Item L6 Tech Replacement PagesMonroe County Comprehensive Plan Update
Conservation and Coastal Management 93 Technical Document: Sept. 2011
"Disturbed wetlands" occur throughout the Keys. In the Keys, disturbed wetlands are
generally wetlands which were originally characterized as one of the other five wetland
categories.
The methods used to inventory wetland habitats are described in Section 3.8 (Living
Marine Resources). Map Series 3.3 depicts the wetlands within the Upper, Middle, and
Lower Keys and selected offshore islands, which are characterized by mangrove forests,
salt marsh, buttonwood wetlands, salt ponds, and freshwater wetlands (disturbed
wetlands are not mapped).
3.9.1 Wetlands Permitting and Wetlands Protection Planning in Monroe County
Wetlands in the Florida Keys are regulated by federal and State agencies, and by the County
Comprehensive Plan and the LDRs. A permit is required for certain activities within
wetlands, as defined by these agencies. The primary federal jurisdiction for the USACE
over wetlands is derived from Section 404 of the Clean Water Act, 33 U.S.C. 1344, 1972, as
amended in 1977, 1981, and 1987, with the Water Quality Act. Other programs are Section
10 the Rivers and Harbors Acts of 1899, which regulates construction, excavation, or fill in
navigable waters; the National Environmental Policy Act of 1969; and the Endangered
Species Act (ESA) of 1973. The federal regulations are contained in 33 CFR 320‐330 and
have evolved over time to reflect added authorities and developing case law. The Clean
Water Act Section 404(b)(1) Guidelines (40 CFR, Part 230), USACE Regulations (33 CFR
Part 332), and associated guidance require that project effects to waters of the United
States, including wetlands, be addressed through a sequence of avoidance, minimization
and then compensation for unavoidable impacts. In 2008, the USACE Rules 33 CFR Parts
325 and 332 and USEPA Rules 40 CFR Part 230 were finalized accounting for
“Compensatory Mitigation for Losses of Aquatic Resources.” This sequence is also followed
by State agencies prior to permit issuance [Rule 40E‐4.091 (1)(a) F.A.C. (Basis of Review)].
Under the Marine Protection, Research, and Sanctuaries Act, a permit is required for the
transportation of dredged material that is to be deposited in the ocean. Disposal sites are
selected with criteria developed by USEPA and the USACE.
Both FDEP and SFWMD have permitting authority over impacts to wetlands under State
law. A memorandum of agreement between the two agencies divides the types of projects
applying for permits between the two agencies. Most relevant to private‐sector
development, all residential projects in excess of four units and all commercial projects
receive permits from the SFWMD, and smaller residential projects receive permits from
FDEP. Transportation projects (road and air) also fall under SFWMD permitting authority,
whereas FDEP permits projects limited to beach and shoreline impacts with no associated
upland residential or commercial development.
SFWMD also regulates the management and storage of surface waters, including dredging
or filling in wetlands, by requiring Environmental Resource Permits (ERP). Any proposed
surface water management system involving a project site 100 acres or more in size or
with more than 1 acre of wetland impacts would require an Individual Permit. In most
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cases, project sites less than 100 acres in size with less than 1 acre of wetland impacts
qualify for a Standard General, Noticed General, or No Notice General Permit.
FDEP also oversees activities in wetlands that are:
• located on Florida’s natural sandy beaches facing the Atlantic Ocean, the Gulf of Mexico,
the Straits of Florida or associated inlets;
• activities that extend seaward of the mean high water (MHW) line (the SFWMD
oversees activities landward of the MHW);
• activities that extend into sovereign submerged lands; and
• activities that are likely to affect the distribution of sand along a beach.
FDEP also regulates activities including beach restoration or nourishment; construction of
erosion control structures such as groins and breakwaters; public fishing piers;
maintenance of inlets and inlet‐related structures; and dredging of navigation channels that
include disposal of dredged material onto the beach or in the nearshore area.
Prior to the permitting process, a wetland Jurisdictional Determination (JD) is required.
Wetland boundaries are determined by:
• The USACE Interim Regional Supplement to the 1987 Wetland Delineation Manual:
Atlantic and Coastal Plain Region (Federal Manual); and
• Chapter 62‐340 F.A.C., “Delineation of the Landward Extent of Wetlands and Surface
Waters”.
The Federal Manual is the current accepted methodology developed jointly by the USACE,
the USEPA, USFWS, and the USDA NRCS. Wetland boundaries are verified by the regulatory
agencies and then the boundaries are usually instrument surveyed. The permit application
is a joint application to the State agencies (SFWMD and FDEP) and the USACE. The State
ERP authorizes all activities permitted by SFWMD and FDEP; the USACE would issue its
own permit.
In general, wetlands in the County are protected by the LDRs and by the Comprehensive
Plan policies as “environmentally sensitive lands.” However, this term is not defined in the
LDRs or in the Comprehensive Plan. For example, Section 114‐3 (Surface Water
Management Criteria) of the LDRs establishes procedures to assist in the protection of the
water resources, including the reservoir of freshwater on Big Pine Key and the nearshore
waters. These include existing and proposed water management systems. Stormwater
management systems are coordinated with SFWMD and FDEP. Another example is
contained in Section 118‐4 (Wetland Open Space Requirements) which states that no
development activities, with some exceptions, are permitted in mangroves, freshwater
wetlands and in undisturbed saltmarsh and buttonwood wetlands. The open space
requirement in these habitats is 100 percent (no clearing is allowed). Undisturbed
freshwater wetlands, salt marsh and/or buttonwood association wetlands are considered
to be habitats with the highest sensitivity and development under the LDRs requires
clustering in areas with lowest sensitivity [Section 118‐7 (General Environmental Design
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Criteria)]. Sec. 118‐10 (Environmental Design for Specific Habitat Types) specifies design
criteria for mangroves, wetlands, and submerged lands.
In practice, all proposed developments are required to obtain State and federal permits for
activities that would alter jurisdictional wetlands. The State of Florida mandates that all
State agencies and local governments use the Uniform Mitigation and Assessment Method
(UMAM) for evaluation of all wetland impacts and mitigation measures (Section
373.414(18), F.S. and Chapter 62‐345, F.A.C). Wetlands are evaluated for existing
conditions and mitigation requirements are determined for the proposed impacts by using
UMAM. In the Florida Keys, a specific wetlands evaluation procedure was developed called
the Keys Wetland Evaluation Procedure (KEYWEP). It was developed as part of the
Advanced Identification of Wetlands [see Section 3.9.2 (Monroe County Advance
Identification of Wetlands (ADID) Program)]. The LDRs mandate the use of KEYWEP only
for lands classified as disturbed with salt marsh and buttonwood association [Section 118‐
10 (Environmental Design For Specific Habitat Types)]. Because disturbed salt marsh and
buttonwood wetlands are the only land use that is developable under current LDRs, this is
the only situation where KEYWEP is mandated for use in the Florida Keys. However,
certain salt marsh and buttonwood wetlands that are determined by KEYWEP to have
moderate or low functional capacity (KEYWEP index of 7.0 or less) are “suitable for filling
with appropriate mitigation,” if also authorized by FDEP and USACE permits. KEYWEP
should continue to be used to determine if a proposed wetland impact is permittable. If a
proposed impact is permittable, mitigation would be determined in accordance with
UMAM. Prior to the mandated use of UMAM in Florida, KEYWEP (under the federal ADID
program) was used by the USACE but only for those projects that proposed to use the Keys
Environmental Restoration Fund (KERF) as mitigation for mangrove, saltmarsh, and
buttonwood wetland impacts and for seagrass impacts. Currently, KERF is a USACE “in‐lieu
fee” program within the County and all functional losses and mitigation requirements will
be determined by using UMAM; KEYWEP will no longer be used to determine mitigation
requirements.
KERF is a program of National Audubon Society, Inc. of Florida. The primary activity of
KERF is restoring and enhancing wetland and upland habitats on public lands throughout
the Florida Keys. It also conducts management activities that are aimed toward producing
and enabling direct habitat restoration and enhancement results. Presently, the USACE and
FDEP allow payment into the fund in lieu of creating and implementing an individual
mitigation plan. Currently, the SFWMD is reviewing the KERF program and how it will be
incorporated into its ERP program.
Wetlands are also protected under the Comprehensive Plan and the LDRs by setbacks and
buffers adjacent to existing or proposed development. In general, setbacks are determined
by State and federal permits. Under the LDRs, the buffer between a wetland and the
proposed development is generally 50 feet with some exceptions that allow a buffer of 25
feet [(Section 118‐10(4)(g)]. The point from which the setback is applied is not specified in
the LDRs.
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The Comprehensive Plan and the LDRs should be revised to:
• Provide a definition of wetlands that is consistent with the State definition and/or
federal definition and provide a definition of wetland boundaries to be the same as
those established through wetland jurisdictional determinations;
• Specify setbacks from the jurisdictional wetland boundary line established during the
wetland delineation process; and
• Reflect a review and evaluation of the Keys Wetland Evaluation Procedure (KEYWEP),
which is used to determine mitigation requirements. The KEYWEP evaluation method,
while highly useful to evaluate wetlands in the Keys, is not used elsewhere in Florida.
The County should determine when and how KERF should be used for wetland mitigation.
The Comprehensive Plan and the LDRs should be revised to reflect this policy. The County
should provide a definition of “environmentally sensitive land” so that wetlands can be
adequately included in the ROGO/NROGO and Tier Overlay Ordinance.
3.9.2 Monroe County Advance Identification of Wetlands (ADID) Program
The Florida Keys Advance Identification of Wetlands (ADID) Program was a joint effort of
the USEPA, USACE, and the County. The ADID program was designed to facilitate the
permitting process under Section 404 of the Clean Water Act of 1973 by providing
comprehensive wetlands mapping and assessment information. The scope of the ADID
Program included the entire Florida Keys, prioritized as follows:
• Privately‐owned lands with development potential on the islands connected by U.S. 1;
• Publicly‐owned lands on the islands connected by U.S. 1; and
• Offshore islands.
The Florida Keys ADID project included mapping of marine and freshwater wetlands
throughout the Keys. Wetlands were mapped at the seasonal high water line, although this
boundary was based on the interpretation of aerial photographs. A field‐based wetland
functional assessment methodology specific to the Florida Keys was developed (KEYWEP).
The KEYWEP methodology is presented in “Technical Summary Document for the Advance
Identification of Wetlands of the Florida Keys” (Kalla, 2000). The ADID project mapped
marine and freshwater wetlands throughout the Keys (within approximately 65,000 acres
of highway‐connected islands) and conducted functional evaluation of these wetlands. The
evaluation separated those wetlands that were “generally unsuitable” for the placement of
fill and those wetlands that were “generally suitable with appropriate mitigation” for the
placement of fill (Kalla, 2000). The ADID maps produced are available in the County Office
of Planning and Environmental Resources.
As described in Section 3.8 (Living Marine Resources), the map series produced for the
ADID program were produced on hand‐drawn maps that were then digitized. The analysis
of the data for the inventory of natural habitats for this Technical Document revealed that
the ADID data did not correspond to the other databases (i.e., the maps did not line up
exactly). The ADID data can be useful for an individual parcel to determine if it contains a
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Conservation and Coastal Management 97 Technical Document: Sept. 2011
wetland with a KEYWEP score but, because of the mapping limitations, the ADID data could
not be used on a County‐wide basis. The County should reconcile the ADID mapping with
parcel‐based mapping so that this information can be captured for land use analyses.
3.9.3 Mangrove Communities
Mangrove wetland communities are addressed above in Section 3.8.1 (Mangroves).
Included are discussions of the following:
• Flora of mangrove communities;
• Existing commercial, recreational and conservation uses of mangrove communities;
• Known pollution problems and/or issues related to mangrove communities; and
• Potential for conservation, use, or protection of mangrove communities.
3.9.4 Salt Marsh and Buttonwood Wetlands
Saltmarsh and buttonwood wetlands are tidally influenced transitional wetlands which lie
landward of the mangrove fringe and seaward of the upland community. Two basic
wetland communities occur in the transition zone in the Florida Keys. Salt marshes are the
lower transitional wetlands. They exist at the interface of land and marine waters,
wherever wave energy is sufficiently low to allow their development and where mangrove
trees are not dense enough to shade out the characteristic vegetation (Montague and
Wiegert, 2001). Buttonwood (Conocarpus erectus) associations are generally higher
transitional wetlands, occurring between the salt marshes and the high upland habitats.
The type of transitional association that develops in the Keys is a function of tide and
topography. In the Lower Keys, where the slope of the intertidal zone is very slight, the
broadest expanse of transitional zones occurs. On Sugarloaf, Cudjoe, Big Torch, Little
Torch, and on a number of other keys, transitional zones occupy areas hundreds of feet in
width. On these keys, much of the eroded oolitic caprock is exposed, creating a karst‐like
substrate with disjunct, shallow depressions containing marl soils. Most of these areas are
wetted only by the highest normal tides and by storm tides. By comparison, in the Middle
and Upper Keys, there is a relatively steep slope to the high ground. In these areas the
transitional zone is quite narrow, with hammock often found within a short horizontal
distance from the high water mark.
Table 3.7 shows the inventory of salt marsh wetlands within the County with a total of
2,552.7 acres. Most are located in the Lower Keys (94 percent) and 18 percent are
privately owned. Table 3.8 shows the inventory of buttonwood wetlands with at total of
3,323.1 acres within the County and like salt marshes, most (72.5 percent) are located in
the Lower Keys. Of that total, 21.7 percent are privately owned.
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3.9.4.1 Flora of Salt Marsh and Buttonwood Wetlands
3.9.4.1.1 Flora of Undisturbed Salt Marsh and Buttonwood Wetlands
Several environmental factors control species distribution in transitional wetlands. These
are functions of elevation and tidal influence and are linearly related to distance from mean
high water. They include duration of tidal submergence; duration of exposure; and
frequency of submergence. Because of the low tidal amplitude (3 feet) in the Keys, the
inundation of the transition zone may be affected by several other factors, including wind
direction and velocity, shoreline exposure, slope, elevation and microrelief. As a result, the
position of an individual plant population within the transitional zone reflects an adaptive
response to a complex set of environmental gradients.
The transitional habitats of the Keys contain species representative of both the adjacent
mangrove and upland communities. In the most seaward subzone of transitional areas
scrub mangrove communities typically occur. These are dominated by small red and black
mangroves with an understory of Glasswort (Salicornia bigelovii), salt grass (Distichilis
spicata), and key grass (Monanthochloe littoralis). Moving upland, there is a change to a
more diverse plant community with fewer mangroves. Depending on drainage and soil
conditions, this association can be either buttonwood or salt marsh.
Salt marshes are dominated by salt‐tolerant herbs, shrubs, and grasses. Some salt marshes
are mixtures of fleshy halophytes, including glasswort (Salicornia bigelovii), purslane
(Sesuvium portulacastrum), and saltwort (Batis maritima). Other marshes are dominated
by grasses, including salt grass, key grass, and dropseed, and occasional marsh fimbry
(Fimbristylis spadicea), sea daisy, saltwort, buttonwood and small mangroves. These
grasses and herbs occur as small, disjunct populations forming a mosaic. In some cases, a
single population will occupy an area of about a half acre, whereas in others, the same
species might be represented by only a few individuals. This distributional variability
probably reflects the area's microrelief, which determines drainage and soil salinity.
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