Water and water problems in the southwest Florida water management district and some possible solutions - March 1974


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Water and water problems in the southwest Florida water management district and some possible solutions - March 1974

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Title:
Water and water problems in the southwest Florida water management district and some possible solutions - March 1974
Creator:
Parker, Garald G. (Garald Gordon), 1905-2000
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Language:
English
Physical Location:
Box 3

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Subjects / Keywords:
Aquifers -- Hydrogeology -- Everglades (Fla.) ( lcsh )
Hydrology -- Florida -- Biscayne Aquifer (Fla.) ( lcsh )

Notes

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 previously-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.

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University of South Florida
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University of South Florida
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The University of South Florida Libraries believes that the Item is in the Public Domain under the laws of the United States, but a determination was not made as to its copyright status under the copyright laws of other countries. The Item may not be in the Public Domain under the laws of other countries.
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032968560 ( ALEPH )
891343127 ( OCLC )
G16-00645 ( USFLDC DOI )
g16.645 ( USFLDC Handle )

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WATER AND WATER PROBLEMS IN THE SOUTHWEST FLORIDA WATER MANAGEMENT DISTRICT AND SOME POSSIBLE SOLUTIONS BY 1/ GARALD G. PARKER, C.P.G. -llcertified Professional Geologist, Chief Hydrologist and Senior Scientist, Southwest Florida Water Management District, P.O. Box 457, Brooksville, Florida 33512

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WATER AND WATER PROBLEMS IN THE SOUTHWEST FLORIDA WATER MANAGEMENT DISTRICT AND SOME POSSIBLE SOLUTIONS BY Garald G. Parker, C.P.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 previously-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.

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WATER AND WATER PROBLEMS IN THE SOUTHWEST FLORIDA WATER MANAGEMENT DISTRICT AND SOME POSSIBLE SOLUTIONS BY GARALD G. PARKER, C.P.G. 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! Figure l. -Graph of rainfall departure from normal at the Tampa and Lakeland National Weather Service Station, 1950-1973, inclusive. 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. These records are indicative of why streamflow during these years has reached new records for 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 -1-

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storage greatly depleted, and why the normally wetlands now look "high and dry" as many of the land-sales promoters are telling gullible customers. This District, as with other parts of the Floridan Peninsula, has a history of flood alternating with drought, but when the population was sparce and water-supply needs were small, these vagaries of nature were more in the nature of nuisances than of serious consequences. Also, in those earl~ 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 unprece dented rate--about 6,000 persons a week are now moving into Florida and the District is gett~ng 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, auto mobiles, 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 unle~s ways and means are quickly effected to alleviate such inundations. It was for these purposes, chiefly,-that the State Legislature established the Southwest Florida Water Management District in 1961 by -2-

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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 2). This area makes the District about Figure 2.-Index map of the Southwest Florida Water Management District the same size as the State of Maryland and larger than any of the follow ing states: Connecticut, Delaware, New Hampshire, New Jersey, Massachusetts, Rhode Island, or Vermont. ( Under authority of Chapter 378, Florida Statues, 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 for -~, reser-voirs. 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 Figure 3.-Map of the Southwest Florida Water Management pistrict showing works of the Four River Basins Project, Florida, U.S. Army Corps of Engineers in cooperation with the Southwest Florida Water Management District. this ~uge project. Since that time work has progressed on the Four River Basins Project, -3-

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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 (FDA1s) in the Green Swamp not constructed, likewise the . Upper Hillsborough and Lower Hillsborough River FDA's are unconstructed; and at the downstream end of the project, the Tampa Bypass Canal, designed to carry flood waters around the Tampa urban .area, is currently (February, 1974) abou:t half completed. Not only has the project 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 forecast. This lag in needed construction has become one of our major problems, and is a nagging one. We cannot afford to undergo another Donna, yet if it comes, the damag~s 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. Thereare now no sure means of handling Oklawaha River floods north of State Route 40 (S.R.#40). This despite the fact that much of the roadfill bordering the Oklawaha channel at S.R.#40 bridge has been removed to increase the flood-carrying capacity past the bridge. The channel from S.R.#40 to the St. Johns River simply may not handle huge • -4-

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floods, but the capability would have been available had the Cross Florida Barge Canal been completed as planned. 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-resoures 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 citizns, including many of the land developers, have either failed to recognize 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 oecause 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. The fact is, however, that we are only comparatively wate~ rith-compared to a desert, for example. Later in this paper, we will develop an understanding of approximately how much fresh water is available for • -5-

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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 Figure 4.-Potentiometric Map of the Southwest Florida Water Management District and surrounding area for May_ 1973 conditions. 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 ab~ve 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 potentiometric surface. Water in the aquifers flows "down hill" or down gradient WW11A.cl1 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 Figure 5.-Potentiometric flow lines, major hydrologic divides and salt-water encroachment zone in the Southwest Florida Water Management District. 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) th_e Pasco High, about 30 miles west; -6-

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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 5, 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 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 5). 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 its entire length does any flow cross this major divide except where the line crosses the 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. Gealogical Survey, the Florida Bureau of Geology, and of the Southwest Florida Water Management District, that, despite old wives tale's to the contrary, there are no mysterious 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 l.ive on a 11hydrologic island11, and from this draw the highly -7-

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important conclusion that we are totally dependent for all of our water supplies on precipitation that falls on the land south of this allimportant 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 qallons 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 fa 11 s ! (Vi sher 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 bi_llion 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 othen-1ise would have wasted to the sea and hold it for periods of up to about six weeks. -8-

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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 temporary 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. Additionally, 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 cent. 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 storages remain relatively constant from year to year and in general, over the period of record, this has been the situation. This 15 inches of water received annually as recharge to our aqui.fers 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 13.411 (640,000 gpd/mi2) and the available water cro~ (in this instance the allowable -9-

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developable part of the water crop) at 10.7" (480,000 gpd/mi2). Additionally, at least until future studies shall permit better under standing of the water crop locally available in other parts of the District, we are currently applying these values District wide. When sufficient local datadl"li? available, revisions will be made as required. Chances are, this will generally cause some reductions in the values now being applied. 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 year. We recognize, too, that as more and more land developments in the area occurs and as each new occupant of currently undeveloped land demands his just share of that part of it recharged on his own land, of the water crop, 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 consumptive 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 tq capture for consumptive use up to 1/3 of the potentia water crop. That would give us 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 problems. -10..,,,_

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But some informed people hold that we really do not have any water problems at all--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 ff people would space themselves out where the water fs abundant and not waste ft, there would be no major problems; or ff we were to spend all the money needed either to import water from such large sources as the Suwannee River or the Apala chicola, 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 6,000 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 wo~ld be a story all of itself; suffice it to say that the 1.75 million we had fn 1970 fs conservatively expected to grow about as follows: 1.93 fn 1975; 2.13 in 1980; 2.41 in 1985; 2.74 in 1990; 3.10 fn 1995 and 3.50 in 2000. These are values I Figure 6.-A forecast of population growth and water demand compared with ayailable water crop fn the Southwest Florida Water Management District, 1970-2000 have developed, based on my best judgment of rapidly changing economic and demographic sets of conditions (Figure 6) . • How much water, for single-use purposes only, will this burgeoning population require? This is difficult to estimate, but based on our past experience, the per capita use might be expected to increase. According -11-

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to Murray (1968), our national water use in 1965 was 1,600 gallons per capita 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 the 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 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 exceedi-ng Nature's annual recharge rate (Stewart et al, 1971). 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, Distri 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 phospl and citrus industries, which generally are self-supplied. However, I do not for the District use rate to increase because the urbanization process is gra ualJy 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 becomes 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 -12-

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about 350 mgd whereas, as noted above, it is now about 250 mgd. This largely resulted from District pressures on the industry to eliminate wast~ 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, but the cutback has reversed a previously steady dropping of the water levels in the area. In 1972-73 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 wa~ 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 availabiliti of a:bout 250 mgd formerly used--by ,the ,phosphate-: ,industr--y., •: Jhi s . wi l1 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 populati-on may use, by the year . 2000, about twice . . as much water as we now use., ,or :3.5: .bgd,(f'ig . ,, .6) .a;• Producing . •this: wateft ; without.-~unduly ~ 1 1 ower.ing water . J eve ls : in the..iaqu.ifer~-Dr •.ea using ' -streams -to .,dryi up; or -causi .ng inacceptably lowered lake levels~ or causing or,creating a greater sink hazard than now exists, or causing salt-water encroacbment 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 6) shows that demand is expected to equal Nature's annual usable recharge by about 1984_ , just 10 years hence. If -13-

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this is correct, by about 1984 we will begin mining water on a wide scale all over the District. This could not be tolerated very long, particularly in the shore zone along the Gulf Coast where already an encroaching wedge of salt water has been mapped {Figure 5}. Further lowering of fresh water levels in the coastal zone would inevitably result in additional salt-water encroachment 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 in this audience know that recently New Port Richey's became salty, or that hundreds of privatelyowned wells in thecoastal 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 attriblltable 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" homesites available with salt-water access to the Gulf or the Bay. Some channels have been 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 -14-

PAGE 17

only fresh water existed. Also, they introduce sea-level into areas of former higher, fresh-water levels, and eventually fresh-water head to sea level along their channels and inland e distances. This results in upsetting a long established between fresh water and salt-water in the aquifer resulting~ dge of salt water replacing the lighter, overlying fresh water 5) thus the salt-water canals and channels bring about a two-fold e f resh water in the coastal zone: (1) at the surface where from the can a 1 s -and channe 1 s seeps downward and outward from the ,oo"oors of the channels; and (2) at depth in the aquifer by -s ,nent of the salty water from the Gulf (Reichenbaugh, 1972; . ( ~5). :: r problem of water supply relates to the big coastal springs 1rict and their potential for water supply (Mann and Cherry, 1969)". ~d!IOUght this appears to be a reasonable prospect, but a glance at T01ter zone in Figure 5, shows that all but one of the big ~-dngs, Weeki-Wachee, lie within this zone and Weeki-Wachee lies 9~1 ide of it. Crystal River Springs is a complex of big and ~,ver lgs in the estuary of Crystal(; the average flow is about _ lomosassa Springs (135 mgd) and Chasschowitza Springs (130 mgd), 11 River, all are affected by tides and all to some extent are j ~ d by salt-water. Taking municipal-supply water, in amounts exceed\:::-few mgd, directly from any of these big tide-affected springs would T:invite further salt-water contamination. Weeki-Wachee (115 mgd) , :2, slightly contaminated with a total dissolved solids content of ;-, it, too, could experience a sudden rise of salinity, should its be lowered a few feet by pumping. 11ow of these four big coastal springs averages 970 mgd, or enough -15-

PAGE 18

water at 200 gpcd for non-industrial and non-irrigational 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 therefrom 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 acquistion 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 -16-

PAGE 19

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 i, 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 wate~ supplies for the inland counties and cities can be developed without incurring serious difficulties, largely because water levels in these uplandareas are much higher than along the coast and most importantly 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. -17-

PAGE 20

Hil 1 s _borough and Pinell as, the two 1 argest 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 19201s. Tampa dammed the nearby Hillsborough River and this surface-water supply, augmented by up to 18mgd 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, Figure 7.-Map of idealized drawdowns in cones-of-der~ssion surroundinQ the Eldridge-Wilde, Cosme-Odessa, and Section 21 Well Fields for average pumpages shown in June, 1973 in the upper Tampa Bay region. 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, horizonal 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 ~atisfied 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 established (partly in Pinellas and partly in Hillsborough). As -18-

PAGE 21

population grew and pumpage increased from 5 to 8 mgd in the early days to about 80 mgd total in 1973, pressures grew for more and more water. So a fourth well field, St. Pete's South Pasco, was put into 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 well fields, and it was noticed additionally that vegetation began showing signs of stress. All this coincided with the drought years that began in 1961 (Figure 1). 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 l, 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 ~ystematic 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 fundam~ntal problems of cause-and-effect of drought vs increased well-field pumpage, drainage operations, roadbu1lding, 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. -19-

PAGE 22

To visualize pumpage effects of the well fields, Figures 7 and 8 were Figure 8.-Map of calculated areas required to produce the recharge needed to supply__E.!!_mpage from the major well fields in the upper Tampa Bay region . . 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 (fig. 8) These circles approximate actual drawdowns and spread of the cones-of-depressio 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 8 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 th, currently the District is using ~40,000 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 1 miles of recharge is required. It is readily seen that, again, large wellfield 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, -20-

PAGE 23

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 th-e high rates they have been pumped in recent years. The problems associated with these well fields are problems the District has inherited. To help solve these problems the District formally adopted' Order 73-10 which established an offically designated 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 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 District-proposed 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 representative 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 -21-

PAGE 24

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 inadequate. 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, Hernando, 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 protec1 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 -22-

PAGE 25

our water supply --water-demand dilemma. The quicker the authority and the State Water Plan are established the better for all concerned. -23-

PAGE 26

I -1 [ X PLANA TION 0..-.. ,... ••II .,... _,.._.._ .. • ... ,. 19n --60--..._...,., ................. ... ---------------------------.. ----.... ' -----.. -, -, ARROWS INDICATE DIRECTIONS Oi= RE-6IONAl-FLOW IN FLOR\DAN Aa.uu=e.R. 0 C. ..... 0 I POTENTIOMETRIC SURFACE OF HORIOAN AQUIFER SOUTHWEST FLORIOA WATER MA>,AG[M[NT DISTRICT UAY 1973 0 P,epo r•d bt us GEOLOGICAL suR,EY .;:n(I ,ne "u~EAU of ~ECL:~Y F'lOAlOA OLPAR rt.t[~T o f ,,..\ f1Jw.AL k[ SOUifC(S t't1) SOITIIWEST FI.OHIU,\ WATEII l>ISTHICT ---

PAGE 27

ll 3.70 ~t\J '-J 'J 3 .20 ..... , ~ !ti 2.70 ..: C) ~J () 2.38 () "' '2.'20 j::;: l") G: < l.70 FIG. 7.-t1 FO,?ECilST or POPULAT/0,V 6ROtVTH and WATER DEMAND COMPARED WITH A!IAILABLE WATER CROP IN SWFWMD, YEARS /970-2000. PREPARED BY = SOUTHWEST FLORIDA WATER MANAGEMENT DISTRICT I Jon.'Z2, l914 . Population and Water Demand AYA/lABLE WATER CROP /NO/STRICT IC370 l
PAGE 28

-..:.. •' . . ,:

PAGE 29

I i..REA lOTALU' OEWATERED OF AVERAGE DAILY RECHARGE WITH PLANNED MIN/-MUM 1-'UMPAGE ' RATE S . C rews Lake CYPRESS CREEK W ELL FIE L D 1.49 ~Q. Ml. 30 MGO 4'1.IS SQ. Ml j{ MORRIS BRIDGE WELL FIELD


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