Title: Surface Water in Florida
Full Citation
Permanent Link: http://ufdc.ufl.edu/WL00002905/00001
 Material Information
Title: Surface Water in Florida
Physical Description: Book
Language: English
Publisher: Fla Engineering and Industrial Experiment Station
Spatial Coverage: North America -- United States of America -- Florida
Abstract: Richard Hamann's Collection - Surface Water in Florida
General Note: Box 12, Folder 1 ( Materials and Reports on Florida's Water Resources - 1945 - 1957 ), Item 19
Funding: Digitized by the Legal Technology Institute in the Levin College of Law at the University of Florida.
 Record Information
Bibliographic ID: WL00002905
Volume ID: VID00001
Source Institution: Levin College of Law, University of Florida
Holding Location: Levin College of Law, University of Florida
Rights Management: All rights reserved by the source institution and holding location.

Full Text

Surface Water in Florida*


Surface water is the water which is moving above
the surface of the ground. It makes no difference in
the definition whether a moment before it was, or a
moment later it will be, beneath the surface of the
ground. Surface and ground water are closely interre-
lated, especially in a land of low, flat relief like Florida.
Water may change its habitat, so to speak, several
times before it reaches the sea. In its defined channels
surface water occurs as rivulets, brooks, branches,
creeks, rivers, lakes, ponds, sloughs and marshes, and
variations and combinations of these forms.
The circulation of the earth's water supply, sparked
by the sun, is called the hydrologic cycle. The origin
of all water in the hydrologic cycle, as far as the land
surface of the earth is involved, may be considered as
being precipitation. Of course, the water in the at-
mosphere is replenished by evaporation, the largest
part of which comes from the ocean. The ocean is
estimated to hold about 95 per cent of the water on
the earth, with most of the remainder frozen in the
polar ice caps or as permafrost; it yields to evaporation
an estimated 80,000 cu. mi. per year, or 88 million
billion gallons.
In Florida, according to the U. S. Weather Bureau,
average rainfall ranges from 46 in. to 64 in. per year.
The areas of lower rainfall are centered in Levy
County on the west coast, in the lower Kissimmee
Valley, and along the upper east coast; the areas of
higher precipitation are in the southeastern part of
the peninsula and in extreme west Florida. The
average annual precipitation for the state is 53 in.
In addition to this water from precipitation, water
flows into Florida from the neighboring states of Ala-
bama and Georgia via several streams.
Essentially all water is moving, whether above the
ground or beneath the ground; therefore, water can
be considered as a transient or recurring resource.
We can't hoard or stockpile it except in minor amounts
but we can control it to some degree, and abuses of
this vital resource can be reduced.
Surface water has many uses, some of which com-
pete with each other. In Florida surface water is
used for the following: industrial, municipal, and rural
water supplies, steam power, irrigation, navigation,

*Publication authorized by the Director, U. S. Geological
tU. S. Geological Survey, Ocala, Florida.

dilution for wastes, fish and wildlife conservation, and
recreation. In Florida recreation is a most important
use and a most valuable contribution to the economy
of the state. Five million people each year visit this
state for recreation. The State Chamber of Commerce
estimated that in 1952 the tourist industry brought
$900,000,000 worth of business into Florida. It is
true that many of the tourists visit the coasts, but there
are many who probably would not come here were it
not for the beautiful lakes and inland waterways of
the state.
Most rivers in Florida tend to be sluggish because
of the comparatively flat topography and correspond-
ingly low slopes. Approximately 50 stream basins
drain the state. The longest river wholly within the
state is the St. Johns, whose main channel runs north
from its headwaters near the Indian River-St. Lucie
County line southwest of Vero Beach, nearly 300 miles
to the Atlantic Ocean opposite Mayport. At the head-
waters of the main stem of the St. Johns, the elevation
of the water surface stands between 20 and 25 ft. above
sea level, which gives a very small amount of fall
in a river for so long a distance. The drainage area of
the St. Johns River is about 8,000 sq. mi.
A few of the other larger stream basins wholly with-
in the boundaries of Florida are the Kissimmee, 2,910
sq. mi.; the Oklawaha, which is a part of the St. Johns
basin, 2,130 sq. mi.; the Withlacoochee-the one in
the west-central part of the peninsula-about 2,000
sq. mi.; the Peace, about 1,700 sq. mi.; the Santa Fe, a
tributary of the Suwannee, 1,440 sq. mi.; the Wacca-
sassa, about 1,100 sq. mi.; the Hillsborough, 690 sq. mi.;
the Aucilla, 680 sq. mi.; the Steinhatchee, 580 sq mi.;
and the Fenholloway, 470 sq. mi. The St. Marys, of
course, is the boundary between Georgia and Florida
in the northeastern part of the state. The Suwannee
has a drainage area of about 10,000 sq. mi., half of
which is in Georgia. The Apalachicola drains 17,000
sq. mi. before it reaches Florida. West of the Apalachi-
cola are several large streams and innumerable smaller
ones-the Choctawhatchee draining 4,640 sq. mi.; the
Yellow, 1,390 sq. mi.; the Blackwater, 868 sq. mi.; the
Escambia, 4,220 sq. mi.; and the Perdido, 919 sq. mi.;
all of which drain part of Alabama.
South of Lake Okeechobee natural well-defined
streams are few. Manmade canals remove the water
that once stood in shallow sheets or moved very slowly
southward through the Everglades. After these canals

I _

were dug it was learned that uncontrolled drainage was
not the best method of utilizing the reclaimed lands
and that a plan of water control was necessary for
maximum benefits and for conserving the soil in the
area. Now a comprehensive project is under con-
struction, but that is a subject on which a number of
papers have been written, one of which is on this
program. Suffice it to say that there are about 4,400
sq. mi. in the southeastern Florida drainage area, with
[our major and several minor drainage canals.
Lake Okeechobee, having an area of 700 sq. mi., is
the second largest fresh-water lake wholly within the
boundaries of the United States, being exceeded in
size only by Lake Michigan. Its principal outlets for
control purposes are the Caloosahatchee River and
the St. Lucie Canal, and connected to it are the Ever-
glades canals, which sometimes flow toward the lake
and sometimes away from it.
Of lakes, Florida has an abundance. Estimates of
the number run as high as 30,000. The larger ones,
in addition to Okeechobee, are Lakes George, Apopka,
Istokpoga, Tsala Apopka, Crescent, Orange, and Loch-
loosa; the group around Leesburg and Tavares-Lakes
Dora, Harris, Eustis, and Griffin; the chain in the
Sanford area-Harney, Jessup, and Monroe; the upper
Kbisimmee group-East Tohopekaliga, Tohopekaliga,
C)press, Hatchineha, and Kissimmee; the upper St.
Johns chain-Blue Cypress, Washington, Winder, and
Poinsett; southwest of Lake Okeechobee lies Lake
Trafford; and, of course, there are many, many more.
The yield of the various watersheds in Florida
varies from area to area and from time to time. The
distribution as to time largely parallels the time distri-
bution of the rainfall. Although the distribution is
more even in Florida than in other parts of the country,
there are dry and wet seasons. The streamflow pat-
tern in western Florida is similar to that of other
southeastern states; however, the seasons of high and
low water in peninsular Florida are different from
those in all other parts of the country. The eastern
part of the country has its high water in the winter
and early spring, while in the west high water usually
corner in early and late spring. Peninsular Florida
usually has its high water in the fall. In other parts of
the country, excluding peninsular Florida, low-water
periods usually occur in the fall and early winter,
while in Florida the low-water season is usually in the
eaill summer.
Nlaximum annual discharges of streams in the
United States range widely from as much as four times
the average to as little as one-fourth of the average,
while in Florida maximum annual discharges range
only hrom twice the average to one-half the average.
This makes Florida's water situation more favorable

than in many other states because the more the flow,
the better suited it is for most purposes.
Springs are of tremendous benefit to Florida
streams, particularly during the low-water season
when they sustain the flow of the streams. Florida has
17 springs of the first magnitude-those which have an
average flow of more than 100 cfs (65 mgd)-more than
any other area of like size in the country. The Snake
River basin in Idaho has 15 such first magnitude
springs and the Ozark region of Missouri has 12. Silver
Springs, at more than 800 cfs, and Rainbow, at about
700 cfs, are among the largest springs in the United
States. Of second magnitude springs-those between
10 and 100 cfs (6.5 to 65 mgd)-Florida has 49.
Runoff-the discharge of water in surface streams-
varies considerably from place to place in Florida. In
general, owing to differences in a number of factors-
principally geology, topography, vegetation, and evapo-
ration-we find that peninsular Florida has consider-
ably less runoff than west Florida. In west Florida
average rainfall is higher than in peninsular Florida
north of Lake Okeechobee, but the difference is not
enough to account for the much larger amounts of
runoff in west Florida.
To give a comparison of the difference in runoff,
an analysis has been made of a 7-year period, 1947-53,
of basins wholly within the state. The average runoff
shown by the Geological Survey's gaging station records
has been converted to inches per year over the respec-
tive watersheds. This gives a generalized appraisal of
runoff which can be compared with annual rainfall.
The accompanying map of Florida (Fig. 1) shows
lines of equal average annual runoff for the period
It should be kept in mind that the period selected
was slightly wetter than normal. The years 1947, 1948,
and 1953 were wet and the four years, 1949-52, were
dry, and the sum of the departures from normal for
the wet years is more than the negative sum for the
dry years, with the result that the average annual rain-
fall for the seven years-statewide-was 7 per cent above
normal. This period was selected for analysis because
of the better areal coverage in the gaging of streams
during this time than during earlier periods.
With concentrated discharges of ground water into
surface streams such as where large springs exist, and
especially when this ground water crosses surface drain-
age lines, many anomalies are evident on a runoff map.
Therefore, the map is not intended to convey the
meaning that each unit of area contributed equally,
but to show, as far as practicable, the areal variation
in the state.
For the period 1947-53 the average yearly runoff
ranges from less than 5 in. to more than 80 in. In



Figure 1. 25



eninsular Florida the average runoff ranges from 10
o 15 in. and in west Florida from 10 to 30 in. In areas
where large springs discharge into surface streams the \
measured runoff increases sharply. For example, the
)klawaha River between Moss Bluff and a point just
bove Silver Springs has an average of only about 5
n. of runoff annually, whereas the next area down-
tream, which includes Silver Springs, shows an average
unoff of 25 in. Another example is in west Florida.
confina Creek, draining 150 sq. mi., shows a runoff
f 52 in. a year for the period studied, whereas no
their area in that part of the state has a runoff of more
han 30 in. a year. The area of the Santa Fe River
rainage basin between High Springs and Fort White
s unusually high in runoff, which is due to pickup
rom ground water. Here it appears that more than
0 in. runs off an area of 130 sq. mi. This is an in-
PrPetinc river in that th T*rlo l tre rr-,r IdA f



.... eam g. oes JI oI...L n unIHJL erfl -S
ground for about three miles near O'Leno State Park.
After it emerges from the ground it usually has a
considerably different amount of flow. It apparently
gains flow from the ground during low-water periods
and loses during high water, but it is between High
Springs and Fort White that the large gain occurs.
The annual runoff from the entire United States
has been estimated to be about 9 in. Average annual
precipitation over the United States is estimated to
be about 30 in., of which about 21 in. is lost to evapor-
ation and transpiration. In Florida the statewide
average runoff is estimated to be 14 in. per year. As
this is the residual from an average rainfall of 53 in.,
the average loss is 39 in. The runoff includes ground-
water discharge into streams before they reach the
ocean but, of course, does not include the discharge of
offshore springs, which are known to exist.
For all practical purposes, the annual runoff repre-

sents the upper limit of the water potentially available
for development. Florida is now using something over
a billion gallons of water per day for all uses. Florida's
average annual runoff of 14 in., if spread uniformly
over the year, would be at the rate of 40 billion gallons
per day, which leaves a large margin of safety.
Records of streamflow extending back for 25 years
indicate that if all streams in Florida were flowing
simultaneously at their minimum rates-a very un-
likely occurrence-the total flow of all streams in the
state would be 7 billion gallons per day, which
is still considerably more than is being used at this
time. This is not to say that Florida has no problems,
but it is more a question of distribution of the water
resources than it is of the total quantity.

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