Florida Administrative Code
62 - DEPARTMENT OF ENVIRONMENTAL PROTECTION
62B - Beaches and Coastal Systems
Chapter 62B-33 - RULES AND PROCEDURES FOR COASTAL CONSTRUCTION AND EXCAVATION (PERMITS FOR CONSTRUCTION SEAWARD OF THE COASTAL CONSTRUCTION CONTROL LINE AND FIFTY-FOOT SETBACK)
Section 62B-33.024 - Thirty-Year Erosion Projection Procedures
Universal Citation: FL Admin Code R 62B-33.024
Current through Reg. 50, No. 187; September 24, 2024
(1) A 30-year erosion projection (30-YEP) is the projection of long-term shoreline recession occurring over a period of 30 years based on shoreline change information obtained from historical measurements. A 30-YEP of the location of the seasonal high water line (SHWL) shall be made by the Department on a site specific basis upon receipt of an application with the required topographic survey, pursuant to rules 62B-33.008 and 62B-33.0081, F.A.C., for any activity affected by the requirements of section 161.053(5), F.S., except applications for those structures located landward of a General Permit Line established under chapter 62B-34, F.A.C. An applicant may submit a proposed 30-YEP for a property, certified by a professional engineer licensed in the state of Florida, to the Department for consideration.
(2) A 30-YEP shall be determined using one or more of the following procedures:
(a) The
Department shall determine the 30-YEP for beaches where there is no beach
nourishment or restoration project, and no coastal armoring, and the beaches
that are not adjacent to an inlet, as follows: An average annual shoreline
change rate (SCR) in the location of the MHWL at a Department reference survey
monument shall be determined as set forth in subparagraphs
62B-33.024(2)(a)
1. through 3., F.A.C., and multiplied by 30 years (Calculated Erosion
Distance). The location of the 30-YEP is determined by projecting the location
of the existing SHWL, as depicted on the application survey, landward by the
Calculated Erosion Distance (SCR x 30 years). (see Figures 1 and 3):
1. The SCR shall be derived from historical
shoreline data obtained from coastal topographic surveys and maps, controlled
aerial photography, and similar sources approved by the Department. Data from
periods of time that clearly do not represent current prevailing coastal
processes acting on or likely to act on the site shall not be used.
2. The SCR shall include the zone spanned by
three adjacent Department reference monuments on each side of the site. A
lesser or greater number of reference monuments can be used as necessary to
obtain a rate representative of the site, and a rationale for such use shall be
provided.
3. In areas that the
Department determines to be either stable or accreting, a minus one-foot per
year SCR shall be applied as a conservative estimate.
(b) If coastal armoring is present at the
site, the Department shall determine whether or not the 30-YEP shall stop at
the armoring. The applicant shall provide scientific and engineering evidence,
including a report with data and supporting analysis certified by a
professional engineer licensed in the state of Florida, which verifies that the
armoring has been designed, constructed, and maintained to survive the effects
of a 30-year storm and has the ability to stop erosion of the MHWL for 30
years. The Department shall waive the requirement for the applicant to provide
scientific and engineering evidence if the Department determines the
information is not necessary in order to make the erosion projection
determination.
(c) Some shoreline
areas, such as those adjacent to or in the vicinity of inlets without jetty
structures, can experience large-scale beach-width fluctuations with or without
net erosional losses. Other beach areas can fluctuate greatly due to the
observed longshore movement of large masses of sand, sometimes referred to as
sand waves. In these areas, a 30-YEP shall be estimated from the available data
at the SHWL landward limit of the large beach-width fluctuations within the
last 100 years.
(d) Beach
nourishment or restoration projects shall be considered as follows:
1. Future beach nourishment or restoration
projects shall be considered as existing if all funding arrangements have been
made and all permits have been issued at the time the application is
submitted.
2. Existing beach
nourishment or restoration projects shall be considered to be either a one-time
beach construction event or a long-term series of related sand placement events
along a given length of shoreline provided such projects have resulted in and
will continue to result in the presence of sand seaward of the ECL. The
Department shall make a determination of remaining project life for such
existing beach nourishment or restoration projects based on the project
performance, the likelihood of continuing nourishments, the funding
arrangements, and consistency with the Strategic Beach Management Plan adopted
by the Department for managing the state's critically eroded shoreline and the
related coastal system.
3. The
pre-project SCR shall be calculated as set forth in subparagraphs
62B-33.024(2)(a)
1. through 3., F.A.C., derived from historical shoreline data for the time
period before the first restoration occured. The Department will use the
following stepwise procedure to determine the 30-YEP on a beach with a beach
restoration or nourishment project. (see Figures 2 and 3):
a. The Department shall determine the
distance between the MHWL and the SHWL, using either a pre-project survey or
current locations of these lines, as appropriate. That distance will be added
landward to the location of either an established ECL or pre-project surveyed
MHWL, as appropriate, to establish the pre-project SHWL (PSHWL).
b. The difference between 30 years and the
expected remaining life (in years) of the existing beach nourishment project
will be multiplied by the pre-project SCR to determine the projected distance
of erosion. The projected distance of erosion will be added landward to the
location of the PSHWL calculated under subparagraphs
62B-33.024(2)(a)
1. through 3., F.A.C., and will represent the 30-YEP.
4. If the Department is unable to
scientifically determine a pre-project erosion rate due to a lack of
pre-project data, the Department shall set the 30-YEP along an existing,
reasonably continuous, and uniform line of construction that has been shown to
be not unduly affected by erosion.
FIGURE 1: 30-YEP Calculation for a Non-restored Beach
30-YEP = (Historical Erosion Rate feet/year) X (30 years) landward of the existing SHWL
FIGURE 2: 30-YEP for a Restored/Nourished Beach
30-YEP = (30 Project Credit years) X (Historical Erosion Rate feet/year) landward of the Pre-Project SHWL
FIGURE 3: Cross-Section of Figures 1 and 2.
(e) The 30-YEP shall extend no farther
landward than the CCCL. In the event that the plane of the seasonal high water
elevation does not intercept the upland terrain on the site, the 30-YEP shall
stop at the CCCL, unless it is determined to be stopped by armoring as
described in paragraph
62B-33.024(2)(b),
F.A.C.
(f) When the Department
approves a permit for new, repaired, or significantly modified coastal
structures or activities that affect the lateral movement of sand along the
shore, the change in site conditions can significantly affect the future
shoreline location. In these areas, if the Department is unable to use historic
data to determine a 30-YEP, the Department shall make a 30-YEP assessment based
on the best available information and shall provide the rationale to all
interested parties.
(g) If a
specific SRC for a 30-YEP has not yet been determined for a given area, but the
Department can determine that a proposed structure is sufficiently landward
such that it will not likely be affected by a worst case erosion projection
estimate, then the proposed structure shall be considered as being landward of
the 30-YEP. Such an estimate shall be based on the topography, geomorphology,
the erosion experienced at the site thus far, the sand supply situation,
ongoing coastal processes and coastal management, and any other applicable
coastal engineering factors.
(h) In
the event the Department is unable to make a site specific 30-YEP following the
procedures in this rule section, the Department shall make an assessment based
on the best available information and shall provide the rationale to all
interested parties.
(3) The Department shall continue to develop, maintain, and update a database of shoreline data for assistance in making 30-YEPs.
Rulemaking Authority 161.053(20) FS. Law Implemented 161.053(5) FS.
New 11-10-85, Formerly 16B-33.24, 16B-33.024, Amended 1-26-98, 6-13-04, 5-31-07, 10-4-18.
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