SAJ-1996-05620(SP-LCK)

TO WHOM IT MAY CONCERN:  The Jacksonville District of the U.S. Army Corps of Engineers (Corps) has received an application for a Department of the Army permit pursuant to Section 404 of the Clean Water Act (33 U.S.C. §1344) and Section 10 of the Rivers and Harbors Act of 1899 (33 U.S.C. §403) as described below:

APPLICANT:            Martin County

                                 Attn: Kathy FitzPatrick,

                                 2401 SE Monterey Rd.

                                 Stuart, FL 34996

WATERWAY AND LOCATION:  The project site is located within the St. Lucie Inlet, Peck’s Lake, Intracoastal Waterway, and along the shoreline of the Hobe Sound National Wildlife Refuge, St. Lucie Inlet Preserve State Park, within the waters of the Atlantic Ocean from the Florida Department of Environmental Protection (FDEP) monuments R-59 to R-73 (Sections 1, 12, 16, 17, 18, 20, 21, 26, 28, 35, and 36; Townships 38, 39, and 40 South; Range 41 and 42 East); Martin County, Florida.

Directions to the site are as follows: Take exit 79A to merge onto FL-786 E/PGA Blvd. 2) Slight right onto Lake Victoria Gardens. 3) Take the 1st right onto FL-811 N/Florida A1A Alt N. 4) Turn left onto N SR-A1A N/US-1 N. 5) Turn right onto N SR-A1A N. 6) Turn right onto SE Bridge Rd/County Rd 707. 7) Take the 2nd left onto North Beach Road. The north end of North Beach Road will end at approximately R-76.

PROJECT PURPOSE:

Basic:  The basic project purpose is Inlet maintenance and shoreline stabilization.

Overall:  The overall project purpose is maintenance dredging of St. Lucie Inlet with beneficial use of dredged material by bypassing sand to neighboring beaches.

EXISTING CONDITIONS and project history: The St. Lucie Inlet Federal Navigation Project falls under the jurisdiction of the U.S. Army Corps of Engineers (Corps), who is primarily responsible for maintenance dredging of the St. Lucie Inlet. Martin County is the local sponsor and the State of Florida is a cost-share partner.  These agencies work in close coordination to maintain navigable depths within the St. Lucie Inlet and provide sand bypassing to the County’s beaches consistent with the State-approved Inlet Management Plan (IMP).  Approximately 470,000 cubic yards (cy) to 550,000 cy of sand is dredged from the St. Lucie Inlet impoundment basin and navigational channel (Cut 1) every two to three years. The impoundment basin was last dredged in 2018 and planning for the next event is anticipated to take place in 2021 or 2022.

The beaches along the St. Lucie Inlet Preserve State Park (SLIPSP) are within the continuous segment of critically eroded shoreline and have not been nourished previously. More recent episodic erosion has been exacerbated to the extent that there is loss of dune vegetation and marine turtle nesting habitat. 

To determine areas of potential hardbottom within the newly expanded project area of the SLIPSP, an initial desktop analysis was conducted that included historical and current aerial imagery, 2010 side-scan sonar survey data, and FDEP’s 2015 benthic habitat dataset.  In-water field diver surveys were conducted in November 2018. The study area extended to 350 meters (m) offshore from R-43 (south jetty) to R-62.  No hardbottom was observed within the survey area from R-43 to R-54. This area consisted of fine to coarse grained sand. Hardbottom is present from R-54 to the southern limits of the survey area R-61. The hardbottom is low relief and observed from 90 m to 350 m from the shoreline. The hardbottom consisted of vacant and live wormrock, and consolidated substrate.

Nearshore hardbottom monitoring has been occurring within from R-57 to R-70 since 2007. Biological monitoring was conducted annually from 2007-2016 in association with past dredging and sand placement events. The last sand placement event for Martin County within their existing authorized fill template occurred in 2014.

PROJECT HISTORY: The Corps issued a Department of the Army (DA) permit on  December 21, 2011, authorizing the dredging of approximately 550,000 cy of sand (80,000 cy from the navigable channel and 470,000 cy from the Impoundment Basin). The 550,000 cy of beach quality sand dredged from the entrance channel and the impoundment basin shall be placed either transported via pipeline along the beach to the fill template or placed on a barge, transported south along the Intracoastal Waterway (ICW) and pumped across at Peck’s Lake through one of two pipeline corridors.  Beach placement of the compatible sand will be placed from R-59 to R-75. The authorization expires on December 21, 2021.  The proposed fill template is as follows:

From R-59 to R-65, the maximum fill template shall entail a berm width of 100 feet at elevation +7.4 feet NAVD with a 10:1 slope to the existing profile with a transition from R-65 to R-66.

From R-66 to R-75, the maximum fill template shall entail a berm width of 150 feet (up to 200 feet at R-70) at elevation +7.4 feet NAVD, with a 10:1 slope to the existing profile with a transition from R-75 to R-76A.

The Corps modified the permit on January 23, 2012 to increase the proposed dredge material to 673,000 cy and to deepen a section of the transition area to a depth of -12-feet NGVD. The Corps issued a Modification to our DA permit on May 4, 2017 to conduct the following activities:

1)            Perform maintenance dredging of the navigable channel during any time of the year on an “as-needed” basis to ensure safe navigability of the inlet. The dredged material would be placed along the shoreline described below or within the offshore Borrow Area B.

2)            Discharge of dredged material from the St. Lucie Inlet within a 562-acre offshore disposal area identified as “Borrow Area B”. This borrow area is located offshore Jupiter Island located approximately between R-109 and R-118. Use of Borrow Area B would allow for storage of dredged material that may be utilized by others for future nourishment/re-nourishment events, authorized under a separate permit. The maximum frequency of use of the offshore disposal site would coincide with the maintenance dredging frequency of every 3 to 5 years.

PROPOSED PROJECT:  The applicant proposes the reauthorization of a maintenance dredging project within the St. Lucie Inlet and an expanded beach fill template. Approximately 673,000 cy of beach compatible sand would be dredged from the entrance and interior channel (203,000 cy) and Impoundment Basin (470,000 cy), with a widener between the entrance and interior channels and a transitional area between the interior channel and the impoundment basin.  To restore the authorized navigation depths, the following areas will be dredged and all areas will be hydraulically or mechanically dredged with a 2-foot allowable over-dredge depth:

Entrance channel (STA 30+00 to STA 22+00) will be dredged to -16 feet mean lower water (MLLW);

Widener (STA 34+00 to STA 30+00) will be dredged to -10 feet MLLW on the western side transitions to -16 feet MLLW on the eastern side;

Interior channel (STA 42+00 to STA 34+00) will be dredged to -10 feet MLLW’

Impoundment basin located between STA 42+00 and STA 30+00 will be dredged to -16 feet MLLW, and

Transitional area located between the impoundment area and the channel will be dredged to -9.36 feet MLLW.

Dredged material shall be place either along the shoreline south of the St. Lucie Inlet at the below specified locations, or placed within the offshore Borrow Area B. Use of Borrow Area B would allow for storage of dredged material that may be utilized by others for future nourishment/re-nourishment events, authorized under a separate permit. Placement of material along the beach will be transported via pipeline and pumped across Peck’s Lake through one of the two pipelines corridors.  Material will be placed within the previously authorized construction template as well as a new expanded area. The fill template varies as follows:

New area (no previous nourishment): From R-44.5 to R-59, the beach fill template has a design dune crest elevation of +10 feet NAVD 88 with 1V:5H side slopes and a design beach berm elevation of +7.5 feet NAVD 88, with a seaward slope of 1V:10H.  Since R-45 is within the taper from the south jetty, the design dune crest width is 10 feet, while the design berm crest width is approximately 30 feet.  From R-46 to R-52, the design dune crest width varies from 40 to 60 feet and the berm crest width varies from approximately 50 to 80 feet.  The berm crest width between R-53 and R-50 varies from approximately 50 to 60 feet from the existing ground survey.

Existing area: From R-59 to R-65, the maximum fill template shall entail a berm width of 100 feet at elevation +7.4 feet NAVD 88 with a 10:1 slope to the existing profile with a transition from R-65 to R-66.

Existing area: From R-66 to R-73, the maximum fill template shall entail a berm width of up to150 feet (up to 200 feet at R-70) at elevations +7.4 feet NAVD 88 with a 10:1 slope to the existing profile with a transition from R-72 to R-73.

Maintenance dredging of the navigable channel can occur any time of the year on an “as-needed” basis to ensure safe navigability of the inlet. Maintenance dredging of the full project can occur any time of the year; however, the frequency of dredging the impoundment basin will not exceed more than one full event every two years. Beach placement is allowed to take place within the fill template on an as needed basis outside of sea turtle nesting season.

AVOIDANCE AND MINIMIZATION INFORMATION:  The applicant has provided the following information in support of efforts to avoid and/or minimize impacts to the aquatic environment:  The existing regulatory authorizations for maintenance dredging of the St. Lucie Inlet include beach placement along the beaches of the Hobe Sound Natural Wildlife Refuge (HSNWR).  The authorized beach template at the HSNWR was designed conservatively at the north end where hardbottom is nearest to shore.  Sand was dredged and placed along the HSNWR beaches in 2008, 2012, and 2014. Hardbottom monitoring according to the permitted biological monitoring plan was performed annually from 2009 to 2016 and no secondary impacts due to beach placement were documented. At the south end of the proposed modified template, the design is based on the same conservative design already authorized at the north end of the HSNWR that has proven to successfully avoid impacts to the nearshore hardbottom.  It is anticipated that impact to hardbottom habitat will be avoided. From R-53 to R-59, the design dune is intended to match the existing survey profile and maintain the currently existing dune so no dune crest width from the existing survey is given.

From R-54 south, the hardbottom advances nearer to shore.  In this area, an Equilibrium Toe of Fill (ETOF) analysis was performed to guide the design to avoid nearshore resource impacts. The ETOF analysis, as described by Dean’s Beach Nourishment; Theory and Practice (2002), is based on the cross-sectional volume of fill between the June 2019 existing ground survey and the fill template, sediment grain size of fill material, berm elevation, depth of closure, and the MHW elevation. However, the applicant calculated an adjusted ETOF based on the Dean approach.

Beach placement of dredged material on the beaches of the SLIPSP is not expected to cause unacceptable cumulative impacts.  Between the south jetty and R-54, hardbottom communities are sufficiently far offshore that impacts are not of concern.  From R-54 to R-59, hardbottom is closer to shore.  At R-57 the hardbottom edge is approximately 150 linear feet from the seaward limit of the ETOF and at R-58 the hardbottom edge is approximately 15 linear feet from the seaward limit of the ETOF. At this location the fill template is designed based on the currently authorized beach fill template at the adjacent beaches of the HSNWR and aims to maintain current dune conditions with slight increases to the berm width to match the template for the adjacent beaches to the south.  The HSNWR template was designed to avoid adverse impacts to the nearshore hardbottom.  Nearshore hardbottom monitoring following placement of dredged material in 2012 and again in 2014 demonstrated that the design has avoided cumulative impacts to the nearshore hardbottom.  Applying the same design from R-54 to R-60 aims to similarly avoid nearshore hardbottom impacts. The existing biological monitoring plan for the applicant will be updated to include sand placement along the shoreline at SLIPSP.

COMPENSATORY MITIGATION:  The applicant has provided the following explanation as to why compensatory mitigation should not be required: The beach fill template is designed to avoid direct impacts to submerged resources.  Biological monitoring of the nearshore hardbottom will be performed to monitor for any secondary impacts. The uplands in the SLIPSP have experienced severe erosion and placement of fill will mitigate the erosion, restore dune vegetation and restore and enhance shorebird and marine turtle nesting habitats. However, the Corps will determine if secondary impacts to hardbottom result from the placement of fill or the movement of sand.

CULTURAL RESOURCES:  The Corps is not aware of any known historic properties within the permit area.  By copy of this public notice, the Corps is providing information for review.  Our final determination relative to historic resource impacts is subject to review by and coordination with the State Historic Preservation Officer and if applicable, those federally recognized tribes with concerns in Florida and the Permit Area.

ENDANGERED SPECIES:  The Corps has determined the proposal may affect the endangered and threatened nesting sea turtles (Chelonia mydas, Eretmochelys imbricate, Lepidochelys kempii, Dermochelys coriacea, Caretta caretta, Lepidochelys olivacea), the threatened piping plover (Charadrius melodus), Scrub Jay (Aphelocoma coerulescens), and the Rufa red knot (Calidris canutus rufa).  The Corps also determined that the project may affect, but is not likely to adversely affect the threatened West Indian manatee (Trichechus manatus),.  The project would not adversely modify the manatee’s designated critical habitat or the loggerhead designated terrestrial critical habitat Unit LOGG-T-FL-09. The Corps has determined that the project is consistent with the Statewide Programmatic Biological Opinion (2015-SPBO, Service 2015), and the Programmatic Piping Plover Biological Opinion (P3BO, Service 2013). The Corps will request initiation of formal consultation with the U.S. Fish and Wildlife Service pursuant to Section 7 of the Endangered Species Act by separate letter.

The Corps has determined that the proposal may affect the smalltooth sawfish (Pristis pectinata), endangered and threatened swimming sea turtles (Chelonia mydas, Eretmochelys imbricate, Lepidochelys kempii, Dermochelys coriacea, Caretta caretta).  The Corps also determined that the project may affect but is not likely to adversely affect the northern right whale (Eubalaena glacialis), Johnson’s seagrass (Halophila johnsonii), and would not adversely modify the Loggerhead LOGG-N-19 Reproductive, Migratory, and Breeding designated critical habitat. The Corps will request initiation of formal consultation with the National Marine Fisheries Service pursuant to Section 7 of the Endangered Species Act by separate letter.

ESSENTIAL FISH HABITAT (EFH):  This notice initiates consultation with the National Marine Fisheries Service on EFH as required by the Magnuson-Stevens Fishery Conservation and Management Act 1996. The proposal would directly affect 36.3 acres of un-vegetated habitat from the maintenance dredging.  The proposal would directly affect 70.5 acres of inter- and sub-tidal beach habitats below the mean high water line by direct burial and equilibration of the fill (41.7 acres of which has never had sand placement). This benthic habitat is utilized by various life stages of penaeid shrimp complex, reef fish, stone crab, spiny lobster, migratory/pelagic fish, and snapper/grouper complex.  There is hardbottom adjacent to the ETOF of the fill template near R-57 and R-58. The applicant will comply with best management practices to minimize effects from sedimentation and turbidity. The proposed dredged material meet the criteria in the FDEP-approved Sediment Quality Control/Quality Assurance Plan dated September 11, 2011. The applicant will also comply with updated biological monitoring plans. Our initial determination is that the proposed action would not have a substantial adverse impact on EFH or Federally managed fisheries in the South Atlantic Region.  Our final determination relative to project impacts and the need for mitigation measures is subject to review by and coordination with the National Marine Fisheries Service.

SECTION 408: The applicant may require permission under Section 14 of the Rivers and Harbors Act (33 USC 408) because the activity, in whole or in part, would alter, occupy, or use a Corps Civil Works project (specifically the St. Lucie Impoundment Basin and a portion of the beach placement area).

NOTE:  This public notice is being issued based on information furnished by the applicant.  This information has not been verified or evaluated to ensure compliance with laws and regulation governing the regulatory program.  The jurisdictional line has been verified by Corps personnel.

AUTHORIZATION FROM OTHER AGENCIES:  Water Quality Certification is required from the Florida Department of Environmental Protection and/or one of the state Water Management Districts.

COMMENTS regarding the potential authorization of the work proposed should be submitted in writing to the attention of the District Engineer through the Palm Beach Gardens Regulatory Permits Section, 4400 PGA Boulevard, Suite 500, Palm Beach Gardens, FL 33410, or via email to Linda.C.Knoeck@usace.army.mil within 30 days from the date of this notice.

The decision whether to issue or deny this permit application will be based on the information received from this public notice and the evaluation of the probable impact to the associated aquatic resources.  This is based on an analysis of the applicant's avoidance and minimization efforts for the project, as well as the compensatory mitigation proposed.

QUESTIONS concerning this application should be directed to the project manager, Ms. Linda C. Knoeck, in writing at the Palm Beach Gardens Regulatory Permits Section, 4400 PGA Boulevard, Suite 500, Palm Beach Gardens, FL 33410, by electronic mail at Linda.C.Knoeck@usace.army.mil or by telephone at (561)472-3531. 

IMPACT ON NATURAL RESOURCES: Preliminary review of this application indicates that an Environmental Impact Statement may be required. Coordination with U.S. Fish and Wildlife Service, Environmental Protection Agency (EPA), the National Marine Fisheries Service, and other Federal, State, and local agencies, environmental groups, and concerned citizens generally yields pertinent environmental information that is instrumental in determining the impact the proposed action will have on the natural resources of the area. By means of this notice, we are soliciting comments on the potential effects of the project on threatened or endangered species or their habitat.

EVALUATION: The decision whether to issue a permit will be based on an evaluation of the probable impact including cumulative impacts of the proposed activity on the public interest. That decision will reflect the national concern for both protection and utilization of important resources. The benefits, which reasonably may be expected to accrue from the proposal, must be balanced against its reasonably foreseeable detriments. All factors which may be relevant to the proposal will be considered including cumulative impacts thereof; among these are conservation, economics, esthetics, general environmental concerns, wetlands, historical properties, fish and wildlife values, flood hazards, floodplain values, land use, navigation, shoreline erosion and accretion, recreation, water supply and conservation, water quality, energy needs, safety, food, and fiber production, mineral needs, considerations of property ownership, and in general, the needs and welfare of the people. Evaluation of the impact of the activity on the public interest will also include application of the guidelines promulgated by the Administrator, EPA, under authority of Section 404(b) of the Clean Water Act and the criteria established under authority of Section 102(a) of the Marine Protection Research and Sanctuaries Act of 1972. A permit will be granted unless its issuance is found to be contrary to the public interest.

The US Army Corps of Engineers (Corps) is soliciting comments from the public; Federal, State, and local agencies and officials; Indian Tribes; and other Interested parties in order to consider and evaluate the impacts of this proposed activity. Any comments received will be considered by the Corps to determine whether to issue, modify, condition, or deny a permit for this proposal. To make this decision, comments are used to assess impacts on endangered species, historic properties, water quality, general environmental effects, and the other public interest factors listed above. Comments are used in the preparation of an Environmental Assessment and/or an Environmental Impact Statement pursuant to the National Environmental Policy Act.  Comments are also used to determine the need for a public hearing and to determine the overall public interest of the proposed activity.

COASTAL ZONE MANAGEMENT CONSISTENCY: In Florida, the State approval constitutes compliance with the approved Coastal Zone Management Plan.

REQUEST FOR PUBLIC HEARING: Any person may request a public hearing. The request must be submitted in writing to the District Engineer within the designated comment period of the notice and must state the specific reasons for requesting the public hearing.