Volume 14 Number 1 February 1975
Reprinted from the
WATER AND WATER PROBLEMS IN THE
SOUTHWEST FLORIDA WATER MANAGEMENT DISTRICT
AND SOME POSSIBLE SOLUTIONS'
Garald G. Parker, CP.G.
ABSTRACT: It is estimated that by about 1984 water demand in the District will nearly equal
Nature's average annual replenishment of the supply and that, thereafter, unless means are
developed to augment our in-District resources, water mining will be required on a grand scale.
Sources of augmentation include: (1) reduction of wastes; (2) industrial recycling of pre-
viously-used water: (3) use of municipal sewage effluents; (4) desalination of brackish ground
water; (5) aquifer recharge from all available, high-quality sources, particularly flood waters;
and (6) importation of excess waters from such out-of-District sources as the lower courses of
the Suwannee and Apalachicola Rivers. To achieve maximum beneficial uses of in-District
sources a regional water and sewer authority is needed that can develop and transmit water
from all available sources to the various county and city systems on a wholesale basis. It is
envisioned that such a supply system would tie together all production sources, much as the
electrical generation and supply systems are currently organized into regional electric power
hookups. At least two bills are currently before the Florida Legislature to achieve these goals.
Each of us has, at one time or another, suffered some problem caused by too much
water when we did not need it or too little water when we did need it. Here in the
Southwest Florida Water Management District (SWFWMD), a day seldom passes that
water or water-related news does not make headlines in the newspapers or command
prime time in TV and radio reporting.
As a matter of fact, the District (Figure 1) was formed as a result of four consecutive
years of excessive precipitation beginning in 1957 and culminating in the disastrous
floods associated with Hurricane Donna in September, 1960 (Parker, 1973). This must
have wrung Nature's rainmaking machines dry because we have not had a flood since!
Subsequently, beginning in 1961, the District has experienced only two years of
rainfall in excess of normal. All the rest, 11 out of 13, have been years of deficiency,
totalling 104.15 inches at the Tampa station and 86.98 inches at the Lakeland station; for
Tampa, this is about equivalent of a normal two-years rainfall (Figure 2). These records
are indicative of why streamflow during these years has reached new records for
SPaper No. 74072 of the Water Resources Bulletin. Discussions are open until August 1, 1975.
2Certified Professional Geologist, Chief Hydrologist and Senior Scientist, Southwest Florida Water
Management District, P. O. Box 457, Brooksville, Florida 33512.
WATER RESOURCES BULLETIN
VOL. 11, NO. 1 AMERICAN WATER RESOURCES ASSOCIATION FEBRUARY 1975
long-term low flows. why lake levels have likewise set new long-term low stages, why the
wet prairies, swamps. and marshes are mostly dry or their storage greatly depleted, and
whyv the normally wetlands now look "high and dry" as many of the land-sales promoters
are telling gullible customers.
Figure 1. Index map of the Southwest Florida Water Management District.
However, in and surrounding those areas of the District where large ground-water
withdrawals occur, the drought effects have been compounded and made much more
severe by ground-water pumping. These effects are especially prominent in and surround-
ing the major municipal and industrial well fields in the upper Tampa Bay area. For
example, Pinellas County's Eldridge-Wilde. and St. Petersburg's Cosine-Odessa and Sec-
tion 21 well fields all produce water from that part of the upper Tampa Bay area which is
largely drained by Brooker Creek.
Since these well fields came into heavy production, beginning about 1961 and with
notable increase beginning in 1963, Brooker Creek's flow regimen has been drastically
altered. Double-mass analysis indicates that, by 1963, the average flow of the creek had
been reduced by about 50 per cent. This flow reduction was accompanied by notably
lowered ground-water levels over the entire upper half of Brooker Creek basin, by low-
ered lake levels to a greater extent than lakes outside the Brooker Creek basin, and by
severe stresses on the vegetation in formerly swampy areas in and immediately adjacent to
the well fields. These stresses were brought about by the lowered water levels which
SCA.E iN MOOES
-I -----;- ..- ---------- --7- ---- -,--. -.- I
WATER PROBLEMS IN SOUTHWEST FLORIDA 3
uW: Chart based on data
compiled from NATIONAL
WEATHER SERVICE Records.
IN IACHES ABOVE WO BELOW NRiWL.
CIMM As *arreA. 9Tr97 AWN AVrMU \AL
19RSIS 1 O -/97N m.W11A
1985 19W0 t96 1910
25 mo Charts prepared
SMMU1 T S suiCt
5- Olive, low
RAINFALL for TAMPA
r7 /N INCHES ABOVE OR BEOW Nd*MAL-
NORMAL- 51.57 In.
635 BASED ON PERIOO
/OF RECOR /1931'/960
: i.. *:-!. ,
;1221 I t IO N
CUMULATIVE E/ARTW7 MrOM NO MAL "
PERID /ft//-IV73 /04.15 A (~nwuS)
Figure 2. Graph of rainfall departure from normal at the Tampa
and Lakeland National Weather Service Stations, 1950-1973, inclusive.
dropped the water table below the root zone and caused the demise of many species of
water-loving plants such as cypress trees, willows, cat-tails, wax-myrtle and many others.
It is obvious that pumping from these major well fields has preempted about one-half of
the available water crop from the Brooker Creek basin, thus worsening the drought
The District. as with other parts of the Floridan Peninsula, has a history of flood
alternating with drought. but when the population was sparse and water-supply needs
were small. these vagaries of nature were more in the nature of nuisances than of serious
consequences. Also, in those early days. settlements and roads were generally not built on
the floodplains of the streams. in the deep swamps, or on man-made lagoonal islands only
a few feet above sea level. These are places where, in the normal course of weather events,
damaging floods not only can be expected to occur but do happen. Today our population
is growing at an unprecedented rate about 6.300 persons a week are now moving into
Florida and the District is getting more than its share of these newcomers (known to the
oldtimers here as "snowbirds"): and too many of these new Floridians settle on flood-
prone lands, all too often enticed there by unscrupulous developers. It is estimated that.
because of such occupation of the floodplain of the Hillsborough River where it passes
through Tampa and Temple Terrace. the damages to property alone caused by the March.
1960 hurricane, which dropped more than 27 inches of rain in a four-day period.
amounted to more than six million dollars (SWFWMD. 1971). The above estimated losses
do not include damages to lawns. shrubs. automobiles, or to the inconveniences, sickness.
and other human misery associated with such floods. Should a similar flood hit this area
in the near future, the damages would doubtless be many times greater unless ways and
means are quickly effected to alleviate such inundations.
It was for these purposes, chiefly, that the State Legislature established the Southwest
Florida W\ater Management District in 1961 by enacting Chapter 61-691. Florida Statutes.
As established, the District encompasses about 10,400 square miles including all or parts
of 15 counties in central-western Florida (Figure 1). This area makes the District about
the same size as the State of Maryland and larger than any of the following states:
Connecticut. Delaware. New Hampshire. New Jersy. Massachusetts. Rhode Island. or
Under authority of Chapter 378. Florida Statutes. known as the Flood Control Act.
the District is empowered to cooperate with agencies of the federal government to effect
flood-control and water management. It also provides for and establishes a water-
resources development account in the State's general revenue fund. This fund provides
financial assistance to the District as grants-in-aid for purchase of lands to be used as
water-storage or flood-detention areas, and reservoirs.
The U. S. Congress, in 1962. established the Four River Basins Project as described in
House Document 585. 87th Congress, 2nd Session. 1962. Under this authority flood-
control and flood-alleviation works were begun cooperatively in October, 1962 by the
District and the Corps of Engineers. Figure 3 shows the locations of the major elements
of this huge project.
Since that time work has progressed on the Four River Basins Project. but not nearly
as rapidly as was scheduled. mostly because of lack of necessary funds to actively pursue
the project works. Should another "wet" hurricane, such as Donna, strike the District
within the next few years. it would find the Green Swamp and Little Withlacoochee
Flood Detention Areas (F)A's) in the Green Swamp not constructed. likewise the Upper
Hillsborough and Lower Hlillsborough River FDA's are unconstructed; and at the down-
stream end of the project. the Tampa Bypass (anal, designed to carry flood waters
around the Tampa urban area. is currently (May, 1974) about half completed. Not only
ias the plroect lagged badly but the protection the project would provide is totally
unavailable and will be until the works are completed a date that now cannot be
ltiecast. This lag in needed construction has become one of our majoi problems, and is a
- i -:;-';~'----L-------- _-_--__ _
WATER PROBLEMS IN SOUTHWEST FLORIDA
i. '" .
NREEN SWA MPI
Four River Basins Project, Florida, U. S. Army Corp of Engineers
will be ca hi
River floods north of State Route 40 (S.R. No. 40). This despite the fact that much of
P. I A..
Figure 3. Map of the Southwest Florida Water Management District of the
Four River Basins Project, Florida, U. S. Army Corp of Engineers
in cooperation with the Southwest Florida aa after Management District.
nagging one. We cannot afford to undergo another Donna, yet if it comes, the damages
will be catastrophic.
Some other parts of the Four River Basins Project have fared better because the local
projects are smaller and the costs are much lower a good example is the Oklawaha River
Basin. There a new and efficient lock and dam are in operation at Moss Bluff. Dikes and
levees have been repaired after a massive break this past summer in the right-bank levee
just upstream from Moss Bluff, and the silted-up downstream channel has been dredged
out to restore the full carrying capacity of the channel. But the closing down of the Cross
Florida Barge Canal Project has rendered the efficient handling of floods in the lower
Oklawaha River highly uncertain. There are now no sure means of handling Oklawaha
River floods north of State Route 40 (S.R. No. 40). This despite the fact that much of
the roadfill bordering the Oklawaha channel at S.R. No. 40 bridge has been removed to
increase the flood-carrying capacity past the bridge. The channel from S.R. No. 40 to the
St. Johns River simply may not handle huge floods.
Destructive as they are when such major catastrophes occur, floods are a sometime
thing as Porgy sang of women in "Porgy and Bess." But our biggest problem is one that
we have with us always and that grows bigger and more complex every day: water supply.
How and where.are we to obtain the fresh, clean water that our burgeoning population
requires? How shall our available water-resources be appraised, conserved and protected,
developed, transported, and sold to the several millions of new customers now flocking to
this District? These are major problems to those concerned with providing and managing
our water supplies.
Too many citizens, including many of the land developers, have either failed to recog-
nize the problem or have chosen to ignore it. To these people one simply turns on the
faucet and the water gushes forth. Or, if existing supplies run low, one just drills more big
wells anywhere they are needed and the water pours out millions of gallons a day,
without end, either from flowing artesian wells or, where the wells do not flow, by means
of big pumps. And this attitude itself is a tremendous problem to overcome, particularly
because in the past, some "water experts" have told the people that we have far more
water here than we could ever need and also, perhaps, because our conventional wisdom
tells us that, since we get an average of 55 inches of rain a year, we are therefore water
rich beyond all our future needs.
j' The fact is. however, that we are only comparatively water rich compared to a
desert, for example. Later in this paper, we will develop an understanding of approxi-
mately how much fresh water is available for use, but next, let us look at where our water
comes from and where it goes.
Figure 4, a potentiometric map of the District for May, 1973, was prepared by the U.
S. Geological Survey as a part of our cooperative program with them. The potentiometric
map shows, by means of contours on the artesian pressure surface, the height above mean
sea level at which water in wells tapping the Floridan Aquifer stood in May, 1973. Water
levels are measured in hundreds of such wells, converted to mean sea level (msl) altitudes,
and contours drawn by the U. S. Geological Survey cartographers to represent the potent-
Water in the aquifers flows "down hill" or down gradient much as it does on the land
surface. Thus, it flows from high altitudes to lower altitudes and, in doing so, each flow
path or flow line in the aquifers must cross any given potentiometric or water-table
contour at right angles and must reach the next lowest contour in the shortest distance
possible. On a plane surface this would be a straight line, and sometimes in aquifers the
flow lines are straight, but more commonly they are curved. The arrows on Figure 5
indicate directions of regional flow and generally they fly from highest points of recharge
to lowest points of discharge. Note that the Green Swamp High is the highest point of
recharge shown on the map. 120 feet above msl. and that there are only two other such
major highs: (1) the Pasco High. about 30 miles west; and (2) the Putnam Hall High,
about 100 miles north. Both of these latter highs top out at 80 feet msl. Water flows out
radially in all directions from each of these three major ground-water recharge highs in
the peninsula and. by drawing lines along drainage divides, as on Figure 6. one can define
ground-water basins that are self-contained hydrologic units.
The principal hydrologic divide that needs to be recognized is one that separates north
S and west Florida from central and south Florida. It is herewith formally named the
Peninsular Florida Hydrologic Divide and is shown by the heavy line (Figure 6). The
divide begins on the Gulf Coast at Cedar Key. passes west and north of the Waccasassa
River Basin through Bronson and continues northeasterly about to Lake Geneva, then
turns southeasterly through Putnam Hall almost to Palatka, then on past Satsuma,
Crescent City. and Seville to New Smyrna Beach on the Atlantic Coast. At no place along
'ts entire length does any flow cross this major divide except where the line crosses the
WATER PROBLEMS IN SOUTHWEST FLORIDA
) .. .. .
POTENTIOMETRIC SURFACE OF FLORIDAN AQUIFER
SOUTHWEST FLORIDA WATER MANAGEMENT DISTRICT
U GEOLOGICAL SURVEY
SOUTHWEST FLORIDA WATER MANAGEMENT DISTRICT
BUREAU of GEOLOGY
FLORIDA DEPARTMENT of NATURAL RESOURCES
C E C
Figure 4. Potentiometric map of the Southwest Florida Water
Management District and surrounding area for May, 1973 conditions.
SH E N DR Y
I igure 5 I'tenti~mietric map with arrows indicating
directions ot rclional iflo in I loridan Aquifer.
H E RY
.L.,;,- .L .~
WATER PROBLEMS IN SOUTHWEST FLORIDA
POTENTIOMETRIC SURFACE OF FLORIDAN AQUIFER
SOUTHWEST FLORIDA WATER MANAGEMENT DISTRICT
EU'E A S UE
SFiLuWES- 'LI -U AA'E" U C ULEWECS 3US'fC-
FLR" SA -DEPlR YVEf' '-' AL E :
SALT- WATER ENCROACH-
.MENT ZONE BORDERED
INLAND BY 250 MG/L
ISOCHLOR AT -100
,P PENINSULAR HYDROLOGIC
S HE ND'
. .. "EP _EN O R .
Figure 6. Potentiometric map showing major hydrologic divides and salt-water
encroachment zone in the Southwest Ilorida Water Management District.
tidal estuary of the St. Johns River south of Palatka. Note that not a single flow-arrow
crosses it: instead they either fly away from it or, in some places are parallel to it. We
conclude from this map. and other related hydrologic studies made by scientists of the U.
S. Geological Survey. the Florida Bureau of Geology, and of the Southwest Florida Water
Management District, that, despite old wives' tales to the contrary, there are no myster-
ious underground streams flowing down from the mountains of Tennessee, Kentucky,
West Virginia, the Carolinas, or even from Alabama and Georgia to emerge here in our
District or, for that matter, anywhere south of the Peninsular Hydrologic Divide. We
are as effectively separated from water sources north of the divide as we would be if we
were living on an island. In fact, we might well say that we do live on a hydrologicc
island", and from this draw the highly important conclusion that we are totally depend-
ent for all of our water supplies on precipitation that falls on the land south of this
all-important hydrologic divide.
Florida's average annual rainfall ranges from about 40 inches in the lower Keys to
about 64 inches in the Everglades and in a small area over Okaloosa and Walton Counties
in the Florida Panhandle (Hughes et. al., 1971). State-wide it averages about 56 inches
and District-wide about 55 inches. This seems like a lot of water and it is. In fact, 55
inches of water falling on only one square mile amounts to about 957 million gallons, and
over the approximate 10,000 square miles of our District, this means that every year, on
the average, we receive as rainfall. 9.57 trillion gallons of water. Yes, it is a lot of water!
The trouble is, we have no way of capturing a large part of this water for our use.
Evaporation from wet surfaces and transpiration by plants and animals, collectively called
evapotranspiration, gets the first cut and that share is about 40 inches, or nearly 73
percent of all the rain that falls! (Visher and Hughes, 1969; Parker, G. G., 1971) This
amounts to a loss per square mile of 696 million gallons or a District-wide loss of about 6
trillion. 960 billion gallons every year.
We can, to a limited extent, increase the available water crop by the storage of as much
of the flood flows as possible. Lacking deep valleys in which to build large and efficient
surface storage reservoirs, we must depend upon shallow, temporary storage in flood
detention reservoirs (FDA's. Fig. 3). In the FDA's we can capture some flood water that
otherwise would have wasted to the sea and hold it for periods of up to about six weeks.
Holding a pool of water much longer than this would kill or damage flora and fauna of
the FDA's; even holding the storage this long may be ecologically harmful. Such tempor-
ary storage will allow for some direct seepage recharge into the subjacent aquifers and
also will permit time for the transfer of some of this water by conduits to other areas
where the water table has been lowered. Such sites have large additional subsurface
storage capability. They exist mostly in and around each of the large well fields. Addi-
tionally. by proper location and judicious pumping of our larger future well fields in the
FDA's, much induced recharge and storage will be developed. This will increase the rate
and volume of ground-water storage and effectively increase the water crop. The amount
of increase cannot now be accurately forecast but may be as much as twenty (20) per
The quantity left over from the original 55 inches of precipitation after the 40-inch
loss to evapotranspiration, is only 15 inches. Of this residual, about 14 inches runs off as
streamflow to the Gulf or Atlantic Ocean and 1 inch discharges to the same places in the
form of ground-water flow. The above calculations presuppose that our surface-water and
ground-water storage remain relatively constant from year to year and in general, over
the period of record, this has been the situation.
WATER PROBLEMS IN SOUTHWEST FLORIDA
This 15 inches of water received annually as recharge to our aquifers and as runoff in
our streams is essentially all that man could ever even hope to capture for his uses, and we
will call this our potential water crop. The ultimate available water crop that can be
harvested for consumptive use when our District is fully developed is much smaller,
perhaps 1/3 to 1/4 of this. Currently, in the Upper Tampa Bay area where the big well
fields have been developed (Fig. 7), we are evaluating the total water crop at 13.4 inches
(640,000 gpd/mi2) and the available water crop (in this instance the allowable develop-
able part of the water crop) at 10.7 inches (480,000 gpd/mi2).
Additionally, at least until future studies shall permit better understanding of the
water crop locally available in other parts of the District, we are currently applying these
values District wide. When sufficient local data are available, revisions will be made as
required. Chances are, this will generally cause some reductions in the values now being
In making these value judgments, we recognize that the water resources are not now
fully developed. Perhaps in some places such as the Upper Tampa Bay area, they are,
instead, about one-half developed. Thus, at the present time, we may be safe in allowing
so large a developable fraction of the total new water that nature supplies us with each
j year. We recognize, too, that as more and more land developments in the area occur and
as each new occupant of currently undeveloped land demands his just share of that part
of it recharged on his own land, the time may come when 100 per cent of the water crop
will be demanded.
However, if all the 15 inches of the total water crop of the District were harvested and
consumptively used, our streams would dry up and cease flowing, an intolerable situation.
So let us be cautious and plan to leave ultimately at least 2/3 of the annual runoff. This
would maintain the streams in a reasonable good state, and allow us to capture for
consumptive use up to 1/3 of the potential water crop. That would give up about 5
inches, which is 87 million gallons a year (mgy) per square mile or 870 billion gallons a
year (bgy) District-wide. Reducing this to a daily value, 870 bgy equals 2.38 billion
gallons a day (bgd). This is the estimated size of our possibly available water crop for
consumptive uses. How many persons would this support, and how many persons are we
expecting to have to support in the future? The answers to these questions are a measure
of the quantity-of-water problems we face, to say nothing of the quality-of-water prob-
But some informed people hold that we really do not have any water problems at all -
S we only have people problems; and others say that we do not have water problems we
only have money problems. To some considerable extent both these statements are true
because if people would space themselves out where the water is abundant and not waste
it, there would be no major problems; or if we were to spend all the money needed either
to import water from such large sources as the Suwannee River or the Apalachicola, or
desalinate the tremendous quantities of brackish ground water and the limitless quantities
of ocean and Gulf waters, or renovate and reuse our municipal sewage, there would be
more than enough fresh water for all but at a large cost. But these cliches beg the
question. In the first instance, we do have the people, more and more of them everyday,
and in the second instance, the costs involved are enormous and people are not yet
desperate enough to pay such prices for fresh water.
As mentioned earlier, about 6,300 new immigrants move to Florida weekly. We will
not take time or space here to develop the population explosion story in the District, for
that would be a story all of itself; suffice it to say that the 1.75 million we had in 1970 is
^ s r
s g a
c v *
^ :- r^
*a c n
S -0 C
WATER PROBLEMS IN SOUTHWEST FLORIDA 13
conservatively expected to grow about as follows: 1.93 in 1975: 2.13 in 1980; 2.41 in
1985; 2.74 in 1990; 3.10 in 1995 and 3.50 in 2000. These are values I have developed,
based on my best judgment of rapidly changing economic and demographic sets of
conditions (Figure 8).
a I i-'
J9O 320 3 20
I 2 ,- 2-1
r ti us
-0 ,Po ,,
R 1701270 41
m i e AVAILABLE WAiTER CROP toIN DISTRICT (68 u a e u3
0s 2W20 -2~20 *
19170 19 w100 19 190 20 100
require? This s difficult to estimate but based on our past experience, the per capital use
might be expected to increase. According to Murray (1968), our national water use in
1965 was 1.600 gallons per capital per day (gpcd) and by 1970 this had increased to 1,800
gpcd (Murray and Reeves, 1972). Here in the District, we probably use considerably less
than this because we do not have either the intensive industrial development of the
industrial East or tie expansive irrigation of the irrigated West. We do have, however, a
tremendously large phosphate industry in the Upper Peace and Alafia River Basins that
currently uses about 250 mgd (which is about five times as much water as Tampa now
uses) and a huge citrus try industry in the same area that, including both irrigation and citrus
processing, uses about 200 mgd. Their combined use of water in the past 20 or so years,
has caused a lowering of the potentiometric surface over about 350 square miles of 40 to
60 feet, and over nearly 1,300 square miles of 20 to 40 feet. Obviously, ground water is
being mined in this area at a rate far exceeding Nature's annual recharge rate (Stewart et
Whereas in a smaller SWFWMD country village, the gpcd usage rate may be about 60
to 75 gpcd and in the larger, non-industrial towns or cities the usage rate may be about
125 to 225 gpcd (Healy, 1972), I estimate that, District wide, our current usage is about
1.000 gpcd: this is considerably higher than municipal use rates because of the very large
water requirements in the phosphate and citrus industries, which generally are self-
supplied. However, I do not look for the District use rate to increase because the urban-
ization process is gradually replacing irrigated acreage with housing developments which
require far less water, acre-for-acre; furthermore, the phosphate industry should reach a
peak about 1990-1995, and thereafter reduce its requirements for water as the mines
gradually become exhausted of ores, probably about 2010-2030. It is of importance to
note that. up to about the close of 1971, the phosphate industry's total use of water had
gradually increased to about 350 mgd whereas, as noted above, it is now about 250 mgd.
This largely resulted from District pressures on the industry to eliminate waste of water
and to reuse water again and again in a variety of recycling processes. Not only has the
industry cut back its pumpage, while at the same time increasing the industrial output,
S but the cutback has reversed a previously steady dropping of the water levels in the area.
In 1972 and 1973 water levels rose regionally in the phosphate district's big cone-
of-depression for the first time in more than 25 years. In parts of the area the rise was as
great as 18 feet and over nearly 1.000 square miles it was about 10 feet. This is a partial
solution to one of the great problems that we attacked shortly after our regulatory
powers became active in January 1970. A benefit to be expected resulting from the
phosphate phase-out shortly after the turn of the 21st Century will be the new avail-
ability of about 250 mgd formerly used by the phosphate industry. This will be a
tremendous boon to water-supply needs of the population of the District at that time.
Even though it is not expected that the rate of use will increase, this burgeoning popula-
tion may use, by the year 2000, about twice as much water as we now use, or 3.5 bgd
(Fig. 8). Producing this water without unduly lowering water levels in the aquifers, or
causing streams to dry up, or causing unacceptably lowered lake levels, or causing or
creating a greater sink hazard than now exists, or causing salt-water encroachment on an
accelerating scale, or drying up the marshes and swamps, or other economic and social ill
results, will take a great deal of careful planning and well executed developments based
on a greatly increased and detailed fund of hydrogeologic and hydrobiologic knowledge
than is now available.
Let us give this increased need for water some detailed consideration. The water-
demand curve (Figure 8) indicates that demand is expected to equal Nature's annual
usable recharge by about 1984, just 10 years hence. If this is correct, by about 1984 we
will begin mining water on a wide scale all over the District. Thiscould not be tolerated
very long, particularly in the shore zone along the Gulf Coast where already an en-
croaching wedge of salt water has been mapped (Figure 6). Further lowering of fresh
water levels in the coastal zone would inevitably result in additional salt-water encroach-
ment and further loss of wells and perhaps of additional well fields.
It will be recalled that both Tampa and St. Petersburg lost their original downtown
well fields in the late 1920's due to salt-water encroachment. Yet old-timers tell us that
originally fresh water was available in shallow wells right down to the shoreline all along
the Gulf Coast, even as it formerly was in the Miami area along Biscayne Bay. Not many
know that recently New Port Richey's well field became salty, or that hundreds of
privately-owned wells in the coastal zone from upper Pinellas County northward have
recently been ruined by salt-water encroachment.
The cause for this problem here in the District's west coast (Cherry, Stewart and
Mann, 1970) are basically the same as those causing the well-known Dade and Broward
County salt-water problems, namely an areal lowering of water levels in the coastal zone
(Parker et al. 1955). Some small part of this lowering is attributable to pumping from
wells, but most of it has been caused by dredging the estuaries and lower reaches of such
streams as the Anclote, Pithlachascotee, and other small coastal streams, as well as a
proliferation of stub-end finger canals along the shoreline to make "water-front" home-
sites available with salt-water access to the Gulf or the Bay. Some channels have been
WATER PROBLEMS IN SOUTHWEST FLORIDA 15
dredged for drainage purposes, as those in the Rocky Creek and Sweetwater Creek basins.
All such tidal canals and channelized natural streams thus become arms of the sea,
introducing salt water far inland and spreading salty water along their entire inland
reaches where previously only fresh water existed. Also, they introduce sea-level condi-
tions into areas of former higher, fresh-water levels, and eventually reduce the fresh-water
head to sea level along their channels and inland considerable distances. This results in
upsetting a long established equilibrium between fresh-water and salt-water in the aquifer
resulting in a deep wedge of salt-water replacing the lighter, overlying fresh-water (Parker,
1955) thus the salt-water canals and channels bring about a two-fold attack in the fresh-
water in the coastal zone: (1) at the surface where salt-water from the canals and channels
seeps downward and outward from the walls and floors of the channels; and (2) at depth
in the aquifer by inland movement of the salty water from the Gulf (Reichenbaugh,
1972; Parker, 1945).
Another problem of water supply relates to the big coastal springs of our District and
their potential for water supply (Mann and Cherry, 1969). At first thought this appears to
be a reasonable prospect, but a glance at the salt-water zone in Figure 6, shows that all
but one of the big Coastal Springs, Weeki-Wachee, lie within this zone and Weeki-Wachee
lies barely outside of it. Crystal River Springs is a complex of big and small springs in the
estuary of Crystal River; the average flow is about 590 mgd. Homosassa Springs (135
mgd) and Chassahowitza Springs (130 mgd), like Crystal River, all are affected by tides
and all to some extent are contaminated by salt-water. Taking municipal-supply water, in
amounts exceeding only a few mgd, directly from any of these big tide-affected springs
would be only to invite further salt-water contamination. Weeki-Wachee (115 mgd) is
now only slightly contaminated with a total dissolved solids content of 70 mg/1 but it,
too, could experience a sudden rise of salinity, should its water level be lowered a few
feet by pumping.
Total flow of these four big coastal springs averages 970 mgd, or enough water at 200
gpcd for non-industrial and non-irrigation communities totalling about 4.850,000
persons. But, with Weeki-Wachee currently excepted, to be so used the water would have
to be desalinated; and before even this relatively expensive means would be utilized the
riparian rights of property owners abutting on the springs or the rivers that flow there-
from would have to be purchased, leased or otherwise obtained. This might be done;
however, many property owners would probably not want to sell their riparian rights. In
such cases it would require condemnation in the courts and could delay the acquisition of
water rights for a long time.
Granted that riparian rights might be obtained, another big hurdle would be satisfying
the State and Federal agencies charged with protecting the environment especially the
biologic community that taking a large part of the flow of the big springs would not
upset the long-established equilibrium between the relatively fresh-water flow of the big
coastal springs and the highly saline seawaters of the Gulf of Mexico. It is the brackish
mix of these two waters upon which the entire food web of the estuaries, coastal bays
and other tidal inlets depends. Causing the salinity of these waters to increase markedly
might be disastrous to the nursery areas for game and food fishes and for the shell fishes
of this part of the coast.
Development of additional large water supplies from those big springs that have been
turned into tourist attractions would run into stubborn and costly opposition from the
operators as well as from the tourist industry of the State.
All these are serious problems to be overcome. It is my personal belief that no water
should be taken directly from any of these big coastal springs. Instead, in the coastal strip
several miles inland, a dispersed system of small well fields or single large wells could
intercept some of the spring discharge. How much and just where these interceptions
would occur would depend on studies now being undertaken by the U. S. Geological
Survey as a part of their cooperative program with the District. and by District hydro-
geologists working on this project with consulting hydrologic firms. I would hazard the
estimate that about 250 mgd could be so developed, a supply sufficient for a new
population of about 1.25 million people in the coastal zone of Citrus, Hernando, Pasco
and northern Pinellas Counties. However, such development cannot be made haphazardly
or by independently-operating local communities. It should be accomplished as part of a
regional water-supply and sewerage authority, empowered to own, develop and operate
wells, well fields, pipelines, pumping stations, treatment plants, and other essential
elements of a regional developmental and wholesale water-supply authority. Its function
would be to produce and deliver to county-wide and city water-supply systems water at.
wholesale rates for their retail sales within their areas of responsibility.
Perhaps the biggest problem of all that is related to solving the water-supply needs of
our burgeoning population, is getting the various counties and cities to work together
harmoniously and cooperatively in solving their water problems. To date, and in the
foreseeable future say to the year 2000 it appears that water supplies for the inland
counties and cities can be developed without incurring serious difficulties, largely because
water levels in these upland areas are much higher than along the coast and most impor-
tantly because they are miles distant from encroaching salt-water from the Gulf of
Mexico. But not so for the populous zone developing in coastal counties such as
Hillsborough, Pinellas. Pasco. Hernando, Citrus, and Levy Counties.
Hillsborough and Pinellas, the two largest users, include Tampa and St. Petersburg and
are rapidly outgrowing current supplies. These two cities, as mentioned previously, lost
their well fields to salt-water encroachment in the late 1920's. Tampa dammed the nearby
Hillsborough River and this surface-water supply, augmented by up to 20 mgd pumped
from nearby Sulfur Spring, has carried them, with some difficulties during dry seasons, to
the present time. However, the Hillsborough River's low-flow regimen prohibits further
development of that source. As a result, the city is now planning to utilize ground-water
from a six square-mile well field in SWFWMD's Lower Hillsborough Flood Detention
Area (Figure 7). Later, a standby well field near Thonotasassa may be put into service.
These sources should supply the city with about 60 mgd and another 10 to 20 mgd could
be made available from the Tampa Bypass Canal which, in effect, is essentially a huge,
horizontal well tapping the highly permeable Tampa Limestone, the upper member of the
Floridan Aquifer. With this additional water made available from the Tampa Bypass
Canal. Tampa's water requirements should be satisfied to at least the year 2000.
Northwest Hillsborough County, previously a rural region of mostly citrus and cattle
grazing with large areas of wet prairies, cypress strands, bayheads and lakes, is now
rapidly becoming urbanized (SWFWMD, 1973). Formerly sparsely populated when St.
Petersburg put its first inland well field (Cosme-Odessa) into operation in 1932 and later
another well field, (Section 21) in 1963, the area now appears to be the fore-runner of
another Los Angeles-type sprawling, un-coordinated and unplanned area of growth. Into
this same area, in 1956. another well field, Pinellas County's Eldridge-Wilde was estab-
lished (partly in Pinellas and partly in Hillsborough). As population grew and pumpage
increased from about 8 mgd in the early days to about 80 mgd total 1973, pressures grew
for more and more water. So a fourth well field, St. Pete's South Pasco, was put into
WATER PROBLEMS IN SOUTHWEST FLORIDA
service in 1972. Sites are shown on Figure 7.
In the meantime trouble was brewing in the Northwest Hillsborough area where
numerous shallow wells went dry. Lake levels, too, fell drastically, particularly some of
those with leaky bottoms situated near the big wells fields, and it was noticed addition-
ally that vegetation began showing signs of stress. All this coincided with the drought
years that began in 1961 (Figure 2). The falling water levels and dying vegetation were
attributed by local residents to pumping and by the well-field operators to the drought.
Definitive hydrologic records were not available and, to some extent still are not, to fix
causes and point the way to solution. However, with the activation of the SWFWMD
(Regulatory) on January 1, 1970, efforts were begun by the new, small District staff to
begin collecting needed data. Also, the U. S. Geological Survey cooperative data program
was enlarged to enable the Survey to gather systematic hydrologic and geologic data
particularly relating to the relationship of the water-table aquifer to the Floridan Aquifer.
This program is continuing, but no amount of current coverage can ever make up for data
not gathered in prior years on rainfall. evapotranspiration, recharge, runoff and water use.
So the fundamental problems of cause-and-effect of drought vs increased well-field
pumpage, drainage operations, roadbuilding, new homes, etc. have not been adequately
solved to date (SWFWMD, 1973). Additional time and records will be needed to evaluate
the real effects of all the factors bearing on the matter.
To visualize pumpage effects of the well fields. Figures 7 and 9 were prepared. Figure
7 shows, by means of calculated concentric potentiometric drawdown contours around
only three of the major well fields, the depth and area covered by the cone-of-depression
where pumpages are as indicated. These circles approximate actual drawdowns and spread
of the cones-of-depression as measured and mapped by the U. S. Geological Survey in
their quarterly water-level mapping of the area. The overlapping of the cones-
of-depression indicate the effects of well-field interference. It is obvious that these well
fields were placed too closely together to produce such large water quantities.
Figure 9 graphically presents, by calculated circular areas surrounding each major well
field, the area in square miles that is required to supply the recharge to the aquifers which
provides the water pumped from each well field. The size (area) of each circle was
determined by using an average value of recharge equal to 650,000 gpd per square mile.
Earlier it was indicated that currently the District is using 640,000 gpd/mi2 as the total
water crop and dividing this into the quantities pumped. The value of 650,000 was an
earlier quantity used. Thus, where a well field is pumping 50 mgd, 76.9 square miles of
recharge is required. It is readily seen that, again, large well-field overlapping effects
occur, another indication that the well fields are too closely spaced together.
The spacing of these well fields and the quantities of water which they were designed
to produce are not in harmony with the hydrogeology of the region. I venture to say that,
had the SWFWMD been in existence in the 1950's prior to the development of the
existing, operational well fields, none of them or possibly only one, would have been
located where they now are; nor would the District ever have permitted the fields to be
pumped at the high rates they have been pumped in recent years. The problems asso-
ciated with these well fields are problems the District has inherited. To help solve these
problems the District formally adopted Order 73-1D which established an officially desig-
nated Water Shortage Area (Figure 7) within which certain restrictions are applied on
pumpage, irrigation, drilling of new wells and the waste of water.
Needless to say, the problems related to the lowering of water levels in the Upper
Tampa Bay Region, especially in the vicinity of each of the big well fields, have caused
1.49 Sq. Mi.
4.15 Sq. Mi.
B0 MED 4
..... n s1.. \9,
" "co:"P 1 ODSSA 46.15 Sq.M. HILLSBOP
:w-_ 250 AtV/L C/#saoj
BW ayE :& AT- -IWO FT MSL,
Figure 9. Map of calculated areas required to produce the recharge needed to
supply pumpage from the major well fields in the Upper Tampa Bay region.
I I -
- --- x -~II-'----
WATER PROBLEMS IN SOUTIIWI ST FLORIDA
violent reactions. A "water war" lacking only shot-gun and dynamiting activities, has
been going off and on during the past two decades. However, a conciliatory pact was
agreed upon between the contending parties and the District when, on November 14,
1973, St. Petersburg and Pinellas County agreed to accept reduction cuts on production
from their well fields, and Pasco County agreed reluctantly to the joint development
of another big well field in the County. This is the source to be developed on the site of
the District's Cypress Creek F.D.A. (flood detention area). An agreement, facetiously
called "a treaty", was signed by representatives of Pasco, Pinellas and Hillsborough
Counties, the City of St. Petersburg, and the District.
Thus, a short-term solution to some of our most urgent water problems seems to have
been reached. However, bickering still continues and a long-term solution still has not
been reached. Basic to this solution will be the development of a plan. on which our Staff
is currently working, to develop for useful purposes all the available water crop in the
District that can be taken for consumptive uses without either harming the environment
or the holdings of the property owners. But this undertaking is a difficult assignment and
already objections are being raised to the exportation of any water from inland areas of
the District to the coastal areas where the fresh-water supply need is the greatest. Already
Pinellas County has outgrown its water supply: so have coastal parts of Hillsborough and
Pasco Counties. To the south, in the lower Peace River Basin and other urbanizing coastal
areas of Charlotte and Sarasota Counties, local fresh-water supplies are currently inade-
quate. The Tampa Bay area cannot look southward for new supplies, nor, with the
urbanization taking place along the 1-4, U. S. 27 and U. S. 17 corridors to the east, can
the Tampa Bay and northern coastal strip along U. S. 19 look eastward to the Green
Swamp. The only way is north, and this means to the landward strip in Pasco, Hemando,
Citrus and Levy Counties lying east of the big springs and the salt-water encroachment
zone and generally west of the Withlacoochee River; also a possibility exists of the
inclusion in the State Water Plan of export of excess flows from such big up-state streams
as the Suwannee and the Apalachicola. In any event, an aqueduct would need to be built
to transport water from the water excess areas of the north to the growing urbanizing
areas of the south, somewhat as California has done.
However, as indicated earlier, going northward into the Withlacoochee and Waccasassa
Basins or into the Suwannee or Apalachicola basins where excess water now exists, will
meet with strong resistance. It can only be achieved when a regional water-supply system
is established which is incorporated into a workable and acceptable State Water Plan that
will guarantee to supply and protect the water resources of this entire rapidly-growing
region. Several bills have been introduced in the legislature to establish such a regional
water-supply authority and a State Water Plan is currently being prepared, but only time
will tell who and what that authority will be and the new sources of water that will be
tapped. However, this appears to be the only way out of our water-supply water-
demand dilemma. The quicker the authority and the State Water Plan are established the
better for all concerned.
Cherry, R. N., Stewart, J. W. and Mann, J. A., 1'97(. General hydrology of the Middle Gulf Area,
Florida: Florida Department of Natural Resources. Bureau of Geology, Report on Investigations
No. 56, 96 p., Tallahassee, Fla.
Healy, H. G., 1972, Public water supplies of selected municipalities in Florida, 1970: Florida Depart-
ment of Natural Resources, Bureau of Geology, Information Circular No. 81, 213 p., Tallahassee,
Hughes, G. H., Hampton, E. R. and Tucker, D. F., 1971, Annual and seasonal rainfall in Florida:
Florida Department of Natural Resources, Bureau of Geology, Map Series No. 40, Tallahassee, Fla.
M\ann, J. A. and Cherry, R. N., 1969, Large springs of Florida's Suncoast, Citrus and Hemando
Counties. Florida: Florida Department of Natural Resources, Bureau of Geology, Leaflet No. 9, 23
p., Tallahassee, Fla.
Murray, C. R., 1968, Estimated use of water in the United States, 1965: U. S. Geological Survey,
Circular 556. 53 p., Washington, D. C.
Murray, C. R., 1972, Estimated use of water in the United States, 1970: U. S. Geological Survey,
Circular 676, 37 p., Washington, D. C.
Parker, G. G., 1945, Salt-water encroachment in southern Florida: American Water Works Association
Journal, Vol. 37, No. 6, p. 526-542.
Parker, G. G.. 1955a, The encroachment of salt water into fresh, in The Yearbook of Agriculture,
1955: 84th Congress, 1st Session, House Document No. 32, p. 615-635; 723, Washington, D. C.
Parker, G. G., Ferguson, G. E. and Love, S. K., 1955b, Water resources of southeastern Florida with
special reference to the geology and ground-water of the Miami Area: U. S. Geological Survey,
Water-Supply Paper 1255, 965 p., Washington, D. C.
Parker, G. G., 1971, From the Desk of the Chief Hydrologist: The Hydroscope, Vol. 2, No. 11, p. 3,
Southwest Florida Water Management District, Brooksville, Fla.
Parker, G. G., 1973, Highlights of water management in the Southwest Florida Water Management
District: Ground Water, Vol. 11, No. 3, p. 16-25, Brooksville, Fla.
Reichenbaugh, R. C., 1972, Sea-water intrusion in the upper part of the Floridan Aquifer in coastal
Pasco County, Florida: Florida Department of Natural Resources, Bureau of Geology, Map Series
No. 47, Tallahassee, Fla.
SWFWMD, 1971, Environmental statement regarding Tampa Bypass Canal, p. 22, Brooksville, Fla.
SWFWMD, 1973, Environmental Assessment of Upper Tampa Bay Watershed in Hillsborough, Pasco
and Pinellas Counties, Florida: Southwest Florida Water Management District, October 12, 1973,
122 p., Brooksville, Fla.
Stewart, J. W., Mills, L. R., Knochenmus, D. D. and Faulkner, G. L., 1971, Potentiometric surface and
areas of artesian flow, May 1969, and change of potentiometric surface 1964 to 1969, Floridan
Aquifer, SWFWMD, Florida: U. S. Geological Survey Hydrologic Atlas HA-440, Washington, D. C.
Visher, F. N. and Hughes, G. H., 1969, The difference between rainfall and potential evaporation in
Florida: Florida Department of Natural Resources, Bureau of Geology, Map Series No. 32,