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“Florida is blessed with water. Water makesthe difference between desert and flourishinggreen plants, as much of the land around theearth at the same latitude is desert.” — Peggy Lantz, The Florida Water Story

Florida is, indeed, blessed with water.Yet you cannot see most of Florida’s freshwater: it seeps beneath the ground throughsand and gravel and flows through cracksand channels in underlying limestone. Theamount of ground water under Florida’sforests, pastures, cities, marshes, roads,schools and suburbs is mind-boggling:more than a quadrillion gallons. This isequivalent to about one-fifth of the waterin all five of the Great Lakes, 100 times asmuch water as in Lake Meade on theColorado River, and 30,000 times the dailyflow to the sea of Florida’s 13 major rivers(Conover 1973). In fact, Florida has moreavailable ground water in aquifers thanany other state.

Florida also has abundant surfacewater in springs, rivers, lakes, bays andwetlands. Of the 84 first-magnitudesprings (those that discharge water at arate of 100 cubic feet per second or more)in the United States, 33 are in Florida —more than in any other state. WithinFlorida’s boundaries are approximately16,000 kilometers (10,000 miles) of riversand streams and 7,800 lakes (Kautz et al.1998). Although more than half of Florida’soriginal wetlands have been drained ordeveloped (Noss and Peters 1995), the statestill has vast and diverse wetlands. TheFlorida Everglades and Big Cypress Swampcover much of southern Florida, and someFlorida wetland communities, such asmangrove swamps and hydric (wet)hammocks, rarely occur in other states.

In Florida, ground water and surfacewater are connected, often in complicatedand changing ways that are invisible at theland’s surface. Lakes may disappear intosinkholes, springs may bubble upthrough new breaks in underlying

Chapter 3

Florida’s Water Resources

KEY IDEASKEY IDEASKEY IDEASKEY IDEASKEY IDEAS

• Most of Florida’s water is ground water.• No rocks. No water.• Ground water is replenished by rainfall.• Surface water in the form of rivers,

lakes, bays and wetlands is abundant.• Much of Florida has a karst terrain

with sinkholes, underground cavernsand an active interchange betweensurface water and ground water.

• Pollution on the land’s surface mayend up in drinking water.

• Wetlands perform many valuablefunctions and are protected by lawfrom development.

• Estuaries are nursery areas for manysport and commercial fish andshellfish.

VOCABULARYVOCABULARYVOCABULARYVOCABULARYVOCABULARY

Alluvial river

Aquaculture

Aquifer

Blackwater river

Brackish

Discharge

Drainage basin

Estuary

Fill

First-magnitudesprings

Karst

Recharge

Runoff

Sheetflow

Sinkhole

Spring

Spring-fed river

Streamflow

Tributary

Watershed

Wetland

50

rocks, and water may flow one way at theland’s surface and quite a different wayunderground. This is because much ofFlorida has what geologists term a karstlandscape.

Karst landscapes are underlain bylimestone (mostly calcium carbonate), asoluble rock composed of shell fragments,limey mud and sand. Limestone is easilydissolved by water charged with carbondioxide (CO

2). As rain falls, it mixes with

CO2 in the air. As it soaks through the

ground’s surface, the water gathers moreCO

2 from decaying plants. Water charged

with CO2 forms a weak acid (carbonic acid)

that reacts with limestone to dissolve it.In many parts of the world, land slopes

gradually to the sea. “One can always walkdownhill, arriving eventually at a streamthat can be followed to a river, which canbe followed to the ocean. A characteristicfeature of karst landscapes is that the landusually slopes down into closeddepressions from which the only exit isunderground” (White 1988:19–20).

The name karst derives from theSlovenian kars, meaning rock, and was first

used by the Germans to describe a highplateau in Slovenia with numerous cavesand disappearing streams. Karst is nowused to describe similar areas around theworld. Well-developed karst features mayalso be found in south-central Kentucky,the Yucatan peninsula, parts of Cuba andPuerto Rico, southern China and westernMalaysia, as well as in Florida. Rivers andstreams are few and even absent in mostkarst areas of the world. Because Floridahas high water tables and flat terrain, karstareas in Florida have more rivers andstreams than karst areas elsewhere.

Limestone banks, Suwannee River

WatershedsWatershedsWatershedsWatershedsWatersheds

Today, rather than looking at land andwater resources as separate, unrelatedparts, water managers consider theconnections within a watershed ordrainage basin. Every part of the Earth’sland surface is within a watershed. Divides(ridges, peaks or areas of high ground)separate watersheds. Because water flowsdownhill, rain falling on these divides mayflow in opposite directions, becoming partof different watersheds. For example, fromthe Great Divide in North America thecontinent’s river systems flow in oppositedirections.

A watershed is the land area thatcontributes runoff, or surface water flow, toa water body. The water resources within awatershed are affected primarily by what

happens on the land within thatwatershed. Anything on the land

within the watershed, however far

from the water body, can eventually reachand impact that water resource. Someexamples of contaminants that may bepicked up by water in the watershed aresoil particles (suspended materials) andchemicals (dissolved materials), such asnutrients, pesticides, oils and gasolineresidues.

The shape of the land defines awatershed. Water flows both above andbelow the ground from points of higherelevation to points of lower elevationthrough the force of gravity. Rainfall that isnot absorbed by the soil but flows to alarger body of water is known as runoff;runoff collects in channels such asstreams, rivers and canals. The smallchannels, in turn, flow to larger channelsand eventually flow to the sea. Thesechannels or streams are also known astributaries. The slope of the land, as well as

Photo credit: Joann Mossa

51

Surface Water Drainage

Source: Mossa 1998

52

the amount and type of vegetation and soiland the type of land use, determine the rateand amount of runoff that enters a waterbody. More water soaks through sandy soilsthan through clay soils; gentle slopes allowmore time for rain to soak into the groundor to evaporate than do steep slopes; andnatural areas generally allow more water toenter the ground than areas that are coveredwith houses or pavement. Vegetation alsoabsorbs water and slows its movement.

Florida’s karst terrain and flattopography sometimes make determiningwatershed boundaries difficult. In some

places the drainage pattern is best describedas “disjointed” because streams and riversdo not form continuous channels on theland surface (Mossa 1998) — they maydisappear underground in sinks ordepressions. Large rivers may form fromsprings issuing from the aquifer, and surfacewater watersheds may be quite different fromgroundwater watersheds. Some portions ofFlorida are poorly drained (Mossa 1998).There are few or no streams or channels inthese areas, and water flows across thesurface through extensive swamps ormarshes. This is known as sheetflow.

Watersheds

River watershed

Small local streams draining coastal regions

Lake Okeechobee integrated drainage small local streams draining into Lake Okeechobee

Disjointed drainage these areas without continuousnatural channels may drain into surrounding basins or into the sea through marshes, swamps, ground water orconstructed channels. In south Florida's managed watershed,drainage is by canals more often than by marshes, swampsor ground water.

Source: Mossa 1998

53

Aquifers

In much of south Florida, the naturallandscape has been altered with huge publicworks projects, making the region a managedwatershed. Canals, pumping stations andwater-control structures, such as dikes andweirs, have altered the watershed. The

historic swamps, marshes and associatedsheetflow are greatly altered or are replacedby urban development and agriculture anddrained by canals. Public and privateentities are responsible for water movement,especially the discharge of floodwater.

Ground WaterGround WaterGround WaterGround WaterGround Water

AQUIFERSAQUIFERSAQUIFERSAQUIFERSAQUIFERSAquifers are underground rocks that

hold water. In Florida, three aquifers areused for water supply: the Floridanaquifer, the intermediate aquiferand the surficial aquifer. Innorthwest Florida, thesurficial aquifer iscalled the sand andgravel aquifer, and insoutheast Florida it iscalled the Biscayneaquifer.

The Floridanaquifer has been calledFlorida’s rain barrel(Parker 1951) and isone of the mostproductive aquifers inthe world. Each dayFloridians use about2.5 billion gallons ofwater from theFloridan aquifer. Itunderlies 250,000square kilometers(100,000 square miles)in southern Alabama,southeastern Georgia,southern SouthCarolina and all ofFlorida. Over most ofFlorida, the Floridanaquifer is covered bysand, clay or limestonethat ranges in thicknessfrom a few feet in parts ofwest-central and north-centralFlorida to hundreds of feet insoutheastern Georgia, northeasternFlorida, southeastern Florida and the Source: Berndt 1998

54

westernmost Panhandle. Within theaquifer, water may travel quickly or veryslowly. In parts of the aquifer with cavesand large conduits, water may travelseveral miles in only a few hours. Wherewater-filled spaces are small andunderground routes convoluted, it maytake days, weeks or even years for water totravel the same distance.

In the past several decades, increasedpumping of ground water has loweredwater levels in the Floridan aquifer inseveral places in Florida and Georgia,including the Panhandle, northeastern andsouthwestern Florida, and southeasternand coastal Georgia (Berndt et al. 1998).

Recharge To and DischargeFrom the Floridan Aquifer

Water is replaced in the Floridanaquifer by rainfall that soaks into theground. This is referred to as recharge.Recharge does not occur everywhere. Insome places (mostly along the coasts andsouth of Lake Okeechobee) water flowsout of, rather than into, the aquifer. Thisis referred to as discharge. In other areas,thick clay covers the aquifer and slows orstops the downward flow of water. Areasof high recharge only occur in about 15percent of the state and include the well-drained sand ridges of central and west-central Florida. Sand is porous, whichmeans water can easily flow through it.Limiting intensive development in high

Source: Berndt 1998

55

recharge areas is critical for maintainingwater supplies: water cannot soak throughpavement.

In some parts of Florida, the Floridanaquifer is not a suitable or drinkable sourceof fresh water. In some places, it is too farbelow the surface; in other places, the wateris salty. The surficial sand and gravel aquiferis the major source of fresh water inEscambia and Okaloosa counties innorthwest Florida, and the surficialBiscayne aquifer is the major source of freshwater in Dade and Broward counties insoutheast Florida. Between the surficialaquifers and the Floridan aquifer in someparts of the state is the intermediate aquifer.This aquifer is an important source of freshwater in Sarasota, Charlotte and Gladescounties. The remainder of the state usesthe Floridan aquifer as its main source ofdrinking water.

SINKHOLESSINKHOLESSINKHOLESSINKHOLESSINKHOLESSinkholes are dramatic testimony to

the fragile nature of the limestoneunderlying the state. A sinkhole is adepression in the land surface causedwhen rainwater dissolves limestone nearthe ground surface or when the roofs ofunderground channels and cavernscollapse. Under natural conditions,solution sinkholes form slowly and expandby the gradual erosion of subsurfacelimestone caused by rainwater. Dredging,constructing reservoirs, diverting surfacewater and pumping large amounts ofground water may result in the abruptformation of collapse-type sinkholes(Berndt et al. 1998). Loss of water fromunderground cavities, compounded bydrought, may cause the overlying rock andearth to collapse. Weight on the top of thecaverns caused by heavy rains orconstruction may also result in collapse.

In early March 1998, as a drillingcompany was drilling an irrigation wellfor a future golf course in western PascoCounty, a massive sinkhole opened upand threatened to swallow the entiredrilling rig. Although the driver got therig out in time, a crane had to retrieve atruck from the 150-foot-wide, 15-foot-deep sinkhole. Shortly after this event,nearly 700 sinkholes, most only a few feetwide, appeared in the surrounding area.

While sinkholes are common in thearea, “this event was unique,” accordingto Mark Stewart, chairman of theGeology Department at the University ofSouth Florida. “I know of no other recentevent in Florida that opened so manysinkholes in one small area.”

According to Tony Gilboy,

SINKHOLE PHENOMENONSINKHOLE PHENOMENONSINKHOLE PHENOMENONSINKHOLE PHENOMENONSINKHOLE PHENOMENON

hydrogeologist for the Southwest FloridaWater Management District, thephenomenon began when thecontractor drilled a hole into theFloridan aquifer for an irrigation well.As he cleaned out the hole usingcompressed air, a commondevelopment practice, a largeunderground cavity collapsed, resultingin the large sinkhole near the drill rig.The force of several tons of dirt fallinginto the cavity caused a massivepressure wave through the aquifer,producing the nearly 700 smallersinkholes on the surrounding property.Heavy rains, which the area had beenexperiencing, may also have contributedby putting pressure on the undergroundcavities, causing them to collapse.

56

The Indians called LakeJackson in Leon CountyOkeeheepkee, meaning“disappearing waters.”Between September 13 and16, 1999, that is preciselywhat the lake did asapproximately 30 milliongallons of water drainedout of the southern portionof the lake through PorterHole Sink into the vastunderlying Floridanaquifer, like bathwater outof a tub. In a few shortdays about half of the popular 4,000-acrelake had gone dry. Water depth in the lakehad been steadily dropping during the longdry summer from a norm of 8 feet to only 2–3feet. Water levels in the aquifer also dropped.At this point, either a plug blocking thesinkhole washed out, taking the lake with it, oronce the lake level dropped below a certainlevel, the remainder drained into the partiallyopened sinkhole. With the water gone, all thatwas visible at the land surface was a canyoncut by the water and a hole 26 feet deep and8 feet wide in the Torreya Formationunderlying the lake. As the local confining unitfor the Floridan aquifer, the Torreya Formationis a combination of clays, sands and somecarbonates with relatively low permeability.Exploring the hole, Florida Geological Surveygeologist Dr. Tom Scott found a passage to thenorthwest about 20 feet into the Floridanaquifer. Several months later two passageswere visible, the one to the northwest that hadexpanded to 30 feet and one to the eastrunning about 30 feet. In the spring of 2000,the remainder of the lake, the northernportion, drained through Lime Sink.

Although some homeowners may not behappy with the loss of their lakefront property,and fishermen will have to go elsewhere,natural drainage can be healthy for a lake.

Pollutants andsediments from runoffand nutrients fromfertilizer and deadvegetation build up inthe water and on thelake bottom. When thelake is dry, the sedimentis hardened andcompacted by air andsunlight. Exposure to theair also oxidizes some ofthe nutrients. TheNorthwest Florida WaterManagement District,

Leon County, the Florida Department ofEnvironmental Protection and the Florida Fishand Wildlife Conservation Commission optedto help nature along by removing some of thenutrient-rich sediments from the dry lake bed.When the lake refills, its water quality and itsecology will be improved.

Lake Jackson is a closed basin — nowater enters or leaves the lake throughstreams or rivers. Nor does ground waterenter the lake through major springs. The lakeis totally dependent on rainfall. A return tonormal rainfall amounts should cause the laketo refill by replenishing the aquifer andpossibly plugging the sinkhole with thesediments that run off the dry lake bottom.

Lake Jackson has gone dry several othertimes during the twentieth century — in 1907,1909, 1932, 1935, 1936, 1957 and 1982.According to geologist Scott, when theSpanish arrived in the 1500s they chronicled aprairie, not a lake. In 1716, Spaniard Diego dePeña also found a vast prairie where hereported seeing over 300 buffalo and a fewcows. In 1959, another sinkhole in the lakebottom, Lime Sink, was plugged with cementand various objects as people tried to helpnature along. After draining, the lake can staydry for years, but in 1982 the lake refilled inonly three months.

DISAPPEARING WDISAPPEARING WDISAPPEARING WDISAPPEARING WDISAPPEARING WAAAAATERSTERSTERSTERSTERS

Lake Jackson Photo credit: Tom Scott

57

SPRINGSSPRINGSSPRINGSSPRINGSSPRINGSSprings are a “window” into the aquifer

from which they flow. Cool in the summerand warm in the winter, they are among themost sought-after of all the state’s naturaland scenic resources. Most of Florida’ssprings are found in the northern half ofthe state and flow from the Floridanaquifer. As rainwater enters and rechargesthe aquifer, pressure is exerted on the wateralready in the aquifer. This pressure causesthe water to move through cracks andtunnels in the aquifer. Sometimes thiswater flows out naturally to the landsurface at places called springs. When theopenings are large, spring flow maybecome the source of rivers. TheIchetucknee is an example of a river createdby a spring. Springs also make substantialcontributions to the flow of other rivers.Manatee, Fanning, Troy and Blue springscontribute nearly 368 million gallons eachday to the Suwannee River.

For thousands of years, NativeAmericans settled near springs and fishedin spring-fed streams. Spanish explorerPonce de Leon came to Florida seeking aFountain of Youth, as well as gold and othertreasures. Travelling in Florida in 1774,botanist William Bartram described waterissuing from one of the springs along theSt. Johns River as “perfectly diaphanous,”with fish appearing “as plain as lying on atable before your eyes, although many feetdeep in water” (Van Doren 1955:135).Today, springs are popular with both

tourists and residents. Many of Florida’slargest springs have been incorporated intostate parks, including Manatee, Homosassa,Silver, Wakulla and Ichetucknee. Wakulla andSilver springs have been popular locationsfor movies. Majorie Kinnan Rawlings’ TheYearling, as well as more than 100 episodesof the popular TV series Sea Hunt, werefilmed at Silver Springs. The Creature fromthe Black Lagoon and some of the Tarzanmovies were shot at Wakulla Springs.

Rain falling onto nearby recharge areasand entering the aquifer is the source ofmost of Florida’s ground water, includingwater that flows from springs. Contrary topopular belief, underground rivers do notcarry water into Florida from other states(Spechler and Schiffer 1995). Caverns in theaquifer are sometimes large andinterconnected and may transmit waterunderground for several miles, but there areno underground rivers. The 320 knownsprings in the state discharge nearly8 billion gallons of water each day, morethan all the fresh water used in the stateeach day (Spechler and Schiffer 1995).

Large withdrawals of water from wellsnear a spring can cause the flow of thespring to stop. Silt or sediments building upin the spring can also cause loss of flow. Theonly large spring in Florida known to haveceased flowing is Kissengen Spring, about4 miles southeast of Bartow (Berndt et al.1998). The spring stopped flowing in 1950(Rosenau et al. 1976).

Surface WaterSurface WaterSurface WaterSurface WaterSurface Water

the peninsula, streamflow is south. In thelower southeastern portions of thepeninsula, rivers flow east to the Atlantic.In the northeastern and east-centralportions of the peninsula, the St. JohnsRiver flows north to the Atlantic and otherrivers flow east to the Atlantic. The onlymajor river that does not flow to the gulf orto the Atlantic is the Kissimmee River,which flows south and discharges toLake Okeechobee (Nordlie 1990).

RIVERSRIVERSRIVERSRIVERSRIVERSFlorida’s largest rivers are in the

northern part of the state. Portions of thewatersheds of many of these rivers are inGeorgia and Alabama. Even the largestrivers in Florida — the Apalachicola, theSuwannee and the St. Johns — have only afraction of the flow of the continent’s andthe world’s largest rivers.

In the Panhandle, rivers flow south tothe gulf; along the west coast, rivers flowwest to the gulf. In the central portion of

58

Florida’s rivers may be classified aspredominantly alluvial, blackwater orspring-fed. Alluvial rivers, such as the greatMississippi, have large, well-defineddrainage basins, carry high sediment loads

and have large forested floodplains.These rivers typically flood each year

(usually in the winter in Florida),

depositing a rich load of sediment. All ofFlorida’s alluvial rivers are in the Panhandle.The Apalachicola, Choctawhatchee,Escambia and Ochlockonee are examples.

Blackwater rivers have dark, stainedwaters from decomposing plant materials.Typically they drain pine flatwoods andcypress swamps. Many of Florida’s rivers are

WHAT IS STREAMFLOW?WHAT IS STREAMFLOW?WHAT IS STREAMFLOW?WHAT IS STREAMFLOW?WHAT IS STREAMFLOW?

1. Select a straight area in a stream and stretcha rope across it. The rope should have marks atequal intervals. Four or five intervals should besufficient. Secure the rope across the stream.One way to do so is to tie it around trees.

2. Wade in and measure the depth of the waterbelow each of the interval marks. Calculate thearea of the cross section by averaging thedepth and multiplying by the width of thestream. OR, measure depth in three placesacross the stream in a straight line, then dividethe total by four to get the average depth of thestream. The reason you take three depthmeasurements and divide by four is to take intoaccount the shallow areas of the stream.

3. Select a length of stream to measure thevelocity and mark each end with an object suchas a rock. A distance two or three times thewidth of the stream is usually enough.

4. Measure the velocity by putting a float in thestream and using a stopwatch to measure theamount of time it takes for the float to travel fromthe upstream marker to the downstream marker.An orange or an orange peel may be used as afloat. Repeat until you have recorded velocitiesbelow each marked interval on the rope.Average the velocities and multiply by 0.85 (thisnumber corrects for the fact that velocity has onlybeen measured at the surface).

5. Calculate streamflow by multiplying thecorrected average velocity by the area of thecross section.

Professional hydrologists use specialinstruments called current meters to measurestreamflow.

Streamflow, also known as discharge, isthe volume of water passing a point in acertain amount of time. The slope of thewatershed surrounding the stream or river, thepermeability and water storage capacity of thesurrounding soils, and the rainfall pattern allaffect streamflow. Current or velocity measuresthe distance traveled by the water during acertain length of time. Velocity depends on thedepth of the stream or river, the slope andfriction due to the texture of the bottom and theshape of the river or stream channel. Velocity ishighest just under the water’s surface becausethe friction between water and air is slight.Faster currents are found at the outside of abend. The stream’s force erodes the outeredges. Slower water is found on the inside of aturn and is often where soils will be deposited,forming sandbars.

Bottom type is closely related to the velocityof streamflow. Fast water has more energyand scours or carries away all but the largestparticles of soil, sand or rock. So the bottoms offast-flowing rivers and streams are rock,rubble and gravel. These are generally foundin the upper stretches of a river system. Slowerwater allows fine particles (sand, silt and clay)to be deposited, resulting in sandy or muckybottoms.

In the United States, river discharge is mostcommonly measured in cubic feet per second.In her book Fresh Water , British Columbiannaturalist E. C. Pielou outlines a method formeasuring flow in a small stream. (Be sure toselect a stream that is safe to wade.)

Materials: rope marked at equal intervals,measuring stick, stop watch, oranges

59

blackwater types, including New River innorthwest Florida, which drains Tates HellSwamp, and the Withlacoochee,Hillsborough and Peace rivers in centralFlorida, which begin in the Green Swamp(Clewell 1991).

Spring-fed rivers are most common inthe karst regions of north-central Floridawhere limestone is close to the groundsurface. Spring water is cool year-round,and clear. The Wakulla, Silver,Weekiwachee, Rainbow and Crystal riversare spring runs issuing from five ofFlorida’s 33 first-magnitude springs. TheChipola, St. Marks, Aucilla, Santa Fe,Ocklawaha and Homosassa are alsospring-fed rivers (Clewell 1991).

Many Florida rivers are a mixture ofthese types. For example, the Suwanneebegins as a blackwater river draining theOkefenokee Swamp. As it travels south, itbecomes a spring-fed river, as manysprings contribute to its flow. As itapproaches the gulf, it has a low-forestedfloodplain characteristic of alluvial rivers(Kautz et al. 1998).

LAKESLAKESLAKESLAKESLAKESFlorida has thousands of lakes, large

and small. By far the largest (1,890 squarekilometers or 730 square miles) is LakeOkeechobee, which extends into Glades,Hendry, Martin, Okeechobee and PalmBeach counties. Lake Okeechobee, thesecond largest lake wholly within theUnited States, has an average depth of 2.6meters (8.6 feet) (VanArman et al. 1998).Most of Florida’s other lakes are alsoshallow (between 2 and 9 meters, or 6.5and 29.5 feet, deep), although a fewsinkhole lakes are hundreds of feet deep(Heath and Conover 1981). Over one-thirdof the lakes in Florida are found in fourcentral Florida counties (Osceola, Orange,Lake and Polk).

Most of Florida’s lakes were formed inthe same manner as sinkholes. Groundwater dissolved limestone, formingunderground cavities; the roof of thesecavities collapsed, forming a depression,which then filled with ground water andrainwater. Other lakes were once

depressions in the sea bottom, and stillothers were carved out by rivers.

According to Thomas Scott, manytheories exist for the origin of LakeOkeechobee, including meteorite impact,compaction of underlying rock depositsand faulting along the northern part of anancient lagoon (pers. com). Dr. Scott, ageologist with the Florida GeologicalSurvey, thinks the lake developed from alarge lagoon that existed at the northernend of the Everglades.

In addition to natural lakes, Floridaabounds in constructed lakes and pondscreated by digging into the shallow watertable for fill (sand and rock), for irrigation,mining or aquaculture (commerciallygrowing fish or other water species). Lakesand ponds are also designed and created tomanage stormwater runoff from developedareas or to serve as reservoirs.

WETLANDSWETLANDSWETLANDSWETLANDSWETLANDSWetlands is a general term for portions

of land periodically covered by fresh wateror salt water. Over the past 400 yearsnumerous words have been used todescribe these areas including swamp,tidal swamp, coastal swamp, marsh, tidalmarsh, salt marsh, salt meadow, bog, fen,morass, overflowed land and quagmire(Moss 1980). Terminology has changed aspeople’s perceptions of the value of theselands have changed. The term wetlandsbegan to appear in the 1950s, along with aconcern for the preservation of these landsas wildlife habitat (Moss 1980). In 1953, theU.S. Fish and Wildlife Service definedwetlands as “lowlands covered withshallow and sometimes temporary orintermittent waters….and holding waterlong enough to grow moist-soil plants”(quoted in Moss 1980:200). The wetlandsdefinition found in Florida law today(Chapter 373.019, FS) is based onvegetation and soil, as well as on thehydrologic conditions. Topography is nolonger considered part of the definition.Some wetlands actually have higherelevation than surrounding land.

Wetlands are often classified asswamps or marshes, depending on

60

In Florida, when a proposed land usepotentially affects a wetland, a permit isrequired. The permitting criteria first attemptto ensure that the wetland will be preserved.When some impact to the wetland isunavoidable, the permit conditions mayrequire restoration or mitigation at anothersite. Wetland mitigation usually means thatmore wetlands than those impacted will bepreserved, protected or restored either at theimpacted site or at another site.

In order to protect wetlands and theirvaluable functions, it is necessary tounderstand exactly what they are. As definedin subsection 373.019 (22), F.S., wetlands arethose areas

inundated or saturated by surface water orground water at a frequency and a durationsufficient to support, and under normalcircumstances do support, a prevalence ofvegetation typically adapted for life insaturated soils. Soils present in wetlandsgenerally are classified as hydric or alluvial,or possess characteristics that are associatedwith reducing soil conditions. The prevalentvegetation in wetlands generally consists offacultative or obligate hydrophyticmacrophytes that are typically adapted toareas having soil conditions described above.These species, due to morphological,physiological, or reproductive adaptations,have the ability to grow, reproduce, or persistin aquatic environments or anaerobic soilconditions. Florida wetlands generally includeswamps, marshes, bayheads, bogs, cypressdomes and strands, sloughs, wet prairies,riverine swamps and marshes, hydricseepage slopes, tidal marshes, mangroveswamps and other similar areas. Floridawetlands generally do not include longleaf orslash pine flatwoods with an understorydominated by saw palmetto.

Even with such a long and specificdefinition, identifying wetlands anddetermining their boundaries is not easy.Wetland determination is based on threefactors — hydrology, soil and plants.Identification and delineation are based on

Wetland boundaries appear clearly demarcated by vegetationin this picture. When this is not the case, scientists rely onhydrologic indicators and soil analysis.

FLORIDA’S LEGAL DEFINITION OF WETLANDSFLORIDA’S LEGAL DEFINITION OF WETLANDSFLORIDA’S LEGAL DEFINITION OF WETLANDSFLORIDA’S LEGAL DEFINITION OF WETLANDSFLORIDA’S LEGAL DEFINITION OF WETLANDS

applied science and require field tests.Throughout Florida, all government agenciesnow use the same method to identifywetlands. The methods are Florida-specificrather than national or global. The completemethodology is set forth in the FloridaAdministrative Code, Chapter 17-340.Simply stated, wetlands must have at leasttwo out of the following three conditions:The hydrology — Wetlands are affected bythe frequency and duration of water upon theland. There are thirteen hydrologic indicatorsof wetlands, such as water marks, algal matsand aquatic plants and animals.The soil — Wetland soils are saturated orponded long enough to develop anaerobic,or low oxygen, conditions in the upper part ofthe soil. There are twelve hydric (wet) soilindicators, such as a sulfur odor, dark colorand muck or peat.The plants — Wetlands have more plantsthat grow, reproduce or persist in saturatedor wet conditions than uplands. These arecalled obligate or facultative-wet plants.Common examples are cypress trees, willow,bull rush and cattails.

You should contact your watermanagement district before doing work in,on or around a wetland.

Source: Southwest Florida Water Management District

61

whether the vegetation is dominated bytrees (swamps) or by grasses (marshes).Cypress ponds, strands, prairies, riverswamps, floodplains, freshwater marshes,wet prairies, salt marshes and mangroveswamps are all wetlands.

Wetlands perform many valuablefunctions. They provide vital habitats forfish and wildlife. They improve waterquality by trapping nutrients such asnitrogen and phosphorus, toxicsubstances and disease-causingmicroorganisms. They slow and intercept

runoff, protect shorelines and banks fromerosion, and protect upland areas fromfloods.

Wetlands once covered half of Florida.Over one-half of these wetlands have beendrained for agriculture, flood control andresidential development. Extensive areasof remaining wetlands include theEverglades and Big Cypress Swamp insouthern Florida, Green Swamp in centralFlorida, Okefenokee Swamp near theFlorida-Georgia border, and Tates HellSwamp in northwest Florida.

Wetlands1989

Pre-1900 Wetlands

Source: Fernald and Purdum 1998

Wetlands

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8

7

17

18

6

5

4

3

21

9

10

11

12

13 15

14

16

ESTUARIESESTUARIESESTUARIESESTUARIESESTUARIESThe word estuary is

derived from the Latinaestuarium, meaning boilingtide. Estuaries are coastal areas where thefreshwater current of rivers meets theincoming saltwater tide of the sea. Waterin estuaries is brackish; that is, it is lesssalty than the seawater and more saltythan the river water. Estuaries bydefinition are unstable and change withthe tide as well as with the season. Manyplants and animals are adapted to thechanging conditions found in estuaries.Estuaries are the breeding and nurseryareas for most sea life.

Along Florida’s coasts, NativeAmericans left behind huge shell mounds,testament to the abundance of food foundin estuaries. Today, Florida estuaries stillproduce many kinds and vast amounts ofsport and commercial fish and shellfish.For example, the Apalachicola estuaryprovides between 80 and 90 percent ofFlorida’s oysters (Livingston 1983).

Florida’s estuaries vary greatly in sizeand shape. Some estuaries such as tidalcreeks and spring-fed streams entering theGulf of Mexico are only a few acres in area,whereas the mangrove forests andbrackish portions of the FloridaEverglades are 1,000 square miles. On thegulf coast many of the estuaries end inbays. On the Atlantic coast many of theestuaries are long and narrow andbordered by barrier islands.

The health of an estuary depends on

frequent but gradual changes in the amountof fresh water and nutrients it receives. Thisin turn depends on the health of wetlands.Forested river swamps and freshwatermarshes produce nutrients to feed plantsand animals in estuaries; they slowfloodwaters so that estuaries do not receivetoo much fresh water too quickly; and theyhelp keep soil from eroding and cloggingestuaries with sediment.

Data from National Oceanic andAtmospheric Administration

Florida’sEstuaries

ConclusionConclusionConclusionConclusionConclusion

The health of all of Florida’s vast waterresources depends on us. Choices we makein one place or regarding one type of waterresource may have unforeseen andundesirable consequences elsewhere.Nutrients and pesticides applied to landmany kilometers away from a pristine rivermay seep into the aquifer and end up in

the river through spring discharge. Clear-cutting forested floodplains may harm fishand shellfish by decreasing nutrients andincreasing sediment. Excessive pumping ofground water may result in saltwaterintrusion or drying of wetlands.

Yes, Florida is blessed with water. It’s upto us to use it wisely.