Loading...
HomeMy WebLinkAboutR-80-0055Florida for said "SUPPORTIVE DOCUMENT.S FOLLOW" State RESOLUTION NO. 80 55 A RESOLUTION APPROVING ISSUANCE OF PERMIT, --:- PURSUANT .'TO SECTION 253,124, FLORIDA STATUTES FOR ' THE EXPANSION OF .THE PORT OF MIAMI; --A' DEVELOPMENT OF. REGIONAL IMPACT, PROPOSED BY DADE COUNTY SEAPORT DEPARTMENT FOR LITMUS AND ,SAW--S. ISLANDS AND BAY BOTTOM LOCATED ON BISCAYNEBAY JUST SOUTH OF WATSON .ISLAND. • WHEREAS of Florida o construct the Sam' Metropolitan Dade County has applied t Department'' of Environmental Reg expansion to the Port of Miami, the ulation for a perrmit n Lurimu s and• Islands and Bay Bottom` loca•ted on Biscayne -Bay; and WHEREAS, the City of. Miami has pr.evious1v approved'and issued a Development Order.for the same project; and. WHEREAS,before ar.nroval can be given by the State be obtained from the. City. permit,: approval must of Miami "pursuant to. Section 253.124, Florida: Statutes; and of .WHEREAS, a Biological Survey Deport prepared bv`the"' • State of. Florida, Department of Environmental Regulation is and made a part hereof , the contents of: which are City.Comnission of the City of Miami; NOW, THEREFORE, BE IT RESOLVED.. BY TEE COMMISSION OF THE hereto to the CITY: OF MIAMI,`FLORIDA: Section Project, Seaport located on ATTEST: Section 1. attached familiar Approval is hereby granted ;pursuant; t 253.124, Florida Statutes, for the Port of a ;development of regional impact, pronosec? by Dade Department for Lummus and Sam's I•slands and bav hottom •Biscayne Bay just South of Watson Island: PASSED AND ADOPTED this 24 day Miami JANUARY MAURICE:'A. FERRE Exr_ansion Rountv 1980. CITE CLERK P EPARE AA A nP VED BY: MIC�IALL HAYGOOD ASSISTANT CITY ATTO•Y CIT MAYOR: "DOCUMENT INDEX ITEM NO. RM ANI) CORRECTNESS : TR. A. ORNFY C11Y COMMISSION MEETING OF JAN 2 4 1980 RESOLUTION Nab 0 : 5 5 REMARKS: eeeeeee .23 Joseph R.Grassie; January 18, 1980 City. Manager "Jim Reid, Director-`` Planning Department 'City Commission Meeting January 24,•1980 Agenda Item -- Approval for Filling Land: Port 0f Miami, Expansion Section 253.124 Florida Statutes requires local government to, approveany dredging or 'filling to extend islands within munici- pal -limits. 'It is recornrnended that the Commission approve the dredging and filling toextend certain islands,i.e. Dodge and, Sam'.s Islands, as requested.. by the Dade County''`Seaport Department for the Port` of Miami,_` expansion, per the attached resolution: Section 253.124 Florida. Statutes requires ,the .sPeci,fic..approvaY of local government of any "dredi ng or filling .,to extend i sl ands, wi;thi n muni ci pal limits Further it is required that local government review a-bio logical survey citing; the effects of the proposed dredging or filling operations. The Dade County Seaport Department has requested that the Commission specifically approve the dredging and filling to expand Dodge and Sam's :Islands in Biscayne Bay associated with the Port of Miami expansion and have included 'a biological survey prepared by the,, Department of En vironmental,Resource Management The. Commission,haspreviously issued a DevelopmentOrder approving, with modifications, the Port. of Miami� Development of Regional Impact. (Resolution 79-850;` December 5, 1979) • is recommended that. the ,Commission approve, the extension of -Dodge and Sam' s.Islands,' per the attached resolution. JR:JLJM:dr Encs. Resolution ;Biological Survey `SUPPORTIVE DCCU EI\i.rS FOLLOW" City of Miami Commission' Post Office Box 330708 Miami, Florida 33133 Dear Sirs: Re: File No. 13-19502, Dade County, Metropolitan Dade County Seaport Department The Department of Environmental Regulation staff has performed a biological survey for the above project and offers the following comments to be considered by the Board of Commissioners as required by Subsection 253.124(3), Florida Statutes. This project involves the expansion of the Port of I1iarai facility at Dodge Island in Biscayne Bay, Miami, Dade County, Florida. The project includes the excavation of 11,400,000 cubic yards below mean high water in order to: Widen the existing main channel from 400 to SS0 ft.:.,: along approximately 6,000 linear ft. from the existing turning basin west of Government Cut to Dodge Channel and deepen the main channel to 536.0 ft. mean low water (M.L.W.) - (1,297,000 cubic yards). . To provide a new channel south of Dodge, Lurnmus and Sam's Island. This channel, approximately 12,600 ft. long by S00 ft. wide, would be excavated along with the existing slip on Dodge Island to a depth of -36.0 ft. M.L.W. (6,180,000 cubic yards). ▪ To provide a turning basin with a diameter of 1,600 ft. near the center of the proposed south main channel (2,042,000 cubic yards). . To provide a new channel approximately 2,000 ft. long by 900 ft. wide at the southwest corner of Dodge Island from the inflection point to the Intracoastal Waterway (1,881,000 cubic yards). «S I? 3OE( 1'1t OCU (-)1 1 i ) 8, City of Miami Commission January 17, 1980 Page Two The project also includes the filling of 4,120,000 c.y. below, and 900,000 c.y. above mean high water at the following locations: 1. The southwest corner of Do4ge Island would be expanded by filling approximately 11 acres of submerged bottom (70,000 c.y.). 2. A 227 acre site east of the existing Port facilities on Dodge Island would be expanded by filling 147 acres of submerged bottom and 80± acres of existing uplands on Sam's and Lummus Islands (4,050,000 c.y.). The spoil material not used as fill to expand the Port (6,380,000 c.y.) would be deposited on upland spoil sites on Virginia Key. This dredging/filling activity would be completed within a five (S) year period (1980-1984) during Phase I and Phase IIA of the proposed Port development. Subsequent development would include the construction of 13,870 linear ft. of marginal wharf and the development of the upland to service cruise passenger vessels and oceanborne general cargo commerce. The construction of marginal wharfs would occur in a phased development depending on funding and needs. The proposed expansion indicates the construction of 36.51 of the proposed wharfs (6000 linear ft.) during 1980-1984 (Phase I and IIA) with 63.5% (11,970 linear ft.) being constructed from 1985-1999 (Phase IIB, III and IV). This project is in Outstanding Florida Waters and is within the boundaries of the Biscayne Bay Aquatic Preserve. The existing Port and the proposed Port expansion are in a section of North Biscayne Bay bordered on the north by the McArthur Causeway and on the south by the Rickenbackor Causeway. The City of Miami (mainland) is located on the west side of the basin with several islands including Manzi Beach, Fisher Island and Virginia Key situated to the east. The basin flushes with the Atlantic Ocean through Government Cut and Norris Cut on the east. The major flow into the basin occurs from the Miami River, immediately west of the proposed Port expansion, and tho Intracoastal Waterway which extends through this basin from south Biscayne Bay to the more northern basins of the Bay. efA City of Miami Commission January 17, 1980 Page Three The history of construction in this basin has been documented in the applicant's Development of Regional Impact (D.R.I.). The major impacts from dredging/filling occurred primarily from the construction and maintenance of navigable channels in this basin. The dredging of Fishermen's Channel (1890's) and successive dredging of Government Cut (1920's to present) has resulted in significant damage to seagrass beds which dominated this area of the Bay. Additionally, direct spoiling on adjacent beds, heavy siltation and turbidity, and unconsolidated spoil has resulted in the loss of additional valuable seagrass habitat. The last major construction activity in this area of the Bay occured in the early 1960's with the development of the existing Port. Additional impacts on this basin have occurred from the discharge of domestic sewage both into the Miami River and directly into the Bay. The direct sewage disposal was abated in 19SS with the construction of the City of Miami Wastewater Treatment Plant on Virginia Key. During this time, McNulty (1962, 1970) did extensive benthic biological sampling of this area of the Bay. Present impacts on this basin occur primarily from maintenance dredging of the existing channels and problems associated with recent urban growth. This increased growth has resulted in increased pollutant loading; (heavy metals, greases, oils) in discharges of stormwater, a natural shoreline that is now nearly entirely bulkheaded, and a rapid growth of private and commerc'ial Tsarinas. The major marinas in this basin include the South Beach Marina (402 wet slips) on Miami Beach and Marina Biscayne (182 wet slips) on Virginia Key. A number of smaller private marinas (existing, under construction or in permit processing) are located along the :Miami shoreline associated with high-rise condominiums on '3rickell Avenue. Additionally, large marinas have been proposed in association with the development of Fisher, Watson and Claughton Islands. The proposed South Beach Redevelopment Project also includes a proposed enlargement of the South Beach Marina and additional dockage in the proposed 2.6 miles of upland canals that would, if permitted, also be connected to this basin. Although the basin has undergone multiple impacts over the last 90 years, the biological value of the basin must still be considered high. While the seagrassos have changed in both abundance and composition because of those multiple impacts, much of the shallow bottom remains covered with initial and secondary seagrass growth. Within the "SUPPORTIVE DOCUMENTS FOLLOW" City of Miami Commission January 17, 1980 Page Four SO4 acre study area (D.R.I.), 165.7 acres (331) were vegetated with seagrasses. This seagrass coverage may be low as compared with the entire basin as it reflects a study area that includes Fishermen's Channel, Port of Miami South Channel and a portion of Dodge Channel and the Intracoastal Waterway. These areas are generally considered to be too deep to sustain seagrass growth even if other conditions are optimal. Since the D.R.I. provides the first comprehensive mapping of the vegetation in this area of the Bay, it is difficult to evaluate any changes in the existing seagrass beds over tho last 20 years since major new dredging operations have declined and sewage input has been abated. A comparison of the marine vegetation map (D.R.I.) with a vegetation map determined by benthic grabs in 1960 (McNulty, 1961) indicates: 1. Areas north of Lummus Island once dominated by Ilalonhila baillonis and red algal assemblages ire ire now"'dominato t iiy Halodule wrightii. 2. Areas adjacent to Sam's Island previously dominated by Halodule now have a large (3.4 acres) bed of Thalassia testudinuri. 3. Areas south of Channel marker,#13 that were dominated by Halodule and _Halophila are now dominated by Tharassia. It appears from these observations that this area may, over the last 20 years, have been undergoing succession towards the climax Thalassia community which prevailed before the area was SE5i1Trimpacted by major dredging/ filling operations, sewage wastes, etc. While the density of the grassbeds may be reduced as compared with pristine areas in South Biscayne Bay, these grasses appear to be healthy and productive. This basin, in addition to providing valuable marine habitat, is used for recreational boating (as evidenced by the large number of marinas) and commercial and sport fishing. The specific project site includes Dodge Island, submerged` lands south and east of Dodge Island, Lummus Island, Sam's Island and submerged lands adjacent and between those islands. t City of Miami Commission January 17, 1980 Paso 'five Dodge Island is the site of the existing 284 acre Port of Miami facility. The northwest portion of Dodge Island has been developed to service cruise passenger vessels while the eastern portion is used primarily for oceanborne general cargo commerce. The south and southwest portions of the island have been recently cleared and are presently used for the storage of containerized freight. The island is primarily bulkheaded with marginal wharfs. This application includes the construction of S,S3S linear ft. of marginal wharfs on the remaining undeveloped shoreline. The proposed development of these wharfs on Dodge Island accounts for 29% of the total marginal wharfs proposed in the expansion project. Lummus and Sam's Islands, constructed from spoil material in the 1920's, remain undeveloped. The dominant vegetation on both islands is Australian Pine with a variable margin of mangroves. The eastern side of Lummus Island has the largest tract of mangroves (5.2 acres) within the project limits. This mangrove forest is considered to be a productive and valuable habitat. Since manpower, time and resources were extremely limited for a comprehensive survey of the submerged lands by this Department, the major emphasis was placed on the evaluation of the data supplied by the applicajnt. The applicant's Sublittoral Marine Environmental Survey (S.M.E.S.) and portions of the DevoTopmont o'f-egiona Impact (D.R.I.) dealing with the natural resources (QuFi ion 18) were carefully reviewed and are discussed below. Marino Vegetation The marine vegetation was mapped by the applicant - (Appendix A) using twenty (20) underwater transacts, additional spot checks and aerial photography. The use of these techniques would be expected to provide a reasonably accurate map of the marine vegetation within the project limits. Therefore. no attempt was made by this staff to map the marine vegetation. The benthic vegetation within the project limits was found to be dominated by seagrasses. The dominant species included Nalodule wri htii and SyYringodium filiforme (52 acres; 63.81 offtotal), fialophila baillonis (24.1 acres; 29.6% of the total) and Thalassia testu nuci (5.4 acres; 6.6% of the total). The tots seagrass cover was 81.S acres. "SUPPORTIVE DOCUMENTS 9 City of Miami Commission January 17 1980 Page Six In terns of seagrass cover, tho most valuable areas appeared to be north of Lummus Island and around Sam's Island. This area contained all of the Thalassia (5.4 acres) and 53.8% of the Halodule and Syringodium (28 acres) within the project limits. Seagrass density (mean blade density) was also greatest in these areas. These seagrasses are generally considered to be more productive and provide more valuable habitat than Nalophila, also found within the project limits. Neither the D.R.I. nor the applicant's S.4.B.S. make any attempt to provide comparable quantitative leaf density data for other impacted areas of North Biscayne Bay or pristine areas in South Biscayne Bay. Qualitative comments are occasionally provided which indicate patches of sparse, moderate and dense seagrass cover. Without comparable quantitative data, it is difficult to draw any valid conclusions as to the relative health/density/value of these seagrasses as compared with other areas outside the project limits. The seagrasses observed in the field appeared to be of mixed density yet apparently quite healthy and productive. Uacroinvertebrate Community The macroinvertebrates surveyed by the applicant were collected by trawl and grab samples. The trawl samples, although not quantitative, were used to collect and compare the epifauna while grabs were used to compare the infauna. While this staff has some concerns about the use of the Shannon Index to evaluate taxa containing such few individuals, the total numbers of individuals and taxa collected can validly be used in comparisons of locations within the project limits. Those areas north of Lummus Island and around Sam's Island appeared to have the highest diversity and density compared to other areas within the Port survey. Station #13, located north of Lummus Island, had the greatest number of individuals collected by trawl samples and the highest community diversity of any station. The applicant's comparison included two stations outside of the project limits below Channel darker 13 which were vegetated by dense Thalassia (station 16) and mixed Thalassia/Halodule ff bifaL (station 17). The grab sarap es i idicatod chat station 12, located northwest of Lummus Island, and station 8, located northwest of Sam's Island, had the highest abundance of major taxa.. • City of Miami Commission January 17, 1980 Page Eight From this data it appears that the seagrass beds at those three locations within the Port expansion area are as diverse (11') as other areas in south Biscayne Bay and are slightly more diverse than areas in the more northern sections of the Bay. Species richness and density are generally lower than in those areas sampled in south Biscayne Bay. However, this may simply be an indication of differences in dominant seagrass species. Thalassia apparently supports a community of greater densfty and species richness than any of the mixed grass samples collected within the • Port expansion area. It is also apparent that the samples on the sandy channel edge have a community with lower diversity, species richness and density than do the samples collected within seagrass vegetated areas. This project is expected to have a significant long and short tern adverse impact on the water quality and biological resources of this section of North Biscayne Bay. The following is a list of the impacts which would be expected to occur: 1. The loss by dredging/filling 81.5 acres of productive seagrasses. This includes 5.4 acres of Thalassia; 52.0 acres of Halodulo and Syringodium; and 24.1 acres of Halop1ira7—The role of soagrasses in the marine system has been well 4ocurtontod in the scientific literature. i) Seagrasses serve as the base for an extensive detrital food chain. The macroinvortebrates collected in this study aro for the most part directly dependent on the decaying grass and • its microbes for food. b) Seagrasses serve as a refuge or sanctuary from predators and serve as a nursery ground for many marine invertebrates, and juvenile sport • and commercial fish species. nutrients from surrounding waters and reducing Seagrasses can improve water quality by removing turbidity. Turbidity decreases as the seagrass blades effectively reduce the current velocity which results in the settling of finer suspended • particles. A ' " • 2 • fart:LIVILlij LLOVV City of Miami Commission January 17, 1980 Page Seven While the macroinvertebrate data submitted by the applicant is useful for comparing sites within the limits of the project, little comparable data collected in an identical manner is available for sites outside the project limits. Therefore, it is difficult to compare the data generated by this study with other areas of Biscayne Bay and evaluate the relative value of the habitat. In an attempt to make such comparisons,, this staff collected benthic samples from five stations on 3 July 1979. It should be noted that this staff does not feel that five stations or fourteen (as in the D.R.I.) are sufficient to provide a statistically valid description of the animal community within the SO4 acre study site. However, the number of samples collected by this Department was strictly limited by available sampling and analysis time. The samples were collected by means of a petite ponar grab which quantitatively samples both the poifaunal and infaunal communities but will not provide an adequate sample of the larger more motile invertebrates or the fish. The samples were preserved, sorted and analyzed by standard methods. The samples were dominated by polychaotcs, molluscs and peracarideans (amphipods, isopods, tanaidacens and cumaceans). The stations sampled in thisustudy were compared with stations sampled by the Departient in other areas of Biscayne Bay. Comparisons are justified as all samples were collected with identical sampling gear and techniques from similar shallow seagrass areas and were analyzed by the same personnel using identical procedures and indices. Species diversity is an important parameter of community structure and is considered to be highly influenced by environmental stability, (Sanders, 1965). Two indices are used to indicate diversity in this study. The Shannon -Weaver diversity index ,(H') is a standard, accepted index used by the State of Florida and numerous private and academic studies for analysis of benthic ;am?les. It is sensitive to species richness and equitability yet is relatively sample size independent except for very small samples. Diversity (species richness) is also indicated simply by the number of species collected in identical sample sizes (grabs)) a. • `.. City of Miami Commission January 17, 1980 Page Nino Seagrasses stabilize benthic substrates and= serve as a natural inexpensive and effective means of erosion control. As the submerged area within the project limits would either be filled above the mean high water line or excavated to -36 ft. mean low water, seagrasses would not bo expected to come back in this area. The project will result in the loss of S.6 acres of productive mangroves, The value of mangroves in the detrital based food chain, as a nursery and habitat, as a stabilizer of natural shorelines and in improving water quality has also been well documented. The project would eliminate, by filling, 155= acres of submerged lands and adversely impact the resource value of an additional 264s acres of submerged land that would be excavated to -36 ft. mean low water. This depth would be limiting for the establishment of seagrasses and the establishment of the diverse seagrass animal community. The adverse impact on the ntacroinvertebrato community would be expected to be severe. The density of the macroinvertebrates collected in three benthic samples within the proposed expansion' area indicated a mean density of 5120 individuals/M2. While three samples can not be used to extrapolate densities over large areas with any confidenco, they can be used to give an indication of potential impact. An extrapolation of the macroinvertebrates within a single acre of seagrass yields: S129 ind/M2 x 4047 M3/acres • 20.8 million individuals/acre Further extrapolation seagrass destroyed by this project yields: 20.8 million/acre x 81.5 acres • 1.7 billion individuals. to cover the 81.5 acres o This figure only reflects`the potential impact ,on the macroinvertebrates in the 81.5 acres of seagrass and does not even consider the impact on the 337t acres of non -vegetation submerged bottom. ‘ gg� • n l5 l a V 1 /"\ City of Miami Commission January 17 • 1980 Page Ton The area north of Lunraus Island and around Sam's Island has the highest density and diversity of macroinvertebrates and the most valuable seagrasses within the Port expansion area. The Sublittoral Marine Environmental Survey, prepared for the applicant, recommended that portions of this area be preserved. As this application proposes the dredging/filling of this entire area, the adverse impact in this area would be expected to bo more severe than other areas within the Port expansion site. • Fisheries resources were not adequately assessed in the D.R.I. as all data was generated from benthic trawls which have an extremely poor sampling efficiency. The value of seagrasses as habitat for juvenile commercial and sport fishes is well known. The loss of this habitat and the associated macroinvertebrates (which in part serve as fish food) is expected to result in a significant adverse impact on the fisheries resources. • Water quality degradation would be expected to occur as a result of the construction and operation of the expanded Port facility. Water quality criteria of concern include Turbidity, J.O., Greases 4 Oils, Heavy metals, PCBs, DOD's, and conform. Additionally, increased activity in this basin would increase the potential for spillage of oil, toxic substances or other wastes that could further impact on the remaining resources. ▪ Numerical model depicting the existing circulation pattern of Biscayne Bay along with various alternatives reveal flushing in the vicinity of the Port and this portion of Biscayne Bay is likely to increase due to a greater potential for increased tidal flows. Filling of the channel between Dodge and Lummus Island will divert the flow but will not be a significant impact. All the runoff will be retained in the uplands. Hence, while destruction of certain acreage of the submerged bottom is involved the hydraulics -of the Bay area near the Port is likely to improve. Pursuant to the requirements of Subsection 253.124(3), Florida Statutes, the preceding comments should be duly considered and read into the minutes of tho meeting at which time a determination of local approval is made. To assist in evaluating the project a copy of the application and a set of project drawings aro enclosed (Attachment I, II). • City of Miami Commission January 17, 1980 Page Eleven A sample resolution (Attachment III) prepared by the Department's legal staff is also enclosed. This document is provided to assist the Board of Commissioners in preparing a resolution that will meet the requirements of Subsection 253.124(3), Florida Statutes. The Board of Commissioners is not obligated to use this format so long as the Department is made aware that the requirements of the statute have been fulfilled. SDH/hh Attachru nts cc: Luis Ajamil Warren Strahri' Sincerely, Stephen D. Hart Environmental Specialist Standard Permitting Section