MARTIN COUNTY, FLORIDA INTER-OFFICE MEMORANDUM To the Honorable Board of County DATE: August 14, 2015

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1 TO: MARTIN COUNTY, FLORIDA INTER-OFFICE MEMORANDUM To the Honorable Board of County DATE: August 14, 2015 Commissioners VIA: Taryn Kryzda, County Administrator FROM: SUBJECT: Don Donaldson, P.E. Engineering Department Director US Army Corps of Engineers search for sand sources for Dade County projects Martin County received the Draft Environmental Assessment (EA) and Draft Finding of No Significant Impact (FONSI) from the US Army Corps of Engineers (Corps). Notice was also received of an upcoming public meeting for the project On August , from 6:30-8:30 PM. The meeting will be held at the Town of Jupiter Island Commission Chambers and hosted by the Corps. Official comments on these documents must be submitted in writing by September 26 th, The County has submitted comments on this project twice previously on September 17, 2013 and January 14, 2015 (attached). Many of the same concerns and recommendation from those 2 initial letters remain unchanged. As stated previously by the County in the 2013 letter, concerns are not solely focused on the sand requirements of Dade County which are fairly modest when compared to the needs faced by Broward County in the not-so-distant future. The precedent set here may be the most concerning aspect of the proposed action. Background A study of sand resources off the Southeast Florida coast was conducted (SAND) jointly by the Florida Department of Environmental Protection (FDEP) the Corps and the 5 southeast Counties (Miami-Dade, Broward, Palm Beach, Martin and St. Lucie Counties). With each County providing its projected sand requirements for the next 50 years, and including a 55% contingency, it was determined that a total of 174,101,870 cy of beach quality sand would meet the needs of the southeast region. A geotechnical investigation carried out by the Corps and the FDEP determined that 280,037,956 cy of beach quality sand exists offshore of the southeast Florida coast. The investigation concluded that there was, at minimum, 100,000,000 cy more sand in identified, beach quality deposits than would be needed by the southeast region over the next 50 years. As a consequence of the widening of the continental shelf that occurs south to north in this region, there is a much larger area accessible to dredges in the northern half of the area. Additionally, it has been shown that this area also contains some large deposits of beach quality sand that make up a bulk of the nearly 3 Million cubic yards of sand estimated during the SAND investigation.

2 Miami-Dade and Broward Counties are running out of accessible and environmentally feasible sources of sand, also resulting from the narrowing of the continental shelf. The most immediate need is for upcoming federal Miami-Dade projects addressing storm protection along 10.5 miles of coastline stretching from just north of Bakers Haulover inlet to Government Cut. As a federal project, the Corps is required to complete a Limited Re-evaluation Report (LRR) and National Environmental Protection Act (NEPA) authorization prior to using any new sand source, regardless of its location. When reviewing the 111 potential sand sources identified by the SAND working group the following factors were considered Compatibility grain size and color Complies with federal authorization In use, understudy, significant investment, existing permit by others Estimated quantity Existing geotechnical and seismic info Distance to project Cultural resources information survey conducted/resources mapped These criteria reduced the original 111 sites under consideration to 50 potential sites. The report recognizes that the act of dredging changes bathymetric contours, potentially influencing the size and direction of waves eventually breaking on the shoreline. Therefore, and additional factor, a sand source s proximity to the shoreline, was also considered. To address this risk and uncertainty, sand sources inside of three miles were considered too risky to dredge and were eliminated from further consideration. Issues The Corps is now engaged in these environmental and economic review processes. As required in the NEPA process, the Corps and Bureau of Ocean Energy Management (BOEM) have completed a Draft Environmental Assessment (EA): Identification of Alternative Sand Sources for the Remaining Period of Federal Participation Dade County Erosion Control and Hurricane Protection Project. The EA is conducted to identify environmental effects occurring as a result of utilizing each of the alternative sand sources. The environmental analysis is then combined with the results from the economic analysis performed for the LRR to determine the final recommendation. Although NEPA requires investigation of all environmental impacts, including impacts to the human environment which would include socioeconomic impacts, the issues evaluated do not include any impacts to the economy

3 or lives of the residents of northern counties (where the offshore sand sources are located). The report does however acknowledge the socioeconomic impact from loss of tourist revenue for Miami-Dade County. The issues listed in section of the Draft EA are: Function and values of sand sources as benthic habitat resources Potential impact of pipelines on hardbottom Potential impacts to corals listed under the ESA and designated critical habitat Potential impact on essential fish habitat Impacts and benefits on sea turtle nesting and foraging habitat Impact of current conditions on future public recreational use Potential impacts to adjacent shorelines from dredging sand deposits Further analysis then focused on the specifics of volume, color, grain size, cultural and environmental resource surveys. The 7 sites meeting these specific criteria are listed here and on Figure 4 from the report: Lumus Park; Miami-Dade; 50,000 cy/yr Bakers Haulover Ebb Shoal; Miami Dade; 20,000 cy/yr M4-R105; federal water offshore martin County, 80 miles north of project; 600,000 cy SL10-T41; federal water offshore St. Lucie County, 120 miles north of project; 4,600,000 cy Witherspoon Sand Plant; upland sand source; 120 miles from project; adequate volume Ortona Sand Plant; upland sand source; 120 miles from project; adequate volume ACI Homestead; upland sand source; 35 miles from project; adequate volume The following protocol was established for use of the various sites: Each nourishment would use a single sand source Miami-Dade sources (Lumus Park and Bakers Haulover) would be used whenever available based on recharge Martin County site would be used at the first project requiring no more than 600,000 cy Upland sand sources would be used for projects less than 200,000 cy St. Lucie Offshore would be sued for projects exceeding 200,000 Martin County Site The site in federal waters, 4-5 miles offshore of Martin County sits toward the south end of the

4 County, off of the Town of Jupiter Island (Town) as shown in Figure 5 from the report. The area targeted for dredging (cross hatched section in Figure 6 from the report) contains approximately 600,000 cy of sand compatible to Miami-Dade beaches and is located in water depths ranging from feet. The Corps has estimated a 15 hour round trip dredge/pumpout cycle for this site. Review of the factors that went into this estimation indicates this may be an optimistic projection (average 13.5 kt. speed, no mention of actual dredging time). Figure 6 from the report (at left) shows site M4-R105 outlined in black. This is the site of previous geotechnical investigations. The locations of sampling locations are shown on the diagram and indicate only 2 samples were taken within the targeted area. The crosshatched box denotes the proposed dredging location for the Miami-Dade project. The report s Figure 9 (right) is a map that was intended to show the location of the proposed sand source sites for the Miami-Dade project compared to nearest existing sand sources for Martin and St. Lucie County projects. The figure shows Martin and St. Lucie County s active borrow sites (shaded green) along with the 2 proposed sites (shaded orange) targeted by the Corps for the Miami-Dade project. The southern site is located off the Town of Jupiter Island Figure 9 does not include the active borrow site that is now jointly used by the Town of Jupiter Island and Martin County. This additional site is show here (shaded orange) in Martin County Figure A along with the 2 proposed borrow sites (yellow and grey shading) and the current sand source for the Hutchinson Island Project (shaded orange). The Town s Borrow Site B Martin County Figure A

5 is just landward of the proposed Corps borrow site. Borrow Site B has a limited lifespan, and efforts to expand the site and/or search for other proximal deposits of beach quality sand are under discussion. A letter from the County requesting this site be dropped from further investigation was submitted to the Corp on January 14, 2014 (attached). Additionally, Table 19 (from report) incorrectly shows sand mining projects in Martin and St. Lucie Counties. The table contains none of the Town of Jupiter Island s hopper dredge projects. Martin County s Figure B shows a corrected table. This figure more than doubles the Corps total dredging activity in the area. The associated environmental consequences, mainly related to sea turtle mortality, are thus vastly underrated in the EA. Finally, although the report details the submerged resources existing off the Miami-Dade coast, it is unclear what investigations of hardbottom or other resources have been conducted on the 2 offshore Treasure Coast sites considered for dredging. The Martin County site is deemed to be the next least expensive alternative after the 2 Miami- Dade sand source sites (Lumus Park and Bakers Haulover). Two of the upland sites, Witherspoon and Ortona, are the third least costly sources, if volumes are limited to 200,000 cy or less. Transport costs associated with upland sites reduce the economic advantage for this alternative as volumes increase. Based on Table 10 from the report, the Martin County site could be used as early as 2017, as a source for the Surfside project. Page 5 of 6 eng2015m360.docx

6 The report notes that (a)dditionaly, the State of Florida and the Corps conducted the previously discussed SAND study and determined there are sufficient sand resources for the foreseeable future for all of the counties utilizing the sand off the Southeast Florida coast. What it does not acknowledge is that sand requirements will not end at 50 years, and based on updated sea level rise projections, even these 50 year predictions could easily increase. (See attached Martin County letter to USACOE, 9/17/13) Further, they make no mention of the economic impact that occurs when resources, although still technically available for Martin and St. Lucie Counties, become less accessible and more costly as a result of the Miami -Dade project. Pushing future sand source sites further from existing local projects will make them more expensive to construct as a direct result of leases created for the Miami-Dade project. The report does not discuss the differences in appropriate grain sizes for Treasure Coast and Miami-Dade projects nor does it address the sparse information used to calculate overall sand sources available in the future. (See attached Martin County letter to USACOE, 1/14/14) Finally, the specific request to remove M2 R105 from further consideration, made in the Martin County January 14, 2014 letter, has been ignored. The site M2-R105 is the Martin County site recommended for use in the Draft EA. Page 6 of 6 eng2015m360.docx