HomeMy Public PortalAbout1998-55 Beach Management Plan (Nourishment Plan); Addendum #1RESOLUTION NO. 98-55
A RESOLUTION OF THE VILLAGE OF KEY BISCAYNE,
FLORIDA; ADOPTING ADDENDUM #1 TO THE LONG
RANGE BEACH NOURISHMENT PLAN, VILLAGE OF KEY
BISCAYNE, DADE COUNTY, FLORIDA; PROVIDING FOR
AN EFFECTIVE DATE.
WHEREAS, the Village Council has historically supported beach preservation through
dedicated funding, resolutions, and preparation for the pending beach nourishment; and
WHEREAS, the Village Council adopted Resolution 97-55, dated October 28, 1997,
adopting the Long Range Beach Nourishment Plan for the Village of Key Biscayne; and
WHEREAS, the Long Range Beach Nourishment Plan does not specifically identify the type
and grain size of beach nourishment sand appropriate for Key Biscayne; and
WHEREAS, the Village Master Plan directly supports proper beach nourishment sand
selection through environmental policies 1.7.1 which calls for "minimizing damage to offshore grass
flats" through proper project design, and 1.7.6 which "limits activities that adversely affect habitat
that may be critical to endangered, threatened or rare species or species of special concern",
displayed in Master Plan Appendices A, B, and C; and
WHEREAS, the present and future selection of beach nourishment sand that is most naturally
compatible with the existing and historic surrounding environment will promote longevity of both
the beach nourishment project and the entire Key Biscayne ecosystem;
NOW, THEREFORE, BE IT RESOLVED BY THE VILLAGE COUNCIL OF KEY
BISCAYNE AS FOLLOWS:
Section 1. The Village Council hereby adopts Addendum #1 to the Long Range Beach
Nourishment Plan for the Village of Key Biscayne, Dade County, Florida, to be used as a guide to
sand source selection for beach nourishment projects.
Section 2. Addendum #1 shall be used as a strong guideline within all realistic
practicality, however, it will not supersede other factors or obligate the Village Council to expend
more than what they deem reasonable on a nourishment project.
Section 3. The Village Manager is authorized to request estimates for appropriate
quantities of beach sand for the Proposed Village Beach Nourishment, based on Addendum #1.
Section 4. This resolution shall take effect immediately upon adoption.
PASSED AND ADOPTED this 27th day of October , 1998
&/ .er-('C
OR JOHN F. FESTA
CONCHITA H. ALVAREZ, VILLAGE CLE
APPROVED AS TO FORM LEGAL SUFFICIENC
RICHAi D J. WEISS, VILLAGE ATTORNEY
SANDRA GOLDSTEIN
&ASSOCIATES, INC.
October 20, 1998
The Honorable Mayor and Members of Village Council
Village of Key Biscayne
Dear Mayor and Council Members:
The ocean beach of the Village of Key Biscayne is a centerpiece and valuable natural resource of the
community. This beach is dynamic and subjected to erosive stresses from natural and human
influences. As a result, the beach will need periodic placement of new sand to restore what has been
lost through erosion. It is critical that the quality of new sand placed on the beach maintain the
quality of the beach system with respect to: optimizing the stability in the beach -dune zone,
minimizing release of muddy suspensions into the offshore waters, maintaining comfort for beach
walkers, providing viability for nesting turtles and beach vegetation, and maintaining the aesthetics
of the historic beach.
The following document defines and explains these criteria for quality of new beach sand to be
placed on the ocean beach of Key Biscayne. Defined is both the quality of the sand and the methods
to be used in assessing the quality. The character of the natural historical beach -dune sand of central
Key Biscayne, together with fundamental principles of particle transport, were used to define
specifications for future nourishment sands. A graph of the optimal and minimally -permitted sand
size distribution was adapted from that used by Miami -Dade County for the beaches to the north.
The slightly finer mean particle size and a smaller maximum particle size for the permitted sands for
the ocean beach of Key Biscayne reflects the nature of the historical sands and the more protected
setting than found to the north.
The natural sands of the ocean beach of Key Biscayne are a mixture of quartz sand and skeletal
calcium carbonate fragments. The permitted future sands are also to be a mixture of quartz and
skeletal calcium carbonate grains. The type of grains affect both the temperature of the dry beach -
dune (important to turtle nesting) and the pore -water chemistry of the upland beach -dune (important
to vegetation). Specifically prohibited are calcium carbonate particles derived from disaggregation
(breaking apart) of fossil limestone. Such particles are commonly prone to releasing significant
Specializing in Commercial Real Estate, Buyer and Tenant Representation, Consulting Services
240 CRANDON BLVD., #211, KEY BISCAYNE, FLORIDA 33149, TELEPHONE 305 365 2885, FAX 305 365 0894, PAGER 305 366 431 I
E-MAIL: gosandra@icanect.net
volumes of silt when subjected to abrasion in the beach zone and prone to cementing together under
the influence of rainwater in the back -beach zone.
Included also are the required methods for analysis of sand proposed for placement on the ocean
beach of the Village of Key Biscayne. This was prompted by pre-tests for a nourishment in 1998
that did not recognize the nature of the particles as they would occur when placed on the beach.
Analyses include dry sieving, wet sieving and settling together with microscopic analysis by one
trained in particle analysis. These analyses are designed to prevent placement of sand particles on
the beach that will disaggregate into much smaller particles when wet, particles that are lightweight
(common in some largely hollow skeletal calcium carbonate particles), and particles that are not
durable in the beach zone, resulting in both loss of the particles and creation of large volumes of silt.
Sincerely,
Sandra Goldstein
Village Beach Resources and
Management (BRM) Task Force
Chair and Village Resources Volunteer
2
„ft,
Dr. Hal Wanless
BRM Beach Nourishment Sand Quality
Subcommittee Chair and University of
Miami Geologist
LONG RANGE BEACH NOURISI NT PLAN
VILLAGE OF KEY BISCAYNE
DADE COUNTY, FLORIDA
ADDENDUM 1
SAND QUALITY TO BE USED IN MAINTAINING
THE OCEAN BEACH OF KEY BISCAYNE, FLORIDA
APPROVED BY THE VILLAGE
BEACH RESOURCES AND MANAGEMENT (BRM) TASK FORCE
VILLAGE OF KEY BISCAYNE, FLORIDA
JUNE 17, 1998
ADDENDUM: Future sand nourishment of the ocean beach of the Village of Key Biscayne
shall use only high quality sand that meets the requirements set forth below, so as to
guarantee a beach system that will remain a top quality recreational and protective beach and
have a positive environmental influence. Two types of sand specifications are provided
within: Ideal and Minimum Quality Sand. Ideal is the desired beach fill material and should
be used if it is available and economically feasible.
The ideal sand to be used for future nourishment of the Village of Key Biscayne beach (Figure
1) would be well mixed and have no material finer than 200 microns (0.2 mm), less than 50%
material coarser than 500 microns (0.5 mm), and no material coarser than 1,000 microns
(1 mm). In addition, appropriate sand would contain 25-60% durable natural (not
manufactured/crushed rock) carbonate grains, verified by settling analyses, with the remainder
consisting of natural quartz sand particles (Figure 2).
Minimum quality sand allowed for placement on the Village of Key Biscayne beach (Figure
1) should be well mixed and consist of less than 5% material finer than 80 microns (0.08 mm),
less than 25% finer than 200 microns (0.2 mm), less than 10% coarser than 1,000 microns
(1 mm), and no cohesive sediments and/or rock aggregate particles (including coral
fragments) coarser than 5,000 microns (5 min). Shell material should be no coarser than 3
cm. In addition, minimum quality sand would contain 20-70% durable natural (not
manufactured/crushed rock) carbonate grains, verified by settling analyses, with the remainder
consisting of quartz particles (Figure 3).
PURPOSE: This addendum is intended to provide assurance that the ocean shoreline of Key
Biscayne is maintained as a top quality recreational and protective beach which will positively
affect the offshore marine environment, the beach dune environment, the human and natural
users of the beach -dune system, and the landward environment and developments.
Page 1 of 9
BACKGROUND: The Key Biscayne Atlantic coastline, including the Village beach, is
unique. Any attempt to manage or restore Key Biscayne beaches must be based upon
knowledge of the differences between it and other Atlantic coast beaches.
Key Biscayne is the southernmost sandy barrier island along the Atlantic coast of the United
States. The island and its unique ocean beach were formed over the past several thousand
years as a finger of sand migrated from north to south into the subtropical carbonate'
environments of Biscayne Bay and the Reef Tract. Sands comprising Key Biscayne and its
beach are 30-80% quartz grains that have originated in the weathered Appalachian
Mountains. The remaining 20-70% of the sand is skeletal grains of calcium carbonate (Figure
2). Part of the skeletal component is robust rounded fragments of mollusk shells that have
been incorporated into the beach sands as they moved south from their origin to Key
Biscayne. The remaining skeletal components, 40-60% of the carbonate sand component, are
more delicate porous skeletal fragments of varied shapes derived from the more local marine
environments offshore.
A net southward transport of sand along the beaches of Miami -Dade County, estimated
minimally to be 80,000 cubic yards of sediment per year, is driven by the north and
northeasterly winds following winter cold fronts and storms. The quartz -carbonate sand of
the Key Biscayne shore system extends approximately five miles southeast of the island as a
subtidal spit, and fades out to the east as mud banks.
The Key Biscayne beach, although exposed to numerous winter storms and hurricanes
throughout many years, differs from the Atlantic beaches to the north of Government Cut in
Miami -Dade County in that it lies in the complete protection of the Bahamas Bank and,
therefore, does not normally receive Atlantic Ocean swells. In addition, seaward shallow
water limestone ridges provide some protection from waves generated in the Straits of
Florida. This more protected setting has permitted tidal processes to have greater influence
on the morphology of the barrier island system.
Major natural inlets to the north and south of Key Biscayne (Bear Cut and Cape
Florida/Biscayne Channels, respectively), maintained by tidal exchange with Biscayne Bay,
have been permanent features throughout historic times. Southward drifting sand, caught in
these tidal systems, has formed large flood and ebb tidal deltas. The ebb tidal deltas at both
Carbonate is used to describe environments where the sediment is locally produced from shell or
skeletons of organisms such as Halimeda algae or coral, and/or chemical precipitation from sea water
(oolitic grains and some mud). Skeletal carbonate sand grains may be whole skeletons or broken
fragments. Calcium carbonate sediment can occur as gravel-, sand-, and mud -sized particles. Carbonate
mud particles often form aggregates.
Page 2 of 9
the northern and southern ends of Key Biscayne have formed broad, shallow littoral sand
platforms directly on the Atlantic side of the island that extend to approximately 5,000 feet
offshore. These platforms are composed of quartz -carbonate sand of similar composition (but
not necessarily grain size) as the beach, but of different composition from sand to seaward.
Waves have smoothed the seaward margins of these ebb tidal deltas, and long shore currents
have formed offshore bars extending the deltas southward and northward toward central Key
Biscayne. The southward and westward movement of the Bear Cut ebb shoal has resulted
in a significant sand spit in Crandon Park; this now prominent and unique feature has been
building steadily since the 1920's. The Village of Key Biscayne shoreline is subject to much
greater storm erosion, however, because the central section of the island is not protected by
shallow littoral sand platforms to the seaward.
The exposed seaward margin of the ebb tidal deltas and bars is barren rippled sand. The
interior of the shallow littoral sand platform is sufficiently protected to allow seagrasses to
colonize and flourish. Dominant species of seagrass include turtle grass (Thalassia
testudinum) and manatee grass (Syringodium filiforme). This seagrass cover provides a
stable bottom which permits important bottom dwelling organisms and infauna to persist, acts
as a wave baffling device that actively traps finer suspended sands, and stabilizes substrate
against storm damage through the deeply penetrating rhizome and root mat. Areas of
persistent seagrass cover have accumulated sands that are of much finer grain size than would
be stable on the adjacent bare bottom areas or beaches.
Seaward of the central Key Biscayne beach and the littoral sand platforms of northern and
southern Key Biscayne, the bottom deepens to an exposed limestone surface 20-25 feet in
depth. The quartz -carbonate sands of the shore system do not extend out onto this deeper
seaward shelf. Skeletal carbonate sands occur as subtidal deposits and fill depressions in the
limestone in this seaward zone.
SAND QUALITY: Optimum and minimum acceptable sand qualities are defined to insure
a high quality Key Biscayne beach as the result of any future beach nourishment projects.
These recommendations are based on analyses of historical natural Key Biscayne beach sands,
analysis and performance of materials used in previous Key Biscayne beach nourishment
projects, and general sedimentologic, hydrodynamic, and environmental considerations.
Recommended Sand Quality Parameters: Grain size characteristics of an ideal sand to be
used for future nourishment of the Village of Key Biscayne beach (Figure 1) would have no
material finer than 200 microns (0.2 mm), less than 50% material coarser than 500 microns
2 Littoral refers to a shallow zone seaward of the beach subjected to waves and currents associated with
shallowing waves, long shore drift, and tidal currents near inlets. Off Key Biscayne the shallow littoral
sand platform extends as much as 1 mile seaward of the shore and is composed of quartz -carbonate sand
similar in composition (but not necessarily grain size) to the beach.
Page 3 of 9
(0.5 mm), and no material coarser than 1,000 microns (1 mm). In addition, appropriate sand
would contain 25-60% durable natural (not manufactured/crushed rock) carbonate grains,
verified by settling analyses, with the remainder consisting of natural quartz sand particles
(Figure 2).
Parameters for the minimum quality sand allowed for placement on the Village of Key
Biscayne beach (Figure 1) should consist of less than 5% material finer than 80 microns (0.08
mm), less than 25% finer than 200 microns (0.2 mm), less than 10% coarser than 1,000
microns (1 mm), and no rock aggregate particles coarser than 5,000 microns (5 mm). Shell
material should be no coarser than 3 cm. In addition, minimum quality sand would contain
25-70% durable natural (not manufactured/crushed rock) carbonate grains, verified by settling
analyses, with the remainder consisting of quartz particles (Figure 3).
Natural Beach Sands of Key Biscayne: The natural sand of Key Biscayne beach is 20-70%
skeletal calcium carbonate grains and 30-80% quartz grains (Figure 2). Due to the high
amount of skeletal carbonate grains, sieving and settling analyses give very different results
(Figures 2 and 3). Sieving analysis shows that the sand has two modes of abundance with a
broad fine -skewed unimodal peak. Settling analysis shows that the sand has a more narrow,
generally symmetrical unimodal peak. As explained in the Methods of Analysis section, the
difference occurs because many of the calcium carbonate grains settle together with finer
quartz grains. In other words, the physical size and shape of many of the skeletal carbonate
grains is misleading (i.e. they behave as finer grains than what sieve analysis would indicate).
As a result, the following characterizations of natural and nourishment sands are given as the
results of settling analyses. These results could be directly compared to sieve results of pure
quartz sands or of non -porous, equant calcium carbonate sands (e.g. ooids or rounded
mollusk fragments).
The natural sand of the berm and beach foreslope of Key Biscayne' is a well sorted quartz -
carbonate sand with a unimodal peak at 220-350 microns (0.22-0.35 mm). Settling analyses
show that essentially no material coarser than 500 microns (0.5 mm) exists in the berm and
beach foreslope samples, and that quartz and carbonate fractions are essentially equivalent in
size distribution. A coarser skeletal (mostly mollusk) component is present in the plunge zone
(shallow active wave -washed part of the beach) samples. No material finer than 80 microns
(0.08 mm) is present in any of the natural beach sands. Grains finer than 125 microns (0.125
mm) form 0-10% of the samples; grains finer than 175 microns (0.175 mm) comprise 5-30%.
3 Sands used to characterize natural Key Biscayne Beach sands were collected in October 1972 by H.R.
Wanless as a part of a Sea Grant sponsored research project at the University of Miami. A beach
nourishment project was undertaken in northern Crandon Park in 1969, therefore, only sands from the
beach along the now Village of Key Biscayne and Cape Florida Park are used here. Samples were
collected from (a) just landward of the berm crest, (b) the foreslope of the beach, and (c) in the plunge
zone at the base of the beach.
Page 4 of 9
Sands obtained from the natural beach along the central portion of Key Biscayne not
protected by a shallow littoral sand platform were slightly coarser than to the north or south.
Analysis showed a unimodal peak at 350 microns (0.35 mm) and no material finer than 125
microns (0.125 mm).
Character and Performance of Sands in Historical Beach Renourishment Projects: The
principal sand renourishment project affecting the beach of the Village of Key Biscayne and
Cape Florida occurred in 1987. The sand was derived from an offshore sand source on the
littoral sand platform lying to the southeast of Cape Florida. The sand in the borrow area was
sand that historically moved south from the Key Biscayne beach due to the natural process
of long shore drift. This nourishment sand was very similar to the naturally occurring Key
Biscayne beach in percentage of quartz and carbonate, constituent grain composition, and
grain size.
Sand from the borrow site for the 1987 Key Biscayne beach nourishment was well sorted and
unimodally distributed, with a peak at 250-350 microns (0.25-0.35 mm). The sands contained
0-4% material finer than 125 microns (0.125 mm), 1-12% material coarser than 700 microns
(0.7 mm) by settling, and 0.5% coarser than 1 mm by sieving. The 1987 beach nourishment,
upon construction completion, was anticipated to require nourishments of 154,000 cubic
yards of sand on a schedule of seven year increments. The Village presently anticipates the
use of 120,000 cubic yards for the Proposed 1999 nourishment, thus indicating the
appropriateness of original nourishment sand.
Sedimentological and Hydrodynamic Considerations (Theory and Methodology): Three
fundamental particle size boundaries (40, 200, and 650 microns, or 0.04, 0.2, and 0.65 mm)
relate how particles move in a fluid to the energy required to initiate movement. These
particles move either in suspension or as a bedload.
Suspension: If sufficient energy exists to move particles finer than 200 microns (0.2 mm),
then sufficient turbulence is also present in the fluid to bring them into suspension. Thus,
particles finer than 200 microns (0.2 mm) tend to move as suspended load in the fluid
column.
a) Short-term Suspension: Particles between 200 and 40 microns (0.2 and 0.04 mm)
tend to come out of suspension quickly following the end of the a period of wave or
current energy, or when the energy is no longer affecting the bottom.
b) Long-term Suspension: Particles finer than 40 microns (0.04 mm) tend to remain
in suspension long after the resuspending event, due to ambient turbulence in the
water column.
Bedload: If sufficient energy exists to move particles coarser than 200 microns (0.2 mm),
then they tend to move in contact with the bottom.
Page 5 of 9
a) Bed Load: Particles between 200 and 650 microns (0.2 and 0.65 mm) tend to
bounce (saltate) along the bottom.
b) Traction Load: Particles coarser than 650 microns (0.65 mm) tend to roll or slide
and maintain constant contact with the bottom.
With increasing energy and turbulence traction load will begin to move as bed load, and bed
load as suspension load.
Suspended load material, finer than 200 microns (0.2 mm), is unsuitable as beach sand. A
small amount of finer than 200 micron (0.2 mm) material is common on beaches, but can
easily be suspended and does not remain on the beach. Vegetated coastal dunes are
commonly largely built of 100-200 micron (0.1-0.2 mm) sands, as vegetation traps the finer
wind blown particles. Suspended load material that moves seaward from the beach will move
off of the littoral sand platform unless trapped by seagrass beds.
The quartz sand on Key Biscayne has been transported southward from the Appalachian
Mountains over the last several hundred -thousand years. In the process, most of the coarser
sands have been left behind. The upper limit of natural quartz sand on Key Biscayne beaches
is thus limited in part by what is provided, not by what would be stable on the beach.
Coarse pebbles and gravel on a beach are unpleasant or injurious to walkers, joggers, and
beachcombers, and become dangerous and damaging projectiles during hurricanes.
Irregularly shaped pebbles commonly become fixed on the beach slope. Flat mollusk shells,
in contrast, are generally swept to the base of the beach by wave backswash. Thus shell
fragments poss less of a problem than irregular pebbles.
METHODS OF ANALYSIS: Methods of analysis are discussed so that standard minimum
investigation of appropriate sand sources remains consistent. All potential beach sand
samples should be evaluated for evidence of grain aggregation by binocular microscope before
and after dry sieving. Sands that are mostly quartz naturally disaggregate into individual
grains, and are cohesionless. These may be dry sieved according to standard methods.
Samples containing more than 15% carbonate grains (i.e. according to Recommended Sand
Quality Parameters, all potential Key Biscayne sources) should be analyzed both by sieving
and by settling analysis in which the settling system has been calibrated with respect to quartz
sand.
Dry Sieving: Quartz sands, which are naturally disaggregated into individual grains and
are cohesionless, may be dry sieved according to standard methods. However, all samples
should be evaluated for evidence of grain aggregation by binocular microscope before and
after dry sieving. Regardless of the results from microscopic examination, samples
containing a significant fraction of material less than 62 microns (0.062 mm) should be
wet sieved. Samples containing more than 15% carbonate grains should be analyzed both
Page 6 of 9
by sieving and by settling analysis, in which the settling system has been calibrated with
respect to quartz sands. Reporting of results should be as weight percentage according
to standard methods for sieving.
Wet Sieving: This method is necessary for those samples in which laboratory drying has
aggregated (stuck or cemented together) particles, or in which the sample is provided dry
and particles are aggregated. Small amounts of mud, especially carbonate mud, aggregate
larger grains together. Dry sieving commonly will not disaggregate these grains into their
individual components, as they occur in the aqueous environment.
The sand and gravel fractions should be wet sieved out first, dried and weighed. It is
important that tap water be used in a wet sieve, as distilled water will cause dissolution
of carbonate mud particles. The wet sieving method must use adequate water and
agitation on each sieve to assure particles have adequate opportunity to pass through each
sieve, with all test water being retained. The less than 62 micron (0.062 mm) particles
must be allowed to settle, the clear water decanted, and the remaining fraction dried and
weighed. Reporting of results is as weight percentage according to standard methods for
sieving.
Settling Analysis: This method is used to approximate the hydrodynamic behavior of
particles, and must be utilized when the particles have a shape or effective excess density4
different from that of subrounded quartz. It is imperative to analyze grains by settling in
4 A particle's effective excess density (eed) is the net density of a particle above that of the fluid (density
of the grain minus the density of the fluid). Thus, in water (—density = 1.00 g/cm3), a solid quartz grain
(density = 2.65 g/cm3) will have an effective excess density of 1.65. Quartz is the standard for which
settling analyses are calibrated and from which the hydrodynamic implications of sieving and settling
analyses are understood.
There are two important considerations of effective excess density. First, different mineral grains have
different densities, and solid grains of different density will behave very differently in water. Second,
and most important to considerations here, many carbonate grains have internal pore spaces, and this will
dramatically affect the particles' effective density and behavior in a fluid.
For example, a calcareous algal Halimeda grain, composed of aragonite of density = 2.93 g/cm3, is
commonly about 50% pore space. The effective excess density of a Halimeda particle will be:
eed = (0.5 x density of aragonite) + (0.5 x density of water) - density of water
eed = (0.5 x 2.93) + (0.5 x 1.00) - 1
eed = 1.465 +0.5 -1 =0.965
Thus, the carbonate Halimeda grain has a much lower effective excess density in water, even though it
is made of a more dense mineral than quartz. As a result, a Halimeda particle will behave like a smaller
grain, and settle together with much smaller quartz grains than if it had no internal porosity. The
Halimeda grain will be moved and resuspended much more easily than would be anticipated by its
physical size.
Page 7 of 9
samples containing significant carbonate grains.
When settling analysis is used, sieving must also be done on the sample. This is to
document the physical size of the coarse fraction, which is important to the comfort of
beach users. The initial volume of the sand should be measured so that the settling grain
size can be expressed as a volume per cent. The sediment should be thoroughly wetted
so that no air is in the internal grain pore spaces. As most settling tubes are only
calibrated for grains finer than 1 mm, it may be necessary to sieve the sample through a
1 mm mesh sieve prior to settling. All fluid must be retained from this pre settling sieve
separation and used in the settling analysis.
There are numerous settling methods including visual accumulation tube, electromagnetic
field distortion, and light attenuation. Regardless of the method used, it is important that
results are not affected by internal grain porosity. Most settling results are as volume per
cent, as opposed to weight per cent for sieving.
CONCLUSION: It is the opinion of the Village Beach Resources and Management
(BRM) Task Force that the previous guidelines will help to insure the highest quality sand
for future Key Biscayne beach nourishments. These recommendations have taken into
consideration, to the greatest extent practicable, beach preservation, recreational
amenities, aesthetics, seagrass and sea turtle impacts, coastal vegetation, beach system
enhancement, and storm protection. Although the suggested "Ideal Sand Quality"
spectrum is slightly out of Dade County specifications, we feel that Key Biscayne is
subject to unique hydrodynamic conditions, supported by historic data, and, therefore,
should secure a sand source that uniquely accommodates these naturally imposed
requirements.
Task Force Members feel that these specifications should act, within all reasonable
physical and economic constraints, as the best possible guide to sand source selection for
the Village of Key Biscayne. These specifications are also anticipated to ease the
environmental and construction permit processes.
This Addendum 1 to the Long Range Beach Nourishment Plan for the Village of Key
Biscayne Dade County, Florida is submitted in good faith by the members of the Village
of Key Biscayne Beach Resources and Management (BRM) Task Force.
Page 8 of 9
TASK FORCE MEMBERS:
Sandra Goldstien, Chairperson
Betty Sime, Village Councilmember
C. Samuel Kissinger, Village Manger
James D. DeCocq, Assistant to the Village Manager
Brian Flynn, Coastal Programs Administrator - Miami -Dade County Department of
Environmental Resources Management (DERM)
Henny Groschel-Becker, Marine Geologist - University of Miami, Rosenstiel School
of Marine and Atmospheric Science (RSMAS)
John Hinson, President - Ocean Club Development Company
Sam Houston, Meteorologist - National Oceanic and Atmospheric Administration
(NOAA)
Kris McFadden, Village Coastal Zone Management Intern - University of Miami ,
Rosenstiel School of Marine and Atmospheric Science (RSMAS)
Harold R. Wanless, Geologist - University of Miami
Ex Officio:
Lee Niblock, Park Manager - Bill Baggs Cape Florida State Recreation Area
SAND QUALITY SUB-COMM TTEE:
Harold R. Wanless, Geologist - University of Nfiami - Chairperson le
James D. DeCocq, Assistant to the Village Manager
Brian Flynn, Coastal Programs Administrator - Miami -Dade County Department of
Environmental Resources Management (DERM)
Henny Groschel-Becker, Marine Geologist - University of Miami, Rosenstiel School
of Marine and Atmospheric Science (RSMAS)
Sam Houston, Meteorologist - National Oceanic and Atmospheric Administration
(NOAA) ,
Kris McFadden, Village Coastal Zone Management Intern - University of Miami,
Rosenstiel School of Marine and Atmospheric Science (RSMAS)
Page 9 of 9
N. ►`tom•
1''(1)°
(D O (D
t (D
0 WC:1g B
et a)
0 c4
(I) R:
p.r
O n ` T V P. ) �
wCD
0 • crq2 (Do
cs'
C‘ gB
CA P -ft
CI) (1) 0 ecjP
m� � ¢' ►-t-t
1 A)
O a. ( (DD
O r7 O P) cn OA
cPA
.61 r4
r.„ 0
(To (i)
„, (n) -t PAN
o 1
-,-
O�� Ani
0 co
„ "; B fD~' 0 A)
*dam'` �Oq
t3(D (DDEirt0
ar-
o''�' CD a)..Q
cn N5
m
z
0
n
r
rrl
-n
m
co
0
c
r-
O
m
0
w
0o
r
m
-D
m
0o
m
3SdVO3E '° n
>6
0
0
33
CO
m
m
v_
c
z
m
z
m
PERCENT COARSER BY WEIGHT
cri
O O O O
O
0
0
zn^
N
m
o
F.
0
0
0
O
cri
0
0
O �►
O
CO
O
o 0
O
O
N
O
0
O
N
N
CO
CO
N
0
w
0
0
0
0
0
0
0
N
0
0
O
a3BWfIN 3A3IS abVONb1S 's'n
b31aW0ElaAH
PERCENT FINER BY WEIGHT
Figure 2.
GRAIN SIZE OF NATURAL BEACH SAND ON KEY BISCAY NE
70
60
50
a 40
u
d 30
a
20
10
0
0:031
70
60
50
a 40
v
30
a
20
10
0
0.0625 0.125 0.25 0.5
Grain Size (mm)
•
•
0.031
0.0625 0.125 0.25 0.5
Grain Size (mm)
1
BY SIEVING (WHOLE SAMPLE)
BY SETTLING (WHOLE SAMPLE)
BY SETTLING (QUARTZ FRACTION)
SAMPLE 7210-3A
BERM (15' FROM CREST)
NORTHERN CAPE FLORIDA
1 1 1 i 1 1 1 1
• BY SIEVING (WHOLE SAMPLE)
0. BY SETTLING (WHOLE SAMPLE)
BY SETTLING (QUARTZ FRACTION)
SAMPLE 7210-•3B
MID -BEACH SLOPE
NORTHERN CAPE FLORIDA
2
Figure 3.
GRAIN SIZE OF NATURAL BEACH SAND ON KEY BISCAYNE
70
60
50
a 40
0 30
4
20
10
0
0.031
70
60
50
u 40
d 30
a
20
10
0
0.0625 0.125 025 0.5
Grain Size (mm)
BY SIEVING (WHOLE SAMPLE)
BY SETTLING (WHOLE SAMPLE)
BY SETTLING (QUARTZ FRACTION)
1
1
1 I
SAMPLE 7210-4A
BERM (15' FROM CREST)
10' NORTH OF NORTHERNMOST GROIN
OF KEY BISCAYNE HOTEL
1
2
i i i , I I ' '
• ••x• BY SIEVING (WHOLE SAMPLE)
J
BY SETTLING (WHOLE SAMPLE) I
BY SETTLING (QUARTZ FRACTION)1
1
SAMPLE ?210-4B
MID -BEACH SLOPE
10' NORTH OF NORTHERNMOST GROIN
OF KEY BISCAYNE HOTEL
0.031 .0.0625 0.125 0.25 0.5
Grain Size (mm)
1
2