U.S. Department of the Interior 

U.S. Geological Survey

Aquatic Habitats in Relation to River Flow in 

the Apalachicola River Floodplain, Florida

U.S. Geological Survey Professional Paper 1594

Prepared in cooperation with the

Northwest Florida Water Management District
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Aquatic Habitats in Relation to River Flow 

in the Apalachicola River Floodplain, Florida

By Helen M. Light, Melanie R. Darst, and J.W. Grubbs

U.S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 1594

Prepared in cooperation with the 

NORTHWEST FLORIDA WATER 

MANAGEMENT DISTRICT

The research described in this document was conducted as part of the Apalachicola River 

and Bay Freshwater Needs Assessment developed by the States of Florida, Alabama, 

and Georgia, and the U.S. Army Corps of Engineers for the Alabama-CoosaTallapoosa/Apalachicola-Chattahoochee-Flint River Basins Comprehensive Study.

1998
U.S. DEPARTMENT OF THE INTERIOR 

BRUCE BABBITT, Secretary

U.S. GEOLOGICAL SURVEY 

Thomas J. Casadevall, Acting Director

The use of firm, trade, and brand names in this report is for 

identification purposes only and does not constitute 

endorsement by the U.S. Government.

Library of Congress Cataloging in Publications Data

Light, Helen M.

Aquatic habitats in relation to river flow in the Apalachicola River floodplain, Florida / by Helen M. Light, Melanie R. Darst, 

and J.W. Grubbs.

p. cm. — (U.S. Geological Survey [professional paper ; 1594)

"Prepared in cooperation with the Northwest Florida Water Management District."

Includes bibliographical references (p. ).

Supt. of Docs, no.; 119.16:1594

1. Aquatic habitats—Florida—Apalachicola River. 2. Streamflow—Florida—Apalachicola River. 3. Stream measurements—Florida—Apalachicola River. 4. Floodplains—Florida—Apalachicola River. 5. Fishes—Effects of water levels on— 

Florida—Apalachicola River. I. Darst, Melanie R. II. Grubbs, J.W. III. Northwest Florida Water Management District. 

IV. Title. V. Series. 

QH541.r.W3L54 1998

577.6'09759'92--dc21 985851

CIP 

ISBN 0-607-89269-2

For sale by U.S. Geological Survey, Information Services

Box 25286, Federal Center

Denver, CO 80225
CONTENTS

Abstract.................................................................................................................................................................................. 1

Introduction............................................................................................................................_^ 2

Purpose and Scope....................................................................................................................................................... 3

Acknowledgments....................................................................................................................................................... 3

Background and Terminology..................................................................................................................................... 5

Methods of Study................................................................................................................................................................... 8

Intensive Study Areas and General Survey Sites ........................................................................................................ 8

Hydrologic Data Collection and Analysis................................................................................................................... 8

Characterization of Floodplain Habitats...................................................................................................................... 10

Floodplain Streams and Lakes........................................................................................................................... 11

Floodplain Forests............................................................................................................................................. 12

Computations of Amount of Aquatic Habitat in Relation to River Flow.................................................................... 13

Floodplain Streams and Lakes........................................................................................................................... 14

Floodplain Forests............................................................................................................................................. 15

Analysis of Combined Data for Streams, Lakes, and Forests........................................................................... 15

Flow and Stage Characteristics of the Apalachicola River, 1922-95 .................................................................................... 15

Very Low to Medium Flows........................................................................................................................................ 16

Medium to High Flows................................................................................................................................................ 20

Effects of Entrenchment on Stage in the Upper Reach ............................................................................................... 20

Floodplain Streams, Lakes, and Forests in Relation to River Flow....................................................................................... 22

Upper Reach ........................................... 23

Middle Reach..............................................................._ 28

Nontidal Lower Reach................................................................................................................................................. 34

Area of Aquatic Habitats in the Floodplain in Relation to River Flow ................................................................................. 38

Connected Aquatic Habitat Compared to Isolated Aquatic and Nonaquatic Habitats................................................ 38

Connected Aquatic Habitat in Forests Compared to Streams and Lakes.................................................................... 39

Connected Aquatic Habitat in the Upper, Middle, and Nontidal Lower Reaches....................................................... 40

Connection Depths...................................................................................................................................................... 41

Water Velocities in Connected Aquatic Habitats......................................................................................................... 42

Soils of Floodplain Habitats........................................................................................................................................ 43

Amount of Vegetative Structure.................................................................................................................................. 45

Fishes in River Floodplains of the Eastern United States: Literature Review....................................................................... 45

Application of Study Results................................................................................................................................................. 49

Summary and Conclusions.................................................................................................................................................... 53

References............................................................................................................................................................................. 56

APPENDIXES:

I. Greatest number of consecutive days and total number of days in each year from 1922 to 1995 that 

flow was below given flow values from 4,000 to 16,000 cubic feet per second in the Apalachicola River

at Chattahoochee, Florida........................................................................................................................................ 62

II. Lengths of floodplain streams and lakes connected to main channel of the nontidal Apalachicola River

at flows ranging from 4,000 to 19,000 cubic feet per second.................................................................................. 66

III. Average flows preceding and during 16 navigation windows in the Apalachicola River, 1990-95........................ 77

Contents III
PLATES

1. Connected aquatic habitat in the upper reach of the Apalachicola River floodplain during low,

medium, and medium-high flows .......................................................................................................in back of report

2. Connected aquatic habitat in the middle reach of the Apalachicola River floodplain during low,

medium, and medium-high flows .......................................................................................................in back of report

3. Connected aquatic habitat in the nontidal lower reach of the Apalachicola River floodplain

during low, medium, and medium-high flows ....................................................................................in back of report

FIGURES

1. Map showing drainage basin of the Apalachicola, Chattahoochee, and Flint Rivers in Florida,

Georgia, and Alabama............................................................................................................................................. 4

2. Map showing maj or reaches of the Apalachicola River and location of intensive study areas............................... 6

3. Photograph showing example of general survey site with floodplain stream disconnected from the

Apalachicola River at the time of observation......................................................................................................... 11

4. Diagram showing example of cross section divided into segments based on breaks in slope and

relatively homogeneous vegetative structure........................................................................................................... 12

5. Flowchart for determining amount of aquatic habitat in floodplain streams, lakes, and forests in relation

to flows in the Apalachicola River........................................................................................................................... 13

6. Graph showing lowest 5 percent of daily mean flows in the Apalachicola River at Chattahoochee, Florida,

1922-95 .................................................................................................................................. 17

7. Graph showing river stages during low flows in the Apalachicola River at Chattahoochee, Florida,

1929-95 ........................................................................................................................... 21

8. Map showing Flat Creek intensive study area......................................................................................................... 23

9. Photograph showing Flat Creek during low flow about 1,500 feet upstream of its mouth on the

Apalachicola River.................................................................................................................................................. 24

10. Photograph showing flooded swamp near Flat Creek during high flow.................................................................. 25

11. Map showing Johnson Creek intensive study area.................................................................................................. 26

12-15. Photographs showing:

12. Johnson Creek during low flow about 2,000 feet upstream of its mouth on the Apalachicola River............. 27

13. The Bayou during medium flow about 5 miles upstream of its mouth on the Apalachicola River................. 28

14. Tupelo-cypress swamp with semi-permanent standing water in the floodplain of the

Apalachicola River just north of Flat Creek.................................................................................................... 29

15. lamonia Lake about 2 miles upstream of its mouth on the Apalachicola River.............................................. 29

16. Map showing lamonia Lake intensive study area.................................................................................................... 30

17-19. Photographs showing:

17. Middle Slough about 2,700 feet from its mouth on lamonia Lake ................................................................. 31

18. Outside Lake during medium flow about 1 mile upstream of its mouth on the Apalachicola River .............. 32

19. Sand Slough about 500 feet from its mouth on the Apalachicola River......................................................... 33

20. Map showing River Styx intensive study area......................................................................................................... 35

21 -24. Photographs showing:

21. River Styx during low flow about 2.5 miles upstream of its mouth on the Apalachicola River ..................... 36

22. Main channel of River Styx during low flow about 1,400 feet from its mouth on the Apalachicola River.... 36

23. Kennedy Creek during medium flow about 7,500 feet upstream of its mouth on the Apalachicola River..... 37

24. Tree hummock in a tributary of Kennedy Creek............................................................................................. 37

25-32. Graphs showing:

25. Area of connected aquatic, isolated aquatic, and nonaquatic habitat in the nontidal Apalachicola River

floodplain in relation to flows .......................................................................................................................... 38

26. Area of connected aquatic habitat in forests compared to streams and lakes of the nontidal

Apalachicola River floodplain in relation to flows .......................................................................................... 39
27. Area of connected aquatic habitat in the upper, middle, and nontidal lower reaches of the Apalachicola

River floodplain in relation to flows................................................................................................................ 40

28. Area of aquatic habitat with controlling connections that allow passage of small, medium, and large

fishes in the nontidal Apalachicola River floodplain in relation to flows....................................................... 41

29. Area of still-water and flowing-water habitat in the nontidal Apalachicola River floodplain connected

to the main channel in relation to flows .......................................................................................................... 42

30. Area of flowing-water habitat in the floodplain with 1-way and 2-way connections to the main 

channel in relation to flows in the upper reach of the Apalachicola River, under present (1995) 

entrenched conditions and prior to entrenchment........................................................................................... 43

31. Area of connected aquatic habitat with silt-clay, sandy, and organic soils in the nontidal Apalachicola

River floodplain in relation to flows................................................................................................................ 44

32. Area of connected aquatic habitat with low and moderate to high amounts of vegetative structure in

the nontidal Apalachicola River floodplain in relation to flows ..................................................................... 46

TABLES

1. Basic flow characteristics of Apalachicola River at Chattahoochee, Florida, 1922-95.......................................... 16

2. Greatest number of consecutive days and total number of days per year that flow was below given flow

values from 4,000 to 16,000 cubic feet per second in the Apalachicola River at Chattahoochee, Florida............ 17

3. Number of days per year for multiple-year periods that flow was below given flow values from 4,000 to

16,000 cubic feet per second in the Apalachicola River at Chattahoochee, Florida.............................................. 18

4. Number of days per month that flow was below given flow values from 4,000 to 16,000 cubic feet per

second in the Apalachicola River at Chattahoochee, Florida................................................................................. 19

5. Number of days per year that flow was above given flow values from 16,000 to 200,000 cubic feet per

second in the Apalachicola River at Chattahoochee, Florida................................................................................. 20

6. Decrease in stage in upper reach of Apalachicola River as a result of entrenchment............................................ 21

7. Lengths of floodplain streams and lakes in upper, middle, and nontidal lower reaches of the Apalachicola 

River that are connected to the main river channel at flows ranging from 4,000 to 19,000 cubic feet per 

second..................................................................................................................................................................... 22

8. Occurrence of Apalachicola River fish species in river floodplains of the eastern United States.......................... 47

9. Summary of areas of aquatic habitat in the floodplain that are connected to the main channel of the

Apalachicola River in relation to flows ranging from 4,000 to 16,000 cubic feet per second ............................... 49

10. Area of aquatic habitat in the floodplain that is connected to the main channel of the Apalachicola 

River at flows preceding, during, and after a navigation window and at estimated flows if the window 

had not been implemented...................................................................................................................................... 51
CONVERSION FACTORS, SEA LEVEL DATA, AND ACRONYMS

Multiply

inch (in.)

foot (ft)

mile (mi) 

square foot (ft2) 

cubic foot (ft3)

foot per second (ft/s) 

cubic foot per second (ft/s) 

square mile (mi2)

acre

part per million (ppm)

By

25.4

0.3048

1.609 

929.0 

0.02832

0.3048 

0.02832 

2.590

0.4047

1.0

To obtain

millimeter

meter

kilometer 

square centimeter 

cubic meter

meter per second 

cubic meter per second 

square kilometer

hectare

milligram per liter

Sea Level: In this report, "sea level" refers to the National Geodetic Vertical Datum of 1929 (NGVD 

of 1929)—a geodetic datum derived from a general adjustment of the first-order level nets of the 

United States and Canada, formerly called "Sea Level Datum of 1929."

Acronyms:

ACF

ARQA

FGFWFC

GIS

NWS

NWFWMD

USAGE

USFWS

USGS

Apalachicola-Chattahoochee-Flint

Apalachicola River Quality Assessment

Florida Game and Fresh Water Fish Commission

Geographic Information System

National Weather Service

Northwest Florida Water Management District

U.S. Army Corps of Engineers

U.S. Fish and Wildlife Service

U.S. Geological Survey
LIST OF COMMON NAMES USED AND SCIENTIFIC EQUIVALENTS

FISHES

[Nomenclature follows Lee and others (1980) unless otherwise indicated]

Common names Scientific names

Alabama shad

American eel

Atlantic needlefish

banded pygmy sunfish

banded sunfish

banded topminnow

bandfin shiner

bannerfin shiner

black crappie

black madtom

blackbanded darter

blackspotted topminnow

blacktail shiner

bluefin killifish

bluegill

bluenose shiner

bluespotted sunfish

bluestripe shiner

bowfin

brook silverside

brown bullhead

brown darter

chain pickerel

channel catfish

clear chub

coastal shiner

common carp

creek chub

dollar sunfish

dusky shiner

eastern starhead topminnow

Everglades pygmy sunfish

flagfin shiner

flathead catfish

flier

Florida sand darter

gizzard shad

golden shiner

golden topminnow

goldstripe darter

grayfin redhorse

green sunfish

Gulf darter

Gulf of Mexico sturgeon

hogchoker 

ironcolor shiner

Alosa alabamae Jordan and Evermann

Anguilla rostrata (Lesueur)

Strongylura marina (Walbaum)

Elassoma zonatum Jordan

Enneacanthus obesus (Girard)

Fundulus cingulatus Valenciennes

Notropis zonistius (Jordan)

Notropis leedsi Fowler

Pomoxis nigromaculaius (Lesueur)

Noturus funebris Gilbert and Swain

Percina nigrofasciata (Agassiz)

Fundulus olivaceous (Storer)

Notropis venustus (Girard)

Lucania goodei Jordan

Lepomis macrochirus Rafinesque

Notropis welaka Evermann and Kendall

Enneacanthus gloriosus (Holbrook)

Notropis callitaenia Bailey and Gibbs

Amia calva Linnaeus

Labidesthes sicculus (Cope)

Ictalurus nebulosus (Lesueur)

Etheostoma edwini (Hubbs and Cannon)

Esox niger Lesueur

Ictalurus punctatus (Rafinesque)

Hybopsis winchelli (Girard)

Notropis petersoni Fowler

Cyprinus carpio Linnaeus

Semotilus atromaculatus (Mitchill)

Lepomis marginatus (Holbrook)

Notropis cummingsae Myers

Fundulus escambiae (Bollman)

Elassoma evergladei Jordan

Notropis signipinnis Bailey and Suttkus

Pylodictis olivaris (Rafinesque)

Centrarchus macropterus (Lacepede)

Ammocrypta bifascia Williams

Dorosoma cepedianum (Lesueur)

Notemigonus crysoleucas (Mitchill)

Fundulus chrysotus (Gunther)

Etheostoma parvipinne Gilbert and Swain

Moxostoma n.sp.

Lepomis cyanellus Rafinesque

Etheostoma swaini (Jordan)

Acipenser oxyrhynchus desotoi Vladykov and

Greeley

Trinectes maculatus (Bloch and Schneider) 

Notropis chalybaeus (Cope)

Contents VII
FISHES—Continued

[Nomenclature follows Lee and others (1980) unless otherwise indicated]

Common names Scientific names

lake chubsucker

largemouth bass

least killifish

longnose gar

longnose shiner

mosquitofish

mountain mullet

Okefenokee pygmy sunfish

orangespotted sunfish

pirate perch

pugnose minnow

pygmy killifish

quillback

redbreast sunfish

redear sunfish

redeye chub

redfin pickerel

sailfin shiner

sauger

shadow bass

shoal bass

silverjaw minnow

skipjack herring

snail bullhead

southern brook lamprey

southern flounder

speckled madtom

spotted bass

spotted bullhead

spotted gar

spotted sucker

spotted sunfish

striped bass

striped mullet

sunshine bass

swamp darter

tadpole madtom

taillight shiner

threadfin shad

warmouth

weed shiner

white bass

white catfish

yellow bullhead

yellow perch

Erimyzon sucetta (Lacepede)

Micropterus salmoides (Lacepede)

Heterandria formosa Agassiz

Lepisosteus osseus Linnaeus

Notropis longirostris (Hay)

Gambusia affinis (Baird and Girard)

Agonostomus monticola (Bancroft)

Elassoma okefenokee Bohlke

Lepomis humilis (Girard)

Aphredoderus sayanus (Gilliams)

Notropis emiliae (Hay)

Leptolucania ommata (Jordan)

Carpiodes cyprinus (Lesueur)

Lepomis auritus (Linnaeus)

Lepomis microlophus (Gunther)

Notropis harperi Fowler

Esox americanus americanus Gmelin

Notropis hypselopterus (Gunther)

Stizostedion canadense (Smith)

Ambloplites ariommus Viosca

Micropterus n.sp. cfcoosae

Ericymba buccata Cope

Alosa chrysochloris (Rafinesque)

Ictalurus brunneus (Jordan)

Ichthyomyzon gagei Hubbs and Trautman

Paralichthys lethostigma Jordan and Gilbert

Noturus leptacanthus Jordan

Micropterus punctulatus (Rafinesque)

Ictalurus serracanthus Yerger and Relyea

Lepisosteus oculatus Winchell

Minytrema melanops (Rafinesque)

Lepomis punctatus (Valenciennes)

Morone saxatilis (Walbaum)

Mugil cephalus Linnaeus

Morone hybrid: chrysops X saxatilis

Etheostomafusiforme (Girard)

Noturus gyrinus (Mitchill)

Notropis maculatus (Hay)

Dorosoma petenense (Gunther)

Lepomis gulosus (Cuvier)

Notropis texanus (Girard)

Morone chrysops (Rafinesque)

Ictalurus catus (Linnaeus)

Ictalurus natalis (Lesueur)

Percaflavescens (Mitchill)

rAger and others (1985)

VIII Contents
PLANTS

[Nomenclature for plants follows Godfrey (1988)]

Common names Scientific names

cypress

green ash

overcup oak

sugarberry

swamp laurel oak

sweetgum

tupelo

water hickory 

water oak

Taxodium distichum (L.) L.C. Rich.

Fraxinus pennsylvanica Marsh.

Quercus lyrata Walt.

Celtis laevigata Nutt.

Quercus laurifolia Michx.

Liquidambar styraciflua L.

Nyssa aquatica L. and Nyssa ogeche Bartr.

ex Marsh

Carya aquatica (Michx. f.) Nutt. 

Quercus nigra L.

Aquatic Habitats in Relation to River Flow in the 

Apalachicola River Floodplain, Florida

By Helen M. Light, Melanie R. Darst, andJ.W. Grubbs

Abstract

I

ncreasing demands for water 

in the ApalachicolaChattahoochee-Flint River 

Basin have resulted in conflicts 

among water user groups, the 

States of Georgia, Alabama, and 

Florida, and various Federal 

agencies, particularly during 

periods of regional drought. A 

study of aquatic habitats in the 

floodplain in relation to river 

flow was conducted in the nontidal reach of the Apalachicola 

River in north Florida from 

1992 to 1996. The study was 

conducted by the U.S. Geological 

Survey, in cooperation with the 

Northwest Florida Water 

Management District, as part of 

a larger effort to identify freshwater needs throughout the 

region and develop a mechanism for basinwide water management. The primary results of 

this report are quantitative estimates of the amount of aquatic 

habitat in the floodplain in relation to river flow. The report 

also includes plates showing 

streams, lakes, and floodplain 

forests connected to the main 

river channel at selected flows; 

an analysis of long-term flow

record in the Apalachicola 

River; a review of the literature 

regarding fishes in floodplains 

of the Apalachicola River and 

other rivers of the eastern 

United States; and examples 

showing how this report can be 

used to assess impacts of flow 

alterations on aquatic habitats 

and fishes. The study area consists of about 82,200 acres of 

floodplain that is predominantly 

wetlands, according to the U.S. 

Fish and Wildlife classification 

system.

Very low flows in the 

Apalachicola River, defined 

as flows less than 6,000 cubic 

feet per second (ftVs) at Chattahoochee, Florida, occurred in 15 

of the 74 years of record from 

1922 to 1995. At a river flow of 

5,000 ft3/s, an estimated 

260 acres of floodplain streams 

and lakes is connected to the 

main river channel. Most of 

these areas have shallow waters 

with no flow and are located in 

the middle and nontidal lower 

reaches of the river. These connected aquatic habitats comprise 

a very small percentage 

(0.3 percent) of the entire floodplain at very low flows, yet they 

serve as important refuges for

fishes from the deep, swiftly 

flowing waters of the main 

channel. In the upper reach of 

the river, entrenchment that 

occurred after construction of 

Jim Woodruff Dam lowered 

bed elevations and river levels. 

Many perennial streams in the 

upper reach that were accessible 

to main channel fishes at low 

and very low flows prior to 

entrenchment are now inaccessible because of waterfalls or 

very shallow water at their 

mouths. About 4,000 acres of 

isolated aquatic habitat, mostly 

tupelo-cypress swamps with 

standing water less than 3 feet 

deep, is also present in the 

floodplain at very low flows. A 

review of the literature indicates 

that many species of fishes 

inhabit the quiet, shallow waters 

typically found in isolated 

swamps.

Low flows (6,000- 

10,000 ft3/s at Chattahoochee, 

Florida) occur in most years. 

The median annual 1-day low 

flow for the period of record is 

8,490 ft3/s. About 740 acres of 

aquatic habitat in the floodplain 

is connected to the main channel 

at a river flow of 8,000 ft3/s. 

Most of these areas are tributary
lakes, which are open bodies of 

water having a linear conformation and little or no flow except 

during floods. Large tributary 

lakes in the middle and lower 

reaches of the river, such as 

lamonia Lake and River Styx, 

support diverse fish communities. In a previous study, 44 fish 

species were collected by the 

Florida Game and Fresh Water 

Fish Commission in tributary 

lakes during low flows.

Medium flows (10,000- 

20,000 ft3/s at Chattahoochee, 

Florida) occur every year. At the 

median flow for the period of 

record, which is 16,400 ft3/s, 

approximately 8,300 acres 

(10 percent of the floodplain) is 

connected aquatic habitat. Most 

of these areas are tupelo-cypress 

swamps bordering streams and 

lakes in the middle and nontidal 

lower reaches that are inundated 

by backwater from the main 

channel. Flowing-water habitats 

in more than 200 miles of 

streams and lakes are also connected to the main channel at the 

median flow. The amount of 

vegetative structure in connected 

aquatic habitats is much greater 

during medium flows than during low flows, because water is 

no longer contained in the beds 

of floodplain streams, but is covering vegetation and woody 

debris on streambanks and in 

adjacent swamps. Vegetative 

structure in aquatic habitats provides food sources, protective 

cover, and reproductive sites for 

fishes.

Medium-high flows 

(20,000-50,000 ft3/s at Chattahoochee, Florida) occur every

year. An estimated 40,700 acres, 

which is approximately one-half 

of the floodplain, is connected 

aquatic habitat at 32,000 ft3/s. 

Nearly all aquatic habitat in 

tupelo-cypress swamps that is 

isolated at lower flows is connected to the main channel 

between flows of 20,000 and 

40,000 ftVs. High flows (greater 

than 50,000 ft3/s) occur in most 

years. At the median annual 

1-day high flow of 86,200 ft3/s, 

about 78,000 acres (95 percent 

of the floodplain) is connected 

aquatic habitat. During high 

flows, water is moving through 

most of the floodplain in a general downstream direction. 

Many main channel fishes 

migrate into flooded forests 

where greatly increased food 

sources and abundant vegetative 

structure are available to them. 

Eighty percent, or 73 of the 91 

fish species known to inhabit the 

Apalachicola River have been 

collected in river floodplains of 

the eastern United States and are 

probably present in the Apalachicola River floodplain during 

medium-high and high flows.

In evaluating the impacts 

of flow alterations, it is important to determine types and 

extent of habitat affected, 

address impacts on biotic communities, and make comparisons of altered to historical 

flows. In an example, effects on 

habitat as a result of flow regulation to create a navigation 

window for barge traffic in the 

fall of 1990 were examined. For 

19 days during this period, there 

was approximately 590 fewer 

acres of connected aquatic

habitat than there would have 

been if the navigation window 

had not been implemented. 

Effects of reduced aquatic 

habitat on fishes include reductions in the amount of food, 

protective cover, and spawning 

sites. A hydrologic event with 

flows similar to this period of 

reduced flows occurred once 

every 10 years on average 

(1922-95) and probably would 

not have occurred in 1990 if 

navigation windows had not 

been implemented.

INTRODUCTION

T

n the coastal plain of the southeastern United States, large 

rivers have extensive forested 

floodplains that contain a diverse 

assortment of aquatic and wetland 

habitats (Wharton and others, 

1982; Mitsch and Gosselink, 

1986). Streams, sloughs, ponds, 

lakes, and swamps in these floodplains are alternately connected 

and disconnected from the main 

river channel as river levels fluctuate. Complex relationships exist 

between biological communities in 

floodplain habitats and river flow, 

with floral and faunal distributions 

varying spatially, seasonally, and 

annually (Welcomme, 1979; 

Bay ley, 1995; Power and others, 

1995). During low-flow periods, 

shallow, quiet waters in the floodplain provide refuges for fishes 

from the deep, swiftly flowing 

waters of the main channel (Kwak, 

1988; Baker and others, 1991; 

Leitman and others, 1991). During 

flood events, fishes use inundated 

floodplain forests for food, protective cover, spawning sites and 

nursery grounds (Guillory, 1979;

Aquatic Habitats in Relation t<* River Flow in the Apaiachicota River FJoodplain, Florida
Wharton and others, 1981, 1982; 

Ross and Baker, 1983; Walker and 

Sniffen, 1985; Finger and Stewart, 

1987; Knight and others, 1991).

Increased demands for water 

in the Apalachicola-ChattahoocheeFlint (ACF) River Basin have 

resulted in conflicts among water 

user groups, the States of Georgia, 

Alabama, and Florida, and various 

Federal agencies, particularly 

during periods of regional drought. 

"As a result, widespread concern 

has been expressed regarding the 

need to properly manage the water 

resources so that regional economies may continue to be supported 

within the bounds of the environmental conditions that exist within 

the river systems" (Alabama, 

Florida, Georgia, and the U.S. 

Army Corps of Engineers, 1991, 

p. 1). In the early 1990's, Congress 

funded a study to determine water 

requirements in the ACF River 

Basin (and an adjacent basin) and 

to recommend an interstate mechanism for resolving issues from a 

regional perspective. As a part of 

this study, the Northwest Florida 

Water Management District 

(NWFWMD) initiated a freshwater 

needs assessment for the Apalachicola River and Bay. Water requirements of the Apalachicola River 

are addressed in this report, which 

presents information on the area 

and characteristics of aquatic 

habitats in the floodplain in relation 

to river flow. Results of this investigation can be used to evaluate 

potential impacts of flow alterations (such as increased upstream 

water withdrawals or modified 

water delivery schedules from 

storage reservoirs) on floodplain 

habitat.

Purpose and Scope

This report presents the final 

results of an investigation relating 

aquatic habitats in the floodplain to 

flow in the Apalachicola River. 

This report includes:

(1) Duration and frequency 

statistics of the long-term flow 

record of the Apalachicola River 

based on monthly, annual, and multiple-year periods of analysis.

(2) A description of the 

major types of streams, lakes, and 

forests in the Apalachicola River 

floodplain and the changes that 

occur in those habitats with 

changes in river flow.

(3) Estimates of the area of 

aquatic habitat in the floodplain 

that exist at specific Apalachicola 

River flows ranging from very low 

to very high. Estimates of area 

include total areas of aquatic habitat in the floodplain for each major 

reach of the river and for the entire 

study area, and areas of particular 

types of aquatic habitats in the 

floodplain having characteristics 

that are important to fishes.

(4) A list of the species of 

fishes collected in the Apalachicola 

River floodplain, and a list of additional species that probably inhabit 

the Apalachicola River floodplain, 

based on a summary of the literature on floodplain fishes of the 

eastern United States.

(5) Examples showing how 

the results of this investigation can 

be used to assess impacts of flow 

alterations on aquatic habitat and 

fishes in the Apalachicola River 

floodplain.

The study area addressed in 

this report is the floodplain of the 

nontidal Apalachicola River from 

the Georgia-Florida State line to 

the upper limit of tidal influence 

about 20 mi upstream of Apalachicola Bay (fig. 1). The freshwater 

tidal floodplain is not included in 

the study area. Data collection was 

conducted from 1992 to 1995 and 

data analysis was completed in 

1996. Two interim progress 

reports describing preliminary 

methods and results were published 

during the data-collection period 

(Light and others, 1993; Light and 

others, 1995).

Acknowledgments

This project, jointly funded 

by the NWFWMD and the U.S. 

Geological Survey (USGS), is part 

of the Apalachicola River and Bay 

Freshwater Needs Assessment as 

developed by the States of Florida, 

Alabama, and Georgia and the U.S. 

Army Corps of Engineers 

(USAGE) for the Alabama-CoosaTallapoosa/Apalachicola-Chattahoochee-Flint Comprehensive 

Study. The authors wish to 

acknowledge F. Graham Lewis III, 

NWFWMD, for technical and 

administrative guidance throughout 

the project. Partial funding was 

received from USAGE for two 

related investigations that contributed data to this report. Appreciation is extended to Mary M. Davis, 

USAGE, Waterways Experiment 

Station, Vicksburg, Miss., and 

Joanne U. Brandt, USAGE, Mobile 

District, Ala., for technical and 

administrative guidance in those 

two studies. Leslie L. Batts, formerly with the USGS, is acknowledged for his invaluable support 

with field work. Appreciation is 

also extended to Michael J. Hill, 

Charles L. Mesing, and D. Gray 

Bass, Jr., Florida Game and Fresh 

Water Fish Commission 

(FGFWFC), for assistance in 

assembling and interpreting fish 

data for the Apalachicola River

Introduction
50 MILES

J

50 KILOMETERS

LOCATION 

MAP

EXPLANATION

DRAINAGE BASIN OF 

THE APALACHICOLA, 

CHATTAHOOCHEE, 

AND FLINT RIVERS

STUDY AREA

Base from U.S. Geological Survey digital data, 1972

Albers Equal-Area Conic projection

Standard Parallels 29°30'and 45°30', central meridian -83°00'

Figure 1. Drainage basin of the 

Apalachicola, Chattahoochee, and Flint 

Rivers in Florida, Georgia, and Alabama.

floodplain; Steven E. Ovenden, 

formerly with the USGS, for help 

with organizing and interpreting 

background literature; and Wade L. 

Bryant, USGS, for technical assistance in report preparation. Appreciation for field assistance is 

extended to William I. Stinson III 

and K. Maureen Karns, formerly 

with the USGS; F. Graham Lewis 

III, NWFWMD; Jerry W Ziewitz, 

U.S. Fish and Wildlife Service 

(USFWS); Theodore S. Hoehn, 

FGFWFC; Beth A. Gaza, formerly 

with Florida State University; and 

Duncan T. Johnson, volunteer.

4 Aquatic Habitats in Relation to River Flow in tne Apalachicola River FJoodptain, {Florida
Background and 

Terminology

The Apalachicola River is a 

large alluvial river formed by the 

confluence of the Chattahoochee 

and Hint Rivers (fig. 1). The three 

rivers drain 19,600 mi2 in Florida, 

Georgia, and Alabama. The Chattahoochee flows about 400 mi from 

its source in north Georgia to Lake 

Seminole at the Florida-Georgia 

State line. The Hint River originates just south of Atlanta, Ga., and 

flows about 350 mi before it joins 

the Chattahoochee River. The 

Apalachicola River is 106 mi long 

and falls about 40 ft from the 

Georgia-Florida State line to the 

Apalachicola Bay in the Gulf of 

Mexico. The Apalachicola River 

downstream of Lake Seminole 

drains 2,400 mi2, approximately 

50 percent of which is drained by 

its largest tributary, the Chipola 

River.

The drainage basin of the 

Apalachicola, Chattahoochee, and 

Hint Rivers lies within three major 

physiographic provinces of the 

southeastern United States (Clark 

and Zisa, 1976). Less than 

1 percent of the basin in the northernmost part contains mountains 

and ridges of the Blue Ridge 

Province. The remainder of the 

upper basin north of Columbus, 

Ga., lies in the rolling hills of the 

Piedmont Province. The entire 

lower basin south of Columbus, 

Ga., is in the Coastal Plain Province, which is hilly in the northernmost part, karstic in the central 

part, and contains low lying coastal 

flats in the southernmost part 

(Couch and others, 1996).

The Apalachicola River is 

the largest river in Florida and 

ranks 21st in magnitude of discharge among the rivers of the 

conterminous United States. Mean

annual flow at Chattahoochee, Fla. 

(fig. 2) from 1922 to 1995 was 

22,300 ft3/s. Peak floods are most 

likely to occur in January, February, 

March, or April of each year. Low 

flow generally occurs in September, October, and November. Flood 

patterns vary greatly from year to 

year and may not conform to these 

seasonal trends in any given year. 

In this report, very low flows are 

less than 6,000 ft3/s, low flows are 

6,000 to 10,000 ftVs, medium 

flows are 10,000 to 20,000 ftVs, 

medium-high flows are 20,000 to 

50,000 ftVs, and high flows are 

greater than 50,000 ft3/s. All flow 

values refer to flow in the Apalachicola River at the USGS gage at 

Chattahoochee, Fla., unless otherwise indicated.

There are 16 dams on the 

Apalachicola, Chattahoochee, 

and Flint Rivers. The most downstream dam, Jim Woodruff Dam, 

impounds Lake Seminole at the 

head of the Apalachicola River 

where the Chattahoochee and Hint 

Rivers join. Construction began on 

Jim Woodruff Dam in 1950, and 

filling of the reservoir was accomplished from 1954 to 1957. Congressional authorization for 

navigational improvements was 

approved in 1874 and dredging was 

sporadically conducted from 1874 

to 1956. Dredging to construct the 

modern 9- by 100-ft navigation 

channel began in 1956, with maintenance dredging since that time 

usually conducted on an annual 

basis. Rock removal in the upper 

reach of the river was conducted in 

1957, 1963, 1968, and 1983-84. 

Twenty-nine sets of groins made of 

wooden pilings or stone were 

installed from 1963 to 1970, most 

of which are in the upper reach of 

the river. Six cutoffs, which were 

made from 1956 to 1969 to

improve navigation by straightening bends in the lower reach of the 

river, have shortened the total 

length of the river by approximately 2 mi (U.S. Army Corps of 

Engineers, 1986). Entrenchment 

is riverbed degradation that has 

lowered the elevation of the riverbed in the upper reach of the 

Apalachicola River since the 

construction of Jim Woodruff Dam. 

In an analysis of the effects of a 

variety of navigational improvements on riverbed elevation, it was 

concluded that entrenchment 

"appears to be directly related to 

the presence of the dam" (Simons, 

Li, and Associates, 1985, p. 100). 

Dredging, groins, cutoffs, and rock 

removal appear to have primarily 

local effects on bed degradation 

that are not associated with the 

overall trend of entrenchment. The 

USAGE implements navigation 

windows by regulating flows in the 

Apalachicola River to improve 

navigation during periods when 

channel depths are insufficient to 

allow barge traffic. Immediately 

prior to each navigation window, 

water is stored in upstream reservoirs for 2 to 3 weeks during a 

prewindow period. Flows are 

increased rapidly during a short 

transition period of 1 or 2 days, 

and then water is released in a 

window period of 10 days to 

2 weeks to raise water levels for 

barge navigation on the river.

Aquatic habitats of the main 

channel of the Apalachicola River 

have been surveyed by the 

FGFWFC. Sandbars are relatively 

unproductive with regard to fishes 

and invertebrates, whereas habitats 

such as dike fields, gently sloping 

natural banks, and steep natural 

banks with snags and other submerged structures are significantly 

more productive (Ager and others,

Introduction
85°15'

30°45'

30°30'

30°15'

30°00'

29°45'

85°00'

Lake Seminole

Jim Woodruff Dam

Flat Creek 

intensive 

study area

84°45'

Johnson Creek

intensive

study area

D

Wewahitchka'

Chipola_ 

River

Chattahoochee 

FLORIDA

90 UPPER 

REACH

lamonia Lake 

intensive 

study area

Florida River

MIDDLE

REACH

River Styx 

intensive 

study area

LOWER

*

G (/LF OF

LOCATION 

MAP

'60

EXPLANATION

APALACHICOLA RIVER 

FLOODPLAIN

LONG-TERM SURFACE-WATER 

GAGING STATION

RIVER MILE—Number is 

distance from mouth in miles

10 15 MILES

10 15 KILOMETERS

Base from U.S. Geologjcal Survey digital data, 1972

Albers Equal-Area Conic projection

Standard Parallels 29°30'and 45°30', central meridian -83°00'

Figure 2. Major reaches of the Apalachicola 

River and location of intensive study areas. 

Reach boundaries are based on 

physiographic and geomorphic differences 

described by Leitman (1984).

1986). In this report, the term main 

channel is reserved for the main 

channel of the Apalachicola River 

unless otherwise indicated.

The Apalachicola River has 

the largest forested floodplain in 

Florida. It is 71 mi long, ranges 

from 1 to 5 mi wide, and covers 

approximately 112,000 acres 

(175 mi2) of freshwater tidal and 

nontidal floodplain. In this report, 

the term floodplain refers to the 

nontidal floodplain only and does 

not include open water in the main 

channels of the Apalachicola and 

Chipola Rivers. A floodplain area 

of 82,200 acres is used in calculations in this report; this acreage

6 Aquatic Habitats in Relation to *Hver FJow in the ApaiactwoUi River Ftoodpte*^ FlorIda
represents approximately 

92 percent of the total area that is 

shown within the nontidal floodplain boundary as mapped by 

Leitman (1984). The remaining 

8 percent of floodplain in nontidal 

reaches consists of land areas 

within the floodplain boundary that 

are higher than most annual floods 

or have been converted to nonforested uses. Floodplains as defined 

in this report are predominantly 

wetlands according to the wetland 

classification system of the 

USFWS (Cowardin and others, 

1979; Reed, 1988). However, the 

percentage of this area that would 

be classified as jurisdictional wetlands meeting criteria in State and 

Federal wetland regulations is not 

known. Most of the floodplain 

would be classified by the USFWS 

as wetlands in the palustrine system, but the floodplain also 

includes some areas classified as 

both wetlands and deepwater habitats in the riverine and lacustrine 

system (Cowardin and others, 

1979; Brinson and others, 1981).

About 60 species of trees 

occur in the bottomland forest of the 

Apalachicola River floodplain 

(Leitman and others, 1983). Mixed 

bottomland hardwoods are dominated by water hickory, sweetgum, 

overcup oak, green ash, and 

sugarberry, and grow in the areas of 

higher elevation in the floodplain 

(levees, ridges, and flats). Tupelocypress swamps, also called 

swamps in this report, grow in 

depressions and areas of lower 

elevation. Some of these swamps 

are covered with standing water 

year-round; others are inundated 

much of the year but lack standing 

water during the driest months of 

September, October, and November.

Alluvial rivers contain a 

variety of aquatic habitats that 

occur outside the main channel of 

the river but within the floodplain. 

In this report, any part of the floodplain is considered to be aquatic 

habitat when it is inundated; thus, 

the amount of aquatic habitat in the 

floodplain is very low during 

droughts and very high during 

floods. Connected aquatic habitat 

is inundated and connected to the 

main channel with a 2-way connection. In a 2-way connection, a 

level or near-level water passageway exists between a floodplain 

water body and the main channel, 

allowing fish passage in both directions. One-way connections are 

waterfalls or very shallow water 

dropping into the main channel at 

the mouths of streams. One-way 

connections block access for main 

channel fishes to enter streams, but 

allow stream fishes to enter the 

main channel. Isolated aquatic 

habitat has no water passageways 

connecting it to the main channel. 

During the dry season, many 

isolated aquatic habitats hold water 

at levels that are higher than stages 

in the main channel. A sill, or 

controlling sill, is that part of a 

streambed that determines the 

elevation of the water connection 

between the upstream and downstream parts of a stream, or 

between a stream and the main 

channel. Still-water habitat is any 

aquatic habitat with nonflowing 

water.

A floodplain stream is any 

conduit of periodically or continuously moving water in the floodplain that is of sufficient size and 

development to have a recognizable channel with bed and banks. 

Perennial streams flow continuously and intermittent streams 

flow only during part of the year.

When intermittent streams are not 

flowing, their streambeds may be 

filled with water, may be partially 

exposed with isolated pools 

remaining in parts of the bed, or 

may completely lack any surface 

water. Loop streams (which can 

be perennial or intermittent) are fed 

by flow diverted from the main 

channel that flows for a few miles 

through the floodplain and then 

back into the river farther downstream. A floodplain lake is an 

open body of water that is not 

flowing except during floods when 

river water is moving through the 

floodplain in a general downstream 

direction. Tributary lakes are 

open bodies of water in the floodplain that have characteristics of 

both streams and lakes. They 

usually have little or no flow 

during very low, low, and medium 

river flows. Most tributary lakes 

are connected to the main channel 

during low river flows. The linear 

conformations of tributary lakes 

suggest that they may be abandoned main channel courses of the 

Apalachicola River. One of the 

larger examples of a tributary lake 

is lamonia Lake (cover of this 

report; fig. 2) which is approximately 5 mi in length and is nearly 

as wide and deep as the main river 

channel in some places. Tributary 

lake systems often have connector 

streams that divert flow from the 

main channel into the tributary 

lake. Tributary lakes and many 

other streams and lakes are affected 

at times by backwater, which 

means that either river water has 

moved into the stream or lake from 

the main channel, or flowing water 

in the stream or lake is retarded in 

its course by water in the main 

channel.

Introduction
METHODS OF STUI>Y

T

he primary results of the study 

are quantitative estimates of 

the amount of aquatic habitat in the 

floodplain in relation to the full 

range of river flows. These 

estimates can be used by water 

managers to determine changes in 

habitat that may result from flow 

alterations. Flow reductions during 

droughts are of particular concern; 

they can decrease availability of 

aquatic habitat in the floodplain at 

a time when the amount of habitat 

is already at a minimum. During 

low and very low flows, aquatic 

habitats in the floodplain that are 

most affected by changes in river 

flows are streams and lakes. Most 

forested areas are not inundated 

except during higher flows. In an 

effort to address concerns about 

impacts during droughts, field data 

collection in this investigation was 

designed to focus on streams and 

lakes.

Estimates of the amount of 

aquatic habitat in relation to flow 

were made for every stream and 

lake that is connected to the main 

channel of the Apalachicola River 

during very low, low, and medium 

flows. The areal extent of aquatic 

habitat in floodplain forests was also 

quantified in this investigation, but 

with less specific methods than 

those used for streams and lakes. 

Representative floodplain forest 

data were generalized for each 

major reach of the river, rather than 

calculated with site specific estimates. Most of the floodplain forest 

data used in this report were collected in previous studies (Leitman, 

1978, 1984; Leitman and others, 

1983; Mattraw and Elder, 1984; 

Light and Darst, 1997).

Intensive Study Areas and 

General Survey Sites

Data collection in this study 

focused on floodplain streams and 

lakes that were connected to the 

main channel of the Apalachicola 

River at low and medium flows. 

Measurements and observations 

were made at intensive sites many 

times throughout the study period, 

but usually only once at general 

survey sites.

Four intensive study areas 

were selected to represent major 

types of floodplain streams in the 

upper, middle, and nontidal lower 

reaches of the river (fig. 2). In the 

floodplain of the upper reach, 

which extends from river mile 77.4 

to 106.3, there are many perennial 

and intermittent streams that 

receive water from upland 

streams. Intensive study areas were 

selected in the upper reach at Flat 

Creek to represent perennial 

streams and at Johnson Creek to 

represent intermittent streams. Flat 

Creek has a drainage area of 52 mi2 

(Foose, 1981) most of which lies 

east of the floodplain of the 

Apalachicola River. For its most 

downstream 2 mi, Flat Creek flows 

through the river floodplain and 

joins the Apalachicola River at 

river mile 99.6. Johnson Creek 

receives intermittent drainage 

from upland streams west of the 

Apalachicola River floodplain. For 

its most downstream 1.5 mi. 

Johnson Creek lies in the river 

floodplain, joining with the intermittent drainage of another smaller 

unnamed stream before it joins the 

Apalachicola River at river 

mile 94.0.

Large tributary lakes 

affected by backwater from the 

Apalachicola River are the most 

prominent hydrologic features in 

the floodplain of the middle reach

(river mile 42 to 77.4) and lower 

reach (river mile 20.6 to 42). lamonia Lake (mouth at river mile 55.8) 

and its associated tributaries were 

selected as an intensive study area 

to represent tributary lake systems 

in the middle reach. River Styx 

(mouth at river mile 35.3) and its 

associated tributaries were 

selected as an intensive study area 

to represent tributary lake systems 

in the nontidal lower reach. During 

low river flows, both lamonia Lake 

and River Styx receive little water 

from upland drainage (probably 

less than 1 ft3/s).

Approximately 300 general 

survey sites were located at the 

mouths of most floodplain streams 

that met at least one of the following criteria: (1) streams were 

shown on USGS 7.5-minute quadrangle maps; (2) streams were 

apparent on 1:65,000 scale color 

infrared aerial photographs taken 

November 1979 by National 

Oceanic and Atmospheric Administration; or (3) streams were 

observed in the field to have streambed elevations low enough to be 

connected to the main river channel 

during very low, low, or medium 

flows. Most general survey sites 

were located at mouths of streams 

tributary to the Apalachicola River; 

however, some sites were located 

at mouths of streams tributary to 

the lower Chipola River and a few 

of the large tributary lakes, such as 

Florida River and Kennedy Creek 

(fig. 2).

Hydrologic Data Collection 

and Analysis

Hydrologic data for the study 

were obtained from four long-term 

surface-water gaging stations 

located on the Apalachicola River 

(fig. 2) at Chattahoochee (station

8 Aquatic Habitats in Relation to River flow In the Apalachicola River Floodp»ain, Florida
number 02358000), near Blountstown (station number 02358700), 

near Wewahitchka (station number 

02358754), and near Sumatra 

(station number 02359170). At 

the Chattahoochee gage, nearlycontinuous daily stage data were 

collected by the National Weather 

Service (NWS) from October 1921 

until September 1928, and daily 

stage and flow data have been 

collected by the USGS from 

October 1928 to the present (1995). 

A regression relation between daily 

stages measured at the Blountstown gage and 1-day lagged daily 

stages at the Chattahoochee gage 

was used to estimate stages at the 

Chattahoochee gage for missing 

NWS stage data prior to 1929. 

Daily discharge data were estimated for the period 1922-28 

using the NWS stage data and a 

composite pre-entrenchment stagedischarge rating for Chattahoochee 

based on 190 discharge measurements made from 1929 to 1951 

(Light and others, 1993). Daily 

stage data for the Apalachicola 

River near Blountstown were 

collected by the NWS from 1920 to 

1957 and by the USAGE (Mobile 

District) from 1957 to the present. 

Missing data at the Blountstown 

gage were estimated using the 

Chattahoochee-B lountsto wn 

regression relation. Daily stage 

data for the Apalachicola River 

near Wewahitchka were collected 

by the USAGE from October 1955 

to September 1957 and October 

1965 to the present. Daily stage 

and flow data for the Apalachicola 

River near Sumatra were collected 

by the USGS from September 1977 

to the present. Flows below 

15,000 ftVs at the Sumatra gage 

(river mile 20.6) are generally 

affected by tides. Tidal fluctuation 

is approximately 0.5 ft at very low

flows. Tidal effects do not occur at 

river mile 36 or at the Wewahitchka gage (river mile 42). In this 

report, the lower reach of the study 

area was considered to be nontidal 

because tidal effects are minor at 

the downstream end of the reach 

and absent in the upper part of the 

reach.

Records at the Chattahoochee gage were selected for 

analysis of long-term flow because 

of the location of the gage at the 

head of the Apalachicola River, the 

long period of record available 

(1922-95), and the continuity of the 

data. A variety of monthly, annual, 

and multiple-year duration tables 

of daily mean flows for the period 

of record were generated. Nonexceedance durations (durations that 

flows were below given flow 

values) were calculated for flows of 

4,000 to 16,000 ftVs. Exceedance 

durations (durations that flows 

were above given flow values) 

were calculated for flows of 16,000 

to 200,000 ftVs. Annual and multiple-year durations calculated for 

flows of 4,000 to 16,000 ftVs were 

based on climatic years from 

April 1 to March 31 to avoid splitting low flow periods that typically 

occur in summer and fall. Annual 

durations calculated for flows of 

16,000 to 200,000 ftVs were based 

on water years from October I to 

September 30 to avoid splitting 

high flow periods that typically 

occur in winter and spring. Annual 

nonexceedance durations for flows 

of 4,000 to 16,000 ftVs were calculated two ways: (1) greatest number of consecutive days per year, 

and (2) total number of days per 

year that flows were below given 

flow values. All remaining durations were calculated based on total 

number of days per year (which are 

not necessarily consecutive).

Statistical analyses of duration 

tables were conducted to generate 

frequency information (medians 

and percentiles).

Stage-discharge ratings 

reflecting channel conditions prior 

to entrenchment and present 

(entrenched) channel conditions 

were developed at both the 

Chattahoochee and Blountstown 

gages. The composite preentrenchment stage-discharge 

rating for 1929-51 (described 

previously) was used at Chattahoochee. The pre-entrenchment 

stage-discharge rating for Blountstown was based on pre-entrenchment stage at Blountstown from 

1929 to 1951 in relation to 1-day 

lagged flow at Chattahoochee. 

For present conditions at Chattahoochee, the 1995 stage-discharge 

rating was used. For present conditions at Blountstown, unit values 

at Blountstown were plotted in 

relation to flow at Chattahoochee 

using a variety of lag times. The 

plot with the least amount of 

scatter (17 hours) was selected 

and a rating representing average 

conditions was developed from a 

hand-fitted line drawn through the 

points on the plot.

Water-level measurements 

at intensive study areas were made 

periodically at a total of 56 reference point (RP) locations: 23 in the 

upper reach (8 on Flat Creek, 3 on 

the main channel near Flat Creek, 2 

in an isolated swamp near Flat 

Creek, and 10 on Johnson Creek), 

14 in the middle reach (10 on 

lamonia Lake and associated tributaries, 3 on the main channel near 

[amonia Lake, and 1 on a pond 

near lamonia Lake), 19 in the nontidal lower reach (14 on River Styx 

and associated tributaries, 4 on the 

main channel near River Styx, and 

1 in an isolated swamp near River

Methods of Study
Styx). RP locations are identified 

on maps of the intensive study 

areas in a previous report (Light 

and others, L995, figs. 2-5). Nails 

in trees were used as the fixed 

point from which water levels were 

measured with a tape and weight. 

A total of 471 water-level measurements were made at RP locations 

from June 1993 to September 

1994. Most of the RP measurements were made during very low, 

low, or medium flows; however, a 

few measurements were made at 

higher flows to establish an 

approximate elevation relative to 

sea level for each RP. Visual observations of the movement of floating debris were used to estimate 

velocity (to nearest 0.2 ft/s) at 

floodplain RPs at the same time 

that most water-level measurements were taken.

Daily or hourly stage and 

flow data and stage-discharge ratings at all four long-term gages and 

an additional gage at river mile 36 

(station number 023587547, 

approximately 8 mi downstream of 

the Wewahitchka gage) were used 

in conjunction with water-level 

measurements at the RP locations 

to determine relations between 

flow at the Chattahoochee gage and 

stage at intensive study areas. For 

streams and lakes at the general 

survey sites, stage-discharge ratings relating stage at representative 

locations in each major reach of the 

river to flow at Chattahoochee were 

developed by interpolation 

between gages. The representative 

rating for the upper reach was 

selected at river mile 94.1 (mouth 

of Johnson Creek) and for the middle reach at river mile 58.7 (near 

lamonia Lake). Two ratings were 

chosen for the nontidal lower 

reach, one at river mile 35.2 

(mouth of River Styx) for the

upstream half of the lower reach, 

and one at river mile 26.0 (mouth 

of Kennedy Creek) for the downstream half of the lower reach. A 

representative rating for preentrenchment conditions in the 

upper reach at river mile 94.1 

(mouth of Johnson Creek) was 

developed by interpolation 

between pre-entrenchment ratings 

at the Chattahoochee and Blountstown gages. Previously published 

ratings (Leitman and others, 1983, 

fig. 16) were used for some of the 

floodplain forest data in the upper 

reach. Ratings were developed by 

interpolation between gages for all 

other forest data.

The flow at Chattahoochee at 

which each floodplain stream and 

lake was connected to the main 

channel was estimated from field 

observations by the following 

method. A single field visit was 

made to each of the 300 general 

survey sites to determine the difference between the water level of the 

Apalachicola River and the elevation of the streambed (or controlling sill if present). An elevation 

for the river level at each observation site was determined by 

calculating lagged flow at 

Chattahoochee at the time of the 

observation. This flow was 

converted to stage using the representative rating for the appropriate 

reach of the river. For streams 

connected to the river at the time of 

the observation, depths were determined by poling with a graduated 

rod in shallower areas and with a 

depth sounder in deeper areas. For 

streams not connected at the time 

of observation, visual estimates of 

the elevation (to nearest 0.5 ft) of 

the streambed or controlling sill 

above the river level were made at 

most sites. A hand level and graduated rod were used when the sill

was too far from the river to estimate visually. An example of a 

general survey site, at which the 

connecting flow was determined by 

adding the elevation of the streambed to the connecting stage, is 

shown in figure 3.

Field observations at most 

general survey sites were used in 

conjunction with lagged discharge 

at the Chattahoochee gage at the 

time of the field visit to determine 

Chattahoochee flows at which 

streams were connected to the main 

channel. A variation of this method 

was required in the downstream 

half of the nontidal lower reach 

because of variability introduced 

by the greater distance from 

Chattahoochee and the input 

from the Chipola River. Relations 

between flow at Chattahoochee and 

stage at the Sumatra gage were 

determined for average conditions 

by drawing a hand-fitted line 

through a scatter plot of Sumatra 

daily mean stages for the period 

of record in relation to lagged 

Chattahoochee flow. Stages at the 

Sumatra gage at the time of field 

observations in the downstream 

half of the nontidal lower reach 

were converted to average 

Chattahoochee flows using this 

rating. All field observations for 

this part of the lower reach were 

made during periods when stages at 

the Sumatra gage were not showing 

tidal fluctuations.

Characterization of 

Floodplain Habitats

Characterization data of 

floodplain habitats included widths 

and lengths (or areas) of floodplain 

features, land surface elevations, 

general soil type, and amount of 

live or dead vegetative structure. 

Methods used to characterize

10 Aquatic Habitats in Relation to River Flow in the Apalachicola River Floodplain, Florida
streams and lakes were different 

than those used to characterize 

forests.

Floodplain streams and 

/0A;es.--Characterization data were 

collected at 27 cross-section 

locations in the intensive study areas. 

Cross-section locations were selected 

to represent the most common types 

of floodplain streams (based on 

stream width and general forest type 

bordering the stream) in each major 

reach of the river, as determined 

from color infrared aerial photographs and USGS quadrangle maps. 

Of the 27 cross sections, there were 6 

in the upper reach (3 on Flat Creek 

and 3 on Johnson Creek), 9 in the 

middle reach (3 on lamonia Lake and 

6 on tributaries of lamonia Lake), 

and 12 in the nontidal lower reach (6 

on River Styx and 6 on tributaries of 

River Styx). Cross-section locations 

are identified on maps of the intensive study areas in a previous report 

(Light and others, 1995, figs. 2-5).

Most of the cross sections 

established on floodplain streams 

were perpendicular to the channel, 

with end points at recognizable topof-bank elevations on either side of 

the channel (fig. 4). In some cases 

where streambanks were very low, 

cross sections included several hundred feet of low forest adjacent to 

the stream. Surveyed cross sections 

ranged in length from 50 to 1,300 ft. 

Length of all 27 cross sections 

totaled approximately 7,000 ft.

At the time of the survey, 

cross sections were divided into 

segments based on breaks in slope, 

or relatively homogeneous soil 

type or vegetative structure (fig. 4). 

The horizontal length of each 

segment was measured with a 

fiberglass measuring tape. Vertical 

elevation in relation to the water 

level was determined at the endpoints of each segment with a

Figure 3. Example of general survey site with floodplain stream disconnected 

from the Apalachicola River at the time of observation. This unnamed stream 

at river mile 59.7 in the middle reach of the river had a streambed 

approximately 3.5 feet above the water level of the river when lagged flow was 

9,600 cubic feet per second at the Chattahoochee gage. Using a stagedischarge rating representative of the middle reach of the river, the flow at the 

Chattahoochee gage at which this stream would be connected to the main 

channel was determined to be about 16,000 cubic feet per second.

Methods of Study 11
60

ujw 55

Z^J 50

„<

g« 45 

40 

35 

30

10 20 30 40 50 60 70 77 

DISTANCE, IN FEET FROM LEFT BANK 

EXPLANATION

——— LAND SURFACE

~~ ESTIMATED STAGE—median annual 1-day high flow

~ ESTIMATED STAGE—median flow

BMP ESTIMATED STAGE—median annual 1-day low flow 

1 SEGMENT NUMBER

>85% AMOUNT OF LIVE OR DEAD VEGETATIVE STRUCTURE 

WITHIN 3 FEET OF LAND SURFACE, IN PERCENT

Figure 4. Example of cross section divided into segments based on breaks in 

slope and relatively homogeneous vegetative structure. Soil type is silt-clay in 

all segments of the cross section. The estimated stages shown for the cross 

section were based on long-term flow statistics at the Chattahoochee gage 

(1922-95) and were determined by interpolation between gages. An 

adjustment was made to the estimated stage for the median annual 1-day low 

flow to reflect the lowest observed water level at the cross section. The cross 

section is located 1,450 feet upstream of mouth of Johnson Creek in the upper 

reach of the Apalachicola River.

tripod-mounted level and graduated rod. Elevations of the two endpoints of each segment were 

averaged to determine the segment 

elevation that was used in data 

analysis. General soil type in each 

segment was classified as silt/clay, 

sandy, or organic. The amount of 

vegetative structure was visually 

estimated for each segment from 

the percent of the segment length 

that intersected live vegetation, 

woody debris, or other vegetative 

matter within 3 ft of the ground. 

Vegetative structure was recorded 

in the following categories: less 

than 15 percent, 15 to 35 percent, 

35 to 65 percent, 65 to 85 percent, 

and greater than 85 percent.

Observations at other locations in intensive study areas and at 

most general survey sites included 

visual estimates (to nearest 1 ft) of

the width of the streambed (segment numbers 7-10 in fig. 4), width 

of the remaining channel to top of 

banks (segment numbers 1 -6 and 

11-15 in fig. 4), heights of banks, 

and presence or absence of water in 

the streambed.

Widths of the larger streams, 

lengths of all streams, and surface 

areas of all lakes were determined 

using map coverages and digital 

image data in GIS files. Other types 

of information such as drainage 

basin configuration and extent, and 

adjacent forest types were obtained 

from GIS files when needed to 

characterize parts of streams that 

were not observed in the field. GIS 

files contained digital image data 

consisting of 1979 color infrared 

aerial photography scanned at a 

resolution having a pixel size of 

5.9 ft on the ground, and map

coverages consisting of USGS 

7.5-minute quadrangle maps and a 

forest map of the Apalachicola 

River floodplain (Leitman, 1984).

Floodplain forests.—Most 

of the floodplain forest data used in 

this report were collected during a 

USGS study from 1979 to 1982 

known as the Apalachicola River 

Quality Assessment (ARQA). 

Results of this previous study 

included land surface elevations 

and forest types at 223 sample 

points located on 7 line transects 

crossing the Apalachicola River 

floodplain (Leitman and others, 

1983, fig. 34) and a map showing 

areal extent of forest types 

(Leitman, 1984). Major floodplain 

forest types in these reports were 

mixed bottomland hardwoods and 

tupelo-cypress. Other sources of 

forest data used to supplement the 

ARQA data were land surface 

elevations, general soil type, vegetative structure, and forest types on 

the forested parts of 5 of the 

27 cross sections at the intensive 

study areas (in the present study); 

land surface elevations, vegetative 

structure, and forest type on 

21 circular plots located at the 

intensive study areas (Light and 

Darst, 1997); and land surface 

elevations, soil type, and forest 

types at 2 belt transects located 

near the Blountstown and 

Wewahitchka gages (Leitman, 

1978).

Land surface elevations, soil 

type, and vegetative structure for 

each forest type in each major reach 

of the river were summarized from 

the various sources of data listed 

above. Estimates of soil type by forest type were made using soils data 

reported by Leitman (1978), sediment grain size data for ARQA sites 

(Mattraw and Elder, 1984, p. 61), 

and general soil type observations

12 Aquatic i Habiiots in Relation to River Flow in the Apalachicola River Ftoodplain, Florida
collected on the forested parts of the 

cross sections at the intensive study 

areas (in the present study). Estimates of percent cover of vegetative 

structure by forest type were made 

using structure data collected on the 

forested parts of the cross sections 

at the intensive study areas and at 

forest plots described by Light and 

Darst(1997).

The previously published 

map of forest types (Leitman, 

1984) was digitized for use in GIS. 

Minor corrections to polygon 

boundaries were made to adapt the 

map to the more detailed scale used 

in GIS coverages in this study. 

Areas of each forest type in each 

reach were computed from the new 

GIS version of the map.

Computations of Amount 

of Aquatic Habitat in 

Relation to River Flow

Final products of this investigation consisted of amounts of 

aquatic habitat in relation to river 

flow presented in a variety of formats (fig. 5). These products were 

generated by combining habitat

HYDROLOGIC 

DATA

CHARACTERIZATION

OF FLOODPLAIN

HABITATS

FINAL PRODUCTS

FLOODPLAIN STREAMS AND LAKES

Lagged

discharge at

Chattahoochee

[ Field observations ]

of streams and 

I lakes at all sites I

f Surveyed cross 

I sections of streams

and lakes at 

I intensive 

\^ study areas

[ Lengths of

streams and areas 

I of lakes from GIS

Calculations for

_5Le_a_s_ of__strearns_

and lakes

FLOODPLAIN FORESTS

/^ Stagedischarge 

V ratings 1 A J

[ARQA forest ] 

1 transect data I

L n

f Surveyed cross >, ( Areas of ^ 

I sections of forests at j 1 forests from 

intensive study areas V GIS J 

\ and other forest data J ^ ——— - —— -^

^Calculations for 

areas of forests

Lengths and locations

of individual streams

and lakes connected to

river during very low,

low, and medium flows

i

Areas of aquatic 

habitat in floodplain

streams, lakes, and 

forests in relation to

full range of flows

GIS-generated maps

showing streams, lakes,

and forests connected

to river at selected low,

medium, and 

medium-high flows

Figure 5. Flowchart for determining amount of aquatic habitat in floodplain streams, lakes, and forests in relation to 

flows in the Apalachicola River. (ARQA, Apalachicola River Quality Assessment; GIS, Geographic Information System)

Methods of Study 13
characterization with hydrologic 

data.

Final results are expressed in 

relation to river flow rather than 

stage, although stage is more 

directly related to hydrologic conditions in floodplain habitats than 

flow. River stages decline as the 

river flows downstream from the 

upper to lower end of the study 

area, and range in stage decreases 

as the floodplain gets wider and 

flatter near the coast. Thus, relations of floodplain habitats to river 

stage cannot be easily compared 

between sites on the river and cannot be summarized by reach or for 

the entire river. Row, on the other 

hand, is relatively consistent 

throughout much of the river and 

flow relationships can be established between reaches. Additionally, expressing results in terms of 

flow at the head of the river makes 

the results directly usable for water 

managers in determining releases 

from Jim Woodruff Dam and other 

upstream reservoirs. In this report, 

elevations of floodplain habitats 

were initially related to stage and 

then stage was converted to flow to 

allow comparisons and summaries 

of data from different sites.

Area of aquatic habitat was 

calculated for 36 discrete flow values which were selected to provide 

greater detail at very low, low, and 

medium flows, and lesser detail at 

higher flows. Row values used in 

this analysis were set at intervals of 

1,000 ft3/s, from 2,000 to 

23,000 ft3/s. Intervals gradually 

increased with increasing flows; 

remaining flow values were set at 

25,000, 27,000, 29,000, 31,000, 

33,000, 35,000, 40,000, 45,000, 

55,000, 65,000, 75,000, 100,000, 

140,000, and 200,000 ftVs. This set 

of flow values represents the full 

range of flows in the Apalachicola

River from extreme low to extreme 

high. The lowest daily mean flow 

at the Chattahoochee gage in 

the 74-year period of record was 

3,900 ft3/s (Nov. 15-16,1987) 

and the lowest instantaneous flow 

was 2,570 ft3/s (Aug. 6, 1986). 

Extremely low flows of 2,000 ft3/s 

are included to provide habitat data 

in the event that a decreasing trend 

in flows occurs in the future.

Three variables were chosen 

to characterize hydrologic conditions in aquatic habitats in relation 

to river flow because of their 

importance to fish and aquatic 

invertebrate populations: depth, 

connection depth, water velocity, 

general soil type, and vegetative 

structure. Depth indicates average 

water depth of the habitat, whereas 

connection depth is the depth of the 

water at the shallowest control 

point along the connecting passageway from the habitat to the 

main river channel. For many habitats, depth and connection depth 

have the same value, but in isolated 

pools and ponds at low flows, 

depths are sometimes 1 to 3 ft 

when connection depth is zero. 

Depths and connection depths were 

grouped into five categories for 

analysis: 0.01 to 0.49, 0.50 to 0.99, 

1.00 to 2.99, 3 to 6, and greater 

than 6 ft. Two additional categories 

were used for connection depth: 

1-way connection (preventing 

access for fishes from river to 

floodplain) and no connection. 

There were three categories for 

water velocity: 0, 0.1 to 0.5, and 

greater than 0.5 ft/s.

Floodplain streams and 

lakes.--All floodplain streams and 

lakes connected to the main channel at very low, low, and medium 

flows were divided into reaches 

that were relatively homogeneous 

with regard to channel width and

thalweg depth. One of the cross 

sections from an intensive study 

area in the same major reach of the 

river was selected and modified to 

represent each homogeneous 

stream reach. Modifications 

included changes in elevation, 

channel width, thalweg depth, bank 

heights, soil type, or vegetative 

structure. Most floodplain lakes 

were linear in shape, allowing 

cross sections from large streams to 

be used, with modifications, to 

represent lakes. Dimensions and 

characteristics for many reaches 

were determined by field observations. For each stream reach that 

was not observed in the field, a 

known reach that appeared similar 

to the unknown reach on aerial 

photos and maps was identified, 

and a cross section from the known 

reach was applied.

Using the representative 

ratings for each major reach of the 

river, and the flow at Chattahoochee 

at which each floodplain stream and 

lake was connected to the main 

channel (described in the section 

entitled "Hydrologic data collection 

and analysis"), cross-section elevations were related to flow at Chattahoochee. When river flows 

exceeded the connecting flow for a 

stream or lake, depths were calculated for each individual segment of 

the cross section by comparing the 

segment elevation to stages in the 

representative rating. Similarly, connection depths were calculated for 

cross-section segments by comparing the controlling sill elevation to 

stages in the rating. When river 

flows were below the connecting 

flow, all cross-section segments 

were disconnected from the main 

river channel. For each cross 

section, the area and depth of isolated pools (if any) when the stream 

or lake was disconnected was

14 Aquatic Habitats in Relation to R<v*r Flow in the Apalaehicola River Floodptain, Florida
estimated based on observations of 

that stream reach or similar reaches. 

Velocities were estimated for each 

stream reach and for each flow 

value based on field observations of 

that stream reach or similar reaches.

For each segment of the 

cross section, the segment width 

was multiplied by the length of the 

stream reach to determine the area 

in acres. All area data were summarized for each major reach of the 

river, and the resulting data file 

contained the area in acres of many 

different aquatic stream and lake 

habitats, each with a unique combination of characteristics (soil type, 

vegetative structure, depth, connection depth, and velocity) at each of 

the 36 flow values.

Floodplain forests.--Each 

forest transect had a stagedischarge rating relating stage at 

the transect with flow at Chattahoochee. Transects were divided 

into segments based on elevations 

that corresponded to stages in the 

rating for each of the 36 flow intervals. The flow at which each segment of the transect was inundated 

and connected to the main channel 

was determined using the appropriate rating. When river flows 

exceeded the connecting flow for a 

transect segment, depths were 

calculated for the segment by comparing the segment elevations to 

stages in the rating. When river 

levels were below the connecting 

flow, the segment was considered 

to be nonaquatic, unless the 

transect had been observed (either 

in this study or in previous studies) 

to have isolated pools of standing 

water during the dry season.

Water velocities were estimated for each forest type and for 

each flow value based on field 

observations of velocities in that 

forest type in this or previous studies. Estimates of soil type and vegetative cover were determined for

each forest type using methods 

described previously.

For each major reach of the 

river, lengths of inundated transect 

segments of each forest type in 

each elevation category were summarized and then converted to the 

percentage of the total transect 

length in that forest type. Percentages were then multiplied by the 

total area of each forest type in 

each major reach of the river. The 

resulting data file contained the 

area, in acres, of many different 

aquatic forest habitats, each with a 

unique combination of characteristics (soil type, vegetative structure, 

depth, connection depth, and velocity) at each of the 36 flow values.

Analysis of combined data 

for streams, lakes, and forests.-- 

Areal data for streams and lakes 

were merged with areal data for 

forests for each major reach of the 

river and for the nontidal river as a 

whole. Analyses of the data were 

conducted to generate final products in three different formats 

(fig. 5): (1) a list of lengths and 

locations of individual streams and 

lakes connected at very low, low, 

and medium flows; (2) flow-area 

curves showing the area of aquatic 

habitat in relation to the full range 

of flows at Chattahoochee for a 

variety of habitat characteristics; 

and (3) maps generated from GIS 

coverages for each major reach of 

the river showing streams, lakes, 

and forests connected to the main 

river channel at selected low, 

medium, and medium-high flows.

FLOW AND STAGE 

CHARAOTE FUSTICS Of 

THE APALACHICOLA 

RIVER, 1022-95

H

ydrologic conditions are a primary factor in the creation 

and maintenance of river floodplains. River flow builds floodplain 

features such as levees and ridges 

by depositing sediments during a 

flood. Floodplain streams and lakes 

are created from old river channels 

when the river changes course. 

River flow erodes the banks and 

beds of floodplain streams when 

velocities are high enough to scour 

sediments and carry them downstream. Changes in river stage 

alternately connect and disconnect 

floodplain water bodies, changing 

the conditions for fishes and 

aquatic invertebrates, as well as for 

vegetation and other biota. In this 

section of the report, duration and 

frequency statistics of the longterm flow record of the Apalachicola River based on monthly, 

annual, and multiple-year periods 

of analysis are presented. This 

information is important in assessing impacts of flow alterations 

because it can be used to make 

comparisons between altered flows 

and historical flows. This section 

ends with a discussion of altered 

stages that have occurred as a result 

of entrenchment in the upper river. 

All statistical analyses were 

based on daily mean flows of the 

74-year period of record at 

Chattahoochee, Fla., from 1922 to 

1995. Previous hydrologic analyses 

conducted on flow records through 

the year 1980 compared flows 

before and after construction of Jim 

Woodruff Dam, and concluded that 

climatic fluctuations were primarily responsible for higher flows 

after construction of the dam 

(Maristany, 1981; Leitman and others, 1983). The river experienced 

periods of severe drought immediately following those analyses; 

annual low flows in 1981, 1986, 

1987, and 1988 were lower than in 

all previous years for the period of 

record. This raises the possibility 

that flows are exhibiting a slightly 

decreasing trend over time;

Flow and Stage Characteristics of the Apatachicola River, 1922*95 15
Table 1 . Basic flow characteristics of Apalachicola River at Chattahoochee, Florida, 1922-95

[Median annual 1-day low flow is based on annual periods using climatic years of April 1-March 31 to avoid splitting low flow periods that typically occur 

in summer and fall. Median annual 1-day high flow is based on annual periods using water years of October 1-September 30 to avoid splitting high flow 

periods that typically occur in winter and spring]

Flow descriptor Flow value, in cubic feet per second

Flow records used in analysis

Lowest 1 -day flow

Median annual 1-day low flow

Median flow

Median annual 1-day high flow

Highest 1-day flow

iwiin aaies or icwesi ana mgnesi TIOWSJ

3,900 (November 15-16, 1987)

8,490

16,400

86,200

291,000 (March 20, 1929)

years

74.5

74

74.5

74

74.5

Period analyzed

October 1921-March 1996

April 1922-March 1996

October 1921-March 1996

October 1921-September 1995

October 1921-March 1996

however, low flows during the 

1950's drought were of longer 

duration than in the 1980's. Comparisons of the two drought periods 

will be discussed later in this section. Trend analysis with an examination of associated climatic 

differences is needed to determine 

if a trend exists. In the absence of a 

documented trend, the entire period 

of record was preferred for analysis 

of flow characteristics.

Because of both the possible 

trend in the record and the flow regulation that has occurred since construction of Jim Woodruff Dam, the 

use of predictive frequency statistics 

such as recurrence intervals was 

avoided in this study. Frequency 

information is instead described in 

terms of median and percentiles of 

flows that have occurred during the 

74-year period of record. In unregulated streams having long-term 

record with no trends, the median 

flow is approximately equivalent to 

the 2-year recurrence interval flow, 

and the 10th, 25th, 75th, and 90th 

percentile flows are approximately 

equivalent to the 10-, 4-, 1.33-, and 

1.11-year recurrence interval flows, 

respectively.

River flow fluctuates greatly 

from low-water to high-water periods within each year as well as 

from one year to the next. In the

74-year period of record the 

median flow of the Apalachicola 

River at Chattahoochee was 

approximately 16,400 ft3/s, with a 

typical annual range of flows from 

8,490 to 86,200 fWs (table 1). The 

lowest daily mean flow in the 

period of record was 3,900 ft3/s in 

November 1987, and the highest 

was 291,000 ftVs in March 1929.

Very Low to Medium Flows

The greatest number of 

consecutive days and total number 

of days per year that flows were 

below given flow values (annual 

nonexceedance durations) of 4,000 

to 16,000 ftVs for the period 

1922-95 are presented in table 2. 

The durations that occurred under 

normal or typical conditions are 

represented by the median durations. Durations in drier years are 

represented by the 10th- and 25thpercentile durations, and in wetter 

years by the 75th- and 90th-percentile duration. The greatest number 

of consecutive days and total number of days in each individual year 

from 1922 to 1995 are presented in 

appendix IA and IB, respectively.

In a typical year, daily mean 

flows less than 8,000 ftVs did not 

occur in the Apalachicola River at

Chattahoochee. Flows less than 

9,000 ftVs occurred in a typical year 

with a duration of 6 consecutive 

days or 13 total days. Flows less 

than 16,000 ftVs occurred for 93 

consecutive days or 179 total days 

(approximately half of the year).

Flows less than 8,000 fWs 

occurred in 34 of the 74 years of 

record (app. I). Flows less than 

8,000 fWs occurred with a duration 

of 64 consecutive days at the 10th 

percentile, and 20 consecutive days 

at the 25th percentile (table 2). 

Flows less than 6,000 fWs occurred 

in 15 years of the period of record. 

Flows under 5,000 ftVs were rare, 

occurring in only 4 years in the 

74-year period of record (1981, 

1986, 1987, and 1988). Flows 

under 4,000 ft3/s were exceptionally rare and occurred for only 

3 days in 1987 (table 2; app. I).

In 19 of the 74 years of 

record, flows less than 10,000 ftVs 

did not occur (app. I). In the two 

wettest years (1948 and 1975), the 

lowest daily mean flow was 

12,400 ft3/s.

Normal and extreme flows 

must be defined to understand 

known limits of hydrologic conditions that have been experienced by 

biological communities in the system. For example, some streams 

are continuously connected and

16 Aquatic Habitats «n Relation to Hiver Flow in the Apaiachicota River FloodpJain, Florida
flowing under normal and even 

drier than normal conditions, but 

are disconnected and become a 

series of stagnant, isolated pools 

during severe droughts. Fish and 

aquatic invertebrate populations 

that require flowing, oxygenated 

water are greatly reduced during 

droughts and may not be fully 

restored for years, depending upon 

the resiliency of individual species, 

the proximity of aquatic habitat 

that might provide a source for 

restocking, and the amount of 

recovery time before the next 

drought (Starrett, 1951; Larimore 

and others, 1959; Taylor, 1983).

Year-to-year variability is an 

important aspect of hydrologic 

fluctuation that affects the opportunity for recovery between 

droughts. The year-to-year variability of lower flows is graphically 

depicted in figure 6, which shows 

the lowest 5 percent of daily mean

Table 2. Greatest number of consecutive days and total number of days per year 

that flow was below given flow values from 4,000 to 16,000 cubic feet per second 

in the Apalachicola River at Chattahoochee, Florida

[Period of record analyzed is 1922-95. Analysis is based on climatic years of April 1-March 31 to 

avoid splitting low-flow periods that typically occur in summer and fall. In each column, durations are 

expressed first (in bold) in greatest number of consecutive days per year, and second (in italics) in total 

number of days per year, which are not necessarily consecutive. Percentiles indicate frequency of durations over 74-year period of record]

Flow

value, in

cubic feet

persecond

Greatest number of consecutive days and total number of days per year that 

flow was below given flow value for indicated percentile

Extreme 10th 25th 

(dry) percentile percentile

Median

(50th

percentile)

75th 90th Extreme 

percentile percentile (wet)

4.000

5,000

6,000

7,000

8,000

9,000

10,000

11,000

12,000

13,000

14,000

15,000

16,000

3

20

64

80

122

144

192

241

244

256

286

292

293

3

29

67

115

166

208

227

241

261

283

291

303

308

0

0

12

49

64

81

98

110

138

163

179

205

211

0

0

14

68

96

137

157

182

205

227

242

259

267

0

0

0

5

20

45

60

76

105

109

123

129

138

0

0

0

8

36

63

95

133

155

178

197

214

229

0

0

0

0

0

6

19

29

52

61

71

82

93

0

0

0

0

0

13

37

65

92

120

139

160

179

0

0

0

0

0

0

0

9

19

27

36

52

57

0

0

0

0

0

0

0

15

46

72

93

115

130

0

0

0

0

0

0

0

0

7

16

27

32

39

0

0

0

0

0

0

0

0

13

27

41

76

89

0

0

0

0

0

0

0

0

0

2

3

5

8

0

0

0

0

0

0

0

0

0

5

11

17

31

8,000

0 7,500

z 

O

LU 7,000

cc

£ 6,500

LU

LLJ

u- 6,000

O

CQ

g 5,500

ill 5,000

CDCC

g 4,500

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D

4,000

3,500

i i i i I i i i i i i i i i I i i i i i i i i i [ i i i i i i i i | i i i i i i i i i | i i i i i i i i i

o

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CM

Figure 6. Lowest 5 percent of daily mean flows in the Apalachicola River at Chattahoochee, Florida, 1922-95. 

The 1,350 daily mean flows depicted in this graph were not affected by filling of the reservoir at Lake Seminole except for 

2 days with daily means of 7,060 ft3/s in 1954. Almost all reservoir filling occurred during periods when flows were greater 

than 8,000 ft3/s (U.S. Army Corps of Engineers, 1985).
Table 3. Number of days per year for multiple-year periods that flow was below 

given flow values from 4,000 to 16,000 cubic feet per second in the 

Apalachicola River at Chattahoochee, Florida

[Period of record analyzed is 1922-95. Analysis is based on climatic years of April 1-March 31 to 

avoid splitting low flow periods that typically occur in summer and fall. Durations are expressed in 

total number of days per year, which are not necessarily consecutive]

Flow value, 

in cubic feet per 

second

4,000

5,000

6,000

7,000

8,000

9,000

10,000

11,000

12,000

13,000

14,000

15,000

16,000

Median duration in which flow was below given 

flow value, in number of days per year 

for multiple-year period

Two Three Four Five

consecutive

years

0

0

0

0

0

0

6

26

52

76

105

120

136

consecutive

years

0

0

0

0

0

0

0

11

38

62

92

114

129

consecutive

years

0

0

0

0

0

0

0

4

16

58

85

111

125

consecutive

years

0

0

0

0

0

0

0

3

L2

48

83

92

104

Flow value, 

in cubic feet per 

second

4,000

5,000

6,000

7,000

8,000

9,000

10,000

11,000

12,000

13,000

14,000

15,000

16,000

Maximum duration in which flow was below given 

flow value, in number of days per year 

for multiple-year period

Two Three Four Five

consecutive

years

0

6

54

83

114

145

190

208

227

257

271

278

292

consecutive

years

0

6

11

42

101

139

177

199

214

248

258

268

273

consecutive

years

0

0

11

23

53

80

99

117

142

167

182

202

223

consecutive

years

0

0

0

0

4

31

63

83

122

138

160

174

182

flows in relation to time. Nonexceedance durations for multiple-year periods of 2 to 5 years are shown in 

table 3. The upper part of table 3 

shows median durations and the 

lower part shows maximum durations for all multiple-year periods in 

the 74-year period of record. For 

example, flows less than 9,000 ft3/s 

occurred for a total of 13 days in a 

typical single year (table 2), but typically did not occur for two consecutive years (upper part of table 3). 

Rows less than 10,000 ft3/s occurred 

for a total of 37 days in a typical 

single year and 6 days per year for 

two consecutive years under normal 

conditions, but typically did not 

occur for three consecutive years. All 

possible combinations of 2, 3,4, or 

5 years were used to determine the 

durations in table 3. Appendix IB 

gives the durations for each individual year that were used to develop 

this table.

The droughts of the 1980's 

were the most severe in terms of 

single-year low flow durations; 

however, the 1950's drought was 

drier in terms of multiple-year durations (fig. 6; app. IB). More than 

three-quarters of the maximum 

multiple-year flow durations shown 

in the lower part of table 3 occurred 

in the extended drought period of 

1954-58; most of the remaining 

durations occurred during 1984-88. 

Very low flows occurred at other 

times from 1922-95, but typically 

occurred in a single year with flows 

that were not as low as in the 1950's 

or 1980? s and with a return to more 

normal flows the following year.

Seasonal fluctuation is 

another characteristic of river flow 

that has important effects on 

biological processes. Many fishes 

require spawning sites in spring and 

summer, and structural cover for 

juveniles following spawning (Lee

18 Aquatic Habitats in Relation to River Flow in the ApaJachicola River Ftoodplain, Florida
and others, 1 980; Savino and 

Stein, 1982). Availability of 

additional food sources in 

inundated forests helps fishes 

meet increased energetic 

needs for reproduction and 

growth (Killgore and Baker,

1996). Timing of floods 

affects the delivery of detrital 

material from forested areas 

to stream channels of the

floodplain and to the main

river channel as well as to

downstream estuarine habitats, affecting the seasonal 

food supply of riverine and 

estuarine detritivores

(Mattraw and Elder, 1984).

Seasonal variability is

described with monthly

durations for flows from

4,000 to 1 6,000 ft3/s in 

table 4. The upper part of 

table \ shows median flow

durations and the lower part 

shows maximum flow durations for the 74-year period 

of record. September, October, and November are typically the driest months, with 

flows less than 10,000 ft3/s

for durations of 4 to 10 days

of the month. February,

March, and April are the 

wettest months and typically 

do not have flows less than

16,000 ft3/s. Flows during

some months such as January and August are highly

variable. January is among

the wettest months with 

respect to its median flow 

duration, but has maximum

flow durations that are considerably drier. Maximum 

duration of flows less than

5,000 ft3/s for August were

much longer than for any

other month.

Table 4. Number of days per month that flow was below given flow values from 

4,000 to 1 6,000 cubic feet per second in the Apalachicola River at Chattahoochee, 

Florida

[Period of record analyzed is 1922-95. Durations are expressed in total number of days per month, which 

are not necessarily consecutive]

Flow 

value,

in cubic 

feet per 

second

4,000

5,000

6,000

7,000

8,000 

9,000

10,000

11,000

12,000

13,000

14.000 

15,000

16,000

Flow 

value, 

in cubic

feet per 

second

4,000

5,000

6,000

7,000 

8,000

9,000

10.000

11,000

12,000

13,000 

14,000

15,000

16,000

Median number of days per month that flow was below given flow value

April

0

0

0

0

0 

0

0

0

0

0

0 

0

0

May

0

0

0

0

0 

0

0

0

0

1

3 

5

6

June July

0 0

0 0

0 0

0 0

0 0 

0 0

0 0

0 0

2 6

8 11

11 16 

15 18

19 21

Aug.

0

0

0

0

0 

0

0

0

6

13

17

22

24

Sept.

0

0

0

0

0 

0

4

10

18

23

26 

29

30

Oct.

0

0

0

0

0 

0

10

18

23

29

31

31

31

Nov.

0

0

0

0

0 

0

6

16

23

26

29 

30

30

Dec. Jan.

0 0

0 0

0 0

0 0

0 0 

0 0

0 0

0 0

4 0

10 0

14 0 

15 0

19 2

Feb.

0

0

0

0

0 

0

0

0

0

0

0 

0

0

Mar.

0

0

0

0

0 

0

0

0

0

0

0 

0

0

Maximum number of days per month flow was below given flow value

April

0

0

0

0 

0

0

2

7

12

15 

18

26

27

May

0

0

0

I

5

20

26

31

31

31 

31

31

31

June July

0 0

0 0

0 1

15 31 

28 31

30 31

30 31

30 31

30 31

30 31 

30 31

30 31

30 31

Aug.

0

25

31

31 

31

31

31

31

31

31 

31

31

31

Sept.

0

4

30

30 

30

30

30

30

30

30 

30

30

30

Oct.

0

0

31

31 

31

31

31

31

31

31 

31

31

31

Nov.

3

6

30

30 

30

30

30

30

30

30 

30

30

30

Dec. Jan.

0 0

0 0

6 1

23 20

24 24

26 26

31 31

31 31

31 31

31 31 

31 31

31 31

31 31

Feb.

0

0

0

0 

0

7

10

23

26

28 

28

28

28

1 Flow and Stage Characteristics of the Apeteehicola River, 1922-95

Mar.

0

0

0

0 

0

0

0

0

4

22 

26

31

31

19
Table 5. Number of days per year that flow was above given flow values from 

16,000 to 200,000 cubic feet per second in the Apalachicola River at 

Chattahoochee, Florida

[Period of record analyzed is 1922-95. Analysis is based on water years of October 1-September 30 to 

avoid splitting high-flow periods that typically occur in winter and spring. Durations are expressed in 

total number of days per year, which are not necessarily consecutive. Percentiles indicate frequency of 

durations over 74-year period of record]

Flow value, in 

cubic feet per 

second

200,000

140,000

100.000

75,000

65,000

55,000

45,000

40,000

35,000

33,000

31,000

29,000

27,000

25,000

23,000

22,000

21,000

20,000

19,000

18,000

17,000

16,000

Number of days per year that flow was above given flow value 

for indicated percentile

Extreme 25th ^Bnlh" 75th Extreme 

(wet) percentile percentjle) percentile (dry)

9

21

27

32

46

79

100

123

151

168

177

192

205

215

241

265

287

298

312

328

331

338

0

0

3

10

19

33

48

60

78

88

96

110

126

141

152

164

173

178

190

205

218

240

0

0

0

3

6

14

30

42

61

68

75

84

95

103

113

122

132

142

154

165

176

193

0

0

0

0

1

4

12

18

24

29

36

38

44

53

61

74

87

91

105

125

135

143

0

0

0

0

0

0

0

0

0

0

0

0

0

0

1

4

16

21

29

31

38

41

Medium to High Flows

The total number of days per 

year that flows were above given 

flow values (annual exceedance 

durations) of 16,000 to 

200,000 ft3/s for the period 1922- 

95 are presented in table 5. 

Median durations represent typical 

conditions. Wet and dry ends of

the range are reversed compared 

to the nonexceedance durations of 

table 2. Durations in wetter years 

are represented by the 25th-percentile durations in table 5, and in 

drier years by the 75th-percentile 

duration.

In a typical year, daily mean 

flows did not exceed 100,000 ft3/s. 

Typical annual duration was

3 days for flows greater than 

75,000 ft3/s, and 6 days for flows 

greater than 65,000 ft3/s. Flows 

greater than 16,000 ft3/s occurred 

approximately half of the time in a 

normal year.

Short periods during which 

flows were above 100,000 ftVs 

occurred in 25 of the ^4 years of 

record. Duration of flows exceeding 100,000 ft-Ys at the 25th percentile was 3 days (table 5). Flows 

above 140,000 ft3/s occurred in 

12 years of the period of record. 

Flows above 200,000 ft3/s were 

rare, occurring in only 3 years 

(1925- 1929, and 1994). The 1929 

flood holds the record not only for 

the highest flow (291,000 ftVs) 

(table 1), but also for the longest 

duration of any flood exceeding 

100,000 ft3/s (27 days).

In drier years, flows did not 

exceed 75,000 ft3/s. There were 

9 years in the period of record in 

which the highest flows for the 

year did not exceed 55,000 ft3/s. 

The lowest annual 1-day high flow 

was 24,300 ft3/s in 1941.

Effects of Entrenchment on 

Stage in the Upper Reach

Entrenchment or riverbed 

degradation is a typical process 

that occurs downstream of dams in 

the first 1 to 3 decades after dam 

construction (Galay, 1983; Ligon 

and others, 1995). Coarse sediments carried downstream along 

the riverbed are trapped in the reservoir behind the dam. Water lacking coarse sediments is released 

below the dam and tends to erode 

the riverbed, lowering the elevation of the bed. The rate of 

entrenchment of the Apalachicola 

River at Chattahoochee was greatest from 1954 to the late 1960's 

(fig. 7). An additional decrease in

20 Aquatic Habitats ir> Relation to River Flow in the ftpaiachicoia River Roodplain, Florida
LJJ 

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LJJ

49

48

47

LJJ 

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LLJ 

LLJ

45

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LJJ 

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42

41

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Table 6. Decrease in stage in upper reach of Apalachicola River as a 

result of entrenchment

[Chattahoochee gage is at the upstream end and Blountstown gage is at the downstream end of upper reach. Decrease in stage represents the amount that stages have 

dropped for a given flow from pre-entrenchment conditions existing prior to 1954 to 

present (1995) conditions. Values were computed from stage-discharge ratings for preentrenchment and current conditions at each gage]

Figure 7. River stages during low flows in the Apalachicola River at Chattahoochee, Florida, 1929-95. Data points shown 

include all daily mean stages in the 67-year period that have corresponding flow values between 9,500 and 10,500 cubic 

feet per second using the stage-discharge rating in effect at the time. Data prior to 1929 are not shown because no 

discharge measurements were made prior to 1929.

stage of approximately 1 ft 

occurred around 1981. Entrenchment appears to have stabilized 

since then, as no additional 

decrease in stage is apparent from 

1981 to 1995. This agrees with a 

previous analysis conducted by 

Simons, Li and Associates, Inc. 

(1985), except that an aggradational trend since 1981 noted by 

those authors is not apparent in the 

more recent analysis depicted in 

figure 7.

Effects of entrenchment 

decrease with increasing flow and 

with distance downstream of the 

dam (table 6). Decreases in stage 

as a result of entrenchment 

averaged 4.8 ft at the Chattahoochee gage, and 1.9 ft at the 

Blountstown gage at low and 

medium flows. Effects of entrenchment appear to be restricted to the

Flow range,

Decrease in stage as a result of 

entrenchment, in feet

m CUDIC reei per second

4,000 to 15,000

16,000 to 35,000

36,000 to 75,000

76,000 to 100,000

101,000 to 150,000

Greater than 150,000

At Chattahoochee 

gage

4.8

4.7

4.0

3.3

2.2

<1.5

At Blountstown 

gage

1.9

1.9

1.5

1.0

0.6

<0.6

fHow and Stage Cnaractertstics t-f the Apakacrvitola fttvtr, 1922-95 ?1
upper reach of the river. Downstream of the Blountstown gage, 

the river channel thalweg reflects 

alternating cycles of aggradation 

and degradation but there are no 

consistent decreasing trends in 

stage (Simons, Li. and Associates, 

Inc., 1985, p. 100 and fig. 5.2).

FLOODPUMN STREAMS, 

LAKES, AND FORESTS 

IN RELATIONPrO RJVER 

FLOW

T

his section of the report 

describes the major types of 

streams, lakes, and forests of the 

floodplain by river reach, and the

changes that occur in these 

features with changes in river 

flow. Detailed maps and descriptions are provided for streams and 

lakes at the intensive study areas. 

Streams, lakes, and forests 

described in this section are illustrated on plates depicting connected aquatic habitat in the upper 

reach (pi. 1), middle reach (pi. 2), 

and nontidal lower reach (pi. 3) at 

specific flow values selected to 

represent low, medium, and 

medium-high river flows. The 

specific flow values used to represent low flows (8,000 ft3/s) and 

medium flows (16,000 ft3/s) are 

the same on all three plates. The 

specific flow value representing

medium-high flows on the plates 

varies with the reach and approximates the minimum river flow at 

which at least 70 percent of the 

total area of tupelo-cypress 

swamps in the reach is inundated 

and connected to the main channel. These specific flow values are 

31,000 ft3/s for the upper reach 

(pi. 1C), 27,000 ft3/s for the middle reach (pi. 2C), and 23,000 ft3/s 

for the nontidal lower reach 

(pi. 3C). Lengths and locations 

of individual streams connected 

to the main channel at selected 

flows are listed in appendix II 

and summarized in table 7.

Table 7. Lengths of floodplain streams and lakes in upper, middle, and nontidal lower reaches of the 

Apalachicola River that are connected to the main river channel at flows ranging from 4,000 to 19,000 

cubic feet per second

["Connected" means that approximately level water passageways exist between floodplain water bodies and the main river channel, allowing 2-way access for fishes to move from river to floodplain as well as from floodplain to river. Individual stream locations and lengths are given in appendix II. Not included in this table are the main channel of the nontidal Apalachicola River 

which is 86 miles in length, and main channels of the lower Chipola River and Chipola Cutoff which total 17 miles in length]

Flow at 

Chattahoochee

gage, 

in cubic feet 

per second

4,000

5,000

6,000

7,000

8,000

9,000

10,000

11,000

12,000

13,000

14,000

15,000

16,000

17,000

18,000

19,000

Length of streams and lakes connected to main channel at or below given flow 

values, in miles

Upper 

reach

0.8

2.6

5.3

5.3

8.3

9.0

14.4

20.3

20.5

20.5

20.6

20.9

20.9

21.0

24.6

24.6

Middle 

reach

5.2

6.3

8.8

11.9

29.4

32.0

32.2

42.0

57.7

63.0

71.4

79.3

86.7

88.8

93.8

101.5

Nontidal 

lower 

reach

12.7

26.0

39.7

50.3

55.4

65.2

75.2

77.7

83.7

88.3

96.3

98.9

100.6

101.3

104.1

104.1

Total

18.7

34.9

53.8

67.5

93.1

106.2

121.8

140.0

161.9

171.8

188.3

199.1

208.2

211.1

222.5

230.2

22 £ijp3ft. H-fc-it A tg in Relation to River Bow jn the Apalacrncola Rtver Floodptain, Florida
Upper Reach

Flat Creek, an intensive 

study area in the upper reach, is a 

perennial stream draining an 

upland area of 52 mi2 (figs. 8 and 

9). During very low flows, water 

in the mouth of Flat Creek is very 

shallow (less than 3 in. deep) and 

drops into the main channel across 

a sandy delta. Lowered stages in 

the main channel as a result of

entrenchment appear to have 

altered the mouth of this stream 

since the 1950's, making aquatic 

habitat in the Flat Creek drainage 

inaccessible to main channel 

fishes. Prior to construction of Jim 

Woodruff Dam, the mouth of Flat 

Creek was deep enough during 

very low flows for fish and boat 

access (J.M. Barkuloo, retired, 

USFWS, oral commun., 1997).

When the river rises higher than 

the mouth of Flat Creek in its 

present condition, river water 

enters the downstream reach of the 

stream creating an area of backwater with very sluggish flow; but 

farther upstream, Flat Creek is 

still flowing swiftly. During high 

flows, the banks of Flat Creek are 

under water and water flows 

across forests and streams in the

84°54' 84°52'

30°39'

30°37'

5,000 FEET

I I i

1,200 METERS

Base from U.S. Geological Survey digital data, 1972

Albers Equal-Area Conic projection

Standard Parallels 29°3Cr and 45C30', central meridian -83°00'

I I APALACHICOLA RIVER

—— FLOODPLAIN

—> DIRECTION OF FLOW

EXPLANATION

+ 99 RIVER MILE—number is 

distance from mouth, 

in miles.

Figure 8. Flat Creek intensive study area.

^loodutairtStreams, Lakes, and f%r$si» In Peferttor to River Flow
Figure 9. Flat Creek during low flow about 1,500 feet upstream of its mouth 

on the Apalachicola River. Perennial streams with sandy bottoms that originate 

in steep ravines east of the floodplain are unique to the upper reach of the 

river.

general direction of river flow 

(fig- 10).

Mosquito Creek is the largest tributary in the upper reach of 

the river with regard to discharge. 

It is a perennial stream with an 

upland drainage area of 90 mi2 

which lies east of the river 

(pi. 1A). Entrenchment can move 

upstream into tributaries (Galay, 

1983) and appears to have progressed approximately 100 ft into 

the mouth of this creek to a 

bridge, where rock and concrete 

rubble have been deposited in the 

bed and along the banks. The 

spillway created by this rock and 

rubble probably prevented bed 

degradation from progressing 

farther upstream. It also makes 

the entire upstream drainage inaccessible to fish in the main channel during very low flows.

Perennial streams in the 

floodplain originating from the 

upland are features that are common in the upper reach of the 

river but relatively rare in the 

middle and lower reaches. 

Streams draining steep ravines 

which dissect the upland on the 

east side of the river include 

Sweetwater Creek, Rock Creek, 

Beaverdam Creek, Little Sweetwater Creek, and Kelley Branch. 

Spring-fed streams on the west 

side of the river are Spring 

Branch and Blue Spring run 

(pi. IB). At a river flow of 

8,000 ft3/s, most of these perennial streams are waterfalls, allowing no access for fish in the main 

channel (pi. 1A, app. II). Vertical 

drop of waterfalls at this flow 

varies with the stream and can be 

2 ft or more.

Johnson Creek, a second 

intensive study area in the upperreach, is fed by small intermittent

24 Aquatic Habitats in Relation to River Flow in the Apalachicola River Floodplain, FkxW
streams draining the upland west 

of the river (fig. 11). A sill at the 

mouth disconnects Johnson Creek 

from the main channel during 

very low flows. During low and 

medium flows, the first half mile 

of Johnson Creek is still-water 

habitat connected to the main 

channel (fig. 12) and the remaining upstream reaches are a series 

of isolated pools. Sometimes the 

entire stream flows swiftly in 

response to local rains, but then 

returns to its still-water condition shortly afterwards. Consistent flow in Johnson Creek does 

not occur until high flows, when 

the river is flowing through both 

forests and streams of the floodplain in a general downstream 

direction.

Other streams in the upper 

reach that are usually connected 

to the main channel by backwater 

are Ocheesee Creek, Graves 

Creek, and The Bayou (pi. 1C). 

The Bayou and its tributaries are 

the longest stream system

(approximately 9 mi) in the upper 

reach of the floodplain. During 

low flows, the most downstream 

4,000 ft of The Bayou is stillwater habitat connected to the 

main channel. The Bayou is disconnected during low flows 

upstream of that reach by a rubble 

spillway in the vicinity of a small 

bridge used for logging access. 

Upstream from this point to the 

head of The Bayou on the main 

channel at river mile 85.7, the 

stream is a steep-sided and

Figure 10. Flooded swamp near Flat Creek during high flow. During floods, turbid river water moves slowly downstream 

through the floodplain forest at velocities of approximately 0.5 foot per second.

Floodplain Streams, Lakes, and Forests in Relation to River Ftott*
84°58'

30°36' —

30°34' —

Base from U.S. Geological Survey digital data, 1972

Albers Equal-Area Conic projection

Standard Parallels 29°30' and 45°30', central meridian -83°00'

EXPLANATION

I I APALACHICOLA RIVER 

FLOODPLAIN

—> DIRECTION OF FLOW

92+ RIVER MILE—number is 

distance from mouth, 

in miles

Figure 11. Johnson Creek intensive study area.

26 Aquatic Habitats ir FteJaiicn tvRiwr flow in tne Apalachicola River Roodplain, Florida
relatively narrow channel with 

water pooled in the deeper parts 

of the streambed (fig. 13). During 

medium flows, flow from 

Stafford Creek and rising backwater from the mouth connect the 

most downstream 4 mi of The 

Bayou to the main channel 

(pi. IB). During medium-high 

flows the remaining reach of The 

Bayou, from its upstream head on 

the main channel at river mile 

85.7 to the mouth of Stafford 

Creek, is connected and flowing, 

creating a complete loop that 

serves as an alternate flow path 

for river water from the main 

channel (pi. 1C). When streams 

of this type are connected, 

velocity increases to speeds that 

are relatively fast for floodplain 

streams (1-3 ft/s).

Sutton Lake is still-water 

habitat with a connection to the 

main channel that is deep enough 

for access by larger fishes, even 

during very low flows. It is the 

largest area of aquatic floodplain 

habitat that is connected to the 

main channel during low flows in 

the upper reach (pi. 1 A).

About 72 percent of all 

tupelo-cypress swamps in the 

upper reach of the river is connected aquatic habitat at a flow of 

31,000ft3/s(pl. 1C). Large 

tupelo-cypress swamps with 

semi-permanent standing water 

are a prominent feature of the 

upper reach (fig. 14). Many of 

these swamps are fed by groundwater seepage from the steep 

upland bluffs bordering the eastern edge of the floodplain. 

Hydrologic fluctuations in a large 

swamp with semi-permanent 

standing water in the vicinity of 

Beaverdam Creek were measured in the ARQA study 

(Leitman and others, 1983,

Figure 12. Johnson Creek during low flow about 2,000 feet upstream of its 

mouth on the Apalachicola River. Johnson Creek receives a small amount of 

intermittent runoff from upland drainages. During low and medium flows, the 

lower reach of Johnson Creek, shown here, is a still-water habitat connected to 

the river, and the upper reach is a series of isolated pools.

Floodplain Streams, Lakes, and Forests in Relation tc River Flow 27
Figure 13. The Bayou during medium flow about 5 miles upstream of its mouth on the Apalachicola River. Water in the 

stream was isolated from the main river channel and not flowing at the time this photograph was taken; however, the 

narrow, steep-sided channel is evidence of the relatively high velocities that occur when the stream is connected and 

flowing.

fig. 23). The pond level in that 

swamp was perched approximately 12 ft above the elevation of 

the water surface of the river at 

median low flow, and water in the 

swamp was not connected to the 

main channel until flows exceeded 

about 30,000 ft3/s.

Middle Reach

lamonia Lake and its 

tributaries, the intensive study

area in the middle reach of the 

river, is a tributary lake system 

that receives little runoff from 

upland drainage (cover illustration, fig. 15, fig. 16). In some of 

its wider reaches, lamonia Lake 

is as deep and wide as the 

Apalachicola River; yet under 

most conditions. lamonia Lake 

has little or no flow. During flows 

less than 8,000 ft3/s, a sill near 

the mouth of lamonia Lake disconnects it from the main river 

channel (app. II). During low and

medium flows above 8,000 ft3/s, 

lamonia Lake has a nearly level 

water surface for the entire 5 mi 

of its length, with an elevation 

equal to the level of the river at 

the downstream connection at 

river mile 55.8. During high 

flows, river water enters the 

upper and middle reaches of 

lamonia Lake through many 

small connector streams and the 

main body of the lake is flowing 

and sloped in a downstream 

direction.

^uatfc K-^bltal6 in Relation ft River Flow in the Apa^hiejOia River Fioodplam, Florida
Figure 14. Tupelo-cypress swamp with semi-permanent standing water in the floodplain of the Apalachicola River just 

north of Flat Creek. Ground-water seepage from steep upland bluffs bordering the eastern edge of the floodplain provides 

a source of water for extensive areas of semi-permanently wet swamps in the upper reach of the river. The water level in 

these swamps is perched several feet above the low water level of the river.

Figure 15. lamonia Lake about 

2 miles upstream of its mouth on the 

Apalachicola River. With a channel 

width of 400 feet and depths of 20 to 

30 feet, lamonia Lake looks similar to 

the main channel of the Apalachicola 

River. Tributary lakes such as this 

are probably old river channels that 

were abandoned when the river 

changed course.

Floorfplaln Streams, Lakes, and Forests tn Relation to IWiiief Ftow 29
85°06' 85°04* 85°02'

30°19' -

30°17' -

30°15' -

Base from U.S. Geological Survey digital data, 1972

Albers Equal-Area Conic projection

Standard Parallels 29°30'and 45°30', central meridian -83°00'

EXPLANATION

I I APALACHICOLA RIVER 

FLOODPLAIN

—•> DIRECTION OF FLOW

56 RIVER MILE—number is 

distance from mouth, 

in miles

Figure 16. lamonia Lake intensive study area.

30 Aquatic HaMlata in Relation to River Fiow in the Apakachicola River FJoodpiain, Florida
The two largest connector 

streams in the lamonia Lake system 

are the Middle Slough-Bee Tree 

Slough passageway and Mary Slough 

(fig. 16). During low flows, Middle 

Slough is disconnected and most of its 

streambed is dry (fig. 17A). Bee Tree 

Slough is also disconnected but has a 

series of isolated pools in its bed, some 

of which are 5 to 6 ft deep. The controlling sill for the Middle Slough-Bee 

Tree Slough passageway is in Middle 

Slough, about 3,000 ft upstream of its 

mouth on lamonia Lake. During river 

flows of 11,000 ftVs and higher, water 

flows from higher elevations in the 

Apalachicola River through Bee Tree 

Slough and Middle Slough to lower 

elevations in the upper end of lamonia 

Lake (fig. 17B). Relatively high velocities (1.5-2 ft/s) were observed in these

Figure 17. Middle Slough about 2,700 feet from its 

mouth on lamonia Lake (A) partially dry and 

disconnected during low flow and (B) flowing with 

shallow water during medium flow. When connected, 

Middle Slough carries water from the Apalachicola River 

by way of Bee Tree Slough to the upper end of lamonia 

Lake. Relatively high velocities of 1.5 to 2 feet per 

second occur in Middle Slough during higher flows.

B

Flocxipi^in Streams, Lakes, and Forests in Relation to River Flow $1
Figure 18. Outside Lake during medium flow about 1 mile upstream of its 

mouth on the Apalachicola River. This tributary lake is probably a very old river 

channel that has nearly filled with sediment. Much of Outside Lake during 

medium river flow is a shallowly flooded tupelo-cypress swamp with a slightly 

deeper open channel in the center.

connector streams at a river flow of 

20,000 fWs. Mary Slough is 

another connector stream near the 

middle of lamonia Lake. During 

low flows, the west end of Mary 

Slough is connected by backwater 

to lamonia Lake; its east end is

higher in elevation than the water 

surface in the lake and is a series of 

isolated pools during low flows. 

Water flows from the main channel 

through Mary Slough to lamonia 

Lake at a river flow of 13,000 ftVs 

and higher.

McDougal Lake (fig. 16) is 

shallower than lamonia Lake; 

however, the two lakes are 

connected with a level water surface 

even during very low flows. Honey 

Pond (fig. 16) is a shallow floodplain lake with scattered tupelo and 

cypress trees that is isolated from 

lamonia Lake during low flows. 

During medium flows, Honey Pond 

is connected and accessible from 

lamonia Lake by small boats.

Florida River is a large tributary lake in the middle reach that is 

connected to the main channel 

during very low flows. The mouth 

of Florida River has a relatively 

deep connection to the main 

channel, connecting almost 5 mi of 

still-water habitat to the main 

channel during very low flows with 

an additional 3 mi connected during 

low flows (pi. 2A, app. II). About 25 

more miles of streams in this system 

are connected during medium flows. 

During medium flows, water from 

the Apalachicola River flows 

through the lower reach of Equaloxic Creek and Finns Slough into 

the upper Florida River (pi. 2B). 

During medium-high flows, water 

from the Apalachicola River flows 

through Dog Slough into the lower 

Florida River (pi. 2C).

Outside Lake has a very shallow channel about 400 to 500 ft wide 

that is forested with mature tupelo 

and cypress trees except for about 

150 ft in the center of the channel 

(fig. 18). Since the channel of Outside Lake is nearly filled with sediment, it may be a former river 

channel that is older than either 

lamonia Lake or Florida River. During low flows, the first mile of Outside Lake upstream of its mouth is 3 

to 4 ft deep and connected to the 

main channel. Upstream of the first 

mile, Outside Lake is very shallow,

Aquatic HaWUrts in Relation to River Flow in the Apalachicoia River Floodplain, Florida
Figure 19. Sand Slough about 500 feet from its mouth on the Apalachicola River. Dry streambeds are typical of higher 

elevation streams when they are disconnected from the river.

and 2 mi upstream of the mouth the 

lake is a series of shallow isolated 

ponds. As the Apalachicola River 

rises, water from the river moves farther up into the lake. During medium 

flows the lake is also connected to 

the Apalachicola River at its upper 

end through a small stream flowing 

from Dead River (pi. 2B).

Old River and its tributary, 

Baker Branch, are narrow, steepsided streams that receive small 

amounts of flow from two upland 

streams during low flows. During 

medium flows, water from the 

Apalachicola River enters Old River 

at its upstream end and flows back 

into the main channel at the downstream end of Baker Branch (pi. 2).

Equaloxic Creek receives runoff from Big Gully Creek, a stream 

draining a relatively large area of 

flatwoods and acid swamps east of 

the floodplain (drainage area undetermined, probably greater than 20 

mi2). During low flow, water sampled about 3 mi upstream of the 

mouth of Equaloxic Creek had a pH 

of 2.5 (Michael J. Hill, Florida Game 

and Fresh Water Fish Commission, 

oral commun., 1993). Water in the 

main channel of the Apalachicola 

River usually has a pH between 7 

and 8. At a river flow of 7,500 ftVs, 

water in the mouth of Equaloxic 

Creek was observed to be tannin 

stained, with no turbidity, indicating 

that water in the creek originated

from the acidic upland stream rather 

than from turbid backwater from the 

main channel. Water from the river 

moves into the channel of Equaloxic 

Creek during medium flows and connects to the upper Florida River 

through Finns Slough.

Many more streams in the 

middle reach are connected to the 

main channel during medium and 

medium-high flows. At a river flow 

of 19,000 ft3/s, the middle reach has 

4 times as many miles of streams as 

the upper reach (table 7). Higher elevation streams that are connected to 

the river during medium or higher 

flows usually have dry streambeds 

when disconnected from the river 

(figs. 3 and 19). Lower elevation

Floodptein Streams, takes, and Forests Itt fteiatton to Rlv«r Mow 33
streams that are connected to the 

river during low flows contain 

isolated pools of water when they 

are disconnected from the river.

At a river flow of 

27,000 ftVs, about 74 percent of 

tupelo-cypress swamps and 

25 percent of mixed bottomland 

hardwood forests in the middle 

reach are inundated and connected to the main channel 

(pi. 2C). Tupelo-cypress swamps 

are mostly located near the outside edges of the floodplain but 

some swamps are located along 

stream channels, such as those on 

the Florida River and Outside 

Lake. Unlike some of the swamps 

in the upper reach, most middle 

reach swamps have little or no 

standing water in the dry season. 

At a river flow of 27,000 ftVs 

(pi. 2C), connected aquatic habitats in mixed bottomland hardwoods probably consist of areas 

with land surface elevations similar to, or only slightly higher 

than, tupelo-cypress swamps. 

These areas are forested with 

some tupelo and cypress in a 

mixture of water hickory, overcup 

oak, swamp laurel oak, and green 

ash.

Nontidal Lower Reach

River Styx and its tributaries, the intensive study area in the 

nontidal lower reach of the river, 

is a tributary lake system that 

receives very little runoff from 

upland drainage (fig. 20). Over 

4 mi of still-water stream habitat 

in River Styx is connected to the 

main channel during low flows 

(fig. 21). Depths in River Styx are 

highly variable. In the first 

1,300 ft from the mouth, the

channel ranges from 15 to 30 ft in 

depth. Elevation of the water surface at the mouth of River Styx at 

low water is about 7 ft above sea 

level; thus, the elevation of the 

streambed in the deeper locations 

is 10 to 20 ft below sea level. 

About 1,400 ft from the mouth, a 

shallow, sandy sill across the 

river disconnects all upstream 

reaches of River Styx during very 

low flows (fig. 22). Very deep 

reaches continue to alternate with 

very shallow reaches upstream to 

approximately 4 mi from the 

mouth, where the River Styx at 

low water is consistently narrow 

with shallow water and low 

banks. Seven miles upstream of 

the mouth of River Styx, there is 

a wide swamp corridor with occasional isolated pools and no 

recognizable streambed. As the 

river rises from low to medium 

flows, water from the Apalachicola River backs up into the 

mouth of River Styx. During 

medium-high flows, water from 

the river enters at points upstream 

(Florida River and Equaloxic 

Creek) and moves through the 

swamp corridor as sheet-flow. 

When this occurs, the entire 

River Styx system is flowing 

toward its mouth on the Apalachicola River.

The two largest connector 

streams in the River Styx system 

are Swift Slough and Moccasin 

Slough (fig. 20). Both are relatively high velocity streams (1- 

2 ft/s) that carry water from the 

main channel down to the River 

Styx during low flows. Moccasin 

Slough empties into the River 

Styx close to its mouth on the 

Apalachicola River (fig. 20). 

Swift Slough ends about 2.5 mi 

from the mouth of River Styx. At

flows of less than 17,000 ft3/s in 

the Apalachicola River, the River 

Styx downstream of the mouth of 

Swift Slough has little flow. At 

flows of greater than 17,000 ft3/s 

in the Apalachicola River, the 

lower 2 mi of River Styx begins 

to flow more swiftly because 

additional connector streams, 

such as Hog Slough, Grayson 

Slough, and Everett Slough, are 

connected by rising water and the 

River Styx receives a significant 

amount of flow from the main 

channel (pis. 2C and 3C).

The parts of Kennedy 

Creek and Owl Creek that lie 

within the Apalachicola River 

floodplain are tributary lakes 

connected during very low flows 

(app. II, pi. 3A). Both streams 

originate in flatwoods and acid 

swamps in the upland east of the 

floodplain (similar to 

Equaloxic Creek in the middle 

reach) and both streams usually 

have sluggish flow.

Kennedy Creek is deep 

(15-20 ft during low water) and 

relatively wide (100-200 ft) for 

much of its length (fig. 23). The 

still-water habitat in Kennedy 

Creek and its tributaries that are 

connected to the river during low 

flows is extensive, totalling about 

9 mi of streams (4 mi of the 

mainstem of Kennedy Creek and 

an additional 5 mi of connected 

still-water streams). During low 

and medium flows, water in the 

most downstream I mi of 

Kennedy Creek is flowing into a 

stream that connects to the upper 

end of the wide part of Brushy 

Creek (pi. 3A). The wide part of 

Brushy Creek is very deep (20- 

30 ft) at its mouth on the main 

channel and throughout its entire 

length.

34 Aquatic Habitats in Relation to River Flow in the Apalachicola River Floodplain, Florida
30°08' 30°06'

85°08'

85°06' —

85°04' — 5,000 FEET

I I I ._. I

Base from U.S. Geological Survey digital data, 1972

Albers Equal-Area Conic projection

Standard Parallels 29°30' and 45°30', central meridian -83°00' EXPLANATION

| | APALACHICOLA RIVER +34 RIVER MILE—number is 

FLOODPLAIN distance from mouth,

in miles 

—> DIRECTION OF FLOW

Figure 20. River Styx intensive study area.

Floodplain Streams, Lakes and Forests in Relation to River Flow
Figure 21 . River Styx during low flow about 2.5 miles upstream of its mouth on 

the Apalachicola River. River Styx is 200 feet wide and 25 feet deep at this 

location. More than 4 miles of still-water stream habitat in River Styx are 

connected to the Apalachicola River during low flows.

.•£*

-•& »r*t! •^~.^^?^i?21^ j Jk>#»*i!F*itw5S^v^f^"!'

Figure 22. Main channel of River Styx during low flow about 1,400 feet from 

its mouth on the Apalachicola River. The sandy streambed is partly exposed at 

this location. Maximum depths of 1.1 feet were measured at the controlling sill; 

lagged flow at Chattahoochee at that time was 6,100 cubic feet per second. 

Many miles of River Styx upstream of this sill are disconnected during very low 

flows of 5,000 cubic feet per second or less.

During medium flows, 

Kennedy Creek is connected to 

River Styx by Shepard Slough 

and other unnamed streams 

(pi. 3B). Most of the tributaries 

of Kennedy Creek, including 

Shepard Slough and the connector to Brushy Creek, are narrow 

watercourses with shallow beds 

and low forests on the banks. 

These streams are usually too 

shallow to navigate during low 

flows, and during medium flows 

the low banks and surrounding 

forest are inundated and the channel becomes difficult to follow. In 

some reaches, the stream channel 

disappears into a diffuse network 

of streams that flow around tree 

hummocks (fig. 24).

The Chipola River is the 

largest tributary of the Apalachicola River, draining approximately 

1,200 mi2 in Florida and Alabama 

(Foose, 1981). The lower Chipola 

River below Dead Lakes receives 

approximately 70 percent of its 

flow from the main channel of the 

Apalachicola River by way of the 

Chipola Cutoff during low flows, 

and approximately 75 percent 

during medium flows (USAGE, 

written commun., 1994). The 

remaining 25 to 30 percent of the 

flow is from the Chipola River 

upstream of the mouth of Dead 

Lakes. Two streams. Corley Slough 

and Virginia Cut, that previously 

connected the lower Chipola River 

with the Apalachicola River near 

the mouth of River Styx, have been 

altered by dredge spoil deposition 

and no longer serve as connector 

streams during low and medium 

flows (pi. 3). Near its mouth, the 

lower Chipola is connected to the 

Apalachicola River during low 

water by way of Douglas Slough 

and its tributaries. Douglas Slough 

also is a loop stream during very

36 Aquatic Habit **s in delation to River Fle*v in the Apaiachicola River Roodplain, Florida
Figure 23. Kennedy Creek during 

medium flow about 7,500 feet 

upstream of its mouth on the 

Apalachicola River. This tributary 

lake is quite deep (15-20 feet) and 

relatively wide (100-200 feet) for 

much of its length. At the time this 

photograph was taken, lagged flow 

at the Chattahoochee gage was 

13,000 cubic feet per second, and 

most of the low banks and swamps 

adjacent to this stream were 

underwater.

Figure 24. Tree hummock in a tributary of Kennedy Creek. During medium flows, the channels of small streams in the 

vicinity of Kennedy Creek are very difficult to follow when they branch out into a diffuse network of streams flowing around 

tree hummocks.

Floodplaln Streams, Lakes, jpd Forests in Relaifou fo River ftsm
low flows, with both ends connected to the lower Chipola River. 

Several other streams, including 

Maddox Slough, Roberts Slough, 

and Burgess Creek, have both ends 

connected to the lower Chipola 

during medium flows. Lockey 

Lake is deep (10-20 ft) and connected during very low flows. At a 

river flow of 14,000 ftVs, Spiders 

Cut and other streams on the south 

side of the lower Chipola near its 

mouth were observed flowing 

south into the floodplain, probably 

to the upper end of Brothers River, 

which is a large tributary system 

that begins in the floodplain a few 

miles downstream of the mouth of 

the lower Chipola River (fig. 2).

During low flows, the nontidal lower reach has many more 

miles of connected streams than 

both the upper and middle reach 

combined (table 7). In the middle 

reach, almost all connected aquatic 

habitat during low flows is in a few 

large stream systems. However, in 

the lower reach, connected aquatic 

habitat during low flow is located 

in many small streams that have 

low sills and low, flat streambeds. 

At a river flow of 19,000 ftVs, the 

lower reach has about the same 

number of miles of streams connected to the main channel as the 

middle reach.

About 25 percent of tupelocypress swamps in the lower reach 

is inundated and connected to the 

main channel at a river flow of 

16,000 ft3/s (pi. 3B). About 74 percent of tupelo-cypress swamps in 

the lower reach is inundated and 

connected to the main channel at a 

river flow of 23,000 ftVs (pi. 3C). 

Tupelo-cypress swamps cover 

most of the floodplain in the lower 

half of the lower reach and contain 

many small isolated pools of water 

even during low flows. Many

tupelo-cypress swamps of the 

lower half of the lower reach have 

irregular ground surfaces with trees 

growing on hummocks or small 

tree islands (fig. 24).

AREA OF AQUATIC 

HABITATS IN THE FLOODPLAIN I&RELATION TO 

RIVER FtOW

I

n the first part of this section, 

estimated areas of three types of 

floodplain habitats are described in 

relation to river flow: (1) aquatic 

habitat connected to the main river 

channel, (2) aquatic habitat isolated 

from the main channel, and (3) 

nonaquatic habitat. The remainder 

of this section relates estimated 

areas of different types of connected aquatic habitats to river 

flow. Connected aquatic habitats 

are primarily floodplain streams 

and lakes during low flows and 

flooded forests during high flows. 

Connected aquatic habitats in different reaches of the river respond 

differently to increases in flow. 

Depths of controlling sills between

the main channel and aquatic habitats in the floodplain affect fish 

diversity by controlling access 

between diverse habitats. Water 

velocity, soil type, and vegetative 

structure are additional factors 

affecting the composition of fish 

and invertebrate populations.

Connected Aquatic Habitat 

Compared to Isolated 

Aquatic and Nonaquatic 

Habitats

At a river flow of 5,000 ftVs, 

the total area of connected aquatic 

habitat, estimated to be about 

260 acres, is relatively small, comprising only 0.3 percent of the total 

floodplain area (fig. 25). However, 

aquatic habitats that are connected 

to the main channel at very low 

flows are of crucial importance to 

fishes and invertebrates of the 

floodplain. Connected aquatic 

habitats provide shallow, quiet 

waters in floodplain streams and 

lakes as refuges from the deep, 

swiftly flowing waters of the main 

channel.

Aquatic habitat 

isolated from 

main channel

Aquatic habitat 

connected to 

main channel

20 30 40 50 70 100 200

FLOW OF APALACHICOLA RIVER AT CHATTAHOOCHEE. 

IN THOUSAND CUBIC FEET PER SECOND

Figure 25. Area of connected aquatic, isolated aquatic, and nonaquatic 

habitat in the nontidal Apalachicola River floodplain in relation to flows ranging 

from 5,000 to 200,000 cubic feet per second.

38 Aquatic Habitats in Relation to River Flow in the Apalachicola River Floodplain, Florida
Acreage of connected 

aquatic habitat increases rapidly 

with increases in flow above 

14,000 ft3/s. At the median river 

flow of 16,400 ftVs, about 

8,200 acres (10 percent of the 

floodplain) is connected aquatic 

habitat. Most of these areas are 

tupelo-cypress swamps bordering 

floodplain streams and lakes. When 

river flow reaches 32,000 ftVs, an 

estimated 40,700 acres (approximately one-half of the floodplain) 

is connected aquatic habitat. At 

86,200 ft3/s, the median annual 

1-day high flow, about 78,000 acres 

(95 percent of floodplain) is connected aquatic habitat.

At a river flow of 5,000 ftVs, 

approximately 4,000 acres (5 percent of the floodplain), is isolated 

aquatic habitat (fig. 25). Most of 

these areas are swamps with standing water typically less than 1 ft 

deep and rarely deeper than 3 ft in 

the dry season (fig. 14). The area 

of isolated swamps increases to 

about 5,800 acres at the median 

river flow of 16,400 ft3/s. This 

increase is a result of the increase 

in local precipitation that typically 

accompanies increases in river 

flow. Rainfall collects in swamps, 

expanding existing pools and creating new isolated aquatic habitats. 

As the river continues to rise, isolated swamps are eventually 

flooded by the river and become 

connected to the main channel. 

Flow required to flood isolated 

swamps decreases downstream, 

with river flows of 30,000 to 

35,000 ft3/s required to flood most 

isolated swamps in the upper reach, 

and 20,000 to 25,000 ft3/s required 

in the lower reach.

At a river flow of 5,000 ftVs, 

about 77,900 acres (95 percent of 

the floodplain) is forest habitat with 

no surface water present. These

LLJ 

CC

o

3,500

AQUATIC HABITAT CONNECTED 

TO MAIN CHANNEL 

Total

— — — Forests

Streams and lakes

FLOW OF APALACHICOLA RIVER AT CHATTAHOOCHEE, 

IN THOUSAND CUBIC FEET PER SECOND

AQUATIC HABITAT CONNECTED 

TO MAIN CHANNEL

— — — Forests

Streams and lakes

100

FLOW OF APALACHICOLA RIVER AT CHATTAHOOCHEE, 

IN THOUSAND CUBIC FEET PER SECOND

200

Figure 26. Area of connected aquatic habitat in forests compared to streams 

and lakes of the nontidal Apalachicola River floodplain in relation to flows 

ranging from (A) 2,000 to 14,000 cubic feet per second and (B) 5,000 to 

200,000 cubic feet per second.

areas include levees, high flats and 

ridges with forests dominated by 

sweetgum, sugarberry, and water 

oak; low flats with water hickory, 

green ash, overcup oak, and swamp 

laurel oak; and tupelo-cypress 

swamps with damp or saturated 

soils (Leitman and others, 1983). 

At 86,200 ft3/s, the median annual 

1-day high flow, about 4,200 acres 

of the floodplain is dry and 

exposed. Floodplain areas that are 

exposed during high flows areas 

are mostly high levees adjacent to 

the main channel with a few levees 

bordering streams in the interior of

the floodplain. Levees of this 

height are created by flood waters 

with high velocities capable of 

carrying a large amount of coarse 

sediments.

Connected Aquatic Habitat 

in Forests Compared to 

Streams and Lakes

At river flows of 7,000 ft3/s 

or lower, nearly 100 percent of the 

connected aquatic habitat in the 

floodplain is streams and lakes 

(fig. 26A). At these low flows, 

floodplain forests are almost comArea of Aq«**tio Habitats in life ftoodplain in Relation ro River Flow
LU 

DC 

0 

< 500

2

<t 400

En

1 300 

0

=5 200 

O

fe 100

DC 0

i i i i l l l l lilt 'i — i — i — i — i — | — i — i — i — i — | — i — i — i — i — | — i — i — i — i —

A y

- AQUATIC HABITAT CONNECTED / - 

TO MAIN CHANNEL /

— — — Upper reach prior to entrenchment / ....-•

— — Nontidal lower reach ^-

FLOW OF APALACHICOLA RIVER AT CHATTAHOOCHEE, 

IN THOUSAND CUBIC FEET PER SECOND

AQUATIC HABITAT CONNECTED 

TO MAIN CHANNEL

Upper reach entrenched

Upper reach prior to

entrenchment 

Middle reach

Nontidal lower reach

100

FLOW OF APALACHICOLA RIVER AT CHATTAHOOCHEE, 

IN THOUSAND CUBIC FEET PER SECOND

200

Figure 27. Area of connected aquatic habitat in the upper, middle, and 

nontidal lower reaches of the Apalachicola River floodplain in relation to flows 

ranging from (A) 2,000 to 9,000 cubic feet per second and (B) 5,000 to 

200,000 cubic feet per second. __

pletely drained of standing water 

except for the isolated swamps 

indicated in figure 25. At a flow of 

10,000 ft3/s, streams and lakes still 

constitute most of the connected 

aquatic habitat (860 acres), but 

about 210 acres of forest is flooded 

and connected to the main channel. 

Above a flow of 10,000 ftVs, the 

area of connected aquatic habitat 

increases more rapidly in forests 

than in streams and lakes 

(fig. 26A). At the median flow of 

16.400 ftVs, more than 80 percent 

of connected aquatic habitat is 

flooded forests (fig. 26B). As the

river continues to rise above 

median flow, the area of flooded 

forests increases rapidly, but the 

area of streams and lakes shows 

little increase because nearly all of 

them were flooded at lower flows.

The different horizontal 

scales in the two graphs in figure 

26 depict different processes at 

work in the floodplain. In figure 

26A, increases in habitat are shown 

on the order of hundreds of acres as 

the river moves into previously 

isolated streams or dry channels. 

This information is obscured with 

the scale used in figure 26B, which

shows increases in aquatic habitat 

on the order of thousands of acres 

as flow increases and the river 

moves into large areas of the floodplain forest.

Figure 26A and several other 

figures in this section include flows 

of 2,000 ftYs to provide habitat 

data in the event that a decreasing 

trend in flows occurs in the future. 

The full range of river flows shown 

in figures 25 and 26B include flows 

of 200,000 ft3/s. Increases in area 

of aquatic habitat with flow are 

relatively minor above the median 

annual 1-day high flow of 

86,200 ft3/s.

Connected Aquatic Habitat 

in the Upper, Middle, and 

Nontidal Lower Reaches

Connected aquatic habitat 

depicted in figures 25 and 26 represents habitat in the entire nontidal 

floodplain. Connected aquatic 

habitat in each of the three reaches 

of the river responds differently to 

increases in flow (fig. 27).

At flows ranging from 2,000 

to 9,000 fVVs (fig. 27A), the nontidal 

lower reach has the greatest amount 

of connected aquatic habitat and the 

upper reach has the least. The lower 

reach has many deep streams and 

lakes, such as Brushy Creek, Owl 

Creek, and Lockey Lake, that have 

bottom elevations below sea level 

and deep connections to the main 

channel. About 100 acres of aquatic 

habitat in the lower reach is connected at flows below 3,900 ft3/s, 

the lowest recorded daily mean 

flow, compared to about 45 acres in 

the middle reach (mostly in the 

Florida River), and about 11 acres in 

the upper reach (Sutton Lake). 

At flows ranging from 4,000 to 

9,000 ft3/s, the lower reach continues to have the most connected

40 Aquaa; HafeJJate ft SefiH.^ri to ftiver B^ in the Apafachfeote Rhref Ftoodptain, Florida
aquatic habitat as large parts of the 

River Styx and Kennedy Creek systems become connected. In the middle reach, the biggest increase in 

connected aquatic habitat during 

low flows occurs between 7,000 and 

8,000 ft3/s, when the amount of habitat more than triples as lamonia 

Lake becomes connected. The 

increase in flow from 2,000 to 

9,000 ft3/s causes a three-fold 

increase in connected aquatic habitat in the upper reach, from about 10 

to 33 acres. Prior to entrenchment, 

about twice as much aquatic habitat 

was connected in the upper reach 

during low flows than is connected 

in its present entrenched condition.

Area of aquatic habitat 

increases greatly at river flows of 

14,000 ft3/s in the nontidal lower 

reach and 15,000 ft3/s in the middle 

reach (fig. 27B). In the upper reach 

this large increase in aquatic 

habitat does not occur until river 

flow reaches 29,000 ftVs. Some of 

this difference is attributable to 

physiographic changes that occur 

from the upper to the lower reach. 

Topographic relief and land surface 

elevations in floodplains decrease 

in coastal plain rivers as they 

approach the sea. However, most 

of this difference is a result of 

entrenchment that has occurred in 

the upper reach since construction 

of Jim Woodruff Dam. The flow 

associated with a large increase in 

connected aquatic habitat in the 

upper reach was about 19,000 ft3/s 

prior to entrenchment compared to 

29.000 ft3/s in its present 

entrenched condition (fig. 27B).

Connection Depths

Connected aquatic habitat 

addressed in the preceding figures 

and discussion represent habitat 

that is connected at any depth. The

CO 

LU 

DC 

O

X 

O

§O

CO 

LU 

DC 

O

2,000

1,600

1,200

800

400

AQUATIC HABITAT WITH DEPTH

OF CONTROLLING CONNECTION

TO MAIN CHANNEL THAT ALLOWS:

Passage of small fishes 

(depths greater than 0 feet)

Passage of medium fishes 

(depths 1 foot or greater)

Passage of larger fishes 

(depths 3 feet or greater)

4 6 8 10

FLOW OF APALACHICOLA RIVER AT CHATTAHOOCHEE,

IN THOUSAND CUBIC FEET PER SECOND

12

90,000

80,000

70,000

60,000

50,000

40,000

30,000

20,000

10,000

0

B

AQUATIC HABITAT WITH DEPTH

OF CONTROLLING CONNECTION

TO MAIN CHANNEL THAT ALLOWS:

Passage of small fishes 

(depths greater than 0 feet)

Passage of medium fishes 

(depths 1 foot or greater)

Passage of larger fishes 

(depths 3 feet or greater)

10 20 30 40 50 70 100 200

FLOW OF APALACHICOLA RIVER AT CHATTAHOOCHEE, 

IN THOUSAND CUBIC FEET PER SECOND

Figure 28. Area of aquatic habitat with controlling connections that allow 

passage of small, medium, and large fishes in the nontidal Apalachicola River 

floodplain in relation to flows ranging from (A) 2,000 to 12,000 cubic feet per 

second and (B) 5,000 to 200,000 cubic feet per second.

connection depth is very shallow 

for some habitats, allowing passage 

for small fishes but blocking access 

for medium-sized fishes such as 

adult bluegill or redear sunfish, or 

large fishes such as striped bass or 

Gulf of Mexico sturgeon. 

Generally, the area of aquatic habitat that is accessible to medium and 

large fishes is considerably less 

than that accessible to small fishes 

(fig. 28). The connected aquatic 

habitat that allows passage of small 

fishes, as shown in the two graphs 

in figure 28, represents aquatic 

habitat in all nontidal reaches that

is connected at any depth greater 

than zero. The other curves in these 

graphs represent aquatic habitat 

that will allow passage of medium 

fishes (connection depth of 1 ft or 

greater) and large fishes (connection depth of 3 ft or greater).

Accessible habitat is available at different flows for fishes of 

different sizes. For example, 

260 acres of habitat is accessible to 

small fishes at river flows of 

5,000 ft3/s, but this same amount of 

habitat is not available to large 

fishes until flows of about 

10,000 ft3/s (fig. 28A). Large

Area of Aquatic Habitats to the Floodplain in Relation to Rtver Flow 41
1,000

800

600

400

200

AQUATIC HABITAT CONNECTED 

TO MAIN CHANNEL

Total

Still-water habitat

— — — Flowing-water habitat

°2 j — j- -i- -i. _L — i _ i — i— i— J_ .1- -i- -i. -> — I— i— i— i i T I i i i — i I i i

FLOW OF APALACHICOLA RIVER AT CHATTAHOOCHEE, 

IN THOUSAND CUBIC FEET PER SECOND

AQUATIC HABITAT CONNECTED 

TO MAIN CHANNEL

Total

Still-water habitat

Flowing-water habitat

70 100 200

FLOW OF APALACHICOLA RIVER AT CHATTAHOOCHEE, 

IN THOUSAND CUBIC FEET PER SECOND

Figure 29. Area of still-water and flowing-water habitat in the nontidal 

Apalachicola River floodplain connected to the main channel in relation to 

flows ranging from (A) 2,000 to 9,000 cubic feet per second and (B) 5,000 to 

200,000 cubic feet per second.

increases in area of connected 

aquatic habitat occur above flows 

of 14,000 fWs for small fishes, 

above flows of 17,000 ft3/s for 

medium-sized fishes, and between 

flows of 20,000 and 30,000 fWs for 

large fishes (fig. 28B).

Water Velocities in 

Connected Aquatic 

Habitats

Both still-water and flowingwater habitats in shallow floodplain 

water bodies provide refuges for

fishes from the deeper and more 

swiftly flowing waters in the main 

channel. Some fishes, such as redfin pickerel, taillight shiner, flier, 

and warmouth, primarily reside in 

still-water habitats of the floodplain 

and rarely enter the main channel 

(Leitman and others, 1991). Other 

fishes, such as darters, prefer flowing-water habitats in small floodplain streams.

Water velocities in the main 

channel are usually between 1 and 

4 ft/s. Velocities observed in most 

aquatic habitats in the floodplain 

are much lower (0 - 1 ft/s), with the

exception of loop and connector 

streams that carry river water along 

a steeper course than the main 

channel. Velocities of 2 to 3 ft/s 

were observed in the connector 

streams Bee Tree Slough and Swift 

Slough.

Changes in area of connected 

still-water and flowing-water 

habitat in the floodplain in relation 

to river flow is illustrated in 

figure 29. At a river flow of 

5,000 ft3/s, still-water habitat 

covers about 250 acres and flowing-water habitat covers 12 acres 

(fig. 29A). At a river flow of 

9,000 ft3/s, about 790 acres of stillwater habitat exists compared to 

190 acres of flowing-water habitat. 

Area of still-water habitat continues to greatly exceed area of flowing-water habitat until river flows 

reach about 20,000 ftVs (fig. 29B). 

At this river flow, water in connected aquatic habitats is flowing 

in most streams and lakes, but not 

flowing in forests. At river flows 

less than 20,000 fWs, the opportunity for flow-through is limited 

because the water is not high 

enough to break over levees and 

ridges that control connections 

between different parts of the 

floodplain. At river flows greater 

than 20,000 ft3/s, flow-through in 

the floodplain increases and water 

begins to move through large areas 

of floodplain forest. Flowingwater and still-water habitats continue to increase in area until river 

flows are about 40,000 fWs. When 

flows exceed 40,000 fWs, still 

waters are rapidly converted to 

flowing waters as the rising water 

connects more and more of the 

floodplain into a flow-through 

corridor. When flows reach 

65,000 ft3/s, more than 99 percent 

of the connected aquatic habitat in 

the floodplain is flowing.

42 Aquatic Habitats in Relation to River Flow in the Apalachicola River Roodplain, Florida
In the upper reach, there are 

a number of streams such as Flat 

Creek and Mosquito Creek that 

drain relatively large areas in the 

uplands adjacent to the river. The 

source of water for these streams is 

not dependent upon flows in the 

Apalachicola River, and the 

streams continue to flow during 

low and very low flows. However, 

their connections to the river 

during low flows do not allow 2- 

way access for fishes because of 

waterfalls or very shallow water 

dropping into the main channel. 

Small fishes can move from the 

streams into the main channel of 

the river but cannot swim back the 

other way. Streams with 1 -way 

connections cover relatively small 

areas (less than 35 acres), exist 

primarily at flows less than 

11,000 ft3/s, and are found only in 

the upper reach.

The area of flowing-water 

habitat with both 1-way and 2-way 

connections in the upper reach 

under present entrenched conditions is shown in figure 30A and 

under pre-entrenchment conditions 

is shown in figure 30B. At river 

flow of 3,900 ft-Vs, the lowest daily 

mean flow on record, all flowing 

waters in the floodplain of the 

entrenched upper reach have 1-way 

connections to the main channel. 

At this same river flow, prior to 

entrenchment, about half of the 

flowing-water habitat had 2-way 

connections to the main channel, 

and half had 1-way connections. 

Under present entrenched conditions, it is not until flows are about 

11,000 ftVs that nearly all streams 

in the upper reach have 2-way 

connections to the main channel.

DO

X 

O

z> 

o 

<

LL 

O

LU 

DC

CO 

LU 

DC 

O

o

60

40

20

FLOWING-WATER HABITAT IN UPPER 

REACH — ENTRENCHED CONDITIONS:

- With streamflow falling into main channel allowing fish 

access in only one direction

- Connected to main channel with fish access possible 

in both directions

3456789 10 11

FLOW OF APALACHICOLA RIVER AT CHATTAHOOCHEE, 

IN THOUSAND CUBIC FEET PER SECOND

12

60

40

20

FLOWING-WATER HABITAT IN UPPER 

REACH — PRIOR TO ENTRENCHMENT:

- With streamflow falling into main channel allowing fish 

access in only one direction

- Connected to main channel with fish access possible 

in both directions

2 3 4 5 6 7 8 9 10 11 12

FLOW OF APALACHICOLA RIVER AT CHATTAHOOCHEE, 

IN THOUSAND CUBIC FEET PER SECOND

Figure 30. Area of flowing-water habitat in the floodplain with 1 -way and 2- 

way connections to the main channel in relation to flows ranging from 2,000 

to 12,000 cubic feet per second in the upper reach of the Apalachicola River 

(A) under present (1995) entrenched conditions and (B) prior to entrenchment.

Soils of Floodplain Habitats

Variety in soil types affects 

diversity of floodplain fishes 

because many fishes have substrate 

preferences for either sandy or 

muddy bottoms (Lee and others, 

1980). Three major types of surface soils were found in the 

Apalachicola River floodplain: siltclays, sandy soils, and organic 

soils. Approximately 90 percent of 

the floodplain has silt-clay surface 

soils. Silt-clays predominate on 

alluvial rivers because large

amounts of fine-grain sediments 

are carried long distances and 

deposited on the floodplain during 

overbank flows. The percentage of 

connected aquatic habitat with siltclay soils varies with river flow but 

is always relatively high, ranging 

from 85 to 98 percent of the total 

area for any given flow (fig. 31). 

Sandy soils are found on 

about 6,400 acres (8 percent of the 

floodplain). Most of the sandy 

soils in the floodplain are found on 

levees that are flooded only at

Area of Aquatic Habitats in the Floodplain in Relation tc River Flow 43
CO111

DC 

O

3,500

3,000

2,500

2,000

1,500

1,000

500

0

AQUATIC HABITAT CONNECTED 

TO MAIN CHANNEL

——— Total

— — Silt-clay soils

— — — Sandy soils 

.......... Organic soils

2 4 6 8 10 12

FLOW OF APALACHICOLA RIVER AT CHATTAHOOCHEE, 

IN THOUSAND CUBIC FEET PER SECOND

AQUATIC HABITAT CONNECTED 

TO MAIN CHANNEL 

Total

— Silt-clay soils 

— — — Sandy soils 

Organic soils

40 50 70 100 200

FLOW OF APALACHICOLA RIVER AT CHATTAHOOCHEE, 

IN THOUSAND CUBIC FEET PER SECOND

Figure 31. Area of connected aquatic habitat with silt-clay, sandy, and 

organic soils in the nontidal Apalachicola River floodplain in relation to flows 

ranging from (A) 2,000 to 14,000 cubic feet per second and (B) 5,000 to 

200,000 cubic feet per second.

flows greater than 80,000 ft3/s 

(fig. 3 IB). Formation of these 

high levees occurs when alluvial 

flow of relatively high velocity 

leaves the main channel and enters 

the floodplain. The water slows 

down quickly as it enters the forest and immediately drops the 

coarse-grain component of its sediment load, forming a sandy levee 

adjacent to the main river channel. 

Sandy levees also border a few of 

the larger floodplain streams with 

high flow velocities.

In addition to riverbank and 

streambank levees, an estimated 

500 acres of sandy soils is found

in the beds of some floodplain 

streams. Streams observed in this 

study that had relatively high 

velocities (1 ft/s or greater) during 

low or medium flows, had 30 to 

100 percent of their beds composed of sandy soils. Streams with 

little or no velocity during low and 

medium flows had silt-clay beds 

with no sand either in the beds or 

along their banks. The flows at 

which streams with sandy streambeds are connected to the main 

river channel vary greatly. About 

50 acres of sandy-bottom streams, 

such as Flat Creek and Swift 

Slough, is connected at a river

flow of 6,000 ft3/s (fig. 31 A). 

Some streams, like Sand Slough 

(fig. 19) are dry during low flows 

and do not become connected and 

flowing until medium or higher 

flows.

Organic soils are found on 

about 2,700 acres (3 percent of the 

floodplain). Most of the organic 

soils in the floodplain are found in 

large tupelo-cypress swamps in 

the upper reach. These areas are

(1) isolated from the river at very 

low, low, and medium flows,

(2) connected to the main channel 

when flows reach 30,000 to 

40,000 ftVs (fig. 3 IB), and (3) do 

not experience high velocities 

even during floods. When these 

swamps are isolated from the main 

channel, rate of litter decomposition in still-water ponds decreases 

as the amount of oxygen in the 

stagnant water decreases. The 

result is a build-up of organic matter. During floods, these areas do 

not have velocities high enough to 

scour the floor of the swamp and 

remove the organic build-up. This 

lower velocity may be due to their 

large, flat basin-like shape or their 

location outside of the higher 

velocity corridors of flow in the 

floodplain.

The large tupelo-cypress 

swamp in the vicinity of Beaverdam Creek in the upper reach is an 

example of a wet depression with 

organic soils that is pooled and 

isolated from the main channel 

during low and medium flows. 

Flows of about 31,000 ftVs are 

required to connect this swamp to 

the main channel. At a flow of 

57,800 ft3/s, the average velocity 

in this swamp was 0.03 ft/s; at 

87,900 ftVs, the average velocity 

was still quite low at 0.17 ft/s 

(Leitman and others, 1983, 

fig. 25).

44 Aquatic Habitats irt Relation to River Flow to the Apalachicola River Booetplain, Florida
Amount of Vegetative 

Structure

Vegetative structure in 

aquatic habitat provides food 

sources, protective cover, and 

reproductive sites for fishes and 

aquatic invertebrates. Generally, 

floodplain habitat that is terrestrial 

most of the time, such as mixed 

bottomland hardwoods, has more 

vegetative structure than habitat 

that is primarily aquatic. When 

floodplain forests are inundated, 

large amounts of vegetative structure become available to aquatic 

organisms.

The amount of vegetative 

structure measured in floodplain 

forests and on the sloping banks of 

floodplain streams in this study was 

moderate to high (greater than 

15 percent) compared to that of 

floodplain streambeds which was 

usually low (less than 15 percent). 

However, in one-tenth of the total 

length of streambed cross sections, 

vegetative structure was moderate 

to high. Low velocities in floodplain streams allow woody debris 

to collect in parts of streambeds 

(figs. 9, 12, and 13), and live vegetation such as tupelo and cypress 

trees sometimes grow in floodplain 

streambeds (fig. 18). Comparable 

measurements of vegetative structure in the bed of the main channel 

were not made in this study; however, because water velocities are 

considerably higher in the main 

channel than in most floodplain 

streams, vegetative structure in the 

bed of the main channel is probably 

lower than that in streambeds in the 

floodplain. In a study of large riverfloodplain systems by Power and 

others (1995), main channel structure was estimated to be 5 percent 

at low flow, decreasing at higher 

flows as debris was dislodged and 

washed away.

At river flows less than 

9,000 ft3/s, most of the connected 

aquatic habitat is confined to streambeds and is consequently low in 

structure (fig. 32A). When water 

levels in floodplain streams rise out 

of their beds onto the sloping banks 

and into bordering swamp forests, 

the amount of vegetative structure 

in connected aquatic habitat 

increases greatly. This increase in 

structure in connected aquatic habitat begins at flows greater than 

10,000 ftVs; and at 16,000 ftVs, 

about 3,800 acres of aquatic habitat 

with moderate to high structure is 

connected to the main channel 

(fig. 32B). As the river continues to 

rise, the amount of vegetative 

structure available to aquatic 

organisms increases greatly as 

large areas of floodplain forest are 

inundated (fig. 32C).

FISHES IN BIVER FLOOD* 

PLAINS OF fME EASTERN UNITED SWTESs 

UTERATUREffiVIIW

T n the preceding sections, aquatic

habitat in the Apalachicola 

River was described and quantified 

in relation to river flow for the purpose of determining changes in 

habitat that may result from flow 

alterations. Effects of these habitat 

changes on biological communities 

are also important to address in the 

impact evaluation process. Of the 

wide array of organisms that 

depend on aquatic habitat, fishes 

are probably the most well-known 

group. Fish species that have been 

collected in the floodplain of the 

Apalachicola River are listed in 

this section of the report. A review 

of the literature of fishes in the 

river floodplains of the eastern

United States was conducted to 

identify additional species that 

probably inhabit the Apalachicola 

River floodplain.

A total of 131 species of 

freshwater and estuarine fishes 

have been found in the freshwaters 

of the Apalachicola River or the 

lower Chipola River downstream 

of Dead Lakes (Livingston and 

others, 1977; Yerger, 1977; Bass, 

1983; Ager and Land, 1984; Ager 

and others, 1985; Edmiston and 

Tuck, 1987; Hill and others, 1990; 

Light and others, 1993). Of this 

total, 40 species are euryhaline 

estuarine fishes that have been 

found only in the freshwater tidal 

part of the lower Apalachicola 

River and its distributaries. These 

40 species are not addressed in this 

report. The remaining 91 species 

are known to inhabit the nontidal 

Apalachicola or lower Chipola 

Rivers. Of these 91 species, 65 are 

freshwater species that are strictly 

intolerant of salt water, and 

26 species are either freshwater 

species that can tolerate some salt 

water or euryhaline estuarine species that occur in the nontidal river 

(Yerger, 1977).

Eighty percent, or 73 of the 

91 species collected in the 

Apalachicola River, are known to 

occur in river floodplains of the 

eastern United States (table 8). 

Fifty-one of these species have 

been collected in the Apalachicola 

River floodplain (22 common or 

abundant, 29 collected in low numbers), and an additional 22 species 

have been found in other river 

floodplains of the eastern United 

States. Collections of Apalachicola River floodplain fishes have 

been conducted primarily in one 

type of habitat (connected streams 

with sluggish flow) using one 

collection method (electrofishing).

Fishes in River Fjoodplains of tne Eastern UoiKjd States Literature Review 45
CO 

LU 

CL 

<J

gCD

I 

O

O

u_ 

O

1,000

800

600

400

200

AQUATIC HABITAT CONNECTED

TO MAIN CHANNEL 

—— Total

- —— Low amount of vegetative structure

(less than 15%) 

........ Moderate to high amount of vegetative

structure (more than 15%)

CO 

LJJ 

CL 

O

g 

CQ

O

O

u. 

O

CL

CO 

LJJ 

CL 

O

g 

CQ

I 

O

DC

7,000

6,000

5,000

4,000

3,000

2,000

1,000

100,000

80,000 -

60,000

40,000 -

FLOW OF APALACHICOLA RIVER AT CHATTAHOOCHEE, 

IN THOUSAND CUBIC FEET PER SECOND

AQUATIC HABITAT CONNECTED

TO MAIN CHANNEL 

—— Total

• —— Low amount of vegetative structure 

(less than 15%)

Moderate to high amount of vegetative 

structure (more than 15%)

10 12 14 16

FLOW OF APALACHICOLA RIVER AT CHATTAHOOCHEE, 

IN THOUSAND CUBIC FEET PER SECOND

u_ 20,000 -

AQUATIC HABITAT CONNECTED 

TO MAIN CHANNEL

Low amount of vegetative 

structure (less than 15%)

Moderate to high amount 

of vegetative structure 

(more than 15%)

30 40 50 70 100 200

FLOW OF APALACHICOLA RIVER AT CHATTAHOOCHEE, 

IN THOUSAND CUBIC FEET PER SECOND

Figure 32. Area of connected aquatic habitat with low and moderate to high 

amounts of vegetative structure in the nontidal Apalachicola River floodplain in 

relation to flows ranging from (A) 2,000 to 9,000 cubic feet per second; 

(B) 2,000 to 16,000 cubic feet per second; and (C) 5,000 to 200,000 cubic 

feet per second.

Aquatic Hab4t< t* in Relation to River Flow in the Apalachicola River Ftoodplain, Florida
Table 8. Occurrence of Apalachicola River fish species in river floodplains of the eastern United States

[Sources include Baker and others, 1991; Bass and Hitt, 1973; Beecher and others, 1977; Finger and Stewart. 1987; Foster and others, 1988; Guillory, 1979; 

Holder, 1971b; Killgore and Baker, 1996; Knight and others, 1991; Kwak, 1988; Leitman and others, 1991; Light and others, 1995; Ross and Baker, 1983; 

Walker and Sniffen, 1985. Excludes estuarine species that are restricted to the lower Apalachicola River. Excludes tidal floodplain habitats. Common or 

abundant, 1 percent or greater by number: low numbers, less than 1 percent by number]

Occurrence in floodplain of

Apalachicola or other rivers

of eastern United States

Common or

abundant in

Apalachicola

floodplain

collections

Collected in low numbers

in Apalachicola

floodplain

Present in floodplains

of other rivers of

eastern United States;

presence in Apalachicola

floodplain probable

No documented

occurrences in floodplains

of other rivers of

eastern United States;

presence in Apalachicola

floodplain uncertain

Species of fishes known to inhabit the Apalachicola River

Spotted gar1 -2

Bowfin1 '2

American eel

Gizzard shad2

Threadfin shad2

Common carp2

Golden shiner1 '2

Bluestripe shiner

Longnose gar1 -2

Skipjack herring

Redfin pickerel1 -2

Chain pickerel1

Pugnose minnow1 '2

Redeye chub

Coastal shiner

Weed shiner

Bandfin shiner

Lake chubsucker2

Grayfin redhorse

Silverjaw minnow

Bannerfin shiner

Bluenose shiner

Quillback

White catfish

Black madtom

Tadpole madtom1 '2

Southern brook

lamprey

Gulf of Mexico

sturgeon

Alabama shad

Clear chub

Ironcolor shiner

Taillight shiner1 -2

Blacktail shiner2

Spotted sucker1 -2

Pirate perch1 -2

Mosquitofish1 -2

Brook silverside1 '2

Okefenokee

pygmy sunfish1

Snail bullhead

Yellow bullhead1 -2

Brown bullhead1 '2

Channel catfish2

Spotted bullhead

Atlantic needlefish

Eastern starhead

topminnow

Blackspotted

topminnow1 -2

Speckled madtom

Flathead catfish

Golden topminnow1

Pygmy killifish

White bass2

Striped bass

Banded pygmy

sunfish1-2

Dusky shiner

Sailfin shiner

Longnose shiner

Flagfin shiner

Creek chub

Banded topminow

Shadow bass

Redbreast sunfish

Warmouth1 -2

Bluegill 1 -2

Redear sunfish1 '2

Spotted sunfish1

Largemouth bass 1 '2

Black crappie1 -2

Bluefin killifish1

Least killifish1 '2

Sunshine bass

Flier1 -2

Everglades pygmy sunfish

Orangespotted sunfish1

Dollar sunfish

Blackbanded darter2

Striped mullet

Hogchoker

Bluespotted sunfish1 -2

Banded sunfish

Green sunfish1

Spotted bass

Brown darter

Swamp darter

Gulf darter2

Sauger

Shoal bass

Florida sand darter

Goldstripe darter

Yellow perch

Mountain mullet

Southern flounder

Number of species known to inhabit the Apalachicola River

Number

of

species

22

29

22

18

91

'Collected in isolated water bodies in river floodplains of eastern United States (from Light and others, 1995. app. III).

2Evidence of use of floodplain habitats for reproduction (spawning, larval, or young-of-the-year fishes collected) in river floodplains of eastern United 

States (from Light and others, 1995, app. Ill; and Killgore and Baker, 1996).

Fishes in River Ruodplaitis o* the Eastern united Su*«s, literature Review 47
Most of the 22 additional species in 

table 8 that were present in other 

river floodplains would probably be 

found in the Apalachicola River 

floodplain if more comprehensive 

sampling was conducted in other 

types of habitat using a variety of 

collection methods. For example, in 

other river floodplains, white catfish, three species of madtoms 

(black, tadpole, and speckled), and 

small centrarchids such as banded 

pygmy sunfish and bluespotted sunfish were frequently collected with 

seines, dip nets, traps, and rotenone 

(Holder, 1971; Ross and Baker, 

1983; Walker and Sniffen, 1985; 

Finger and Stewart, 1987; Kwak, 

1988; Baker and others, 1991; 

Knight and others, 1991; Leitman 

and others, 1991). Information on 

river floodplain fishes in the eastern 

United States in table 8 was summarized from 14 sources, one of which 

(Baker and others, 1991) summarized floodplain collections in the 

lower Mississippi River from more 

than 70 sources of information. 

The fish communities of 

relatively large streams with 

sluggish flow in the Apalachicola 

River floodplain have been welldocumented by the Florida Game 

and Fresh Water Fish Commission. 

Forty-four species were collected 

during low flows in the following 

six floodplain streams when they 

were connected to the main channel: 

lamonia Lake, Equaloxic Creek, 

Florida River, River Styx, Kennedy 

Creek, and Owl Creek (Hill and others, 1990; Light and others, 1995, 

app. II). The most frequently collected species (in order from most to 

least common) were bluegill, brook 

silverside, bowfin, largemouth bass, 

spotted gar, redear sunfish, spotted 

sucker, warmouth, American eel, 

and redbreast sunfish.

More swiftly flowing streams 

such as Flat Creek, Middle Slough 

(connected to lamonia Lake), and 

Swift Creek (connected to River 

Styx) probably support common 

Apalachicola River species such as 

gizzard shad, threadfin shad, weed 

shiner, blacktail shiner, spotted 

sucker, bluegill, largemouth bass, 

redear sunfish, and redbreast sunfish, 

as well as fishes that prefer smaller 

streams such as flagfin shiner, bandfin shiner, and Gulf darter (Lee and 

others, 1980). The fish communities 

of these streams are relatively 

undocumented, with the notable 

exception of striped bass. The 

Apalachicola River system harbors 

the last remaining native population 

of Gulf race striped bass in the 

Southeast (Wooley and Crateau, 

1983). Flowing streams in the floodplain that have cool water from 

springs or ground-water seepage are 

thermal refuges that are critical to 

the survival in summer of adult 

striped bass, which cannot tolerate 

the wanner waters of the main channel (Moss, 1985; Coutant, 1987; Van 

Den Avyle and Evans, 1990). Sampling efforts by the Florida Game 

and Fresh Water Fish Commission 

confirm that striped bass use more 

than a dozen flowing streams in the 

upper reach of the Apalachicola 

River floodplain as thermal refuges 

(Charles Mesing, FGFWFC, written 

commun., 1995). Entrenchment in 

the upper reach of the river has lowered river stages and greatly 

decreased fish access to these flowing streams during low flows 

(fig. 30).

Isolated water bodies in the 

floodplain are primarily still-water 

habitats with shallow waters (less 

than 3 ft deep) that support fish 

communities distinctly different 

from deep, flowing waters of the 

main channel (Baker and others,

1991). A total of 31 species, identified on table 8, are known to inhabit 

isolated aquatic habitat in river 

floodplains of the eastern United 

States, the most common being redfin pickerel, golden shiner, taillight 

shiner, yellow bullhead, pirate 

perch, mosquitofish, least killifish, 

flier, banded pygmy sunfish, warmouth, bluegill, and black crappie 

(Kwak, 1988; Baker and others, 

1991; Leitman and others, 1991; 

Light and others, 1995). Most or all 

of these species would probably be 

found in the Apalachicola River 

floodplain with expanded collection 

efforts. A few of these species may 

be almost entirely dependent on 

floodplain habitats, residing yearround in still-water habitats of the 

floodplain and rarely entering the 

main channel. Species that primarily 

inhabit isolated aquatic habitats in 

the floodplain have been known to 

tolerate dissolved oxygen concentrations less than 1 ppm (Leitman 

and others, 1991).

Many main channel fishes 

exploit inundated floodplain 

habitats during high flows; these 

habitats are primarily flooded 

forests, with a relatively small percentage of the total area being 

flooded streams and lakes. All 

73 species that have been collected 

in the river floodplains of the eastern 

United States under various hydrologic conditions (table 8), are probably present on those floodplains 

during floods. (A total of 64 species 

have been collected on inundated 

floodplains during high water (Light 

and others, 1995, app. Ill); the 

remaining 9 species found in connected streams and isolated ponds 

probably remain on the floodplain 

during floods, but have not yet been 

collected there at high water.) The 

extent of flood exploitation was similar on the adjacent Ochlockonee

48 Aquatic Habitats in Relation to Rive* Flow in the Apatechicola River FtoodpJain, Florida
River (fig. I) where 75 percent of the 

known main channel species was 

collected in the floodplain during 

floods (Leitman and others, 1991).

Fishes use floodplains to 

fulfill basic needs for food, shelter 

from predators, and reproduction 

(Baker and others, 1991; Wharton 

and others, 1981, 1982). Several 

studies of southeastern rivers 

reviewed by Wharton and others 

(1981) have documented feeding 

on floodplains as evidenced by 

terrestrial invertebrates in the stomachs of fishes collected on inundated floodplains. The abundant 

vegetative structure in floodplain 

habitat such as snags, stumps, 

debris, grasses, and shrubs provide 

excellent shelter from predators 

(Aggus andElliott, 1975; Savino 

and Stein, 1982; Benke and others,

1985; Harmon and others, 1986). 

Evidence of reproduction on other 

river floodplains indicate that at 

least 33 Apalachicola River species 

(identified on table 8) may use 

floodplain habitats for spawning or 

nursery grounds (Guillory, 1979; 

Finger and Stewart, 1987; Leitman 

and others, 1991; Killgore and 

Baker, 1996).

APPLICATION OF 

STUDY RESULTS

educed flows in the Apalachicola River may result from 

increased use of water upstream in 

the Chattahoochee and Flint River 

Basins or when flows are regulated 

for navigation. Understanding the

impacts of these flow alterations is 

important in long-term maintenance of wetland functions in the 

floodplain. The results of this study 

can be used to assess the effects of 

flow alterations on the area of various types of aquatic habitats in the 

floodplain of the Apalachicola 

River. Changes in the types and 

amount of aquatic habitats are 

widely known to produce changes 

in biotic communities (German and 

Karr, 1978; Baker and others, 

1991). Habitat-based evaluations 

are frequently used to assess environmental impacts (Bovee, 1982).

Flow reductions that occur 

when flows are less than 16,000 ftVs 

will result in a decrease in area of 

most types of connected aquatic 

habitat in the floodplain in most 

reaches of the river (table 9).

Table 9. Summary of areas of aquatic habitat in the floodplain that are connected to the main channel of the Apalachicola 

River in relation to flows ranging from 4,000 to 16,000 cubic feet per second

[These data are presented in graphical form for a wider range of flows in figures 25-32; <, less than; >, greater than; >, greater than or equal to; ft, feet; 

%, percent]

Flow at

Chartahoochee 

gage, 

in 

cubic 

feet 

per 

second

4,000

5,000

6,000

7,000

8,000

9,000

10,000

11.000

12,000

13,000

14,000

15,000

16,000

Area of aquatic habitat in the floodplain that is connected to the main river channel at or above given flow value, in acres

Upper 

reach 

under 

entrenched 

conditions 

(and prior 

to 

entrenchment)

12 (32)

17 (43)

24 (52)

24 (55)

31 (60)

33 (63)

36 (70)

51 (83)

52 (91)

54 (99)

56 (110)

62 (200)

63 (290)

Middle reach

47

61

75

96

320

380

400

620

850

1,100

1,400

1,800

2,600

Non-tidal reachlower non-tidal river Entire 

100 160

190 2CO

230 330

290 410

390 740

570 970

630 1,100

720 1,400

950 1,900

1,200 2,300

1,600 3,000

3,100 4,900

4.300 7.000

Forests

0

0

0

17

81

200

210

420

740

1,100

1,700

3,500

5,500

Streams and lakes

158

263

329

394

661

778

856

974

1,120

1,210

1,320

1,420

1.510

Allowing passage of

Small Medium Large 

fishes fishes fishes 

(depths (depths (depths 

>0 ft) >1 ft) >3 ft)

160

260

330

410

740

970

1,100

1,400

1,900

2,300

3,000

4,900

7,000

120

150

250

300

380

600

780

1,000

1,200

1,300

1,800

2,000

2,600

87

110

110

120

150

220

280

340

580

680

810

880

1,100

Still water

150

250

300

370

660

780

810

950

1,100

1,400

2,100

3,800

5,800

£ connection in 

3 upper reach 

o> under >. 

•g entrenched £ -o 

o conditions ~ m 

"• (and prior to 35 OT 

entrenchment)

4.3

12

33

46

86

190

250

450

770

870

950

1,100

1,200

0.3

5.5

12

12

17

19

20

34

35

36

36

42

42

(17)

(25)

(33)

(33)

(33)

(33)

(34)

(34)

(35)

(43)

(53)

(63)

(66)

150 3.7

230 36

280 50

350 57

680 67

890 83

970 90

1,300 97

1,700 100

2,100 110

2,900 120

4,700 130

6,700 130

type

|

6

0

0

0

0

0

0

0

3.2

14

26

49

100

170

Vegetative 

structure

ModerLow ate to 

(<15%) high

150 13

250 15

310 24

380 26

700 45

910 65

980 87

1,200 190

1,400 450

1,600 710

1,900 1,200

2,500 2,400

3,200 3,800

Application of Study Resu Its 49
However, the specific effects of flow 

reductions vary with the range of 

flows at which the reduction occurs. 

For example, a flow reduction of 

1,000 ft3/s will decrease the area of 

aquatic habitat connected to the 

main channel in the entire nontidal 

river about 105 acres if the reduction is from 5,000 to 4,000 ft3/s; 

about 331 acres if the reduction is 

from 8,000 to 7,000 ftYs; and about 

2,090 acres if the reduction is from 

16,000 to 15,000 ft3/s. Generally, 

when flows are between 4,000 and 

16,000 ft3/s, much larger areas of 

connected aquatic habitat are 

affected by flow reductions occurring at higher flows within that 

range than at lower flows. However, it would be misleading to 

conclude from this statement that 

flow alterations occurring at lower 

flows have less impact than those 

occurring at higher flows. Decrease 

in total area of aquatic habitat is an 

important measure of the impact of 

flow alterations; however, relatively 

small decreases in a particular type 

of habitat can be important to certain species, especially at low flows 

when that type of habitat is already 

scarce. For example, cool-water 

streams in the floodplain of the 

upper reach of the Apalachicola 

River are important thermal refuges 

for striped bass. Entrenchment in 

the upper reach of the river has 

lowered river stages and greatly 

decreased 2-way access for fishes to 

flowing streams in the upper reach 

during low water periods (table 9), 

many of which are thermal refuges 

for striped bass. The amount of 

these habitats remaining at low 

flows is already low; thus, even 

relatively minor flow reductions 

during low flows may have a large 

impact on striped bass if cool-water 

streams used for thermal refuges 

are affected.

A few other examples from 

table 9 illustrate how the specific 

effects of flow reductions will vary 

with the range of flows at which the 

flow reduction occurs. Flow reductions that occur when flows are less 

than 5,000 ft3/s will nearly eliminate aquatic habitat having sandy 

soils in the floodplain that is connected to the main channel. Flow 

reductions that occur when flows 

are between 6,000 and 9,000 ft3/s 

will reduce the area of connected 

aquatic habitat in forests when the 

area of that habitat is already less 

than 200 acres, Flow reductions 

that occur when flows are between 

10,000 and 16,000 ft3/s will greatly 

reduce the number of acres of connected aquatic habitat with moderate to high vegetative structure.

Flow alterations that 

occurred in the Apalachicola River 

during 1990-95 are used in the 

following discussion as examples to 

show how the results of this investigation can be used to determine the 

effects of flow alterations on habitat 

area. The USAGE regulated flows 

to create 16 navigation windows 

from 1990 to 1995 to increase the 

amount of time that barge traffic 

could navigate on the Apalachicola 

River (app. III). Immediately prior 

to each navigation window was a 

prewindow period in which water 

was stored in several of the 

upstream USAGE reservoirs for an 

average of 15 days. During the 

navigation window, stored water 

was released at a consistent rate 

sufficient to support navigation by 

barges. The transition period 

between the prewindow and window was typically a 1-day period of 

rapidly increasing flow. The effects 

of flow augmentation have not been 

taken into account with regard to 

the average flows in appendix III; 

these flows were averaged from

actual flows that occurred on the 

dates indicated.

Flows during the period 

October 23-November 24, 1990, 

which included one prewindow 

period and its corresponding window, were selected for use as a 

specific example in this discussion 

and are shown in the green shaded 

area in table 10. The prewindow 

period included in this example 

has the lowest average flow of all 

prewindow periods (app. III). 

Flows during the previous window 

and subsequent prewindow are 

shown outside the shaded area. The 

area of connected aquatic habitat in 

the floodplain was reduced by about 

1,700 acres in a 3-day period (October 20-23) as the previous window 

ended and the prewindow period 

began. After the 19-day prewindow period ended on November 10, 

the area of connected aquatic habitat increased by about 1,900 acres 

in a 2-day transition period. After 

the 13-day window period ended on 

November 24, the area of connected 

aquatic habitat decreased again by 

about 1,800 acres in a 2-day period 

as the next prewindow period 

began. If the window had not been 

implemented, the area of aquatic 

habitat connected to the main 

channel for the prewindow and 

window period from October 23 to 

November 24 would have averaged 

about 910 acres (based on the average flow for that 33-day period). As 

a result of this flow alteration, there 

was about 590 fewer acres of connected aquatic habitat during the 

prewindow period than there would 

have been if the window had not 

been implemented. Also there was 

about 1,300 more acres of connected aquatic habitat during the 

window than there would have been 

if the window had not been implemented.

50 Aquatic Habitats in Relation to River Flow in the Apafachicota River Ftoodplain, Florida
Table 10. Area of aquatic habitat in the floodplain that is connected to the main channel of the Apalachicola River at flows 

preceding, during, and after a navigation window and at estimated flows if the window had not been implemented

[Green shaded rows give data for the period October 23-November 24, 1990, which is used as an example in the text. Data for the transition period of 

1 day are not shown. Average flow for the total period (in italics) represents the estimated flow that may have occurred during the prewindow, transition, 

and window periods if the window had not been implemented. Nonshaded rows give data for the previous window and and the next prewindow. Dates 

and flows for all periods were determined from daily mean flows at the Chattahoochee gage]

Area of aquatic habitat in 

floodplain that is connected

in cubic feet per second

Previous window (water release period)

Prewindow (water storage period)

Total period (prewindow, transition, and window periods 

combined)

Window (water release period)

Next prewindow (water storage period)

Oct. 15-20, 1990

Oct. 23 - Nov. 10, 1990

Oct. 23 - Nov. 24, 1990

Nov. 12-24, 1990

Nov. 26 -Dec. 11, 1990

12,300

5,900

8,720

12,900

6,690

in acres

2,000

320

970

2,200

390

Documenting the impacts of 

flow alterations on biota involves 

diverse and complex investigations that are beyond the scope of 

this study. However, some possible impacts on fishes are described 

in the following discussion and 

might serve as a basis for further 

research. Probably 80 percent of 

fish species known to inhabit the 

Apalachicola River use floodplain 

habitats as a source of food, shelter, 

or reproductive sites. In addition to 

590 fewer acres for 19 days from 

October 23 to November 10, two 

other prewindow periods occurred 

in the fall of 1990, resulting in a 

total of 54 days in which there was 

an average of 540 fewer acres of 

connected aquatic habitat available 

to main channel fishes than if the 

windows had not been implemented (19 additional days with 

400 fewer acres, and 16 additional 

days with 650 fewer acres, as interpolated from table 9 using flows 

from appendix III). A reduction in 

habitat of this magnitude and duration means that food sources were 

reduced for many main channel 

fishes in 1990, which may have 

affected both the survival rate of

some fishes as well as spawning 

success for certain species the 

following winter and spring. Protection from predation was probably compromised also; fishes were 

concentrated into less space during 

prewindows which may have 

affected survival rates for many 

juvenile fishes. Most fishes spawn 

in late winter, spring, or summer; 

however, a few species such as 

redfin pickerel and chain pickerel 

sometimes spawn in the fall (Lee 

and others, 1980). For those 

species, reduced habitat during 

prewindows meant that area available for spawning was reduced in 

1990. Nine of the 16 prewindows 

from 1990 to 1995 (app. Ill) 

occurred in spring or summer, and 

probably affected the availability 

of spawning sites as well as the 

survival rate of larval fishes for 

many species that are spring or 

summer spawners.

Of the 590 fewer acres of 

connected aquatic habitat available 

to main channel fishes during the 

prewindow, an estimated 60 percent was habitat that was drained of 

all standing water and eliminated 

as aquatic habitat for fishes.

Drained areas with no standing 

water included low forest areas, 

dry streambeds, and the exposed 

parts of streambeds that were partially dry and partially covered 

with isolated pools in streams such 

as Johnson Creek (fig. 12), Old 

River, and Moccasin Slough. The 

remaining 40 percent was aquatic 

habitat that was disconnected from 

the main channel and no longer 

accessible to main channel fishes. 

These disconnected aquatic 

habitats include large isolated bodies of water such as lamonia Lake 

(fig. 15) and Kennedy Slough (a 

tributary of Kennedy Creek), as 

well as many small isolated pools 

in partially dry streambeds. Field 

observations made by the authors 

in this and a previous study 

(Leitman and others, 1991) 

indicate that fishes are frequently 

trapped in isolated pools that can 

develop stagnant conditions shortly 

after they are disconnected. Oxygen demand exceeds oxygen supply when organisms are trapped 

and concentrated into small areas; 

the result can be very low dissolved 

oxygen concentrations, especially 

during hot weather.

Application of Study Results 51
During November 24-26, 

1990, river levels at the end of a 

navigation window and the start of 

the next prewindow period dropped 

very rapidly, with flows decreasing 

by 6,210 ftVs in a 2-day period. 

Species such as taillight shiner, 

flier, and warmouth that are known 

to inhabit isolated pools, may not 

be adversely affected by being 

trapped during prewindows 

because they are adapted to low 

dissolved oxygen concentrations. 

Many other species use the floodplain that may either prefer flowing 

waters or be sensitive to low dissolved oxygen concentrations, such 

as redbreast sunfish, Gulf darter, 

and blackbanded darter. Less tolerant species are also likely to be 

trapped in isolated pools, especially if river levels were consistently higher in a previous window, 

and then drop rapidly to very low 

levels. Many fishes may succumb 

to the adverse conditions, or they 

may be stressed by crowding, low 

dissolved oxygen, and high temperatures and become vulnerable to 

infection. Columnaris, a disease of 

fishes that was implicated in a fish 

kill that occurred in summer 1995 

in the Apalachicola River (Charles 

Mesing, FGFWFC, written commun., 1995), is caused by a ubiquitous bacterial organism that is 

common in the water, soil, and 

even on the skin of healthy fish. 

Columnaris disease "is thought to 

result more from stress factors 

which adversely affect the fishes' 

natural defense mechanisms, than

from the presence of the bacteria" 

(Francis-Floyd, 1988).

Assessing impacts of flow 

alterations is complicated by the 

fact that large and sometimes rapid 

fluctuations in flow occur naturally 

in the Apalachicola River. Low 

flows are a relatively common 

occurrence in summer and fall 

under unregulated conditions, and 

frequent storms at that time of year 

may cause rapid increases and 

decreases in river flow. Determining how river level fluctuations 

when flows are regulated for navigation windows differ from the 

fluctuations that might have 

occurred if the windows had not 

been implemented is an important 

component in evaluating the 

impacts of this flow alteration. The 

19-day prewindow from October 

23 to November 10, 1990, shown 

in table 10 included 12 consecutive 

days in which the flow was less 

than 6,000 ft3/s. In that climatic 

year (March 1, 1990-April 30, 

1991) flows below 6,000 ftVs 

occurred only during prewindow 

periods. Rows below 6.000 ft3/s 

for a duration of 12 consecutive 

days have occurred in only 10 percent of the years 1922-95 (table 2) 

which in unregulated streams 

would be equivalent to once every 

10 years on average. Thus a lowflow event of this type is relatively 

infrequent in the period of record, 

and would probably not have 

occurred in 1990 if navigation 

windows had not been implemented. If flow regulation to provide navigation windows for barge

traffic continues to be used in dry 

years, the durations presented in 

table 2 will likely change for low 

and very low flows. Multiple-year 

and monthly flow characteristics 

also will probably change. Flows 

below 6,000 ftVs for a duration of 

12 consecutive days have never 

occurred each year for more than 2 

consecutive years (table 3), and 

have never occurred in the months 

of December through July 

(table 4). Continued use of navigation windows may change other 

characteristics of the flow record 

that were not analyzed in this 

report, such as the number of times 

in the driest months of September, 

October, and November that flows 

increase or decrease by 6,000 ftVs 

in a period of 0 to 3 days.

As the preceding discussion 

implies, a thorough evaluation of 

the impacts of navigation windows 

or of any other type of flow alteration would require additional 

study which is beyond the scope of 

this investigation. One particular 

navigation window was used as an 

example in table 10, other navigation windows and other types of 

flow alterations would result in 

different effects. This report provides detailed information for 

determining the effects of altered 

flows on types and extent of 

aquatic habitat. Other important 

components of impact analysis 

include studies addressing effects 

of altered flows on biotic communities and comparisons of altered to 

historical flows.

52 Aqua*k Hsbltate in Hetetioo to River ttow in t^e Ap«lachftota River Floodp«aio, Hor .da
SUMMARY AND CONCLUSIONS

r • ^he Apalachicola River is a

large alluvial river in northern 

Florida formed by the confluence 

of the Chattahoochee and Flint 

Rivers in Georgia and Alabama. 

Increasing demands for water in 

the three States have resulted in 

conflicts, particularly during 

droughts. Water requirements of 

the Apalachicola River are 

addressed in this report, which 

presents information on aquatic 

habitat in the floodplain in relation 

to river flow. Results of this investigation can be used to evaluate 

potential impacts of flow alterations on floodplain habitat. 

Specific items covered in this 

report are (1) an analysis of longterm flow record in the Apalachicola River, (2) a description of the 

major types of floodplain streams, 

lakes, and swamps in relation to 

river flow, (3) estimates of the area 

of several different types of floodplain habitat in relation to river 

flow, (4) information about the 

species of fishes that occur in the

floodplain, and (5) examples 

showing how these results can be 

used to assess impacts of flow 

alterations on aquatic habitats and 

fishes in the Apalachicola River 

floodplain. The study was conducted from 1992 to 1996 in the 

nontidal floodplain of the Apalachicola River. Hydrologic analyses 

were based on 74 years of river 

stage and flow records (1922-95) at 

Chattahoochee, Fla. All flows in 

the following summary refer to 

flows at the Chattahoochee gage.

Principal conclusions relating to the first four items are grouped by the following general flow ranges:

Very low flows (less than 6,000 ft3/s)

• Very low flows occurred in 15 of the 74 years of record. Flows less than 5,000 ft3/s occurred in only 4 years 

(1981, 1986, 1987, and 1988). The lowest mean daily flow in the period of record was 3,900 ftVs in 

November 1987. The droughts of the 1980's were the most severe in terms of low-flow durations in a single 

year; however, the 1950's drought was drier in terms of multiple-year low-flow durations.

• At a river flow of 5,000 ft3/s, an estimated 260 acres of floodplain streams and lakes is aquatic habitat 

connected to the main channel, most of which is still-water habitat in the nontidal lower reach. The lower 

reach has many streams and lakes, such as Owl Creek and Lockey Lake, with bottom elevations below sea 

level and deep connections to the main channel at very low flows.

• In the upper reach, entrenchment that occurred after construction of Jim Woodruff Dam lowered bed elevations and river stages and altered connections between floodplain streams and the main channel. Many perennial streams in the upper reach, such as Flat Creek and Mosquito Creek, which were accessible to main 

channel fishes at low and very low flows prior to entrenchment, are now inaccessible because of waterfalls or 

very shallow water at their mouths.

• At a river flow of 5,000 ft3/s, about 77,900 acres (95 percent of the floodplain) is forest habitat with no 

surface water present. Major forest types are tupelo-cypress and mixed bottomland hardwoods; surface soils 

are predominantly silt-clays.

• At a river flow of 5,000 ft3/s, about 4,000 acres (5 percent of the floodplain) is isolated aquatic habitat. Most 

of these areas are tupelo-cypress swamps with standing water less than 3 ft deep. The pond level in some 

isolated swamps in the upper reach can be perched as much as 12 ft above the elevation of the low-water 

surface of the river.

• About one-third of the 91 fish species known to inhabit the Apalachicola River have been collected in

isolated aquatic habitat in river floodplains of the eastern United States; the most common being redfin pickerel, golden shiner, taillight shiner, yellow bullhead, pirate perch, mosquitofish, least killifish, flier, banded 

pygmy sunfish, warmouth, bluegill, and black crappie.

Summary and Conclusions
Low flows (6,000-10,000 ft3/s)

• Low flows occur in most years. The median annual 1-day low flow for the period of record is 8,490 ft3/s. 

Flows less than 8,000 ft3/s occurred in 34 of the 74 years of record. Low flows typically occur in September, 

October, and November.

• At a river flow of 8,000 ft3/s, the estimated area of connected aquatic habitat in the floodplain is 740 acres. 

Most of this area is located in tributary lakes, which are open bodies of water with little or no flow that are 

affected by backwater from the main river channel. The largest tributary lakes are lamonia Lake, Outside 

Lake, and Florida River in the middle reach, and River Styx and Kennedy Creek in the nontidal lower reach.

• At a river flow of 8,000 ft3/s, the area of still-water habitat (660 acres) greatly exceeds the area of flowing 

water habitat (86 acres). Both still-water and flowing-water habitats in shallow floodplain water bodies 

provide refuges for fishes from the deeper and more swiftly flowing waters in the main channel.

• At low flows, most of the connected aquatic habitat is confined to streambeds in which the amount of vegetative structure is lower than in other floodplain habitat, but probably higher than in the main channel.

• Forty-four fish species were collected in connected aquatic habitat in the Apalachicola River floodplain 

during low flows, the most common being bluegill, brook silverside, bowfin, largemouth bass, spotted gar, 

redear sunfish, spotted sucker, warmouth, American eel, and redbreast sunfish. These collections were made 

in a previous study by the Florida Game and Fresh Water Fish Commission, primarily in large tributary lakes 

connected to the main channel in the middle and lower reaches of the river.

Medium flows (10,000-20,000 ft3/s)

• Medium flows occur every year. The median flow for the period of record is 16,400 ft3/s. Flows less than 

16,000 ft3/s do not normally occur in the wettest months of February, March, and April; flows greater than 

16,000 ft3/s do not normally occur in the driest months of September, October, and November.

• At river flows above 10,000 ft3/s, the area of connected aquatic habitat increases more rapidly in forests than 

in streams and lakes. At the median flow of 16,400 ft3/s, approximately 8,200 acres (10 percent of the floodplain) is connected aquatic habitat. Most of these areas are tupelo-cypress swamps bordering streams and 

lakes in the middle and nontidal lower reaches that are inundated by backwater from the main channel.

• During medium flows, water in most of the connected aquatic habitat in forests is not flowing. Opportunities 

for water to flow through floodplain forests are limited because the water is not yet high enough to break over 

levees and ridges that control connections between different parts of floodplain.

• At a river flow of 19,000 ft3/s, most of the 230 miles of streams and lakes that are connected to the main channel is flowing. Tributary lakes of the middle and lower reach are still affected by backwater at this flow, but 

are slowly flowing because a considerable amount of water from the main channel is being diverted into them 

by way of connector streams. Bee Tree Slough and Mary Slough are examples of connector streams flowing 

from the main channel into lamonia Lake during medium river flows. Connector streams also carry water 

from one tributary lake to another, such as Shepard Slough, which flows from River Styx to Kennedy Creek. 

Loop streams such as Old River are fed by flow diverted from the main channel that flows for a few miles 

through the floodplain and then back into the river farther downstream.

• The amount of vegetative structure in connected aquatic habitat is much greater during medium flows than 

during low flows. This is because water is no longer contained in the beds of floodplain streams, but is covering vegetation and woody debris on streambanks and in adjacent swamps. Flooded vegetative structure 

provides cover for prey refuges, food sources, and reproductive sites for fishes and aquatic invertebrates.

AtyMtfC Hab-tais Jtt Relation tc Rh'&r Flow in the Apalaehitola River Floodplam, Florida
Medium-high flows (20,000-50,000 ftVs)

• Medium-high flows occur every year. In a typical year of the period of record, flows exceeded 20,000 ft3/s for 

a total duration of 142 days and exceeded 45,000 ft3/s for 30 days. The lowest annual 1-day high flow was 

24,300 ftVs in 1941.

• As flows increase from 20,000 to 50.000 ft3/s, the area of connected aquatic habitat increases from about 19 

to 82 percent of the floodplain. An estimated 40,700 acres, which is approximately one-half of the floodplain, 

is connected aquatic habitat at a river flow of 32,000 ft3/s.

• At flows from 23,000 to 40,000 ftVs, the area of flowing-water habitat is roughly equal to the area of stillwater habitat. Water velocities observed in most flowing-water habitats in the floodplain (less than 1 ft/s) are 

much lower than velocities in the main channel (1-4 ft/s), with the exception of loop and connector streams 

that carry river water at a relatively high velocity along a steeper course than the main channel.

• Nearly all aquatic habitat in tupelo-cypress swamps that is isolated at lower flows is connected to the main 

channel between flows of 20,000 to 40,000 ft3/s. The flow required to flood isolated swamps decreases downstream, with river flows of 30,000 to 35,000 ft3/s required to flood most isolated swamps in the upper reach, 

and 20,000 to 25,000 ft3/s required in the nontidal lower reach. Large areas of organic soils in isolated 

swamps, which comprise about 3 percent of the floodplain, are connected to the main channel at mediumhigh flows.

High flows (greater than 50,000 ftVs)

• High flows occur in most years. The median annual 1-day high flow for the period of record was 86,200 ft3/s. 

Flows above 100,000 ft3/s occurred in 25 of the 74 years of record. The highest mean daily flow was 

291,000 ft3/s in March 1929.

• At the median annual 1-day high flow of 86,200 ftVs, about 78,000 acres (95 percent of the floodplain) is 

connected aquatic habitat. The remaining 4,200 acres of floodplain that is still dry and exposed at this flow is 

mostly high levees adjacent to the main channel. Most of the 6,400 acres of sandy soils in the floodplain are 

found on high levees.

• During high flows, water is moving through most of the floodplain in a general downstream direction. At a 

flow of 65,000 ft3/s, more than 99 percent of the aquatic habitat in the floodplain is flowing.

• Many main channel fishes migrate into inundated floodplain forests where greatly increased food sources and 

abundant vegetative structure are available to them. Eighty percent, or 73 of the 91 species known to inhabit 

the Apalachicola River have been collected in river floodplains of the eastern United States under various 

hydrologic conditions and are probably present in floodplains during floods.

The following are principal conclusions relating to the last item, application of study results to assess 

impacts of flow alterations on aquatic habitats and fishes in the Apalachicola River floodplain:

• Flow reductions that occur when flows are less than 16,000 ftVs will result in a decrease in area of most types 

of connected aquatic habitat in the floodplain in most reaches of the river. Specific effects of flow reductions 

vary with the range of flows at which the reduction occurs.

• Generally, when flows are between 4,000 and 16,000 fWs, much larger areas of connected aquatic habitat are 

affected by flow reductions occurring at higher flows within that range than at lower flows. However, relatively small decreases in a particular type of habitat can be extremely important to certain species, especially 

during low flows when that type of habitat is already scarce. For example, the amount of flowing-water 

habitat in streams of the upper reach is extremely small during low flows. Relatively minor flow reductions

Summary and Conclusions
during low flows may have a large impact on striped bass if cool-water streams used for thermal refuges are 

affected.

Flow regulation to create navigation windows for barge traffic during the period October 23-November 24, 

1990, was selected for use as an example period of altered flows. Flows decreased rapidly by 6,400 ftVs 

immediately prior to the prewindow period, flows increased rapidly by 7,000 ft3/s just prior to the window 

period, and flows decreased rapidly again by 6,210 ft3/s immediately after the window. As a result of this 

flow alteration, there was about 590 fewer acres of connected aquatic habitat during the prewindow period 

than there would have been if the window had not been implemented. Also there was about 1,300 more acres 

of connected aquatic habitat during the window than there would have been if the window had not been 

implemented.

Although detailing the effects of flow alterations on biota was beyond the scope of this study, some possible 

impacts on fishes were described to provide suggestions for further evaluation and research. Reduced aquatic 

habitat in the floodplain limits the amount of food, protective cover, and spawning sites for many species of 

fishes that utilize these areas. When flows are reduced, some areas are drained of all standing water and 

eliminated as aquatic habitat for fishes. Other habitat remains aquatic after flows decrease, but is disconnected from the main channel and can no longer be accessed by main channel fishes. Fishes are likely to be 

trapped in isolated pools, especially if river levels drop rapidly, and may be subjected to crowded conditions 

and low dissolved oxygen concentrations. Many fishes may succumb to the adverse conditions, or they may 

be stressed and become vulnerable to infection.

Assessing impacts of flow alterations is complicated by the fact that large and sometimes rapid fluctuations in 

flow occur naturally in the Apalachicola River. A low-flow event of the type that occurred in the period of 

flow regulation used as an example in this report occurred once every 10 years on average in the 74-year 

period of record, and would probably not have occurred that year if navigation windows had not been implemented. Continued use of navigation windows in dry years will likely change low flow characteristics of the 

river and potentially affect biotic communities in the floodplain.

To thoroughly evaluate the impacts of navigation windows or of any other type of flow alteration, it is important to determine the types and extent of habitat affected, address impacts on biotic communities, and make 

comparisons of altered to historical flows.

REFERENCES

Ager, L.A., and Land, R.S., 1984, 

Annual report for I. Fish 

population study and water 

chemistry of the Chipola River 

and Dead Lakes; II. Creel 

analysis of the Apalachicola 

River below Jim Woodruff Lock 

and Dam; III. Fish population 

study of the major tributaries and 

distributaries of the lower 

Apalachicola River: Florida 

Game and Fresh Water Fish 

Commission, 104 p.

Ager, L.A., Mesing, Charles, and Hill, 

Michael, 1985, Fishery study, 

Apalachicola River maintenance

dredging disposal site evaluation 

program: Final report prepared 

for U.S. Army Engineer District, 

Mobile, Ala., under Contract no. 

DACW01-82-C-0056: Florida 

Game and Fresh Water Fish 

Commission, 73 p., plus 

appendixes.

Ager, L.A., Mesing, C.L., Land, R.S, 

Hill, M.J., Spellman, Mike, 

Rousseau, R.W., and Stone, 

Karen, 1986, Five year 

completion report: Fisheries 

ecology and dredging impacts on 

the Apalachicola river system, 

July 1981 through June 1986: 

Florida Game and Fresh Water 

Fish Commission, 97 p., plus 

appendixes.

Aggus. L.R., and Elliot, G.V., 1975, 

Effects of cover and food on yearclass strength of largemouth bass 

in Stroud, R.H., and Clepper, 

Henry, eds., Black Bass Biology 

and Management: Washington, 

D.C., Sport Fishing Institute, 

p. 317-322.

Alabama, Florida, Georgia, and the 

U.S. Army Corps of Engineers, 

1991, Plan of study: 

Comprehensive study: AlabamaCoosa-Tallapoosa and 

Apalachicola-ChattahoocheeFlint River Basins, 48 p.

Baker, J.A, Killgore, K.J., and Kasul, 

R.L., 1991, Aquatic habitats and 

fish communities in the lower 

Mississippi River: Reviews in

56 Aquatic Habitats In Relation t<* River Ftow in the Apalachicota River Floodplain, Florida
Aquatic Sciences, v. 3, no. 4. 

p. 313-356.

Bass, D.G. Jr., 1983, Rivers of Florida 

and their fishes: Florida Game 

and Fresh Water Fish 

Commission, 97 p.

Bass, D.G., Jr., and Hitt, V.G., 1973, 

Sport fishery ecology of the 

Suwannee and Santa Fe Rivers, 

Florida: Lake City, Fla., Florida 

Game and Fresh Water Fish 

Commission, 187 p.

Bayley, P.B., 1995, Understanding 

large river-fioodplain ecosystems: 

Bioscience, v. 45, no. 3, p. 153- 

158.

Beecher, H.A., Hixson, W.C., and 

Hopkins, T.S., 1977, Fishes of a 

Florida oxbow lake and its parent 

river: Florida Scientist, v. 40, 

no. 2, p. 140-148.

Benke, A.C., Henry, R.L., III,

Gillespie, D.M., and Hunter, R.J., 

1985, Importance of snag habitat 

for animal production in 

southeastern streams: Fisheries, 

v. 10, no. 5, p. 8-13.

Bovee, K.D., 1982, A guide to stream 

habitat analysis using the 

instream flow incremental 

methodology: Ft. Collins, Colo., 

U.S. Fish and Wildlife Service, 

Office of Biological Services, 

FWS/OBS-82-86, Instream Flow 

Information Paper no. 12, 248 p.

Brinson, M.M., Swift, B.L., Plantico, 

R.C., and Barclay, J.S., 1981, 

Riparian ecosystems: Their 

ecology and status: U.S. Fish and 

Wildlife Service, FWS/OBS81/17, 155 p.

Clark, W.Z., Jr., and Zisa, A.C., 1976, 

Physiographic map of Georgia: 

Atlanta, Georgia Department of 

Natural Resources, scale 

1:2,000,000, 1 sheet.

Couch, C.A., Hopkins, E.H., and 

Hardy, PS. 1996, Influences of 

environmental settings on 

aquatic ecosystems in the 

Apalachicola-ChattahoocheeFlint River basin: U.S. Geological 

Survey Water-Resources 

Investigations Report 95-4278, 

58 p.

Coutant, C.C., 1987, Poor reproductive 

success of striped bass from a 

reservoir with reduced summer 

habitat: Transactions of American 

Fisheries Society, v. 116, 

p. 154-160.

Cowardin, L.M., Carter, Virginia, 

Golet, F.C., and LaRoe, E.T., 

1979, Classification of wetlands 

and deepwater habitats of the 

United States: U.S. Fish and 

Wildlife Service, FWS/OBS79/31, 103 p.

Dames and Moore, 1996, Apalachicola 

River Florida River Island site, 

pre-construction water level 

monitoring, Final Report, 

Tallahassee, 13 p., plus appendix 

and illustrations.

Edmiston, H.L., and Tuck, H.A., 1987, 

Resource inventory of the 

Apalachicola River and Bay 

drainage basin: Florida Game and 

Fresh Water Fish Commission, 

303 p.

Finger, T.R., and Stewart, E.M., 1987, 

Responses of fishes to flooding 

regime in lowland hardwood 

wetlands, in Matthews, W.J., and 

Heins, D.C., eds., Community 

and Evolutionary Ecology of 

North American Stream Fishes: 

Norman, University of 

Oklahoma Press, p. 86-92.

Foose, D.W, 1981, Drainage areas of 

selected surface-water sites in 

Florida: U.S. Geological Survey 

Open-File Report 81-482, 83 p.

Foster, Ann, Patrick, Lorna, and 

Barkuloo, J.M., 1988, Striped 

bass and sturgeon egg and larva 

studies on the Apalachicola 

River -1987 progress report: U.S. 

Fish and Wildlife Service Field 

Office, Panama City, Fla., 12 p., 

plus appendixes.

Francis-Floyd, Ruth, 1988,

Columnaris disease: Institute of 

Food and Agricultural Services, 

Gainesville, University of 

Florida, Fact Sheet FA-11, 2 p.

Galay, V.J., 1983, Causes of river bed 

degradation: Water Resources 

Research, v. 19, no. 5, p. 1057- 

1090.

Godfrey, R.K., 1988, Trees, shrubs, 

and woody vines of northern 

Florida and adjacent Georgia and 

Alabama: Athens, The 

University of Georgia Press, 

734 p.

German, O.T., and Karr, J.R., 1978, 

Habitat structure and stream fish 

communities: Ecology, v. 59, 

no. 3, p. 507-515.

Guillory, Vincent, 1979, Utilization of 

an inundated floodplain by 

Mississippi River fishes: Florida 

Scientist, v. 42, no. 4, p. 222-228.

Harmon, M.E., Franklin, J.F., 

Swanson, F.J., Sollins, P., 

Gregory, S.V., Lattin, J.D., 

Anderson, N.H., Cline, S.P., 

Aumen, N.G., Sedell, J.R., 

Lienkaemper, G.W, Cromack, 

K., Jr., and Cummins, K.W., 

1986, Ecology of coarse woody 

debris in temperate ecosystems, 

in MacFadyen, A., and Ford, 

E.D., eds., Advances in 

Ecological Research, v. 15: 

London, Academic Press, 

Harcourt Brace Jovanovich, 

p. 133-302.

Helsel, D.R., and Hirsch, R.M., 1992, 

Statistical methods in water 

resources, New York, Elsevier 

Science Publishers, 522 p.

Hill, M.J., Long, E.A., Rousseau, 

R.W, 1990, 1985-1990 

Completion report: Apalachicola 

River Watershed investigations: 

Study I. General fisheries and 

aquatic habitat survey, Study II. 

Fisheries survey: Florida Game 

and Fresh Water Fish 

Commission, 74 p.

Holder, D.R., 1971, Study XVI, Job 2: 

Population studies—streams: 

Statewide Fisheries 

Investigations F-21-2, Georgia 

Department of Natural Resources, 

66 p.

Killgore, K.J., and Baker. J.A., 1996, 

Patterns of larval fish abundance 

in a bottomland hardwood 

wetland: Wetlands, v. 16, no. 3, 

288-295.

References
Knight, J.G., Bain, M.B., and 

Scheidegger, K.J., 1991, 

Ecological characteristics of fish 

assemblages in two seasonally 

inundated palustrine wetlands: 

Auburn, Alabama Cooperative 

Fish and Wildlife Unit, 65 p.

Kwak, T.J., 1988, Lateral movement 

and use of floodplain habitat by 

fishes of the Kankakee River, 

Illinois: The American Midland 

Naturalist, v. 102, no. 2, p. 241- 

249.

Larimore, R.W., Childers, W.F., and 

Heckrotte, Carlton, 1959, 

Destruction and re-establishment 

of stream fish and invertebrates 

affected by drought: Transactions 

of the American Fisheries 

Society, p. 261-285.

Lee, D.S., Gilbert, C.R., Hocutt, C.H., 

Jenkins, R.E., McAllister, D.E., 

and Stauffer, J.R., Jr., 1980, Atlas 

of North American freshwater 

fishes: Raleigh, North Carolina 

Biological Survey, Publication 

no. 1980-12, 854 p.

*Leitman, H.M., 1978, Correlation of 

Apalachicola floodplain tree 

communities with water levels, 

elevation, and soils: Unpublished 

Ma ( IT'S Thesis, Tallahassee, 

Florida State University.

*————1984, Forest map and hydrologic conditions, Apalachicola 

River floodplain, Florida: U.S. 

Geological Survey Hydrologic 

Investigations Atlas HA-672.

*Leitman, H.M., Darst, M.R., and 

Nordhaus, J.J., 1991, Fishes in the 

forested flood plain of the 

Ochlockonee River, Florida, 

during flood and drought 

conditions: U.S. Geological 

Survey Water-Resources 

Investigations Report 90-4202, 

36 p.

*Leitman, H.M., Sohm, J.E., and 

Franklin, M.A., 1983 [1984], 

Wetland hydrology and tree

*H.M. Leitman is the previous name 

of H.M. Light, the senior author of this 

report.

distribution of the Apalachicola 

River flood plain, Florida: U.S. 

Geological Survey Water-Supply 

Paper 2196-A, 52 p.

Lidstone and Anderson, Inc.. 1989, An 

investigation of the effects of 

Apalachicola River training 

dikes on sediment transport and 

bank erosion: Prepared for U.S. 

Army Corps of Engineers, 

Mobile, Ala. District, under 

Contract no. DACW01-87-D0023, 153 p., plus 6 pis., and 

exhibits.

Light, H.M., and Darst, M.R., 1997, 

Appendix B-Habitat 

characterization data for 

floodplain sites on the upper, 

middle, and non-tidal lower 

Apalachicola River, Florida, in 

Davis, M.M., Tri-State 

comprehensive study riparian 

wetland element: Report I: 

Relationships between flow and 

habitat value in the AlabamaCoosa-Tallapoosa/ApalachicolaChattahoochee-Flint (ACT/ACF) 

River Basins: Vicksburg, Miss., 

U.S. Army Engineer Waterways 

Experiment Station, 

Miscellaneous Paper EL-97-2, p. 

B1-B24.

Light, H.M., Darst, M.R., and Grubbs, 

J.W, 1993, Hydrologic 

conditions in floodplain habitats 

of the Apalachicola River, 

Florida: Annual report of 

progress, October 1992- 

September 1993: U.S. 

Geological Survey Open-File 

Report 93-363, 48 p.

————1995, Hydrologic conditions, 

habitat characteristics, and occurrence of fishes in the Apalachicola River floodplain, Florida: 

Second annual report of progress, 

October 1993-September 1994, 

U.S. Geological Survey OpenFile Report 95-167, 33 p.

Ligon, F.K., Dietrich, WE., Trush, 

W.J., 1995, Downstream 

ecological effects of dams: 

Bioscience, v. 45, no. 3, p. 183- 

192.

Livingston, R.J., Sheridan, P.S.,

McLane, B.C., Lewis, F.G., III, 

and Kobylinski, G.G., 1977, The 

biota of the Apalachicola Bay 

system: Functional relationships, 

in Livingston, R.J., and Joyce, 

E.A., eds., Proceedings of the 

conference on the Apalachicola 

drainage system: Florida Marine 

Research Publication no. 26, 

p. 75-100.

Maristany, A.E., 1981, Preliminary 

assessment of the effects of the 

Jim Woodruff Dam on the 

streamflow distribution of the 

Apalachicola River, Northwest 

Florida: Northwest Florida Water 

Management District Technical 

File Report 81-7.

Mattraw, H.C., Jr., and Elder, J.F., 

1984, Nutrient and detritus 

transport in the Apalachicola 

River, Florida: U.S. Geological 

Survey Water-Supply Paper 

2196-C, 62 p.

Mitsch, W.J., and Gosselink, J.G., 

1986, Wetlands: New York, Van 

Nostrand Reinhold, 539 p.

Mittelbach, F.F., Osenburg, C.W, 

Leibold, M.A., 1988, Trophic 

relations and ontogenetic niche 

shifts in aquatic ecosystems, in 

Ebenman, B., and Persson, L., 

eds., Size-structured populations, 

Berlin, Germany, SpringerVerlag, p. 219-235.

Moss, J.L., 1985, Summer selection of 

thermal refuges by striped bass in 

Alabama reservoirs and 

tail waters: Transactions of 

American Fisheries Society, 

v. 114, p. 77-83.

Power, M.E., Sun, A., Parker, G.,

Dietrich, WE., and Wootton. J.T., 

1995, Hydraulic food-chain 

models, An approach to the study 

of food-web dynamics in large 

rivers: BioScience, v. 45, no. 3, 

p. 159-167.

SB Aquatic Habitats in Relation to River Flow in the ApaJachicola River Floodplain, Florida
Reed, P.B., Jr., 1988, National list of 

plant species that occur in 

wetlands: Florida: U.S. Fish and 

Wildlife Service, NERC88/18.09, 140 p.

Robins, C.R., Bailey, R.M., Bond, 

C.E., Brooker, J.R., Lachner, 

E.A., Lea, R.N., and Scott, W.B., 

1980, A list of common and 

scientific names of fishes from the 

United States and Canada (4th 

ed.): Bethesda, Md., American 

Fisheries Society Special 

Publication no. 12, 174 p.

Ross, S.T., and Baker, J.A.. 1983, The 

response of fishes to periodic 

spring floods in a southeastern 

stream: The American Midland 

Naturalist, v. 109. no. 1, 14 p.

Savino, J.F., and Stein, R.A., 1982, 

Predator-prey interaction between 

largemouth bass and bluegills as 

influenced by simulated, 

submersed vegetation: 

Transactions of the American 

Fisheries Society, v. Ill, no. 3, 

p. 255-266.

Simons, Li, and Associates, 1985, A 

preliminary study of the 

hydrologic, hydraulic, 

geomorphic, and sediment 

transport characteristics of the 

Apalachicola River System, in 

Navigation maintenance plan for 

the Apalachicola-ChattahoocheeFlint Waterway, 1986, U.S. Army 

Corps of Engineers, Mobile 

District, Volume 2, Appendix B, 

p. B1-B168.

Sparks, R.E., 1995, Need for

ecosystem management of large 

rivers and their floodplains: 

Bioscience, v. 45, no. 3, p. 168- 

182.

Starrett, W.C., 1951, Some factors 

affecting the abundance of 

minnows in the Des Moines 

River, Iowa: Ecology, v. 32, no. 

1, p. 13-27.

Stevenson, H.M., 1976, Vertebrates of 

Florida; Identification and 

distribution: Gainesville, 

University Presses of Florida, 

607 p.

Taylor, R.C., 1983, Drought-induced 

changes in crayfish populations 

along a stream continuum: The 

American Midland Naturalist, 

v. 110, no. 2, p. 286-298.

U.S. Army Corp of Engineers, 1985, 

Apalachicola River Basin 

reservoir regulation manual: Jim 

Woodruff Reservoir: Appendix 

A, 78 p.

—— 1986, Navigation maintenance 

plan for the Apalachicola 

Chattahoochee Flint Waterway: 

v. 1, main text, 190 p., plus 

80 plates.

Van Den Avyle, M.J., and Evans, J.W., 

1990, Temperature selection by 

striped bass in a Gulf of Mexico 

coastal river system: North 

American Journal of Fisheries 

Management, v. 10, p. 58-66.

Walker, M.D., and Sniffen, Robert, 

1985, Fish utilization of an 

inundated swamp-stream floodplain: Corvallis, Oreg., U.S. 

Environmental Protection 

Agency, EPA-600/3-85-046, 72 p.

Welcomme, R.L., 1979, Fisheries 

ecology of floodplain rivers: 

New York, Longman, Inc., 317 p.

Wharton, C.H., Kitchens, W.M.,

Pendleton, E.G., and Sipe, T.W., 

1982, The ecology of bottomland 

hardwood swamps of the 

Southeast: A community profile:

U.S. Fish and Wildlife Service, 

FWS/OBS-81/37, 133 p.

Wharton, C.H., Lambou, V.W.,

Newsom, J., Winger, P.V, Gaddy, 

L.L., and Mancke, R., 1981, The 

fauna of bottomland hardwoods 

in Southeastern United States, in 

Clark, J.R., and Benforado, J., 

eds., Wetlands of bottomland 

hardwood forests: Proceedings of 

a workshop on bottomland 

hardwood forest wetlands of the 

Southeastern United States held 

at Lake Lanier, Georgia: New 

York, Elsevier Scientific 

Publication Co., p. 87-160.

Wood, D.A., 1992, Official lists of 

endangered and potentially 

endangered fauna and flora in 

Florida: Florida Game and Fresh 

Water Fish Commission, 25 p.

Wooley, C.M., and Crateau, E.J., 1982, 

Observations of Gulf of Mexico 

sturgeon (Acipenser oxyrhynchus 

desotoi) in the Apalachicola 

River, Florida: Florida Scientist, 

v. 45, no. 4, p. 244-248.

————1983, Biology, population estimates, and movement of native 

and introduced striped bass, 

Apalachicola River, Florida: 

North American Journal of Fisheries Management, v. 3, p. 383- 

394.

Yerger, R.W, 1977, Fishes of the 

Apalachicola River, in 

Livingston, R.J., and Joyce, E.A., 

eds., Proceedings of the 

conference on the Apalachicola 

drainage system: Florida Marine 

Research Publication no. 26, 

p. 22-33.
60 Aquatic Habitats In Relation to River Flow in the Apaiachicola River Roodplata, Florida
Appendixes
Appendix I. Greatest number of consecutive days and total number of days in each year from 1922 to 1995 that flow was 

below given flow values from 4,000 to 16,000 cubic feet per second in the Apalachicola River at Chattahoochee, Florida

A. GREATEST NUMBER OF CONSECUTIVE DAYS 

[Analysis is based on climatic years of April 1-March 31 to avoid splitting low-flow periods that typically occur in summer and fall]

Greatest number of consecutive days in indicated year that flow was below given flow value 

Year 

4,000 5,000 6,000 7,000 8,000 9,000 10,000 11,000 12,000 13,000 14,000 15,000 16,000

1922

1923

1924

1925

1926

1927

1928

1929

1930

1931

1932

1933

1934

1935

1936

1937

1938

1939

1940

1941

1942

1943

1944

1945

1946

1947

1948

1949

1950

1951

1952

1953

1954

1955

1956

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0 0

0 0

0 0

57 63

0 0

3 66

0 0

0 0

0 0

32 58

0 0

0 0

0 0

5 30

0 0

0 0

0 6

0 0

0 9

1 40

0 0

0 0

0 0

0 0

0 0

0 0

0 0

0 0

0 0

0 28

0 24

0 0

64 80

53 70

7 35

7

0

0

98

0

88

0

0

3

95

0

6

4

39

0

0

30

0

44

52

0

2

0

0

0

0

0

0

10

36

52

0

105

85

41

19

0

5

101

0

97

0

0

12

101

11

43

14

46

0

0

52

10

47

89

0

30

3

0

0

0

0

0

20

51

67

0

128

93

50

46

8

7

104

6

98

0

4

19

103

19

84

32

49

2

0

96

57

60

96

2

43

25

2

0

4

0

0

40

54

71

6

155

170

64

49

28

23

106

19

99

0

6

20

106

31

110

44

54

3

3

116

62

66

104

12

45

49

9

3

L2

0

0

42

77

76

12

157

175

68

106

31

35

156

36

107

2

14

32

109

45

121

68

57

10

6

138

73

67

120

24

78

58

10

7

37

0

2

48

78

116

22

158

177

70

107

36

35

156

37

109

6

26

34

109

46

163

84

60

31

18

148

79

68

121

54

79

60

24

24

61

8

19

50

80

117

38

185

178

134

109

36

35

164

43

109

11

28

39

111

51

166

86

61

37

32

169

80

106

123

63

128

74

27

33

67

10

36

90

81

179

53

192

183

135

119 120

60 75

35 35

208 210

43 44

111 118

30 33

33 34

47 52

205 207

52 52

192 217

86 87

62 111

50 51

33 47

173 174

83 85

117 125

128 12S

64 66

129 132

77 110

28 56

81 94

70 70

13 16

37 39

91 105

225 226

180 200

54 55

195 208

183 189

135 135

82 Aquatic Habitats in Relation to Ri^er now in the Apalachicola River f^cwM^lainjRorWa
Year

Greatest number of consecutive days in indicated year that flow was below given flow value

4,000

1957

1958

1959

1960

1961

1962

1963

1964

1965

1966

1967

1968

1969

1970

1971

1972

1973

1974

1975

1976

1977

1978

1979

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

3

0

0

0

0

0

0

0

0

5,000 6,000

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

1

0

0

0

0

2

6

20

0

0

0

0

0

0

0

4

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

40

0

0

0

0

41

6

35

0

12

0

0

3

0

0

7,000

5

0

0

0

0

2

0

0

0

0

0

3

0

0

0

0

0

0

0

0

0

0

0

0

49

0

0

0

0

50

14

68

0

20

1

0

12

0

0

8,000

34

2

0

0

6

5

3

0

0

0

0

30

0

0

0

0

0

0

0

0

0

0

0

0

64

0

0

0

0

122

15

73

0

22

20

3

14

1

13

9,000 10,000

45

7

4

2

16

16

16

0

0

0

0

57

0

0

0

0

0

0

0

0

0

36

0

6

76

0

0

0

6

144

49

81

0

46

23

3

17

1

15

52

24

14

8

49

32

41

0

0

0

0

76

3

4

0

34

0

0

0

0

19

80

0

153

174

0

0

0

44

192

90

83

0

89

23

11

22

3

19

11,000

53

55

14

11

57

43

116

0

2

2

0

76

13

13

3

72

22

29

0

0

40

97

4

162

241

0

2

26

60

208

97

95

3

103

23

15

22

9

19

12,000

77

66

21

35

82

105

117

1

8

24

5

161

55

33

21

93

38

73

0

8

58

112

27

177

244

10

7

65

61

209

132

128

7

105

24

15

23

9

19

13,000

79

107

26

43

83

131

117

2

23

34

14

166

65

49

27

113

45

73

3

16

65

118

50

208

256

49

16

80

78

212

140

232

14

105

35

18

74

10

19

14,000

86

109

31

109

83

136

125

3

28

59

30

210

66

54

33

116

59

77

4

35

68

131

57

209

261

61

30

81

105

213

169

286

15

136

41

53

74

18

20

15,000 16,000

87

128

32

111

91

137

125

5

32

59

49

210

68

57

65

117

66

77

5

41

92

131

58

209

261

75

63

88

110

234

184

292

28

168

55

71

112

18

82

87

134

42

112

92

138

126

8

40

60

60

211

68

57

66

122

67

78

9

64

92

137

59

220

262

96

106

143

216

236

188

293

40

200

111

72

147

18

87

Appendix 63 •
Appendix (.Greatest number of consecutive days and total number of days in each year from 1922 to 1995 that flow was 

below given flow values from 4,000 to 16,000 cubic feet per second in the Apalachicola River at Chattahoochee, Florida-- 

Continued

B. TOTAL NUMBER OF DAYS 

[Analysis is based on climatic years of April 1 -March 31 to avoid splitting low-flow periods that typically occur in summer and fall]

Year

1922

1923

1924

1925

1926

1927

1928

1929

1930

1931

1932

1933

1934

1935

1936

1937

1938

1939

1940

1941

1942

1943

1944

1945

1946

1947

1948

1949

1950

1951

1952

1953

1954

1955

1956

4,000

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Total number of days in indicated year that flow was below given flow value 

5,000 6,000 7,000 8,000 9,000 10,000 11,000 12,000 13,000 14,000

0 0

0 0

0 0

0 57

0 0

0 5

0 0

0 0

0 0

0 45

0 0

0 0

0 0

0 5

0 0

0 0

0 0

0 0

0 0

0 1

0 0

0 0

0 0

0 0

0 0

0 0

0 0

0 0

0 0

0 0

0 0

0 0

0 67

0 54

0 11

0

0

0

82

0

75

0

0

0

79

0

0

0

31

0

0

8

0

14

79

0

0

0

0

0

0

0

0

0

52

27

0

83

115

42

27

0

0

104

0

96

0

0

6

102

0

36

12

53

0

0

38

0

44

115

0

5

0

0

0

0

0

0

11

75

62

0

114

166

101

63

0

14

137

0

144

0

0

20

144

15

91

40

79

0

0

83

18

52

140

0

47

7

0

0

0

0

0

59

104

101

0

145

208

139

85

18

31

161

6

157

0

6

40

161

33

111

71

119

3

0

119

57

60

156

6

75

29

2

0

7

0

0

89

134

132

6

190

227

111

98

43

71

182

42

179

0

9

65

173

46

138

110

150

15

3

137

65

72

187

32

103

49

27

4

29

0

0

111

161

152

33

208

239

199

106

52

88

205

84

226

2

15

87

180

58

170

146

166

47

16

155

74

110

203

52

117

67

55

24

49

0

5

139

180

167

64

227

250

214

110

58

101

216

122

244

12

27

100

189

84

215

178

188

91

55

181

95

149

212

75

125

85

91

59

63

10

23

176

201

178

81

257

264

248

122

64

118

233

153

261

41

30

115

197

109

242

195

203

115

85

199

115

182

221

100

130

108

114

92

72

25

59

226

216

186

101

272

271

258

15,000 16,000

137 149

76 84

124 129

249 254

177 197

277 291

59 70

36 44

135 148

205 207

141 161

259 267

214 231

222 235

131 135

112 156

217 225

131 140

208 232

232 242

117 146

146 174

146 183

136 168

115 124

82 89

35 51

90 114

252 269

230 235

193 204

114 126

290 303

278 292

268 273

' 94 Aquatic Ha^l^ts in Relation to River Flow in the ApalachJcota RJver Roodptairt, Florida 1
Year

Total number of days in indicated year that flow was below given flow value

4,000

1957

L958

1959

I960

1961

1962

1963

1964

1965

1966

1967

1968

1969

1970

1971

1972

1973

1974

1975

1976

1977

1978

1979

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

3

0

0

0

0

0

0

0

0

5,000

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

1

0

0

0

0

10

6

29

0

0

0

0

0

0

0

6,000

14

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

40

0

0

0

0

54

6

35

0

12

0

0

7

0

0

7,000

23

0

0

0

0

4

0

0

0

0

0

5

0

0

0

0

0

0

0

0

0

0

0

0

65

0

0

0

0

96

14

68

0

52

2

0

26

0

0

8,000

53

4

0

0

15

12

3

0

0

0

0

38

0

0

0

0

0

0

0

0

0

0

0

0

81

0

0

0

0

123

19

73

0

76

21

4

33

1

26

9,000

80

31

11

7

47

32

40

0

0

0

0

67

0

0

0

0

0

0

0

0

0

40

0

27

101

0

0

0

6

182

58

81

0

133

23

5

40

1

56

10,000

99

63

19

33

67

81

106

0

0

0

0

83

5

10

0

54

0

0

0

0

45

86

0

153

175

0

0

0

77

192

92

95

0

148

23

15

82

3

69

11,000

117

83

26

64

77

133

136

0

4

7

0

122

25

38

6

72

27

60

0

0

84

105

11

162

241

0

5

53

130

208

116

190

3

159

23

18

94

12

76

12,000

127

122

51

105

87

156

153

1

44

52

13

176

134

91

42

113

42

120

0

20

138

140

92

193

244

10

34

65

142

209

144

261

8

163

29

46

107

13

76

13,000

138

149

62

178

101

171

163

5

75

74

76

230

169

117

61

163

65

128

5

69

165

160

133

227

257

94

48

89

177

212

167

283

14

181

38

72

132

17

79

14,000

143

161

92

215

110

187

173

11

104

93

122

263

186

137

84

179

83

142

18

84

171

177

160

241

261

133

105

150

204

215

182

291

18

194

41

138

140

29

89

15,000 16,000

150

177

114

230

123

206

178

17

125

111

154

273

204

168

92

188

99

162

31

98

182

190

168

250

261

153

122

174

224

234

202

303

63

198

80

169

158

29

134

152

,

192

130

244

129

220

188

31

142

136

178

288

217

190

104

194

112

173

39

107

189

207 ~

179

255

264

156

134

182

229

238

223

308

102

210

123

175

189

33

153

^^^!•iH••••^m^mH»'»n» -"-»!' I I^B Appendix «$
Appendix II. Lengths of floodplain streams and lakes connected to main channel of the nontidal Apalachicola River at flows 

ranging from 4,000 to 19,000 cubic feet per second

["Connected" means that approximately level water passageways exist between floodplain water bodies and the river, allowing 2-way fish 

access from river to floodplain and floodplain to river, rm, river mile; RB, right bank (looking downstream) of Apalachicola River; LB, left bank 

of Apalachicola River; RBC, right bank of lower Chipola River; LBC, left bank of lower Chipola River; Chipl 0,000 (and other similar Chip 

numbers), notation to describe location of stream in number of feet upstream of mouth of lower Chipola River (which is located at rm 27.9 on 

the Apalachicola River); ft3/s, cubic feet per second; ft, feet; inc, including; trib, tributary; conf, confluence; approx, approximately; R, river]

Flow at 

Chattahoochee 

gage1 , in 

ft3/s

Streams and lakes connected at or above and isolated below given flow value2

Name (description of connected reach) and location4

Length5, 

in ft

4,0003 Graves Creek (from mouth at rm 88.8 to 1,960 ft upstream)-RB 1,960

Sutton Lake-mi 78.1 --RB 2,520

unnamed cutoff from rm 50.7 to rm 49.7-RB 2,300

Porter Lake (from mouth at rm 48.2 to 590 ft upstream)-RB 590

Florida R (from mouth at rm 43.2 to to downstream connection of Larkin Slu)~LB 25,010

R Styx (from mouth at rm 35.3 to 1,300 ft upstream)-LB 1,300 

Dead R (from mouth located 1,200 ft upstream of mouth of R Styx to approx 3,000 ft upstream)-LB 3,000

unnamed stream at lower end of Battle Bend (from mouth at rm 28.6 to 320 ft upstream)—LB 320

unnamed stream-rm 27.1--RB 1,670

unnamed stream-rm 27.0-RB 1,170

unnamed stream-rm 26.6-RB 1,980

unnamed stream-rm 24.8-RB 1,230

unnamed stream—rm 24.75—RB 1,320

Brushy Creek (from mouth at rm 24.0 to head at rm 25.7)-LB 8,520

unnamed stream connecting Brushy Creek to Kennedy Creek (from mouth approx 6,400 ft upstream of mouth of Brushy Creek 4,290 

to 2,800 ft upstream)-LB

unnamed stream—rm 23.5—LB 1,460

Scott Creek-rm 23.3-LB 2,230

Owl Creek-rm 22.1-LB6 9,190

Devon Creek (mouth approx 3,400 ft upstream of mouth of Owl Creek)—LB6 780

unnamed stream—rm 21.8—RB 2,350

unnamed stream-rm 21.55-RB 840

unnamed stream~rm 21.3—RB 1,330

Brickyard Creek (from mouth at rm 20.6 to 1,600 ft upstream) inc 1 trib~LB 6,580

White R (from mouth at Chip49,900 to 5,790 ft upstream)-LBC 5,790 

unnamed trib of White R (mouth approx 600 ft upstream of mouth of White R at Chip49,900)~LBC 3,670

Lockey Lake inc unnamed trib~Chipl9,500-RBC 4,440

Douglas Slough (from mouth at Chip8,200 to 3,810 ft upstream)-LBC 3,810

4.000 Subtotal 99,650

66 Aouatfrc Habitats irr Relation to River Flow ifi the Apalachicola River Floodpiain, Florida
Flow at

Chattahoochee

gage1 , in

ft3/s

Streams and lakes connected at or above and isolated below given flow value2

Name (description of connected reach) and location4

Length5, 

in ft

5,000 Sweetwater Creek inc 1 trib--rm 89.3--LB 5,220

Bayou (from mouth on Sutton Lake to US 20)-rm 78.1-RB 4,250

unnamed stream (from mouth at rm 50.7 going north towards Brown Lake to 3,050 ft upstream)-RB 3,050

Outside Lake (from mouth at rm 63.9 to 2,900 ft upstream)-LB 2,900

Swift Slu (from mouth on R Styx to 2,400 ft upstream)-LB 2,400

Moccasin Slough (from mouth on R Styx to 1,100 ft upstream)~LB 1,100

R Styx (from 1,300 ft upstream of mouth at rm 35.3 to approx 18,200 ft upstream)-LB 16,900

unnamed stream inc 1 trib—rm 30.05--RB 5,120

Kennedy Creek (from mouth at rm 26.0 to 26.670 ft upstream)~LB 26,670 

unnamed trib of Kennedy Creek (from mouth 800 ft upstream of mouth of Kennedy Creek to 2,900 ft upstream) inc 1 trib~LB 3,680 

unnamed trib of Kennedy Creek (from mouth 15,800 ft upstream of mouth of Kennedy Creek to 600 ft upstream)-LB 600

3 unnamed tribs of Lockey Lake (mouths 1,600, 2,400, and 2,410 ft upstream of mouth of Lockey Lake)-RBC7 7,170

Douglas Slough (from 3,810 ft upstream of mouth at Chip8,200 to head at Chipl2,700)-LBC7 2,300

unnamed stream-Chip3,400-RBC 2,740

unnamed stream-Chipl,500-RBC 1,500

5,000 Subtotal 85,600

6,000 unnamed stream-mi 101.1 -LB 160

Flat Creek inc 2 tribs-rm 99.5-LB 14,140

Equaloxic Creek (from mouth at rm 51.9 to 6,000 ft upstream)-LB 6.000

lola Lake-mi 45.2-RB 1,100

old channel loop of Florida R (connected at approx 2,600 and 3,500 ft upstream of mouth of Florida R)-LB 5,000

Swift Slough (from 2,000 ft upstream of mouth on R Styx to head at rm 40.3)-LB 11,870

2 unnamed streams inc connection to Douglas Slu-rm 30.3 and rm 30.08-RB 7,550

unnamed stream—rm 26.25—RB 890

unnamed trib of Kennedy Creek (mouth approx 9,000 ft upstream of mouth of Kennedy Creek)—LB 3,630

unnamed trib of Kennedy Creek (from 600 ft upstream of mouth 15,800 ft upstream of mouth of Kennedy Creek to 760 ft 160 

upstream)—LB

unnamed trib (mouth 2,400 ft upstream of mouth of unnamed trib 800 ft upstream of mouth of Kennedy Creek)—LB 1,410

Kennedy Slough (from mouth 1,800 ft upstream of mouth of Kennedy Creek to 7,550 ft upstream) inc 2 tribs-LB 9,790

Shepard Slough (from mouth on Kennedy Creek to approx 3,500 ft upstream) inc 1 trib—LB 9,420

unnamed stream connecting Brushy Creek to Kennedy Creek (from approx 2,800 ft upstream of mouth on Brushy Creek to 2,970 

head at Kennedy Creek)—LB

unnamed stream-nil 22.05-RB 360

unnamed stream-Chip64,500-LBC 4,650

Appendix 67
Flow at 

Chattahoochee 

gage1 , in

ftVs

6,000

Streams and lakes connected at or above and isolated below given flow value2 

Name (description of connected reach) and location4

Gum Drift Slough (from head at Chip52,500 to 6,090 ft downstream)-RB

unnamed stream (from mouth at Chip42,800 to 2,860 ft upstream) inc alternate head at Chip45,700-LBC7

unnamed stream~Chip40,800-LBC

unnamed stream--Chipl8,600-RBC

2 unnamed tribs of Douglas Slough and connecting stream (mouths at 100 and 500 ft upstream of mouth of Douglas Slough at

Length5, 

in ft

6,090

3,300

1,210 .

1,650

2,950

Chip8,200)-LBC

Spiders Cut-Chip2,400-RBC 4,600

6,000 Subtotal 98,900

7,000 Equaloxic Creek (from approx 6,000 ft upstream of mouth at rm 51.9 to 12,010 ft)-LB 6,010

unnamed stream (from mouth at rm 50.7 to south end of Brown Lake)~RB 3,000

Kentucky Lake-fin 43.8-RB 1,830

Larkin Slu (from mouth on Florida R approx 22,400 ft upstream of mouth of Florida R to Gregory Mill Creek)-LB 5,980

2 unnamed tribs of R Styx (from their mouths 5,600 and 7,000 ft upstream of mouth of R Styx to approx 100 ft upstream)-LB 200

unnamed stream-rm 26.15--RB 1,050

2 unnamed tribs of Kennedy Creek (mouths at 1,350 and 1,450 ft upstream of mouth of Kennedy Creek)~LB 1,600

unnamed trib of Kennedy Creek (mouth 22,900 ft upstream of mouth of Kennedy Creek)~LB 3,340

unnamed trib of Kennedy Creek (from 2,900 ft upstream of mouth on Kennedy Creek at approx 800 ft upstream of mouth of 1,460 

Kennedy Creek to 3,560 ft upstream) inc 1 trib~LB

unnamed trib of Kennedy Slough (from 1,000 ft upstream of mouth at 3,000 ft upstream of mouth of Kennedy Slough to 1,500 500 

ft upstream)~LB

Shepard Slough (from approx 3,500 ft upstream of mouth on Kennedy Creek to 7,000 ft upstream)~LB 3,480

unnamed stream—rm 23.35—RB 750

Maddox Slough (from mouth at Chip53,600 following westward course to floodplain edge 1,750 ft upstream)~RBC 1,750

White R (from approx 5,800 ft upstream of mouth at Chip49,900 to 10,800 ft upstream)-LBC 4,980

unnamed stream connecting trib of White R (mouth 600 ft upstream of mouth of White R) to Corley Slough inc Corley Slough 4,470 

to conf with Virginia Cut-LBC7

unnamed stream inc 2 tribs-Chip46,100-LBC7 5,130

Virginia Cut (from mouth at Chip37,300 to 12,790 ft upstream)-LBC 12,790

Burgess Creek (from mouth at Chip35,900 to 8,050 ft upstream) inc 3 tribs-RBC7 12,590

2 unnamed tribs of unnnamed stream (mouths 200 and 600 ft upstream of mouth of unnamed stream at Chip3,400)--RBC 1,710

7,000 Subtotal 72,620

8,000 Mosquito Creek inc 1 trib-rm 105.1--LB 8,580

unnamed stream-rm 95.5—LB6 5,110

Johnson Creek (from mouth at rm 93.9 to 1,810 ft upstream)-RB 1,810

Old R (from rm 77.0 to north end of Baker Branch), Baker Branch, Sutton Creek, and Hicks Creek~RB 33,880
Flow at Streams and lakes connected at or above and isolated below given flow value2 

Chattahoochee 

gage1 , in Name (description of connected reach) and location4 

fWs

8,000 Dead R (at Poloway Point)-rm 7 1 .4--LB

lamonia Lake (from mouth at rm 55.8 to 26,180 ft upstream) inc McDougal Lake, Rudy Slough, and Lots Mill Creek — RB

Equaloxic Creek inc 2 tribs (from 12,010 ft upstream of mouth at rm 51.9 to Big Gully Creek)-LB

Porter Lake (from 590 ft upstream of mouth at rm 48.2 to north end)~RB

Florida R (from downstream connection of Larkin Slu to 26,000 ft upstream of mouth at rm 43.2) inc lower end of Dog Slough

Length5, 

in ft

6.600

33,780

12,010

1,060

5,890

(from mouth on Florida R to 890 ft upstream)-LB

R Styx (from approx 18,200 ft upstream of mouth at rm 35.3 to 20,200 ft upstream)-LB 2,000

unnamed stream~rm 26.3-RB 690

Shepard Slough (from approx 7,000 ft upstream of mouth on Kennedy Creek to 11,000 ft upstream) inc 1 trib~LB 8,580

unnamed stream inc trib-Chip70,000--RBC 1,360

Magnolia Slough-Chip56,100-LBC 1,320

unnamed stream-Chip45,000-LBC7 90

Roberts Slough (from mouth at Chip40,900 to 1,830 ft upstream)-RBC7 1,830

Burgess Creek (from 8,050 ft upstream of mouth at Chip35,900 to conf with Roberts Slough)-RBC7 2,730

Piney Reach Slough--Chip22,500-LBC 4,800

unnamed stream-Chip 10,400-RBC 2,630

unnamed stream-Chip7,900-RBC 720

8,000 Subtotal 134,470

9,000 Rock Creek-rm 95.2-LB6 1,090

unnamed stream inc 2 tribs-rm 88.5--LB 2,760

Outside Lake (from 2,900 ft upstream of mouth at rm 63.9 to 9,000 ft)-LB 6,100

Bee Tree Slough (from mouth at rm 61.1 to 1,320 ft upstream)-RB 1,320

Mary Slough (from mouth on lamonia Lake to 1,210 ft upstream)—RB 1,210

Middle Slough (from mouth on lamonia Lake to 1,900 ft upstream)-RB 1,900

unnamed stream—rm 51.6—LB 2,400

Brown Lake-RB 790

Moccasin Slough (from 1,100 ft upstream of mouth on R Styx to head at rm 38.8)-LB 11,880

unnamed trib of Dead R (mouth approx 3,200 ft upstream of mouth of Dead R on R Styx)-LB 960 

unnamed stream at downstream end of Battle Bend (from 320 upstream of mouth at rm 28.6 to approx 4,430 ft upstream)—LB 4,430

unnamed trib of Kennedy Creek (mouth approx 18,000 ft upstream of mouth of Kennedy Creek at rm 26.0)-LB 700 

Shepard Slough (from approx 11,000 ft upstream of mouth on Kennedy Creek to 14,600 ft upstream) inc 2 tribs-LB 6,860

unnamed stream—rm 24.4--LB 480

unnamed stream—mi 22.1—RB 2, 1 60

unnamed stream-mi 22.0-RB 500

Appendix 69
Flow at 

Chattahoochee 

gage1 , in 

fWs

9,000

Streams and lakes connected at or above and isolated below given flow value2 

Name (description of connected reach) and location4

unnamed stream-Chip65,900-LBC

Gum Drift Slough (from approx 6,100 ft downstream of head at Chip52,500 to conf with Roberts Slough)-RBC7

Roberts Slough (from 1,830 ft upstream of mouth at Chip40,900 to approx 9,400 ft upstream) inc 2 tribs-RBC7

unnamed trib of White R (mouth approx 6,500 ft upstream of mouth of White R at Chip49,900)-LBC

unnamed stream-Chip44,600~LBC7

Van Horn Slough-Chip31,200-LBC

2 unnamed tribs of Piney Reach Slough (mouths 500 and 3,000 ft upstream of mouth of Piney Reach Slough at Chip22,500)~

Length5, 

in ft

2,170

6,090

8,930

2,320

220

1,310

2,510

LBC7

9,000 Subtotal 69,090

10,000 Spring Branch inc 2 tribs-rm 100.6--RB 6,620

Ocheesee Creek inc tribs-rm 93.3-RB 15,880

unnamed stream at Caraway Landing inc trib~rm 90.6—RB 3,990

Little Sweetwater Creek-rm 84.4-LB 2,000

Bee Tree Slough (from 1,320 ft from mouth at rm 61.1 to conf with Middle Slough)-RB 1,320 

3 unnamed tribs of Swift Slough (mouths 2,000, 6,400, and 6,600 ft upstream of mouth of Swift Slough on R Styx)-LB 4,400

Hog Slough (from head at rm 40.0 to mouth on Swift Slough)--LB 8,060

unnamed stream-nil 30.12-RB 1,740

Shepard Slough (from approx 14,600 ft upstream of mouth on Kennedy Creek to approx 18,100 ft upstream)~LB 3,480

unnamed stream~rm 25.9-RB 210

Maddox Slough (fr >prox 1,300 downstream of head at Chip53,600 to conf with Tom Smith Branch)-RBC7 6,740

2 unnamed tribs ol w Ulie R (mouths 1,200 and 1,900 ft upstream of mouth of White R at Chip49,900)-LBC7 1,460

Tom Smith Branch (from conf with Roberts Slough to floodplain edge)-RBC7 8,010

unnamed stream-Chip39,800-LBC7 1,230

Virginia Cut (from 12,790 ft upstream of mouth at Chip37,300 to head approx 24,390 ft upstream) inc 1 trib-LBC7 13,190

unnamed stream-Chip37,250-LBC7 1,470

unnamed stream-Chip26,800-LBC 1,250

unnamed stream-Chip26,700-LBC7 1,560

10,000 Subtotal 82,610

11,000 Blue Spring run and spring (before restoration)-rm 98.0-RB6 1,880

Johnson Creek (from 1,810 ft upstream of mouth at rm 93.9 to 2,530 ft)-RB 720

Beaverdam Creek-rm 84.5-LB 7,960

Bayou (from US Highway 20 to 18,790 ft upstream of mouth on Sutton Lake) inc Stafford Creek-RB 20,370

unnamed trib of Dead R (mouth approx. 3,400 ft from mouth of Dead R at rm 71.4)-LB 1,870 

Outside Lake (from approx 9,000 ft upstream of mouth at rm 63.9 to 17,700 ft upstream) inc Johnson Mill Creek-LB 11,010

Aquatic Kabllale in Relation to River Row in the Apetachicola River Ffoodplain, Florida
Flow at 

Chattahoochee 

gage1 , in 

ft3/s

Streams and lakes connected at or above and isolated below given flow value2

Name (description of connected reach) and location4

Length5, 

in ft

11,000 unnamed slu to Muscogee Lake (from mouth at rm 60.2 to 1,940 ft upstream)--LB 1,940

Middle Slough (from 1,900 ft upstream of mouth on lamonia Lake to Bee Tree Slu)-RB 7,090

unnamed slu to Miller Lake-rm 57.9-LB 3,080

Mary Slough (from 1,210 ft upstream of mouth on lamonia Lake to 2,420 ft)-rm 55.8-RB 1,210

unnamed slu to Queen City Lake~rm 51.4—RB 1,160

unnamed stream—rm 48.4—LB 1,450

unnamed trib of Porter Lake-rm 48.2-RB 1,850

unnamed trib of Florida R (mouth approx 100 ft upstream of mouth of Florida R at rm 43 2)--LB 2,690

unnamed trib of Florida R (mouth approx 12.400 ft upstream of mouth of Florida R at rm 43.2)-LB 1,200

unnamed trib of Florida R (mouth approx 16,400 ft upstream of mouth of Florida R at rm 43.2)—LB 5,540

unnamed trib of Florida R (mouth approx 16,600 ft upstream of mouth of Florida R at rm 43.2)~LB 860

unnamed trib of loop of Florida R (mouth approx 2,400 ft from upstream end of loop at 3,500 ft upstream of mouth of Florida 4,050 

Ratrm43.2)~LB

Everett Slough (from head on Larkin Slu 2,800 ft upstream of mouth of Larkin Slu on Florida R to 6,910 ft downstream)—LB 6,910

Grayson Slough (from mouth on Swift Slough to 2,300 ft upstream)-LB 2,300

R Styx (from approx 20,200 ft upstream of mouth at rm 35.3 to 22,500 ft upstream)-LB 2,300

unnamed trib of Dead R (mouth approx 3,600 ft upstream of mouth of Dead R on R Styx)~LB 860

unnamed stream-rm 30.65-RB 790

Shepard Slough (from approx 18,100 ft upstream of mouth on Kennedy Creek to approx 21,520 ft upstream)~LB 3,420

2 unnamed tribs of White R (mouths 200 and 1,300 ft upsteam of mouth of White R at Chip49,900)-LBC7 2,070

unnamed stream-Chip33,000-RBC7 1,380

11,000 Subtotal 95,960

12,000 unnamed trib of Blue Spring run-RB6 290

trib of unnamed stream at rm 88.5 - LB 310

Kelley Branch (from mouth at rm 81.4 to 350 ft upstream)-LB 350

unnamed stream-rm 69.6-RB 1,840

Outside Lake (from approx 17,700 ft upstream of mouth to north end) inc 5 tribs and Landy Lake)--rm 63.9--LB 29,880

unnamed trib of McDougal Lake~rm 55.8-RB 1,340

Honey Pond and slu connecting to lamonia Lake--rm 55 8-RB 3,890

unnamed stream—rm 55.0—RB 6,800

unnamed stream—rm 54.2—LB 2,350

2 unnamed tribs of cutoff at rm 50.7-RB 4,060

Finns Slough-LB 7,540 

Florida R (from approx 26,000 ft upstream of mouth at rm 43.2 to 39,800 ft upstream) inc Bill's Arm and 2 tribs-LB 25,060

Appt/ndix 7t
Flow at

Chattahoochee

gage1 , in

ft3/s

Streams and lakes connected at or above and isolated below given flow value2

Name (description of connected reach) and location4

Length5, 

in ft

12,000 Everett Slough (from mouth on Swift Slough to 4,430 ft upstream)-LB 

unnamed stream—rm 39.9—LB 

unnamed stream-Hrm 27.2—RB

Shepard Slough (from approx 21,520 ft upstream of mouth on Kennedy Creek to 25,050 ft upstream) inc 1 trib—LB 

unnamed stream inc 1 trib—rm 22.8-RB 

unnamed stream~Chip48,200-LBC7 

unnamed stream-Chip46,400~LBC7 

unnamed stream inc alternate mouth at Chip34,600-Chip35,200-RBC7

unnamed trib of unnamed trib of Douglas Slough (mouth 800 ft upstream of mouth of unnamed trib with mouth 1,400 ft 

upstream of mouth of Douglas Slough at Chip8,200)—LBC

12,000 Subtotal

13,000 unnamed trib of Dead R (located approx 4,700 ft from mouth of Dead R at rm 71.4)—LB

Woods Slu (from conf with Bee Tree Slu to approx 4,790 ft upstream)-RB

unnamed stream—rm 60.9—RB

Mary Slough (first 1,210 ft from rm 58.7 going towards lamonia Lake)-RB

unnamed trib of Rudy Slough—RB

unnamed stream—rm 53.3—RB

Dog Slough (from approx 890 ft upstream of mouth on Florida R to south end of Greenback Lake)—LB

unnamed stream—rm 49.9—LB

unnamed stream—rm 47.3—LB

R Styx (from approx 22,500 ft upstream of mouth at rm 35.3 to 25,900 ft upstream)~LB

unnamed trib of R Styx (from 3,480 ft downstream of head located 9,300 ft upstream of mouth of R Styx to conf with Shepard 

Slough 700 ft downstream)-LB

unnamed stream—rm 35.1—LB 

unnamed stream—rm 30.7—LB 

unnamed stream—rm 27.7—LB

Shepard Slough (from approx 25,050 ft upstream of mouth on Kennedy Creek to conf with 2 tribs of R Styx 27,830 ft 

upstream) inc 2 tribs~LB

unnamed stream—rm 22.15--RB 

unnamed stream-Chip75,800~RBC 

unnamed stream-Chip30,400-RBC 

unnamed stream~Chip32,900~LBC 

unnamed stream~Chip5,800-RBC 

unnamed stream~Chip5,000-RBC 

13,000 Subtotal

4,430

1,070

1,450

7,410

3,830

1,100

2,620

3,770

890

110,280

4,890

4,790

1,490

1,210

1,170

3,680

7,760

1,000

1,850

3,400

700

2,490

2,010

700

9,270

500

380

1,240

1,100

770

1,600

52,000

Aqyatic Habitats In Relation to Wwr Flow In the Apateehicola River Ffoodptain, Florida
Flow at

Chattahoochee

gage1 , in

ft3/s

Streams and lakes connected at or above and isolated below given flow value2

Name (description of connected reach) and location4

Length5 

in ft

14,000 Johnson Creek (from 2,530 ft upstream of mouth at rm 93.9 to 3,240 ft)-RB 710

unnamed stream—rm 62.0--LB 510

unnamed tribs of McDougal Lake and lamonia Lake—RB 6,560

Muscogee Lake—LB 590

Miller Lake-LB 660

unnamed stream-rm 56.2-LB 440

unnamed trib of Honey Pond-RB 2,020

unnamed stream—mi 55.6—LB 1,150

unnamed stream-rm 55.4-RB 640

unnamed stream-rm 53.4-RB 1,970

Queen City Lake and smaller pond—LB 440

unnamed stream-rm 47.1-LB 1,240

Florida R (from approx 39,800 ft upstream of mouth at rm 43.2 to Equaloxic Creek) inc part of Larkin Slu (from approx 6,200 24,380 

ft upstream of downstream mouth on Florida R to reconnection with Florida R), Gregory Mill Creek, and 4 tribs~rm 43.2-LB

unnamed trib of Larkin Slu (mouth approx 1,700 ft upstream of mouth of Larkin Slu on Florida R)~LB 960

Grayson Slough (from 2,300 ft upstream of mouth on Swift Slough to approx 5,100 ft upstream) inc Greenback Lake and part 2,800 

of Silver Lake-LB

unnamed stream connecting Grayson and Everett Sloughs—LB 3,300

Everett Slough (from 4,420 ft upstream of mouth on Swift Slough to 1 1 ,060 ft upstream)-LB 6,640

unnamed stream (from head 3,800 ft upstream of mouth of R Styx to 2,270 ft downstream)~LB 2,270

2 unnamed tribs of R Styx (from 100 ft upstream of their mouths at 5,600 and 7,000 ft upstream of mouth of R Styx to ends)- 1,200 

-LB

unnamed stream (from head 9,300 ft upstream of mouth of R Styx to 3,480 ft downstream)-LB 3,480

unnamed stream inc 1 trib~rm 34.75-LB 4,100

unnamed stream connected by 2 mouths—rm 33.7 and rm 33.62—LB 3,110

unnamed stream-rm 32.15-LB 1,810

Kennedy Slough (from mouth 1,400 ft upstream of mouth of Kennedy Creek to 470 ft upstream)~LB 470

unnamed stream—rm 25.4—RB 1,060

2 unnamed tribs of Virginia Cut (mouths 11,800 and 14,300 ft upstream of mouth of Virginia Cut at Chip37,300)-LBC7 1 1,480

unnamed stream-Chip34,400~RBC 720

unnamed stream-Chip6,700~RBC 890

unnamed trib of Spider Cut (mouth approx 800 ft downstream of mouth of Spider Cut at Chip2,400)-RBC 1,570

14,000 Subtotal 87,170
Flow at 

Chattahoochee 

gage1 , in 

fWs

Streams and lakes connected at or above and isolated below given flow value2

Name (description of connected reach) and location4

Length5, 

in ft

15,000 unnamed stream (from mouth at rm!03.6 to 890 ft upstream) --LB

unnamed stream—rm 98.9—LB6

unnamed stream~rm 90.3—LB

Old R (from north end of Baker Branch to rm 72.9)-RB

James Slough and Dirt Bridge Slu—RB

unnamed stream-rm 62.8-RB

Dog Slough (from rm 50.15 to south end of split channel) —LB

unnamed stream-nil 49.2-RB

Greenback Lake on Dog Slough—LB

unnamed trib of Hog Slough (mouth approx 900 ft upstream of mouth of Hog Slough on Swift Slough)—LB

unnamed trib of Moccasin Slough (mouth approx 1,400 ft upstream of mouth of Moccasin Slough on R Styx)—LB

Dead R (from approx 3,400 ft upstream of mouth on R Styx to end on Swift Slough)~LB

unnamed stream (from head 3,800 ft upstream of mouth of R Styx to 2,270 ft downstream)—LB

unnamed trib of R Styx (mouth 4,200 ft upstream of mouth of R Styx)-LB

unnamed stream (from head 9,300 ft upstream of mouth of R Styx to 3,480 ft downstream)—LB

unnamed trib of R Styx (mouth 23,400 ft upstream of mouth of R Styx)-LB

unnamed stream—rm 39.3—RB

unnamed stream—rm 31.2—RB

unnamed stream—mi 26.4--RB 

15,000 Subtotal 

16,000 unnamed stream—rm 64.9—LB

unnamed stream—rm 59.9—LB

unnamed stream—rm 59.5—RB

unnamed stream—rm 57.5—RB

unnamed stream-rm 53.6-LB

unnamed stream—rm 52.8—LB

unnamed stream—rm 51.2—RB

unnamed stream—rm 47.31—RB

2 unnamed tribs of Outside Lake (at approx 14,200 and 17,300 ft upstream of mouth at rm 43.2)~LB

unnamed stream—rm 41.9—RB

unnamed trib of Florida R (mouth approx 22,100 ft upstream of mouth of Florida R at rm 43.2)~LB

unnamed trib of Larking Slu (mouth 400 ft upstream of mouth of Larkin Slu on Florida R)—LB

Everett Slough (from approx 10,840 ft upstream of mouth on Swift Slough to 13,980 ft)-LB

890

470

250

8,520

15,110

4,860

8,450

2,190

2,790

1,400

910

5,910

2,270

410

3,480

70

1,430

1,920

1,210

62,540

1,210

880

1,520

4,690

910

1,420

770

1,210

3,380

2,830

6,630

600

3,140

74 Aquatic Habitats in Relation to Riv*r Flow irv the ApaJachtcola River Hoodplai.% Florida
Flow at 

Chattahoochee 

gage1 , in 

ft3/s

Streams and lakes connected at or above and isolated below given flow value2

Name (description of connected reach) and location4

Length5, 

in ft

16,000 Grayson Slough (from approx 5,100 ft upstream of mouth on Swift Creek to 9,110 ft upstream)-LB 4,010

unnamed stream connecting Grayson Slough to Everett Slough—LB 5,990

unnamed trib of R Styx (mouth approx 4,600 ft upstream of mouth of R Styx at rm 35.3)-LB 740

unnamed trib of Dead R (mouth approx 3,500 ft upstream of mouth of Dead R on R Styx)—LB 350

unnamed stream—rm 41.1—RB 1,020

unnamed stream-rm 41.08-RB 1,670

unnamed stream-rm 31.8--RB 1,400

unnamed stream—rm 22.3—RB 1,550

unnamed stream-Chip67,200-LBC 1,350

unnamed trib of White R (mouth 8,000 ft upstream of mouth of White R at Chip49,900)-LBC 1,060

16,000 Subtotal 48,330

17,000 Kelley Branch (from approx 350 ft upstream of mouth at rm 81.4 to 1.020 ft)-LB 670

unnamed stream—rm 73.2—LB 870

Gin House Lake-rm 71.0-RBL 1,190

unnamed streams at rm 66.3 and rm 66.25—RB 2,900

unnamed stream-rm 62.6-RB 3,720 

unnamed slu to Muscogee Lake (from approx 1,940 ft upstream of mouth at rm 60.2 to Acorn Lake)--LB 1,940

unnamed stream—rm 31.1 —LB 1,190

unnamed stream-Chip72,000-LBC 1,060

unnamed stream-Chip68,600-LBC 770

unnamed stream-Chip27,700-RBC 850

17,000 Subtotal 15,160

18,000 unnamed stream (from 890 ft upstream of mouth at rm 103.6 to 1,770 ft)-LB 880

Johnson Creek (from 3,240 ft upstream of mouth at rm 93.9 to fioodplain boundary), secondary channel starting 3,200 ft 15,310 

upstream of mouth, inc 1 trib~RB

2 tribs of Bayou (from their mouths on Bayou to 1,410 and 1,150 ft upstream)—rm 79.1 -RB 2560

3 unnamed tribs of Middle Slu-RB 8,750

unnamed stream—rm 54.3—LB 1,270

unnamed stream—rm52.7—LB 3,120

unnamed stream—rm 52.1 —RB 2,310

Acorn Lake (connected to Florida R approx 23,000 ft upstream of mouth)—LB 830 

Alligator Creek (mouth approx 4,800 ft upstream of mouth of Everett Slough on Swift Creek)-LB 10,490

R Styx (from approx 25,900 ft upstream of mouth at rm 35.3 to 32,900 ft upstream)-LB 7,000

unnamed stream-rm 41.4-RB 900

Appendix 7f
Flow at

Chartahoochee

gage1 , in

ft3/s

Streams and lakes connected at or above and isolated below given flow value2

Name (description of connected reach) and location4

Length5, 

in ft

18,000 unnamed stream-rm 34. 1-RB

unnamed stream at Double Points—rm 31.4--LB

unnamed stream—rm 28.25—LB

unnamed stream—rm 27.3—RB

unnamed stream-Chip4,800-RBC 

18,000 Subtotal 

19,000 unnamed stream-rm 75.2-LB

Acorn Lake (connected to Muscogee Lake)—LB

unnamed stream—rm 52.6—LB

Dog Slough (from north end of Greenback Lake to south end of split channel)-LB

unnamed stream—rm 44.7--LB

Elsie Lake, unnamed lake, and connected tribs of Florida R—LB

Everett Slough (from 6,910 ft downstream of head on Larkin Slu to 10,360 ft downstream)—LB

unnamed trib of R Styx (mouth 25,700 ft upstream of mouth of R Styx at rm 35.3)-LB

unnamed trib of Moccasin Slough (mouth 3,100 ft upstream of mouth of Moccasin Slough on R Styx)—LB 

19,000 Subtotal

3,170

1,250

640

1,240

570

60,290

1,390

320

750

6,370

9,100

19,390

3,450

310

220

41,300

TOTAL 318 entries (a single entry represents a single stream, one of a number of partial reaches of a long stream, 

or multiple streams and lakes)

230 miles

1 Flows at which streams are connected were determined from lagged Chattahoocheee flows at the time of field observations.

2 The accuracy of these estimates is greatest for the intensive study sites (Flat Creek, Johnson Creek, lamonia Lake system, River Styx system) because 

those areas were visited many times under a variety of hydrologic conditions. Estimates on most other streams were based on one-time field observations, 

and those estimates should be used as an approximate guide.

3 Most of the streams and lakes listed for 4,000 ft3/s have deep connections to the main river channel and have not been isolated at any time from 1922 

to 1995.

4 Order of streams and lakes is from most upstream location to most downstream in river floodplain. Location within river reach is indicated by colors: 

beige, upper river; light green, middle river; dark green, lower river. Additional description of location is given for features not named on USGS 7.5 minute 

quadrangle maps and named features when necessary.

5 Actual stream lengths may be longer than shown. In most cases, they are derived from lengths that appear on USGS quadrangle maps or infrared 

aerial photography, whichever is longer.

6 These streams on the Apalachicola River were not measured to determine the depth of the connection. An estimate of connection depth was made 

based on the size of the stream, stream velocity, connecting streams, characteristics of drainage basin on aerial photos and maps, and other relevant field 

observations.

7 These streams on the lower Chipola were observed to be connected to the main channel when flow at Chattahoochee was approximately 14,500 ftVs, 

but were not measured to determine the depth of that connection. In each case, an estimate of connection depth was made based on field observations of 

stream size and velocity and characteristics of connecting streams and drainage basin on aerial photos and maps. In some cases the entry includes a combination of measured and unmeasured streams.

76 Aquatic Habitats Ji* Region to ffrvgr FH*» in the Apalacmcoia Riv
Appendix III.- Average flows preceding and during 16 navigation windows in the Apalachicola River, 1990-95

[Data shown in green for the period October 23-November 24, 1990, is used as an example in the text and table 10. Dates and flows for all 

periods were determined from daily mean flows at the Chattahoochee gage. ft3/s, cubic feet per second; na; not applicable because transition 

period was too short to be reflected in daily mean flows; nd, not determined]

Pre-window 

(water storage period)

Dates

Sept 25-Oct 13, 1990

Oct 23-Nov 10, 1990

Nov26-Decl 1,1990

Dec 27, 1990-Jan 8, 1991

Oct28-Novl8, 1991

May 10-24, 1992

June 15-July 1, 1993

July 16-Aug 6, 1993

Aug 26-Sep 6, 1993

Sep 25-Oct 10, 1993

Nov 17-26, 1993

May 23-31, 1994

May 24-29, 1995

June20-July4, 1995

July 20-Aug 5, 1995

Aug 25-Sep 8, 1995

Number 

of days

19

19

15

13

22

15

17

22

12

16

10

9

6

15

17

15

Average 

flow, 

in ftVs

6,930

5,900

6,690

7,370

7,620

9,520

9,440

9,490

6,560

6,670

9,040

9,970

9,970

8,590

8,620

7,790

Transition 

(period of increasing flow)

Dates

Oct 14, 1990

Nov 11, 1990

Dec 12, 1990

Jan 9- 10, 1991

na

May 25, 1992

July 2-3, 1993

Aug 7, 1993

Sep 7, 1993

Oct 11-12, 1993

Nov 27, 1993

na

na

July 5, 1995

Aug 6, 1995

Sep 9, 1995

Number 

of days

1

1

1

2

0

1

2

2

2

2

1

0

0

1

1

1

Average 

flow, 

in ftVs

9,450

8,110

10,200

10,800

0

12,600

11,600

11,500

7,450

10,900

11,700

0

0

13,600

9,950

10,100

Corresponding window 

(water release period)

Dates

Oct 15-20, 1990

Nov 12-24, 1990

Dec 13-24, 1990

Jan 11-22, 1991

Nov 19-29, 1991

May 26- June 6, 1992

July 4- 14, 1993

Aug 8-21, 1993

Sep 8-22, 1993

Oct 13-24, 1993

Nov28-Dec9, 1993

June 1-12, 1994

May 30- June 15, 1995

July 6-17, 1995

Aug 7-22, 1995

Sep 10-20, 1995

Number 

of days

6

13

12

12

11

12

11

14

15

12

12

12

17

12

16

11

Average 

flow, 

in ftVs

12,300

12,900

13,400

16,300

13,500

13,500

15,400

14,000

12,200

12,100

14,900

17,500

19,200

15,600

14,400

14,100

Average 

flow

for total 

period1 , 

in ftVs

8,270

8,720 "

9,680

11,600

9,570

11,300

11,800

11,300

9,630

9,110

12,200

14,300

16,800

11,800

11,400

10,400

AVERAGES FOR ALL PERIODS2

15 8,000 1 nd 12 14,600 11,000

1 Total period is pre-window, transition, and window periods combined.

2 Average flows for all periods were determined by multiplying the average flow for each period by the number of days in the period, adding 

the products together for all periods, and dividing the sum by the total number of days for all periods.

Appendix 77
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