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Resolution 001-1980 RESOLTUION i~ 1-1980 WHEREAS, the BOARD OF COUNTY COMMISSIONERS of MONROE County, Florida, has received an application from Irene Miska, to: Place 200 1in. feet of riprap of MHW for shoreline protection, fill approximately 1500 sq. ft. of a dead-end basin with approximately 200 cubic yards of fill, dredge approximately 2700 sq. ft. of baybottom to _3' MLW and construct 115 1. f. of 4' wide boardwalk over a section of riprap. A drag line would be used for the excavation and to place fill and riprap. An auger truck would be used for placing piles. All materials and equipment have access to the sites over existing uplands. The construction area will be isolated from open waters by turbidity screens until after completion of the work. The project site is on the bayside of Marathon in an area of intense commercial and residential development adjacent to U.S. 1. To the west are a vanety of commercial and residential shoreline developments including motels, seafood houses, marinas, etc. Shoreline alterations include seawalls, boat basins, jetties, etc. To the east are additional residential areas with riprap and seawall shorelines. Numerous shoreline discontinuities are found nearby. Development locally is near 100% of available property. The project site is in and around a dead-end basin that measures about 50' wide x 100' long. Its orientation is to the north. The west side of the basin is a rock and concrete spit that separates this basin from an adjacent one. This shoreline is riprap and poured concrete. The head of the basin has been filled with rock rubble and the east side is an eroding, natural 1imerock escarpment that continues around the adjacent point to the east. Depths at the head of the basin are from -1 to -2' MLW and bottoms consist of silt and organic debris over rock and rock rubble. This bottom condition is due to the accumulation of wind blown floating debris during periods of northwinds and the lack of circulation in this dead-end. This condition exists for about the southernmost 40' of the basin. The remainder of the basin is vegetated with a variety of benthic algae (Udotea, Halimeda, Gau1erpa, Laurencia, Dictyota, etc.) attached to rock rubble and rooted in the several inches of sediment overlying the rock and rubble substrate. This northerly half of the basin is about -2.5' MLW in depth throughout most of the interior and slopes up on both sides to the rock shore- lines. Found here also are numerous ups ide down jellyfish, Ge.ssiopeia. As one proceeds north from the interior of the basin bottom conditions and overlying water quality improves. Offshore depths gradually deepen to -3 and _4' MLW, the bottom remains rocky with this overlying sediment and vegetation consists of various attached algae and turtle grass (Thalassiatestudinum) where adequate sediments exist. The subtidal rocky shorelines around the basin are vegetated by algae and there is a small stand of red mangroves remaining in the S.E. corner of the basin. The natural escarpment around the basin to the east is eroded and has been undercut by-wave action in many places. Vegetation along the base of this escarpment consists of various algae and some turtle grass. The algae communities alluded to serve a similar function as to the seagrasses in stabilizing sediments, providing food and shelter for small crustaceans, po1ychaetes, molluscs and juvenile fishes and in BOOK \j , - 3:~O PAGE ooi APPROVED ON 2-L"f -2- filtering the overlying water column of suspended particles. Fishes observed and those expected to commonly occur in the project site include: snappers (Lutjanidae), grunts (Pomadasyidae), pinfish (La~odon rhomboides), needlefish (Belonidae), silversides (At erinidae), barracuda (Sphyraenidae) and mojarras (Gerreidae). No significant shoreline or upland vegetation exists on the site. The area proposed to be filled is presently a debris trap (especially in the winter) with no significant benthic communities due to the poor condition of the bottom sediments. Filling here will only be moving the trap further out but here it will be more subject to physical forces of the open-water bay system which may reduce the negative effects of the dead-end arrangement. Dredging in the proposed area will remove existing bottom communities and sediments while scraping into hard rock to obtain the desired depth. Bottom discontinuities would be created with adjacent near- shore shallow waters and the sediments that will eventually fill into the dredged area will be unsuitable for the re-establishment of vegetation and accompanying organisms, due to the restricted nature of the basin. As existin? depths throughout much of the basin interior are currently -2.5 to -3 MLW, the need for -3' MLW throughout is not clearly understood. The placement of riprap along the east shoreline will eliminate erosion to the applicant's uplands and provide valuable habitat in the subtidal areas. The construction of a shoreline dock will have no adverse environmental impact on the local area. BE IT FURTHER RESOLVED, by the BOAP~ of COUNTY C01~1ISSIONERS of MONROE County, Florida, that said BOARD hereby given its approval for the construction of the above mentioned project. RESOLVED this ~day of January, 1980, at a Regularly scheduled Meeting. BOARD OF COUNTY COMMISSIONERS MONROE COUNT , FLORIDA ,If ' BY ATTEST: . ~ gz- t.~/d~~- . - -/ <:. Cl ' 2- 2.5