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Group Title: Bulletin University of Florida, Engineering Experiment Station
Title: Study of beach conditions at Daytona Beach, Florida, and vicinity
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
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Permanent Link: http://ufdc.ufl.edu/UF00003200/00001
 Material Information
Title: Study of beach conditions at Daytona Beach, Florida, and vicinity being a synopsis of a report of the Beach Erosion Board of the Office of the Chief of Engineers of the War Department
Series Title: Bulletin University of Florida, Engineering Experiment Station
Physical Description: 10 p. : ill., map ; 23 cm.
Language: English
Creator: Fineren, W. W
United States -- Beach Erosion Board
University of Florida -- Engineering Experiment Station
Publisher: University of Florida
Place of Publication: Gainesville Fla
Publication Date: 1938
 Subjects
Subject: Beach erosion -- Florida -- Daytona Beach   ( lcsh )
Shore protection -- Florida -- Daytona Beach   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
Statement of Responsibility: with comments and digest prepared by W.W. Fineren.
General Note: Cover title.
General Note: "March, 1938."
 Record Information
Bibliographic ID: UF00003200
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: ltqf - AAA4341
ltuf - AJH2718
oclc - 24229663
alephbibnum - 001759635

Table of Contents
    Front Cover
        Page i
        Page ii
    Foreword
        Page iii
    Main
        Page 1
        Page 2
        Page 3
        Page 4
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
    Back Cover
        Page 11
        Page 12
Full Text


UNIVERSITY OF FLORIDA PUBLICATION


Engineering Experiment Station


Bulletin No. 4


STUDY OF BEACH CONDITIONS
At

DAYTONA BEACH, FLORIDA, AND VICINITY


Being a Synopsis of a Report of

THE BEACH EROSION BOARD
of the
Office of the Chief of Engineers of the War Department
with Comments and Digest prepared by
W. W. Fineren, M. E.
Professor of Mechanical Engineering. University of Florida
Member. Florida Peninsular Basin Committee of the
National Water Resources Committee


z


UNIVERSITY OF FLORIDA
Gainesville, Florida
March, 1938




























A TLA N TI C


OCEAN


LOCATION PLAN
mm lr*T


LEGEND:
CLEAN QUARTZ SAND
SAND & SHELL
SHELL DEPOSITS


NOTE;
PLOTTED FROM CORE BORINGS
SPACED AT 5000 FT IN VICINITY OF
H.W.L.. MADE FEB. LMAR. 1936.














REPRODUCTION OF PART OF
PLATES 8 & 0
WAR DEPARTMENT DRAWING


r~~ta~


"""~,











FOREWORD


This bulletin contains quotations from a report prepared by
the War Department of the United States Engineers and intro-
ductory remarks by Prof. W. W. Fineren.

It is issued in the belief that it gives valuable informa-
tion on the preservation of our beaches. Florida, with ap-
proximately one-third of the shoreline of the entire United
States, must protect and conserve these beaches, so that
they always will attract tourists throughout the world.

The Engineering Experiment Station of the University of Flo-
rida has been appointed as the legal constituted authority
for the State of Florida and its subdivisions as liaison
agent with the United States Government on matters pertain-
ing to beach and shore erosion. As such it welcomes in-
quiries and is eager to cooperate with all organizations in
matters pertaining to the preservation of Florida beaches.



Joseph Weil, Director
Engineering Experiment Station










ENGINEERING RESEARCH

BY INVENTION, DISCOVERY, AND CONSERVATION

WILL BUILD A GREATER INDUSTRIAL FLORIDA









STUDY OF BEACH CONDITIONS AT DAYTONA BEACH. FLORIDA. AND VICINITY


PLAN, PURPOSE, AND AUTHORITY: (GENERAL INFORMATION BY THE AUTHOR)

1. Under the provisions of Section 2 of the River and Harbor Act
approved July 3, 1930 (Public No. 520, 71st Congress) and an Act approved
June 26, 1936, (Public No. 834, 74th Congress), an investigation and study
of beach erosion and changes between Ormond Beach and New Smyrna Beach,
Florida, has been made by the United States (acting through the Chief of
Engineers, the Beach Erosion Board, and the District Engineer, Jackson-
ville, Florida) and the State of Florida (acting through the Engineering
Experiment Station, University of Florida, and the City of Daytona Beach,
Florida).

2. The study was initiated by formal application from the Engineer-
ing Experiment Station of the University of Florida, dated August 20,
1935, and was approved by the Chief of Engineers, U. S. Army, November
23, 1935.

3. The purpose of the study was to determine (1) the causes of
erosion of the beach south of Ponce de Leon Inlet and of the erosion and
changes in character of the beach at Daytona Beach which have prevented
its use for the extreme high speed reached in recent speed tests for auto-
mobiles, and (2) the best method of controlling and preventing these
changes. The area covered by the study included the beach from a point
north of Ormond Beach to a point five miles south of Ponce de Leon Inlet,
a total distance of thirty miles.

4. The items to be covered by this investigation as outlined in Part
IV of the application were as follows:

(a) Shoreline Charges. History of changes in the shoreline as
far back as authentic maps are available.

(b) Changes in offshore areas by comparison of hydrography as
far back as authentic maps are available.

(c) Survey of the present conditions of the beach to comprise:

(1) Profiles at 5000 foot intervals from a point approxi-
mately five miles below Ponce de Leon Inlet to Ormond Beach extending
from within the dune line perpendicular to the seacoast to a depth of
twenty-five feet below mean low water.

(2) Intermediate profiles at 1000 foot intervals extend-
ingfrom within the dune line to mean low water.

(d) Determination of the extent and the limits of the effect
of waves and currents in moving sand along the shore.

(e) Study of beach material in relation to that composing the
off-shore area.

(f) Secure sand samples at the midtide line every half mile
for a distance of fifteen miles at each end of the area covered by the
project, and make analysis of them.

(g) Determination of the source and conditions causing the
movement of shell deposits on the beach.

(h) Test pits at each long profile line to be dug at high
water line to a depth of 2 feet below low water and log of sand-shell
strata plotted.

(i) Historical study of effect of storms and tides along the
beach.

-1-









(j) Study of wind and weather conditions at this location
from existing weather records.

(k) Study of the geology of this section of the coast to
determine as far as possible its past history.

(1) Airplane photographs of the area from a point twenty-
five miles north of Daytona to a point fifteen miles below Ponce de
Leon Inlet.

(a) Report by the Beach Erosion Board on the best methods
of protection for the beach to prevent erosion and changes of the beach.

5. The work was carried out Jointly by the United States and the
State of Florida (as contrmplated hy the Ant of Congress previously
mentioned). Upon the recommendation of the Chamber of Commerce of
Daytona Beach, Mr. C. H. Moneypenny, of Daytona Beach, a Registered
Surveyor of the State of Florida, was appointed as a representative of
the Engineering Experiment Station in the field, and the land portion
of the survey was made under his direction. Tests of the beach sands
were made at the University of Florida Engineering Experiment Station
by Professor W. W. Fineren. The off-shore water work was carried on
by survey crews from the office of the District Engineer in Jacksonville,
and the further investigations and results were prepared in the Office
of the Chief of Engineers in Washington by the Beach Erosion Board.
The State of Florida, under direction of the University Experiment
Station, completed the field work and furnished the data required under
Items (e) and (f) of Paragraph 4, and contributed one-half of the cost
of the project. The United States completed the rmalnder of the field
and office work.

PRESENT CONDITION AND EFFECT ON TOURISTS: (BY THE AUTHOR)

6. There sl evidence of erosion along the dunes Lhroughout the
area investigated. A scarp from 2 to 10 feet high has been formed by
storm waves reaching the toe of the dunes. Along the backshore the sand
is usually dry and is readily shifted by the wind. This sand appears to
have the same characteristics as that comprising the dunes.

There are no jetties, groins, or other beach protective structures
except isolated bulkheads around private properties to protect them from
storm damage. These bulkheads are of various types of construction and
aro located well back of the high water line.

7. Daytona Beach is reputed to be one of the finest bathing beaches
in the world. The sand is nearly pure silica and Is very fine, and when
moist and compact is very hard. The beach is wide and gently sloping,
making an Ideal bathing beach. Dotted here and there are many small
patches of very fine red shell and this finely powdered shell is mixed,
to a greater or less degree, with the grayish-white silica sand. In the
immediate vicinity of Daytona and Ormond Beaches the sand is very nearly
pure silica and of a fine floury texture. Until the immediate past few
years probably little thought has been given to the presence of this fine
shell. Since the advent of the automobile it has become more clearly
noticeable, year by year, that these soft pockets of fine red shell would
not stand up under traffic on the beach. However, this was not a matter
of concern, as automobile drivers soon loorned to avoid these red spots
in motoring up and down the beach. This condition first became a matter
of serious moment when Sir Malcolm Cambell, the noted British sportsman.
was forced to abandon his speed trials at Daytona Beach because these
spots could not be avoided at high speeds, thereby providing a menace to
the sport. The loss of this attraction seemed to be a severe blow to the
prestige of Daytona Beach as a point of tourist attraction.


-2-











8. The problem before Daytona Beach, and the State of Florida,
was not so much to save the beach from destruction by the sea as it
was to preserve the racing beach as an asset to the locality,and,
incidentally, to maintain for the State of Florida this additional
attraction for the tourists. In making the survey, no fears were
entertained as to the Immediate destruction of the beach as one of
the foremost bathing resorts in the world, but rather information was
sought which might cause it to retain its popularity as a racing beach
of national and international interest.

GEOLOGY OF THE LOCALITY:

(ALL FOLLOWING PARAGRAPHS IN QUOTATIONS ARE TAKEN VERBATIM FROM THE
REPORT OF THE BEACH EROSION BOARD)

"13. GEOLOGY. The best available information indicates that the
Florida peninsula was formed during the Paleozoic Age as a part of the
Appalachian Plateau.

"14. The plateau gradually sand and became covered by the sea.
As it sank sediment washed from the Piedmont land masses of Georgia
and Alabama were deposited upon it. The heavier materials such as
sands and gravels were deposited chiefly in the northern areas while
the lighter calcareous material was deposited more or less uniformly
oval the remainder of the area. These deposits reached a thickness
of 3000 to 4000 feet during the time the plateau was submerged.

"15. The next period in the history of the plateau was one of
emergence. The uplift was very slow, the land first appeared as a
series of islands, as is evidenced by the existence of fossil sand
bars in the middle of the present plateau. Superficial sand beds over-
lie the entire Florida peninsula. The movement of some of this sand
to the present coast has undoubtedly occurred. With further uplift
the islands enlarged and merged and the intervening straits diminished
until the present peninsula resulted. It was probably during this
emerging period, while the seas aroung the islands were comparatively
shallow, that the greatest part of the prevailing coquina rock was
formed by the deposit of immense quantities of shell in the shallow
warm water. These deposits were intermixed with sand,-mud and other
binding materials and overlaid with sediment. A continuation of the
emergence raised some of the coquina deposits above sea level where
they now appear as outcroppings.

"16. Either following or concurrent with the emergence there
appears to have been a tilting of the plateau around its longitudinal
axis. The west coast was partially submerged, as indicated by the wide
estuaries and off-shore channels of its streams, while the east coast
was correspondingly elevated. As a result of this movement the east
coast manifests the characteristics of an emergent coastline. It is
probable that the barrier strip which now forms the present Atlantic
shore-line was originally started, at least in some sections, as an
off-shore bar which was then elevated above the water surface by the
tilting of the peninsula and built up to its present condition by wave
action and deposits of wind blown sand. This hypothesis enables the
presence of successive paralled ridges which were formerly coastal sand
dunes consisting principally of silica sand to be explained.

"17. Silica sand on the Florida coast is that which has been
carried down to the sea by the Savannah, Altamaha, and other rivers of
Georgia and the Carolinas, and gradually shifted to the southward by
the shore currents and wave action along the Atlantic coast together
with that furnished directly to the beach from the dunes.

-3-









The combined effect of wind and wave action has formed much of this
sand into successive paralled ridges of dunes consisting principally
of silica sand. Due to the geological history above sketched the
underlying material of practically all the beaches contains a large
portion of sand and shell mixture of loose or unconsolidated sedimentary
form which was deposited during the later stages of emergence. Under-
lying the unconsolidated material are the large areas of coquina laid
down as above indicated and formed of shell fragments in various stages
of consolidation. Conditions are therefore favorable for the continued
existence of silica sand beach along the greater part of the coastline
under continued erosion, provided local disintegration of the coquina
does not supply undue quantities of broken shell."
"18. GENERAL CHARACTERISTICS OF EAST FLORIDA BEACHES: The
numerous outcroppings of coquina found along the beach and off-shore
between St. Augustine and Palm Beach (Plate 8) have a material effect
on the shore processes in this area. Coquina is easily weathered and
eroded. It does not form rocky headlands projecting beyond the coast
line as do harder rocks. The exposed strata on the coast are com-
paratively thin allowing undercutting by wave action and dropping of
such strata to the level of the beach.

"19. The coquina outcroppings on the ocean bed off-shore form a
semi-permanent bar or toe which materially retards the rate of erosion
of off-shore areas but does not wholly prevent a recession of the sandy
shoreline. This results in flat off-shore slopes with resulting less
intensive wave action on the beach. No complete survey to determine
the extent of these off-shore outcroppings of coquina has been made.
They have been found at many locations, notably at Flagler Beach and at
Palm Beach where they are present quite close to the shore. This con-
dition, however, was not found at Daytona Beach.

"20. While retarding erosion of the off-shore areas and the beach
these outcropping of coquina furnish in their slow disintegration an
immense volume of shell fragments. In the vicinity of outcroppings on
the beach, the material composing the beach is largely shell. Its
influence on the beach material is felt for a considerable distance on
each side of these areas. During severe storms these beaches may be
swept clear of the shell fragments which may migrate onto beaches a
considerable distance away.

"21. The east coast of Florida is an almost continuous sandy shore
from the Georgia State line to Cape Florida. It is broken at intervals
by inlets connecting the ocean with inner bays and rivers. At and south
of Cape Florida it consists of a series of keys inclosing an area of man-
grove swamps. At its northern end this coastline lies in an almost north
and south direction bearing slightly to the east as one travels south.
This eastward trend increases to Cape Canaveral. South of that Cape the
shoreline runs south and then slightly southeast to a point near Palm
Beach, thence south and west of south to Cape Florida. From Cape Florida
there is an increasing westward trend in a long curved line terminating
in an almost westerly course at Key West. The lands adjacent to the
coast are low and covered with woods and palmetto growth.

"22. The northern part of the coast between the Georgia line and
Palm Beach is exposed to northeast and east storms and to some extent
those from the south east. South of Palm Beach the Bahama Islands and
Cuba afford some protection from all ocean storms.

"23. Mr. James H. C. Martens, in an article published in an annual
report of the Geological Society of the State of Florida, has given an
excellent description of the Florida coast. The following summary based
upon this report and upon observations made by the Board describes the
general character of the beaches in the vicinity studied.










"24. Four miles south of Mantanzas Inlet there is a stretch of
outcropping coquina, known locally as "The Rocks" (Plate 8). This
is the largest area of outcropping "rock" on the Atlantic coast south
of Cape Cod. Immediately south of this formation shell fragments in
the beach increase as one goes south until the maximum shell content
is reached at Plagler Beach abeut 9 miles below the northern limit of
the outcropping area. Here the sand is reddish yellow in color on
account of the large proportion of that color.

"25. From Plagler Beach to Ormond Beach, 14 miles, the shell par-
ticles gradually diminish in volume and the beach is almost pure quartz
sand at the latter point. From Ormond Beach through Daytona Beach to
Ponce de Leon Inlet, 18 miles, the beach is at times entirely free of
shell particles in any noticeable amounts. This is the stretch of
beach used for automobile racing. After certain storms, limited areas
of shifting shell particles are found on the beach which make its
surface soft in spots and undesirable for automobile racing. The
southern part of this stretch of beach is the harder and flatter.
The strand is from 400 to 500 feet wide at low tide, smooth and uni-
form of slope. Dune ridges exist back of the beach except where they
have been leveled off for building purposes. The outermost dunes or
ridges show erosive cutting along the toe of slopes after storms
accompanied by unusually high tides.

"2b. South of Ponce de Leon Inlet the coast line is continuous
to Indian River Inlet, 119 miles. This is the longest unbroken beach
in Florida. Only a few miles of this stretch at the northern end,
included in New Smyrna Beach, is suitable for motoring.

"27. The general effect of beach drifting, by the southward move-
ment of sand from the coastal plain, has been to provide and to main-
tain the supply of silicious material forming the dunes and beaches,
and at places to cover the calcareous materials that were deposited
when the area was under water. The supply of sand on the beach is also
contributed to by that moved by winds and storm waves onto the beach
from theddune areas in rear. At places, the wastage of silica sand
does not appear to be compensated by an adequate supply as is shown
by the isolated areas of outcropping coquina rock and abundant shell
fragments with intervening areas of clean quartz sand. Locations
where coquina is known to exist at the surface of the sand are shown
on Plate 8. At these locations the shell content of the beach material
predominates over the silicious content.

"28. Despite the southward moving sand and its larger quantities
of quartz particles from the northern beaches, there occur very definite
areas of shell deposits which in some cases remain more or less fixed
in position while at others they occur and disappear. The variable
areas of shell are usually constantly changing in size and the percentage
of shell content in the beach mixture. It is the occurrence from time
to time of an unusually large shell content which affects the qualities
of the beach at Daytona Beach."

"55. BEACH SAMPLE ANALYSIS: An investigation of the beach materials
was made to determine their composition and properties. Samples of the
foreshore material were collected at about midtide elevation, from points
a half mile apart along the beach, from about 5 miles north of Flagler
Beach to 6 miles south of Eldora, a distance of 53 miles. They were
analyzed for size of the sand grains, porosity, and the percentage of
shell in the mixture.










"56. Tne curve of percentage of shell shows a range of the shell
content from 2% to 75% with the low shell percentage area in the vicinity
of Daytona Beach. At Flagler Beach, where large quantities of broken
shell are found on the beach at all times, the beach material contains
68% of shell. At Halifax Beach, about 10 miles south of Flagler Beach,
the shell content diminishes to 31%. There are several high and low
points in the curve between these two places but the general trend
shows a sharp decrease in the shell ratio southward as far as Ormond
Beach. Between Ormond and Wilbur-by-the-Sea the shell content of the
Beach sand varies between 5% and 8%. At Wilbur-by-the-Sea, a mixture
having 14% shell was found. The percentage of shell again decreases
and continues low, between the limits of 3% and 11%, across Ponce de
Leon Inlet, and through New Smyrna Beach. Prom the south end of this
beach, there is a sharp increase to 75% at about station 262.5. South
of this point the shell content fluctuates between 57% and 11%, with
an average of about 40%, to the southern limit of the study. (Station
262.5 is about midway between New Smyrna Beach and Eldora. W. W. F.)

"57. The information to be obtained from this curve may be sum-
marized as follows: The shell content of the beach material between
Flagler Beach and Ormond Beach is high. It is very low from Ormond
Beach southward through New Smyrna Beach. South of New Smyrna Beach
the shell content is high. This shows that Daytona Beach is located
on a section of the coast where beach sands are almost pure quartz.
The adjacent beaches both north and south of this 22-mile stretch have
higher shell content.

"58. The diagram on Plate 7* shows that the Abrams Fineness Modulus
of the beech materlAl vArlea from 0.78 to 4.30, and that the fineness of
the sand is almost directly in proportionto the percentage of the shell
content. The finest sands along the 53 mile stretch investigated were
between Ormond Beach and New Smynna Beach.

"59. The peruentabe of voids in the beach mixture varies inversely
with the amount of shell. It was found that the range of percentage of
voids varied between closer limits, 35% and 48%, than the percentage of
shell and the Abrams Fineness Modulus. The percentage of voids for
different points along the beach is shown by the broken line on the dia
gram of Plate 7. When the percentage of shell is least and the sand
finest, the percentage of voids is the highest.

"60. Comparative analyses of the beach materials of the Atlantic
coast from the Georgia State line aniuthward to Upper MatecnmbeKey, a
distance of about 430 miles, are shown in Table 1, Page 8?, of a pamph-
let entitled "Beaches of Florida", by James H. C. Martens, extracted
from the Twenty-First-Twenty-Second Annual Report of the Florida State
Geological Survey, Pages 67-119, 1931. This table shows the percentage
of calcium carbonate as computed roum Lhu actually determined percent
of carbon dioxide on the assumption that all of the carbon dioxide was
present in calcium carbonate.

"61. Plate 8 shows a diagram representing the percent of shell, in
beach material at the different points, as given in Table 1 described above.
A map with the locations of the sampling points is also shown. In the
construction of the curve it was assumed that all of the calcium car-
bonate, as determined, was shell and no allowance was made for the
possibility of a considerable amount of coral sand that might be found
along the southern beaches where samples were obtained.

"62. By referring to the diagram, Plate 8, it is seen that the
plotted points indicate varying quantities of shell in the beach sand.
Prom the Georgia State line to point 3, Mineral City, the sand is almost pure
quartz, the shell content varying from 9.18% to 1 25%. At Flagler Beach,
point 4, the shell content increases to 55.95%, and there drops off
sharply until at point 6, Daytona Beach, the shell content is 1.43%.
*Not reproduced here.









The next point shown is Cocoa Beach, about 72 miles south of Daytona
Beach, where the shell content was determined as 7.25%. There are no
intermediate sampling points along this 72-mile stretch of beach by
which comparison could be made with the analyses shown on Plate 7.
From point 7, Cocoa Beach, southward the general trend of the curve
is upward to point 18, at Upper Matecombe Key, where the shell content
of the beach sand is 97.52%.

"63. The shape of this curve indicates two types of beaches along
the coast of Florida. An almost pure quartz sand beach about 125 miles
long exists at the north end and thence a beach with progressively in-.
crdasing shell content as one goes south. There is a point of high
shell content at Flagler Beach within the limits of the quartz sand
section of the coast which is probably due to the outcropping of co-
quina at "The Rocks", and a second area of nearly pure quartz sand at
Daytona Beach, the shell content progressively increasing southward.

"64. BORINGS AT HIGH WATER: An examination of the subsurface
material of the beach was made by core borings along the approximate
coast line. Borings were made at every 5000 foot interval along the
beach from a point north of Ormond Beach southward to New Smyrna Beach
and extended from the surface to about 2 feet below mean lwr water.
A stratigraphic profile was constructed from these borings which is
shown on Plate 9.

"65. The stratigraphic profile shows a thin veneer of clean quartz
sand underlain by a sand and shell mixture that is intersperced with
small pockets of pure shell, and deposits of clean sand. In the vicinity
of the inlet the clean quartz sand extends from the surface to the
bottom of the borings. There is one point, station 130, near Ormond
Beach, where the sand and shell mixture extends to the surface of the
beach.

"66. This diagram indicates that the sand-shell mixture was
deposited during the time when this portion of the coast was submerged,
and that during and since its emergence the flow of the quartz sand from
the north and that drawn from the dunes in rear have covered the sand-
shell deposit except at points where these earlier deposits were higher
than the surrounding ateas."

"87. EFFECT OF STORMS: There are very few factual data available
on the effect of storms on Daytona Beach except for the storm of November
26-29, 1932. Long-time residents state that this was the worst storm
within their memory, about 40 years. Storms since that time have been of
comparatively slight intensity and have had little effect on the beach
beyond leveling the small dunes which form on the shore in front of the
main line of dunes.

"88. The storm of November, 1932, was believed to have originated
near Bermuda. Tides about 2 feet above normal were recorded and the wind
velocity was about 50 miles per hour blowing from the northeast at Daytona
Beach. Unusually high waves in advance of the storm were noticed on the
teach.

189. The officer in charge of the U. S. Coast Guard Station at Flag-
ler Beach reported that the beach in that vicinity was lowered about 2 or
3 feet but that in no place was the bluff eroded more than 1 or 2 feet
shoreward. The beach along the section known as "The Rocks", between
Flagler Beach and Matanzas Inlet, Plate 8, was lowered considerably,
undermining parts of the coquina outcrop and causing them to drop about
3 feet.

"90. The erosion between Ormond Beach and Coronado Beach was more
severe. The beach was lowered from 2j to 4 feet. The high unprotected
sand bluffs were eroded from 20 to 75 feet. Along those sections where
there were short disconnected bulkheads the banks were washed out behind
the bulkhead









causing failure in some cases. Where there were longer more substantial
bulkheads, there was comparatively little damage beyond the lowering of
the beach.

"91. At the concrete automobile ramp at Ormond Beach, the beach was
lowered about 3 feet exposing the lower end of the ramp. In the section
from Ponce de Leon Inlet northward for 6 miles the seaward line of high
dunes was completely washed away destroying about one mile of paved high-
way which paralleled the coast just shoreward of these dunes. At Coronado
Point, on the south side of Ponce de Leon Inlet, the storm waves broke
through a low point in the barrier ridge of dunes, a few hundred feet
south of the inlet, and water 4 feet deep flowed across the ridge and
into the Hillaborough River. South of Coranado Beach erosion was less
severe.

"92. Shortly after this storm, fine coquina shell began to appear
in quantity at Daytona Beach. This movement of shell continued for
about two years in such quantities as to soften the beach surface and
present a considerable handicap to automobile traffic. During the past
year of two the movement of shell has apparently decreased or stopped
altogether since only a comparatively small amount of the coquina is now
found at Daytona Beach. The movement may have originated during the
storm in the stretch of beach north of Ormond, particularly at "The
Rocks" where a great deal of shell is constantly being placed on the
beach by disintegration of the coquina rock.

"93. A comparison of photographs taken immediately after the 1932
storm and at the same places in February, 1937, shows that the losses
caused by that storm have been entirely replaced so far as the elevation
of the beach itself is concerned. Where the large dunes were badly
eroded north of the inlet the beach is wide and small dunes are forming
on the back berm."

DISCUSSION

'94. The geological history of this section of the Florida coast
and a study of the effect of the November 1932 storm indicate that the
presence of coquina outcroppings both at the beach and offshore has a
material effect upon the general coast line which is beneficial by
exerting a stabilizing effect. The offshore outcroppings stabilize the
offshore and those on the beach slow down the process of erosion and
at the same time furnish material for the beach. The material eroded
from the coquina outcroppings does not appear to migrate very far from
its source during normal conditions, or else in migrating it becomes so
finely divided as not to be noticeable. During periods of severe storms
the accumulation of disintegrated coquina near the outcroppings may be
carried out some distance from shore by wave action and upon return of
normal weather conditions be moved in the direction of littoral drift
and appear on the beach some distance from the source.

"95. In regard to alleged erosion in the vicinity there is some
discrepancy between statements by long time residents of Daytona Beach.
Some believe that there has been a considerable movement landward of
the mean high water line while others believe there has been little or
no movement in the past 40 years. The shoreline changes for the 62
years, 1874 to 1936, Plate 3* show that between Ormond Beach and New
Smyrna Beach, there has been no permanent recession except in the
vicinity of the inlet where the north lip receded and the south lip
extended northward. The ocean shoreline immediately south of the inlet
as far as Coronado Beach receded as the inlet moved northward. Since
1928 there has been a recession of about 50 feet for a distance of two
miles below Daytona Peach and a like recession along the front of New
Smyrna Beach.
N*ot reproduced here. -8-










"96. The changes in the offshore depths up to 24 feet below
mean low water, between 1925 and 1936, show a flattening of bottom
slope north of the inlet and a steepening south of the inlet. Be-
yond the 24-foot depths north of the inlet the long profiles shown
on Plate 4inrdicate accretion wall offshore at Ormond Beach but
erosion at Daytona Beach and to the south. These latter profiles
show that the bottom between two miles and ten miles offshore is
very flat with depths of about 60 feet below mean low water.

"97. The buLLum amplone and offshore borings did not show any
considerable concentration of shell which would account for the
presence at certain times of patches of shell on the beach. The
bottom samples together with the beach samples showed that at the
time of the survey the greater concentration of shell in the samples
occurred near shore. Practically all samples containing 105 or more
of shell occurred within depths of 6 feet below mean low water with
the percentage increasing near the low water line. The beach from
Ormond to New Smyrna consists of a foot or two of fine quartz sand
covering a mixture of sand and shell.

"98. During the storm of November, 1932, the accumulation of
shell on the beach at "The Rocks" was completely removed. Shortly
after this storm fine coquina shell began to appear in quantities
in the vicinity of Daytuna Beauch. This movement continued for about
two years in such quantities as to form many soft pockets in the
beach and to make it unsafe for high speed automobile driving. During
the past two years this movement of shell to the beach has practically
ceased. A comparatively small amount of the shell is now found. This
absence of shell may be attributed to either of two causes; the lack
of disturbing storms or accumulations of additional fine sand on the
beach which has resumed its fair weather conditions and so covered up
the shell deposits.

"99. Shell arising from disintegration of outcrops of coquina
located at "The Rocks" travels southward under wind and wave influence
and arrives in varying volumes at the sand beaches in the vicinity of
Daytona Beach. This shell usually appears at some interval after the
storm which initiated the muvementL roum "The Rocks". Shell becomes
comminuted more rapidly than silica sand and is more readily dissolved
and dissipated in salt water. Much of it is probably removed from
beach drift by this action. That which remains is not distinguishable
from silica sand by a visual examination but can be detected by leach-
ing with hydrochloric acid.

100. The fine quartz sand on the local beach has two possible
sources of supply which are probably jointly responsible for its pre-
sence. Some sand drifting down the beach through the northward shell
area probably continues its southward movement through the shell areas
and immediately offshore and feeds the beaches to the south. A second
source of supply of sand to the beaches is the erosion of the adjacent
sand dunes. Storm waves attack the toe of these dunes with a severity
in proportion to that of the aLurs and the eroded material is dragged
into the sea with that removed from the beach and is available for
return to the beach upon the return of fair weather and moderate wave
action.

101. The evidence obtainable indicates that, except during the
two years following the storm of November, 1932, the undesirable con-
dition of shell pockets on Daytona Beach is not increasing. During the
early speed trials on the beach, the speeds were so much lower that
soft spots were not a serious drawback. It is only since the speeds
have increased to over 270 miles per hour, requiring a speedway about
12 miles long for starting and stopping, that the pockets of coquina
have proved such a serious menace.


*Not reproduced here.


-9-










CONCLUSIONS

"102. The results of this study show that although there has been
erosion of the dunes between Ormond and New Smyrna during times of high
storms, there has been no serious or permanent recession of the high
water line. The offshore area is stable and material removed from the
foreshore by storms is replaced after a return to normal conditions.

"103. Patches of coquina shell on the Daytona Beach area are
caused by storm waves removing accumulations of shell from the beach in
the vicinity of "The Rocks" and upon a return to normal condition the
movement of this shell onto the beaches to the south. The amount of
shell to the north of Ormond will furnish a fairly good indication of
when shell may be expected to appear again in large quantities at
Daytona Beach.

"104. The predominant littoral drift along this section of the
coast is from north to south. A long jetty extending to the 24-foot
depth curve at the southern end of the shell beach north of Ormond would
in all probability prevent the movement south of all except finely
divided shell. Such a structure would prevent to a large extent the
littoral movement of sand from the north and would partially starve the
beaches to the south.

"105. An effective method of preventing a recurrence of large
quantities of coquina shell on Daytona Beach would be the construction
of a bulkhead or seawall the entire length of the shell beach from
Matanzas Inlet to a point a short distance above Ormond Beach. This
bulkhead would have to be placed at the present low water line to hold
the present accumulation of shell and to prevent further disintegration
of the outcropping coquina. While there is some disintegration of the
offshore outcropping of coquina it is believed that this is relatively
small and that it is continually being moved from its source and so does
not form accumulations. The cost of such a structure would be pro-
hibitive.

"106. The prevention of erosion of the dunes at Daytona Beach and
New Smyrna during high storms can be accomplished by the construction of
a bulkhead at the foot of the dunes. This bulkhead would not be attacked
except during heavy storms and then for only a short period. The cost of
such a bulkhead of steel piling or creosoted wood would be approximately
$40.00 per linear foot. It is not believed that this protection would be
justified except in the fully developed sections where the damage caused
by further erosion would destroy valuable property. The erosion of the
dunes is a probable source of sand supply for the beach. Preventions of
this erosion might have a harmful effect on the beach.

"107. It is the opinion of the Board that there is no serious problem
of erosion over the area covered by this study. No indication was found
to show that the driving beaches have deteriorated or will deteriorate to
an extent to prohibit use at other than racing speeds. Any possible con-
struction with a view to prevent soft spots from accumulation of coquina
shell in the interest of racing is considered so expensive as to be Im-
practicable.






































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