include variations of degrade geometry, construction of culverts, and/or construction of spreader swales in the L-4 Levee. The Corps will prepare supplemental NEPA documentation to address environmental considerations related to the construction of the proposed L-4 degrade design refinements. 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 notice with any interested party.
Please provide comments on the L-4 degrade design refinements within the CEPP North study area and how these changes should be evaluated. USACE will accept written comments regarding the proposed project up to 30-days from the date of this letter.
Comments may be submitted to:
U.S. Army Corps of Engineers, Jacksonville District
Attn: Jacob Thompson, Project Biologist
701 San Marco Blvd.
Jacksonville, FL 32207-8915
or email CESAJ-CEPPNorth@usace.army.mil
All comments will be summarized, addressed, and used to inform the CEPP North Phase Validation Study. For more information on the project, including up to date meeting information, please go to the following website: https://www.saj.usace.army.mil/Missions/Environmental/Ecosystem-Restoration/Central-Everglades-Planning-Project/.
The signed document with map can be viewed at:
https://usace.contentdm.oclc.org/utils/getfile/collection/p16021coll7/id/25730
