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COVER PHOTOGRAPH:

The Landsat image on the cover shows the extent of the flood plain in the Apalachicola River basin, 

Florida. The dark color of the flood plain is caused by low reflectance from floodwaters. The river (600 

feet wide) is barely visible in the center of the flood plain (1-6 miles wide). The Apalachicola River flows 

from Lake Seminole (at the top), 106 miles south, to Apalachicola Bay (near the bottom of the scene). 

The numerous white squares near the top of the scene are agricultural fields in Florida and Alabama. 

The large red area east of the river is a pine forest (Apalachicola National Forest). The faint brown color 

on the bird's-foot delta at the river mouth depicts marsh grass. The light blue colors near the beaches at 

the bottom of the scene represent a combination of shallow water and ocean currents that carry high 

suspended sediment loads.

The false-color composite was obtained on February 6,1977, by a Landsat multispectral scanner and 

includes bands 4,5, and 7. The scene ID is 2746-15190, and more information on this and other satellite 

images is available through the U.S. Geological Survey, EROS Data Center, Sioux Falls, SD 57101.
Chapter D

HYDROLOGY AND ECOLOGY OF THE 

APALACHICOLA RIVER, FLORIDA: 

A SUMMARY OF THE 

RIVER QUALITY ASSESSMENT

By JOHN F. ELDER, SHERRON D. FLAGG, 

and HAROLD C. MATTRAW, JR.

U.S. GEOLOGICAL SURVEY WATER-SUPPLY PAPER 2196 

Apalachicola River Quality Assessment
DEPARTMENT OF THE INTERIOR 

DONALD PAUL MODEL, Secretary

U.S. GEOLOGICAL SURVEY 

Dallas L. Peck, Director

UNITED STATES GOVERNMENT PRINTING OFFICE: 1988

For sate by the Books and Open-File Reports Section, U.S. Geological Survey 

Federal Center, Box 25425, Denver, CO 80225

Library of Congress Cataloging in Publication Data

Elder, John F.

Hydrology and ecology of the Apalachicola River, Florida.

(U.S. Geological Survey water-supply paper; 2196-D)

Bibliography: p.

Supt. of Docs, no.: I 19.13:2196-0

1. Hydrology Florida Apalachicola River Watershed. 2. Water qualityFlorida Apalachicola River Watershed. 3. Ecology Florida Apalachicola River Watershed. I. Flagg, Sherron D. II. Mattraw, H.C. III. Title. 

IV. Series.

GB705.F5E44 1987 363.7'3942'0975992 86-600332
PREFACE

The Apalachicola River Quality Assessment was part of a national river 

quality assessment program of the U.S. Geological Survey. The authors would 

like to thank the members of the Subcommittee on River Quality Assessment of 

the Advisory Committee on Water Data for Public Use for their interest and 

support.

Robert A. Canham, Executive Director 

Water Pollution Control Federation 

Washington, D.C.

Dr. E. J. Cleary 1 

Professor Emeritus 

Department of Environmental 

Health and Engineering 

The University of Cincinnati 

Cincinnati, Ohio

James B. Coulter, Secretary2 

Maryland Department of 

Natural Resources 

Annapolis, Maryland

Ival V. Goslin 

Engineering Consultant 

Water Resources 

Western Engineers 

Grand Junction, Colorado

Dr. Laurence R. Jahn

Vice President

Wildlife Management Institute

Washington, D.C.

John E. Kinney 

Sanitary Engineer 

Ann Arbor, Michigan

Walter A. Lyon

Deputy Secretary for Planning 

Pennsylvania Department of 

Environmental Resources 

Harrisburg, Pennsylvania

John A. Roller, Superintendent 

Water Division

Department of Public Utilities 

Tacoma, Washington

Dr. Lois K. Sharpe 

Environmental Consultant 

Falls Church, Virginia

Dr. Clarence J. Velz 

Professor Emeritus 

Public Health Engineering 

The University of Michigan 

Ann Arbor, Michigan

1 Chairman 

2Vice Chairman

III
CONTENTS

Preface Hi

Abstract Dl

1.0 Background D2

1.1 Basin characteristics D2

1.2 Basin history D4

1.3 Basin management and environmental concerns D6

1.4 Information needs D8 

2.0 Apalachicola River Quality Assessment D10

2.1 Activities D10

2.2 Objectives D12

2.3 Flood-plain forest D14

2.4 Leaf-litter production and decomposition D16

2.5 Flooding hydrology D18

2.6 Water budget D20

2.7 Total and dissolved carbon transport D22

2.8 Particulate carbon transport D24

2.9 Nitrogen transport D26 

2.10 Phosphorus transport D28 

3.0 Overview and implications D30

3.1 Flood-plain role in nutrient transport D30

3.2 Impact of river and wetland on Apalachicola Bay D32

3.3 Trace substances D34

3.4 Influence of dams D36

3.5 Effects of channel modifications D38

4.0 Conclusions of the Apalachicola River Quality Assessment D40 

5.0 Summary D42

6.0 Scenes of the Apalachicola River D42 

Selected references D44 

Conversion factors D46
HYDROLOGY AND ECOLOGY OF THE

APALACHICOLA RIVER, FLORIDA: 

A SUMMARY OF THE RIVER QUALITY ASSESSMENT

By John F. Elder, Sherron D. Flagg, 

and Harold C. Mattraw, Jr.

ABSTRACT

During 1979-81, the U.S. Geological Survey conducted 

a large-scale study of the Apalachicola River in northwest 

Florida, the largest and one of the most economically 

important rivers in the State. Termed the Apalachicola River 

Quality Assessment, the study emphasized interrelations 

among hydrodynamics, the flood-plain forest, and the 

nutrient-detritus flow through the river system to the estuary. 

This report summarizes major findings of the study. Data on 

accumulation of toxic substances in sediments and benthic 

organisms in the river were also collected.

Because of the multiple uses of the Apalachicola River 

system, there are many difficult management decisions. The 

river is a waterway for shipping; hence there is an economic 

incentive for modification to facilitate movement of barge 

traffic. Such modifications include the proposed construction 

of dams, levees, bend easings, and training dikes; ditching 

and draining in the flood plain; and dredging and snagging 

in the river channel. The river is also recognized as an 

important supplier of detritus, nutrients, and freshwater to 

the Apalachicola Bay, which maintains an economically 

important shellfish industry. The importance of this input to 

the bay creates an incentive to keep the river basin in a 

natural state. Other values, such as timber harvesting, 

recreation, sport hunting, nature appreciation, and wildlife 

habitat, add even more to the difficulty of selecting 

management strategies.

Water and nutrient budgets based on data collected 

during the river assessment study indicate the relative 

importance of various inputs and outflows in the system. 

Waterflow is controlled primarily by rainfall in upstream 

watersheds and is not greatly affected by local precipitation, 

ground-water exchanges, or evapotranspiration in the basin. 

On an annual basis, the total nutrient inflow to the system is 

nearly equal in quantity to total outflow, but there is a 

difference between inflow and outflow in the chemical and 

physical forms in which the nutrients are carried. The flood 

plain tends to be a net importer of soluble inorganic 

nutrients and a net exporter of paniculate organic material.

Analysis of long-term records shows that dam construction in the upstream watersheds and at the Apalachicola 

headwaters has had little effect on the total annual waterf low 

but has probably suppressed low-flow extremes. Other 

effects include riverbed degradation and channelization 

which have to do with alteration of the habitat for aquatic 

biota and changes in flood-plain vegetation.

Whatever management decisions are made should 

take into account the impact on the natural flooding cycle. 

Flooding is crucial to the present flood-plain plant community 

and to the production, decomposition, and transport of 

organic material from that community. Permanent, substantial changes in the natural flooding cycle would be likely 

to induce concomitant changes in the flood-plain environment and in the nutrient and detritus yield to the estuary.

D1
1.0 BACKGROUND

7.7 Basin Characteristics

The Apalachicola River, the largest river in Florida, 

flows 106 miles through the northwest Florida Panhandle 

and empties into the Apalachicola Bay in the Gulf of 

Mexico (fig. 1.1). Its upstream limit is the Jim Woodruff 

Dam, 1 mile downstream of the confluence of the 

Chattahoochee and Flint Rivers. Lake Seminole, the 

37,600-acre reservoir impounded by the dam, provides the 

headwater inflow to the Apalachicola River, but there are 

no other dams on the river. The Chattahoochee flows 

about 430 miles from its source in north Georgia to Lake 

Seminole at the Florida-Georgia State line. The Flint 

River originates south of Atlanta, Ga., and flows about 

370 miles before it joins the Chattahoochee River.

The major tributary to the Apalachicola is the 

Chipola River. At the time of the Apalachicola River 

Quality Assessment, the Chipola River was constrained 

by a weir near Wewahitchka, Fla., to form a pool called 

Dead Lake. The control gates were removed in 1984 

(although the weir remains), allowing the pool to drain to 

preweir levels. Immediately downstream of the weir, the 

Chipola is joined by water from the Apalachicola River 

flowing through the Chipola Cutoff distributary. These 

waters rejoin the main stem of the Apalachicola 13 miles 

downstream.

The Brickyard Cutoff, a distributary channel, is 

located near Sumatra, Fla., at Brickyard Landing and 

conveys water from the Apalachicola River to the Brothers 

River. The Brothers River rejoins the Apalachicola 8 miles 

south of the Brickyard Cutoff. The Apalachicola River 

then flows 6 miles south, where it connects to the Jackson 

River and flows southeast into Apalachicola Bay, one of 

the most productive shellfish areas in the United States.

The entire Apalachicola-Chattahooch.ee-Flint River 

drainage basin is 19,600 mi 2 in area and encompasses parts 

of Georgia, Alabama, and Florida. The part below the 

dam, which drains directly into the Apalachicola River, 

has an area of 2,400 mi 2, half of which is the Chipola River 

subbasin.

Each winter and spring the rising waters of the 

Apalachicola flood the adjacent wetlands for 3-5 months. 

The flood plain occupies 175 mi2 and broadens downstream from 1/2-mile wide just below Lake Seminole to 

more than 7 miles wide near the mouth. It is heavily

forested with cypress, tupelo, and mixed hardwood trees, 

which thrive on the periodic inundation.

The mean annual flow of the Apalachicola River at 

its headwaters near Chattahoochee is 22,300 ft 3 /s (1928- 

82). Low flows are generally about 10,000 ft 3 /s, and high 

flows may exceed 100,000 ft 3 /s. The flow increases by 

about 25 percent over the course of the river.

A geologic description of the area by Schnable and 

Goodell (1968) indicates that the river basin consists 

primarily of sediments of Holocene age with some late 

Pleistocene sediments near the mouth of the river. The 

riverbed is composed primarily of Pleistocene deposits 

consisting of sand and coarse gravel. Sands and clays have 

been deposited constantly over time and add to the natural 

high turbidity of the river. Flood-plain soil has a wide 

range of textures and colors because it is made up of a 

variety of sediments deposited under highly variable flow 

conditions. Near Blountstown and Wewahitchka, Fla., 

Leitman (1978) found flood-plain soils to be predominantly 

clay with some silty clay and occasionally clay loam. 

Sands on point bars were predominantly fine and very fine 

sands and were of the micaceous type, whereas most 

Florida sands are siliceous. Cation exchange capacity of 

flood-plain soils generally ranged from 20 to 50 meq/ L, 

and organic concentration ranged from 1 to 20 percent 

(higher near the surface). These levels are higher than most 

Florida soils except peats and mucks. The pH of 

Apalachicola flood-plain soils ranges from 5.0 to 5.7 

(Wharton and others, 1982).

Average annual rainfall in the Apalachicola River 

basin in Florida is 58 in (1941-70), and mean annual 

potential evapotranspiration is between 39 and 45 in (U.S. 

Department of Commerce, 1973). Average annual rainfall 

in the basin of the Chattahoochee and Flint Rivers in 

Georgia is 52 in. Georgia rainfall has a greater influence on 

Apalachicola River flows than does Florida rainfall 

because only 11 percent of the basin of the Apalachicola, 

Chattahoochee, and Flint Rivers is in Florida. However, 

flows in the lower river can be substantially increased by 

Florida rainfall.

Mean annual air temperature in the Apalachicola 

River basin in Florida is 66° F. Mean January air 

temperature is 52 ° F, and mean July air temperature is 81 

°F (U.S. Department of Commerce, 1973).

D2
85°30' 85°15' 85°00' 84°45' 84°30'

32°

30°

28°

86° 84° 82° 80°

Apalachicola River 

drainage system

100 200 KILOMETERS

31°00'

30°45'

30°30'

30°15'

30°00'

29°45'

WOODRUFF DAM

_GEORGIA 

CHATTAHOQCHEE FLORIDA

100 river 

miles

'SWEETWATER 

CREEK 

80 river 

miles

EXPLANATION 

Flood plain

CHIPOLA\ 

CUTOFF

WEWAHITCHKA V

(\

20 river 

miles

Apalachicola River 

basin boundary 

Drainage divide foi 

gaging stations

B

Figure 1.1. The drainage basins of (A) the Apalachicola, Chattahoochee, and Flint Rivers in Florida, Georgia, and Alabama and 

of (B) the Apalachicola and Chipola Rivers in Florida.

D3
1.0 BACKGROUND Continued

1.2 Basin History

The Jim Woodruff Dam (fig. 1.2/1) was constructed 

by the U.S. Army Corps of Engineers. Construction began 

in 1950, and filling of the reservoir was accomplished in 

several stages from May 1954 to February 1957. The 

primary use of the dam is to improve navigation for barge 

traffic, with power generation as a secondary benefit. The 

U.S. Army Corps of Engineers is authorized to maintain a 

channel 100 ft wide and 9 ft deep. Dredging for the 9-ft 

depth began in 1956 in preparation of the completion of 

the Jim Woodruff Dam (Harry Peterson, U.S. Army 

Corps of Engineers, oral commun., 1980). Including the 

Jim Woodruff Dam, 16 dams are on the Apalachicola, 

Chattahoochee, and Flint Rivers (fig. 1.25). Most of the 

dams were built by local or private organizations for 

power generation. The oldest dam, the Eagle and Phenix, 

was built in 1834. Most of the remaining small dams were 

built near the turn of the century.

The U.S. Army Corps of Engineers made four 

cutoffs (fig. 1.2C)in 1956-57 and three more in 1968-69 to 

straighten bends in the river that were particularly difficult 

for barges to navigate. Groins (dikes perpendicular to 

banks) were installed to improve navigability by creating 

scour in the channel area of the river (fig. 1.2D). There are 

29 sets of groins, mostly in the upper river. Constructed of 

wooden pilings or stone, the groins were installed from

1963 to 1970 (Harry Peterson, U.S. Army Corps of 

Engineers, oral commun., 1980).

The major land use in the flood plain is forestry. 

Most areas were first cut between 1870 and 1925 (Clewell, 

1977, p. 11) and have been logged once or twice since that 

time. Other extensive uses are beekeeping for tupelo honey 

production, commercial and sport fishing, and hunting. A 

few areas on the flood plain have been cleared for 

agriculture and residential developments. However, there 

are no large urban centers, and there is very little 

industrialization.

With the exception of a cattle ranch south of 

Wewahitchka, Fla., most of the flood plain in the lower 

reach of the river (south of river mile 20) is publicly owned. 

The State of Florida Environmentally Endangered Lands 

Program purchased 44 mi2 of flood plain in 1977-78. 

According to Florida Statutes, land below the "ordinary 

high waterline" of the river is owned by the State. In 

addition, as of October 1984, the Apalachicola River was 

designated by the Florida Department of Environmental 

Regulation as an "Outstanding Florida Water" (OFW). 

This designation prohibits development which would 

significantly degrade water quality and applies to the 

entire river except for two reaches (near mile 103 and mile 

77).

D4
DISTANCE. IN MILES

B

Figure 1.2. Controls on the Apalachicola River: (A) Jim Woodruff Lock and Dam, (B) altitudes of the 16 dams on the 

Apalachicola, Chattahoochee, and Flint Rivers, (C) cutoff of a meander on the Apalachicola River above its confluence with 

the Chipola River, and (D) river training dikes at mile 100 on the Apalachicola River.

D5
1.0 BACKGROUND Continued

7.3 Basin Management and Environmental Concerns

Questions about the most beneficial management 

strategies for the Apalachicola River result from the 

diverse values and possible uses of the system. Figure 1.3 

shows separate uses and the likely management strategy 

employed for each use. Some uses call for mechanical or 

physical alteration of the natural system to maximize 

utility of the system for commercial benefit. Others benefit 

by limited intervention in the natural system. Examples of 

engineered controls are dredging, dam construction, 

channelization, clearcutting, and road construction. 

Examples of water utilization are irrigation, water consumption by industry, and discharge of municipal or 

industrial wastes to the river.

Shellfish harvesting in Apalachicola Bay is a 

multimillion-dollar industry that provides a major source 

of income and a way of life for residents of Franklin 

County, Fla. (Livingston and others, 1974; Prochaska and 

Mulkey, 1983). This resource could be threatened by 

disruption of the natural flow of river water and its 

constituents in the river system (Livingston and others, 

1974). The other major use of the system which yields a 

high economic return is its use as a waterway for freight 

transport by barges. Barging is the most fuel-efficient 

means of freight transport (Eastman, 1980), but it requires 

continual maintenance and navigational improvements in 

the river channel. Multiple use creates the possibility of a 

dilemma in developing management strategy: how to 

enhance the function of the system as a resource of one 

type without damaging it as a resource of another type.

Besides shipping, uses which may result in some 

alterations in the natural system include agriculture, 

timber harvesting, and urban development of the basin. 

To date, such activities have occurred only on a very 

limited scale, and most of the basin remains in a relatively 

natural state. One purpose of the OFW designation is to 

maintain the natural state of the water system.

Benefits which could result from active utilization of 

the river basin resources include the possibility of a 

stimulus to the local economy due to income from

agriculture and industry, increased employment, and 

recreational use of reservoirs which would be impounded 

by new dam construction. There would also be a 

probability of increased flood control and decreased 

impediment to mobility of barges and other large vessels. 

On the other hand, new problems would also be likely. 

Altered flooding patterns would probably eliminate large 

areas of the flood-plain forest and, in general, would 

decrease its productivity (Leitman and others, 1983). This 

would in turn have the probable effect of altering the 

nutrient, detritus, and sediment flows to the bay, resulting 

in structural changes in the estuarine community and 

impacting the shellfish industry. There would also be a 

likely decrease in the diversity of aquatic organisms in the 

freshwater system after channelization, scouring, and 

reservoir construction (Smalley and Novak, 1978). New 

reservoirs would inevitably bring new problems (such as 

algal blooms and aquatic weeds) that would require costly 

maintenance. Finally, there is the possibility of contamination by hazardous wastes that could result from the 

development of agriculture or industry in the basin.

The tradeoffs involved in management decisions 

may be synthesized in the following general statements:

It is unlikely that humans, through accident or design, will 

produce altered systems that behave as efficiently as 

natural ones which represent the culmination of over 200 

million years of evolution and at least 10,000 years of 

biological acclimatization. Much of the activity of the next 

decade will be spent attempting to undo environmental 

damage of the last century and, hopefully, implementing 

wise protection and management strategies for existing 

quality environments (Cummins and Spengler, 1978).

There exists no reason to believe that the current ecological 

situation represents an unfortunate state that is incapable 

of improvement through conscientious, intelligent management. ... Sound planning should be able to assure that 

the benefits derived from technology will continue to 

outweigh its disadvantages (Cairns, 1978).

D6
PREDOMINANT BASIN MANAGEMENT STRATEGIES

Engineered controls and 

water utilization

Shipping: barge traffic

Timber harvesting

Urbanization

Agriculture

Natural controls and limited 

intervention in natural cycles

Shellfish industry, 

Apalachicola Bay

Harvest of natural resources 

other than timber

Wetland Preserve: Wildlife habitat

Recreation 

Esthetic values

Figure 1.3. Basin uses and associated type of management in the Apalachicola River basin.

D7
1.0 BACKGROUND Continued

1.4 Information Needs

At the time of the initiation of the Apalachicola 

River Quality Assessment, relatively little was known 

about the processes controlling the flow of water, sediments, nutrients, or detritus in this large river-wetland 

system. These types of systems had not been a major focus 

of ecological study, partly because of the complexities of 

dealing with two interacting subsystems (river and wetland) 

and poor documentation of methods. In terms of available 

information, the Apalachicola River was a kind of missing 

link between the upstream and the downstream environments, both of which had been under study for several 

years. Upstream, heavy metals and pesticides were 

monitored in water, organisms, and sediments of Lake 

Seminole by the U.S. Army Corps of Engineers (1980). 

The study also included general hydrologic data about the 

reservoir and the Chattahoochee and Flint Rivers. Downstream, Apalachicola Bay had been the site of intensive 

investigation for many years by Livingston and others 

(1974).

Some of the important information needs for the 

Apalachicola River basin are outlined in figure 1.4. 

Information from the three main physiographic units of 

the basin the upland areas, the flood plain, and the 

river were all needed to understand functions of the 

system as a whole. Any type of budget estimates would

also require information about flows into the Apalachicola 

system from the upstream watersheds and out of the 

system to the estuary.

The Apalachicola River Quality Assessment filled 

some of the information gap about the river basin. In 

particular, the study produced estimates for water and 

nutrient budgets, descriptions of hydrologic features of 

the river and wetland, an assessment of relations between 

hydrology of the wetland and the forest community, and 

the measurement of the extent of accumulation of 

potentially toxic substances in benthic organisms and 

bottom sediments. It also included some methods development for the collection of data from large rivers and 

forested wetlands. There is still much to be learned about 

the system, however, particularly with respect to the 

variability of water and nutrient budgets from year to 

year. Furthermore, very little work has been done to 

describe chemical and biological processes within the river 

water, flood-plain soils, and vegetation which affect the 

nutrient and toxicant chemistry of the river water and 

sediments. Continued fieldwork, supported by laboratory 

experiments, would be valuable in adding information 

important for understanding the contribution from the 

river and the wetlands to estuarine productivity.

D8
-* 

> UPSTREAM SYSTEM

 OUTPUT TO APALACHICOLA RIVER

VJLAK LAKE SEMINOLE

«/«* 

tt

RIVER FLOOD PLAIN

 HYDROLOGIC FEATURES HYDROLOGIC

FEATURES EFFECTS

 WATER BUDGET

 NUTRIENTS. DETRITUS 

FLOW

 METHODS OF STUDY

ON VEGETATION

WATER QUALITY 

CHANGES EFFECTS 

ON WETLAND

METHODS OF STUDY

UPLAND

 LAND USE IMPACTS

ESTUARY

 OUTPUT FROM APALACHICOLA RIVER-EFFECTS 

ON ESTUARINE PRODUCTIVITY

APALACHICOLA BAY

Figure 1.4. Information needs by basin unit.

D9
2.0 APALACHICOLA RIVER QUALITY ASSESSMENT

2.1 Activities

In February 1979, the U.S. Geological Survey began 

data collection for a 2-year intensive investigation of the 

Apalachicola River and its associated wetland, a vast 

flood plain covered with a dense bottom-land hardwood 

forest. Data collection for the investigation, called the 

Apalachicola River Quality Assessment, continued until 

December 1980. Data analysis and interpretation followed, 

and a series of reports, each addressing a major objective 

of the study, was published. These reports were "Production and Decomposition of Forest Litter Fall on the 

Apalachicola River Flood Plain, Florida" (Elder and 

Cairns, 1982); "Wetland Hydrology and Tree Distribution 

of the Apalachicola River Flood Plain, Florida" (Leitman 

and others, 1983); and "Nutrient and Detritus Transport 

in the Apalachicola River, Florida" (Mattraw and Elder, 

1984).

In addition to this report series, other publications 

focused on specific questions addressed in the investigation. 

These publications, listed in order of publication date, 

were "Nutrient Yield of the Apalachicola River Flood 

Plain, Florida: River-Quality Assessment Plan" (Mattraw 

and Elder, 1980); "Riverine Transport of Nutrients and 

Detritus to the Apalachicola Bay Estuary, Florida" (Elder 

and Mattraw, 1982); "Riverine Transport of Nutrients 

and Detritus to Apalachicola Bay" (Elder, 1983); "Accumulation of Trace Elements, Pesticides, and Polychlorinated Biphenyls in Sediments and the Clam 

Corbicula manilensis of the Apalachicola River, Florida" 

(Elder and Mattraw, 1984); "Forest Map and Hydrologic 

Conditions, Apalachicola River Flood Plain, Florida"

(Leitman, 1984); and "Nitrogen and Phosphorus Speciation and Flux in a Large Florida River-Wetland System" 

(Elder, 1985).

A workshop in Tallahassee, Fla., in April 1982, 

provided an additional mode of information transfer from 

the Apalachicola River Quality Assessment. The workshop 

was cosponsored by the Northwest Florida Water 

Management District and the U.S. Geological Survey. It 

included participation by personnel from various local, 

State, and Federal agencies, local universities and colleges, 

and private organizations. Information presented at the 

workshop was collated in a workbook entitled "Apalachicola River Flood-Plain Processes in Nutrient Transport" and distributed to all participants.

This final Apalachicola River Quality Assessment 

report summarizes the principal results and conclusions of 

all of the elements of the investigation. The primary 

purpose of this report is to provide information that will 

aid those who are involved, either directly or indirectly, in 

implementing best management practices for the Apalachicola River basin. The rationale for selecting certain 

management practices may have transfer value to other 

similar systems in the Southeastern United States. In view 

of the many values and uses of the Apalachicola River 

system, some of which are illustrated in figure 2.1, it is 

clear that management decisions are not easy ones. The 

more they can be based on scientific knowledge, the more 

likely such decisions will be beneficial to the stability of the 

system and to users of this valuable natural resource.

D10
Figure 2.1. Examples of the different uses and values of the Apalachicola River system: (A) Oystering in Apalachicola Bay, (B) 

barging on the river, (O beekeeping on the river bank, and (D) flood-plain vegetation: swamp lily and (f) flood plain forest: 

Ogeechee tupelos.

D11
2.0 APALACHICOLA RIVER QUALITY ASSESSMENT Continued

2.2 Objectives

The Apalachicola River Quality Assessment was 

one part of a national river-quality assessment program of 

the U.S. Geological Survey. The broad objectives of the 

national program were (1) to define the character, interrelations, and apparent causes of existing river-quality 

problems and (2) to devise and demonstrate the analytical 

approaches and the tools and methods that would provide 

a sound technical basis for planners and managers to use 

in assessing river-quality problems and evaluating management alternatives (Greeson, 1978).

The specific goals of the Apalachicola River Quality 

Assessment conformed to these broad program objectives 

with the modification that the investigation was process 

oriented rather than problem oriented. The Apalachicola 

River system supports largely undisturbed forested wetlands on the flood plain and highly productive estuaries at 

its mouth, the Apalachicola Bay. The overall purpose of 

this assessment was to investigate river-wetland relations 

and controlling factors that influence the yield of nutrients 

and detritus to the bay.

Specific objectives of the study are listed below.

1. To describe how tree distribution on the flood plain is 

related to the pattern of inundation (duration, level, 

and frequency).

2. To assess the importance of leaf production and 

decomposition on the flood plain to detritus and 

nutrient yields.

3. To identify major sources of nutrients to the river 

system and to quantify transport of nutrients and 

organic detritus in various parts of the system.

4. To determine the extent to which potentially toxic 

trace elements and organic substances accumulate in 

benthic organisms and sediments.

Figure 2.2 shows diagrammatically the interaction 

of basin characteristics and processes to produce nutrient 

and detritus outflow. The relations addressed by the first 

three objectives of the study are highlighted in red 

(objective 1), green (objective 2), and blue (objective 3). 

The fourth objective was quite distinct from the others in 

that it was not involved with processes that affect the 

export of nutrients and detritus to the bay. Unlike the rest 

of the study, this part was oriented more toward 

monitoring a particular problem or potential problem, 

and there was little focus on methods development.

D12
OTHER NUTRIENT SOURCES

C Stage J

» (inundation)- 

1 V /

c Soils

FLOOD-PLAIN 

DYNAMICS

t 

f

/

1 

// A

//^Decc Y

4

M

(

Tree species 

distribution

Nutrient-detritus 

transport

NUTRIENT AND DETRITUS SOURCES NUTRIENT BUDGET

Figure 2.2. The interaction of basin characteristics and processes to produce nutrient and detritus outflow.

D13
2.0 APALACHICOLA RIVER QUALITY ASSESSMENT Continued

2.3 Flood-Plain Forest

The forested flood plain of the Apalachicola River, 

with an area of 175 mi2, is the largest in Florida. Of the 211 

different species of trees growing in the north Florida area, 

about 60 are found on the Apalachicola River flood plain. 

It is dominated by the general forest type, oak-gumcypress, defined by the U.S. Forest Service as bottom-land 

forest in which 50 percent or more of the stand is tupelo, 

blackgum, sweetgum, oak, and cypress, singly or in 

combination (U.S. Forest Service, 1969, p. 9). The oakgum-cypress type is very common on the flood plains of 

southeastern alluvial rivers; however, this general forest 

type has been divided into numerous specific types that 

various authors define differently from river to river.

Leitman and others (1983) identified 47 tree species 

in the Apalachicola flood plain. Baldcypress and two 

species of tupelo (water and Ogeechee) dominate the 

swamp areas of the flood plain. Together they account for 

over half of the relative basal area (percentage of the total 

cross-sectional stem area) of the entire flood-plain tree 

community. Other common species are Carolina ash, 

swamp tupelo, sweetgum, overcup oak, planertree, green 

ash, water hickory, sugarberry, diamond-leaf oak, American elm, and American hornbeam. The nomenclature 

follows Kurz and Godfrey (1962).

Leitman and others (1983) also defined five major 

forest types in the Apalachicola River flood plain and 

listed the composition of each in terms of relative basal 

area and density for each species. The types were defined 

on the basis of sampling results from eight transverse 

transects crossing the flood plain at approximately equally 

spaced intervals from Jim Woodruff Dam to Apalachicola 

Bay. The five types defined were type A (sweetgumsugarberry-water oak); type B (water hickory-green ashovercup oak-diamond-leaf oak); type C (water tupeloOgeechee tupelo-baldcypress); type D (water tupeloswamp tupelo); and type E (water tupelo-baldcypress). 

Biomass increased downstream and was greatest with 

forest types C, D, and E.

Forest types A and B were lumped together (type 

AB) for mapping (Leitman, 1984) because their color 

infrared signatures were indistinguishable. Similarly, types

D and E were lumped into a single type (DE). In addition, 

there were three minor forest types that were not sampled 

by Leitman and others (1983). These were pine (loblolly 

pine with scattered sweetgum, water oak, American 

hornbeam, and possumhaw); A/pine (sweetgum, sugarberry, water oak, and loblolly pine); and P (pioneer, 

dominated by black willow, in sandy soil along river 

margins). Type M is salt-marsh vegetation found only 

near the estuary, and type U is unidentified due to 

alteration by clearing, cultivation, or construction.

Water in the flood plain influences the distribution 

of trees because the availability of oxygen is severely 

restricted in saturated and inundated soils. Water-logging 

tolerance varies with species, environmental conditions, 

and season (Whitlow and Harris, 1979). Flooding during 

the dormant season has little or no effect because the 

oxygen requirements of plants are very low, but as little as 

3 days of flooding during the growing season can affect 

seedlings of certain intolerant species such as yellow 

poplar (Southeastern Forest Experiment Station, 1958). 

Seedlings of many species can survive soil saturation 

without standing water for much longer periods than they 

can survive complete inundation (Hosner, 1960; Hosner 

and Boyce, 1962).

Flooding can also influence the many other factors 

that affect tree distribution, such as seed dispersal and 

germination, seed consumption by animals, type of soil, 

availability of nutrients, competition, temperature, salinity, 

fire, and man's activities. In general, types C, D, and E are 

commonly found in permanently saturated soils, whereas 

types A and B are not (Leitman and others, 1983).

Figure 2.3 shows how the relative proportion of 

cover types changes from upper to lower river. Type AB is 

the major type in the upper and middle river and decreases 

in importance downstream of Wewahitchka, nearly 

disappearing in the tidal reaches of the river from Sumatra 

to the mouth. The tupelo-dominated types, Cand DE, are 

significant but minor in the upper and middle river and are 

dominant in the lower river. Marshes dominate the flood 

plain in the lower 10 miles of the river and are insignificant 

in the other 97 miles.

D14
REACHES OF APALACHICOLA RIVER

100

Upper Middle Lower river 

* river river

EXPLANATION

^^ WATER HICKORY-SWEETGUM-OVERCUP 

^^H OAK-GREEN ASH-SUGARBERRY

DE

TUPELO-CYPRESS WITH 

MIXED HARDWOODS

TUPELO-CYPRESS 

PIONEER

MARSH

SWEETGUM-SUGARBERRY-WATER OAKLOBLOLLY PINE

UNIDENTIFIED

B

5 MILI

J

I

5 KILOMETERS

Figure 2.3. Relative proportion of cover type changes from upper to lower river (from Leitman, 1984): (A) Area, in percent, of 

each mapping category, excluding open water, for five reaches of the Apalachicola River. (B) Upper river flood-plain 

segment showing distribution of forest cover types. (C) Lower river flood-plain segment showing distribution of forest cover 

types.

D15
2.0 APALACHICOLA RIVER QUALITY ASSESSMENT Continued

2.4 Leaf-Litter Production and Decomposition

Litter-fall measurements were made from September 

1979 through August 1980 in the Apalachicola River flood 

plain of northwest Florida. Litter fall was collected 

monthly from nets located in 16 study plots (fig. 2.4/1). 

The plots represented the five forest types in the swamp 

and levee areas of the Apalachicola River flood plain. The 

measurements showed that 43 species of trees, vines, and 

other plants contributed to the total litter fall. Average 

annual litter fall was determined to be 7,100 Ib/acre and 

resulted in an annual deposition of 4 X 105 tons of organic 

material in the 175-mi2 flood plain.

Figure 2AB shows that about half of the litter 

production was distributed among the major tree types. 

Slightly less than half was composed of nonleaf material. 

Tupelo and baldcypress are both swamp species; hence the 

swamp community accounts for 31 percent of the litter 

production as leaf material.

Decomposition rates of leaves from five common 

flood-plain tree species were measured using a standard 

leaf-bag technique. Leaf decomposition was highly species 

dependent. Tupelo (Nyssa spp.) and sweetgum (Liquidambar styraciflud) leaves decomposed completely in 6 

months when flooded by river water. Leaves of baldcypress 

(Taxodium distichum) and diamond-leaf oak (Quercus 

laurifolid) were much more resistant. Water hickory 

(Carya aquaticd) leaves showed intermediate decomposition rates. Decomposition of all species was greatly 

reduced in dry environments. Carbon and biomass loss 

rates from the leaves were nearly linear over a 6-month 

period, but nitrogen and phosphorus leaching was nearly 

complete within 1 month.

Why is litter fall and decomposition important? It 

has been estimated (Cummins and Spengler, 1978) that as 

much as 60 percent of the particulate organic matter in a 

stream may originate as leaf litter. This material is rapidly 

colonized by stream micro-organisms fungi and bacteria.

These organisms accelerate the decomposition of the 

material and release nutrients which are important to the 

primary productivity of the system. The micro-organismleaf association also serves as a food supply for consumers 

in the river and estuary. Micro-organisms and leaf particles 

are ingested together like "peanut butter on crackers." The 

"peanut butter" provides most of the nutrition, but the 

"crackers" are necessary as a substrate (Cummins and 

Spengler, 1978, p. 4).

If the annual litter production of 4 X 105 tons were 

totally flushed into the channels, it could produce a mean 

concentration increase of 7 mg/ L of organic carbon. This 

is not likely to be the case, of course, because of natural 

recycling within the flood-plain communities. It is nevertheless a major potential source of nutrients and detritus 

to the river and estuary.

The transport of organic litter from the flood plain 

to the river depends on flooding. Extensive floods with 

high flow velocities in the interior of the flood plain can 

mobilize large amounts of material. The timing of the 

flood is important. The major annual flood normally 

occurs several months after the peak litter-fall period. If it 

occurs earlier, there could be more litter deposited directly 

on the water surface, but there is less opportunity for 

decomposition prior to transport.

In comparison with other systems worldwide, the 

Apalachicola forest annual litter-fall production rate of 

7,100 Ib/acre is high. It is greater than those of many 

tropical systems and almost all warm temperate systems. 

Because most other systems that have been studied are not 

wetland systems, this comparison adds credence to the 

suggestion (Odum, 1979) that wetlands are more productive than uplands in comparable latitudes. Leaf decomposition rates in the Apalachicola environment appear 

to be similar to those found in comparable studies of other 

systems.

D16
Nonleaf material 

42%

Major

levee

species

19%

Other

major

swamp

species

11%

7100 (pounds/acre)/year

B

Figure 2.4. Litter fall in the Apalachicola River flood plain: 

(A) Leaf-litter collection net and (8) annual litter fall in the 

Apalachicola River flood plain.

D17
2.0 APALACHICOLA RIVER QUALITY ASSESSMENT Continued

2.5 Flooding Hydrology

If any single characteristic of the Apalachicola River 

system can be said to be the most critical to its character 

and function, it is the flooding cycle. In any riverine 

system, floods are important reset mechanisms, scouring 

old deposits and growth and redistributing stored organic 

matter and dried soils. In the Apalachicola, where the 

forested flood plain occupies 15 percent of the entire basin 

area, it is especially important. The flood-plain community 

structure is controlled largely by the annual flooding cycle 

(Leitman and others, 1983). This community does not 

exist in its present form in nonflooded areas, and it would 

not exist if the flooding cycle were to change significantly 

and permanently.

Discharge in the Apalachicola River generally ranges 

over about an order of magnitude each year from 10,000 

to 100,000 ft3 / s. High flow periods nearly always occur in 

late winter or early spring. Hydrographs for 1979-80 at 

two sites (fig. 2.5/1) illustrate the flow variability. They 

also show the discharge above which flooding occurs at 

both sites. The flooding threshold at the upper site 

(Chattahoochee) is higher because of more relief and 

greater channelization. At the downstream site (Sumatra), 

flooding is evident for several months of the year.

A series of water-level and current-meter discharge 

measurements at medium and high flood stages were made 

across two transects during the spring of 1980. One 

transect was near Sweetwater Creek, 6 miles upstream

from Bristol, and the other was at Brickyard Landing, 6 

miles south of Sumatra. The distribution of water level, 

flow, and velocity measured at two stages for each transect 

are shown in figures 2.55 and 2.5C.

An analysis of the flow patterns at the Sweetwater 

intensive transect on March 11 and 18, 1980, shows that 

instantaneous water levels vary considerably across the 

flood plain at moderate flood stage (fig. 2.55). The flood 

plain carried 10 percent of the flow on March 11 and 26.6 

percent of the flow at a higher stage on March 18. 

Velocities increased in the main channel and the east flood 

plain but decreased in the west flood plain with higher 

stage.

Flow patterns at the Brickyard transect on March 14 

and 19, 1980, show that instantaneous water levels are 

fairly uniform across the flow corridor at both medium 

and high flood stages (fig. 2.5C). The flood plain at this 

site has two major channels, Brickyard Cutoff and 

Brothers River, which convey a high percentage of flow 

during flooding, especially at lower flood levels. Those 

two flood-plain channels carried 27.7 and 24.1 percent of 

the total flow on March 14 and 19, respectively. The 

remainder of the flood plain, excluding Brickyard Cutoff 

and Brothers River, carried 35.0 and 44.3 percent of the 

total flow during medium and high flood stages, respectively. Velocities were higher in most sections of the 

flood plain at the higher stage.

D18
2000 FEET

600 METERS

VERTICAL SCALE 

GREATLY EXAGGERATED

(0 U.

Chattahoochee

I I I

200.000 

O 100.000 

Sj § 60.000 

0 g 20.000

- m 10,000

g"5 200. 000 Sumatra

* K- 100.000 

O u 60.000

20.000

10.000

I I I I \ \ I I I I I I

I I I

^ A» A»

040 « £ o / f /

1979

T

1980

EAST WEST EAST WEST

FEET

FEET

20 i 31.6%

SEA 

LEVEL

FEET

 ^-APALACHICOLA 

RIVER

14% of Q

V=0.56 feet

per second

BROTHERS - 

RIVER

9% of Q 

V=0.36 

feet per 

second 

23.3% of Q 

V=2.27 feet 

per second

SEA 

LEVEL

EXPLANATION

Q MEAN DAILY DISCHARGE. 

V MEAN DAILY VELOCITY.

 WATER LEVEL ON MARCH 16. 1960.

TOTAL Q 87.900 CUBIC FEET/SECOND.

 WATER LEVEL ON MARCH 11. 1980.

TOTAL Q 67.600 CUBIC FEET/SECOND.

EXPLANATION 

MEAN DAILY DISCHARGE. 

MEAN DAILY VELOCITY.

WATER LEVEL ON MARCH 19. 1960.

TOTAL Q 103.000 CUBIC FEET/SECOND.

WATER LEVEL ON MARCH 14. 1980.

TOTAL Q 70.000 CUBIC FEET/SECOND.

B C

Figure 2.5. Flooding on the Apalachicola River: (A) Discharge for Chattahoochee and Sumatra gages, Apalachicola River, 

February 1979 to June 1980; dashed lines show flooding thresholds. (B) flow and velocity distribution at medium and high flood 

stages at the Sweetwater transect, and (C) flow and velocity distribution at medium and high flood stages at the Brickyard 

transect.

D19
2.0 APALACHICOLA RIVER QUALITY ASSESSMENT Continued

2.6 Water Budget

A water budget for the Apalachicola basin during 

the 1-year period from June 3, 1979, to June 2, 1980, was 

described by Mattraw and Elder (1984). Continuous 

discharge records from gages at each of seven sampling 

sites on the river and its tributaries, plus rainfall and 

ground-water-level measurements and evapotranspiration 

estimates, provided the basis for the calculations.

An equation which expresses the water budget of the 

Apalachicola River system is

WO- WI + P, Pdp +GW+CR-Ret ±r

where all terms represent volumes of water and are defined 

as follows:

WO = outflow at the downstream limit;

WI = inflow at the upstream limit;

Pro - precipitation runoff;

Pd - direct precipitation in river and flood plain;

G W - ground-water discharge;

CR = input from the mouth of Chipola River;

Ret = evapotranspiration of river-derived water; and

r - residual the amount required to balance the

equation (equivalent to an error term and not 

associated with any known component of the 

budget).

The water budget described by this equation is 

depicted diagrammatically in figure 2.6. The numbers 

shown with each component give overall estimates for the 

1979-80 study year; their derivations and seasonal breakdowns are detailed by an earlier report (Mattraw and 

Elder, 1984). Several of the major components, shown by 

large circles, can be subdivided into more specific 

categories. Only the components or subcomponents which 

provide direct input to or outflow from the river-wetland 

system are included in the equation.

Inputs exceeded losses, resulting in a 25-percent 

gain in waterflow from Chattahoochee to Sumatra. More 

than half of the input was contributed by the Chipola 

River. The water budget of the Apalachicola basin is 

heavily streamflow dominated; water volumes involved in 

precipitation, ground-water flow, surface-water runoff, 

and evapotranspiration are relatively minor compared to 

channelized inputs ( WI and CR).

D20
APALACHICOLA RIVER

-FLOOD-PLAIN BOUNDARY

BASIN BOUNDARY

EXPLANATION

Wl = Inflow at upstream limit. 

WO = Outflow at downstream limit. 

CR = Inflow from Chipola River. 

GW = Ground water.

GWO = Ground-water flow 

out of basin.

ET = Evapotranspiration (total).

P = Precipitation.

Pgw ~ Precipitation which

recharges ground water.

Pro = Precipitation which enters

river as surface-water runoff.

P<jp = Direct precipitation to river 

and tributaries.

<et = Evapotranspiration from 

riverine and flood-plain 

storage.

et = Precipitation which exits 

as evapotranspiration.

Values in cubic miles.

Figure 2.6. Apalachicola water budget.

D21
2.0 APALACHICOLA RIVER QUALITY ASSESSMENT Continued

2.7 Total and Dissolved Carbon Transport

As in any river system, nutrients are transported by 

the flowing waters into the estuary in enormous quantities. 

Thousands of tons of organic carbon, nitrogen, and 

phosphorus are transported annually into the estuary and 

supply a critical base for the highly productive estuarine 

food web. There are two important questions with respect 

to nutrient transport in the Apalachicola system. How 

much does flooding and the flood-plain community 

contribute to or remove from the riverine nutrient flow? If 

there were no flooding, would the nutrient yield to the 

estuary be different?

Organic carbon was one of three major nutrients 

whose transport was studied intensively in the Apalachicola 

River Quality Assessment. Samples for analysis of both 

dissolved organic carbon (DOC) and particulate organic 

carbon (POC) were collected in 1979-80 at the seven sites 

shown in figure 2.7A. The first four sites were on the main 

river channel; the fifth site was a transect across the lower 

flood plain, including Brickyard Cutoff and Brothers 

River; the sixth site was in Little Sweetwater Creek, a 

small ground-water-fed tributary; and the seventh site was 

in the Chipola River. Samples were collected monthly 

during low-flow periods and much more frequently during 

the flood of March and April 1980.

Organic carbon transport estimates for four sampling 

dates representing different flow and growth conditions 

are shown in figure 2.7B. The transport rate, in tons per 

hour, was calculated as the product of concentration and 

discharge for the day indicated. The data were taken at site 

4, the most downstream main-stem site.

Some similarities and some differences in the data 

for the four dates are immediately obvious. The dissolved

fraction predominated over the particulate fraction at all 

times. Such predominance of DOC over POC is common 

to many river systems (Naiman and Sibert, 1978). The 

amount of POC was almost constant on the first three 

dates, although the total carbon transport dropped substantially in November. Both dissolved and particulate 

fractions increased in March, during the spring flood.

Factors which may explain the observations shown 

in figure 2.1 B include flow variability coupled with 

biological (photosynthetic) activity which produces organic 

material. In June 1979, riverflow was quite low, but 

photosynthetic activity was high; the relatively high 

carbon transport was primarily a reflection of high DOC 

concentrations due to the high autotrophic production 

rate. In November, this production rate was much lower, 

causing the decrease in DOC. However, litter fall was 

high, and the flow rate had increased slightly since June, 

maintaining POC at nearly the same level. In late February, 

productivity was just beginning to increase, and the flow 

rate was also higher; a significant increase in DOC flow 

had occurred. Finally, in March, the very high flow of the 

spring flood produced a major increase in both POC and 

DOC transport.

Flooding in March caused an increase in organic 

carbon transport, but the data indicate that the total 

increase was not nearly as high as might be expected from 

the increase in flow. DOC concentrations were lower on 

March 19 than on February 28 in spite of the flow increase. 

POC outflow, however, did increase substantially in 

March and became a much larger fraction of the total 

load over 10 percent as opposed to about 5 percent in 

February. This effect of flooding on POC is examined 

further in the next section.

D22
85°00' 84°45' 84°30'

30°45' -

30°30' -

30°15' -

30°00' -

29°45' -

29°30' -

3

gffi

B

17,700 

(6/18/79)

23,600 

(11/20/79)

30,000 

(2/28/80)

109,000 

(3/19/80)

ORGANIC CARBON

I I Dissolved 

| J Participate

20 40 60

TRANSPORT, IN TONS PER HOUR

80

Figure 2.7. (A) The ApalachicolaChipola River subbasin, showing 

sampling sites, and (6) organic carbon 

transport near Sumatra on four 

specific dates in 1979 and 1980.

D23
2.0 APALACHICOLA RIVER QUALITY ASSESSMENT Continued

2.8 Paniculate Carbon Transport

The particulate organic carbon (POC) fractions 

shown in figure 2.7B are expanded in figure 2.8A. The 

total POC load is divided into four fractions according to 

particle size and mode of transport. The suspended load, 

sampled by pumping water through nested sieves and a 

filter, was separated into (1) the very fine (VF) fraction, 

with a particle-size range of 0.0000018-0.0024 in; (2) the 

fine (F) fraction, with a particle-size range of 0.0024-0.04 

in; and (3) the coarse (C) fraction, with a particle size 

greater than 0.04 in. The bottom-load (B) samples were 

collected with a net of 0.04-in-mesh size held on the 

bottom at midchannel.

As in nearly all streams and rivers (Naiman and 

Sedell, 1979), the concentrations of organic carbon 

decrease as particle size increases. On all of the days 

represented in figure 2.8,4, the VFPOC fraction amounted 

to considerably more than the sum of the other fractions. 

This feature probably enhances the value of the particulate 

material as a nutrient source because of the greater 

surface:volume ratio in finer particles.

The flooding effect on POC, as shown by the data of 

March 19, was very different than its effect on DOC (fig.

2.1 B). Total POC transport increased by almost five times

from February 28 to March 19, more than the increase in 

waterflow. Other data collected in the study suggested that 

this concentration increase in POC during flooding was 

due to flushing of particles out of the flood plain. 

Although the flood plain seems to produce very little net 

increase in dissolved carbon transport, there can be little 

doubt that it does serve as a source for POC.

The POC transport capacity of the Apalachicola 

floods is further illustrated by figure 2.85. This graph 

compares the cumulative transport of all fractions of 

carbon at Sumatra with the transport curves that would be 

observed if the rates were constant during the entire year 

(using January 4, 1980, as the date for determining 

constant rate). Observed data in the spring months of 1980 

were offset considerably from the constant rate curves. On 

close inspection, the most critical "flushing periods" 

appear to be quite distinguishable for the different 

fractions. For example, the principal CPOC surge occurred 

in April, while the FPOC was released somewhat earlier 

and had a slower transport rate in April. Bottom-load 

material (BPOC) showed one of its greatest surges in 

November, coinciding with the period of heaviest litter 

fall, and then increased again in winter and spring periods 

as greater areas became inundated.

D24
6/18/79

11/20/79

2/28/80

3/19/80

PARTICULATE 

ORGANIC CARBON

I I Very fine 

I | Fine 

[££] Coarse 

IH Bottom load

0 234567 

TRANSPORT, IN TONS PER HOUR

CO

z

1 oo.ooo F

cc 

o

O. 

CO

z

< 10.000

cc

o

m 

cc

o

o 1000

z

CD

cc 

o

lil 

Sc

100

o

Icc

<

Q.

lil

10

JJASONDJFMAMJ 

1979 1980

o

Figure 2.8. Paniculate organic carbon transport near Sumatra: (A) Paniculate organic 

carbon transport near Sumatra on four specific dates in 1979 and 1980, and (B) paniculate 

organic carbon transport for June 1979 to June 1980 (logarithmic vertical scale).

D25
2.0 APALACHICOLA RIVER QUALITY ASSESSMENT Continued

2.9 Nitrogen Transport

The mass of nitrogen transported by the Apalachicola 

River to its estuary is approximately 10 percent of the 

mass of organic carbon. The total yield during a 12-month 

period in 1979-80 was over 23,000 tons. Graphical 

representations of nitrogen transport on the same four 

sampling dates that were previously shown for carbon are 

given in figure 2.9A. Nitrogen in aquatic systems is 

measurable in four principal fractions: (1) oxidized 

inorganic nitrogen, consisting of dissolved nitrate (NO3.) 

and nitrite (NO2.) ions; (2) reduced inorganic nitrogen, 

consisting of dissolved ammonia (NH3); (3) dissolved 

organic nitrogen (DON) associated with various soluble 

organic compounds; and (4) particulate organic nitrogen 

(PON) associated with suspended organic material 

(detritus) such as leaf particles and micro-organisms.

Nitrate and DON tend to predominate in the 

Apalachicola waters, although PON can occasionally be a 

major fraction of the total. The November sampling date 

represents a condition in which the particulate species 

form a large fraction; the total nitrogen load was relatively 

low, but litter deposition was occurring at a very fast rate 

at the time, contributing high amounts of PON.

The March flood coincided with increases in nitrate 

and DON concentrations, causing an increase in the total 

nitrogen transport rate which exceeded the relative increase 

in waterflow. These increases in concentration are probably 

attributable to two primary causes. The nitrate increase 

was quite gradual during the winter; this is normal in

aquatic systems during nongrowing seasons when biological uptake of nitrate is diminished. The examination 

of all nitrate data from the study (Elder, 1985) indicated 

that nitrate concentrations followed a definite seasonal 

pattern low in late summer and increasing to maximum 

levels in late winter. The large increase in DON during the 

flood (March 19) probably was attributable to flushing of 

soluble organics from flooded areas throughout the upper 

basins (Chattahoochee and Flint) as well as from the 

Apalachicola flood plain.

One of the important characteristics of the inorganic 

nitrogen data is illustrated in figure 2.95. The data points 

represent means of all samples collected at a site during the 

study, and the plots show variation over the course of the 

river. Ammonia concentrations decreased considerably in 

a downstream direction, while nitrate concentrations were 

nearly the same at sites 1 and 4. (Sites 2 and 3 had higher 

means, but because of the time variability shown by 

standard error bars, the differences are probably not 

significant.) As a result, the ratio of ammonia: total 

inorganic nitrogen decreased in a downstream direction 

from 0.14 at site 1 to 0.08 at site 4. Mass balance 

calculations (Elder, 1985) showed that ammonia loss 

during transport was quite consistent, the result being that 

the 12-month ammonia export was over 50 percent less 

than the sum of its imports. The system was clearly a net 

consumer of ammonia, although it was a net exporter of 

organic nitrogen and some carbon and phosphorus species.

D26
6/18/79

11/20/79

2/28/80

3/19/80

\ i i i i i i r

NITRATE PLUS 

NITRITE

AMMONIA

DISSOLVED 

ORGANIC NITROGEN

PARTICULATE 

ORGANIC NITROGEN

2468 

TRANSPORT, IN TONS PER HOUR

10

DC 

LUIDC 

LU 

0_

CO

DC 

O

_J

z 

O

DCIZ 

LU

o

z 

O 

o

0.4

0.3

0.2

0.1

Nitrate

10 20 30 40 50 60 70 80 90 100

I

SITE 1 SITE 2 SITE 3 SITE 4 

B MILES DOWNSTREAM FROM LAKE SEMINOLE 

Figure 2.9. (A) Nitrogen transport on four specific dates in 1979 and 1980 and (B) changes in 

inorganic nitrogen concentrations with stream location.

D27
2.0 APALACHICOLA RIVER QUALITY ASSESSMENT Continued

2.70 Phosphorus Transport

Primary productivity in Apalachicola Bay is phosphorus limited during summer and autumn each year 

(Livingston and Loucks, 1979). The ratio of soluble 

reactive phosphorus (SRP) to dissolved inorganic nitrogen 

in the Apalachicola River generally ranges from about 

1:20 near the headwaters to about 1:40 near the mouth. 

This suggests an imbalance which can lead to the phosphorus limitation in Apalachicola Bay. It also indicates 

net consumption of SRP in the flood plain.

Just as ammonia nitrogen became a smaller fraction 

of dissolved inorganic nitrogen from upstream sites to 

downstream sites, SRP also became a smaller fraction of 

total phosphorus (fig. 2.10). At the headwaters, dissolved 

phosphorus was composed entirely of SRP. Farther 

downstream, SRP decreased while the total dissolved 

phosphorus concentration increased slightly, reflecting a 

downstream increase in dissolved organic phosphorus. At 

site 4, SRP comprised only about 50 percent of the 

dissolved phosphorus concentration. There was a small 

overall downstream increase in total phosphorus concentration, maintained by slightly increasing concentrations of both particulate and dissolved phosphorus.

On an annual time scale, the phosphorus mass 

balance for the entire river system shows a mixed result 

similar to that for nitrogen. There was net import of SRP 

and net export of other dissolved phosphorus and 

particulate phosphorus.

Unlike nitrogen, phosphorus is relatively insoluble 

in neutral or alkaline pH conditions. Particulate forms 

tend to predominate, as is indicated by the difference 

between total and dissolved phosphorus shown in figure 

2.10. Much particulate phosphorus is associated with iron, 

calcium, and other metals and can sorb to sediments and 

detritus suspended in the river water. Hence, the pulses of 

detritus flow during floods, which became evident by 

analysis of POC, tend to be accompanied by pulses of 

particulate phosphorus transport. As shown in table 

2.10, more than two-thirds of the phosphorus transport in 

1979-80 was in particulate form.

Table 2.10-1. Amounts and percentages of phosphorus load at Sumatra (site 4) during 12-month period of 6/3/79-6/2/80.

Phosphorus fraction

Load

(tons)

Percent

of

total

Particulate 

Soluble nonreactive 

Soluble reactive

1,230

310

250

69

17

14

Total 1,790

D28
O.O7

Z

o

_J

_J 0.06

QCa 0.05

CO1-

< 0.04 

Q.

Z

- 0.03

O

H 

< 0.02

1- 

Z 

III

O 0.01

O 

O

c

I I I

-

_j_J°i2i -;

-

-

T Dissolved 

I I I

) | 10 20 30

I I I I I

us T -I -

_Phosph2IiiS J J -

~~*^ii^ * Ph555h7?U8 ~

i i i i i

40 50 60 |?0 80 90 100

SITE 1 SITE 2 SITE 3 SITE 4

MILES DOWNSTREAM FROM LAKE SEMINOLE

Figure 2.10. Changes of phosphorus concentrations with stream location. Data represent 

means from 20-41 samples with standard errors as shown by error bars.

D29
3.0 OVERVIEW AND IMPLICATIONS

3.1 Flood-Plain Role in Nutrient Transport

Having examined some of the characteristics of the 

occurrence and transport of various species of organic 

carbon, nitrogen, and phosphorus, it becomes quite 

evident that the flood plain does have an influence on 

nutrient yield. However, the influence is not as simple as 

might be implied by viewing wetlands as either sources or 

sinks for nutrients. The Apalachicola wetland fluctuates 

between being an importer and being an exporter, 

depending on numerous variables. As was suggested by de 

la Cruz (1979), it is more appropriate to depict the wetland 

as a transformer than either as a source or as a sink.

The transformer role of the flood plain is diagrammatically illustrated in figure 3.1. An amount (X) of a 

given mix of nutrients (A) is transported into the flood 

plain. After some processing within the flood plain 

(incorporation of processes including biological uptake, 

complexation, oxidation, reduction, sorption, and precipitation), a different mix (5) is output in an amount ( Y). 

Over an annual cycle, the quantities of input and output 

are not greatly different, hence X is approximately equal 

to Y. In qualitative terms, however, the output may be 

very different from the input, hence A is unequal to B. By 

affecting nutrient chemistry more than total nutrient 

loads, the river-wetland system plays a critical role in

supporting estuarine productivity. The forms of nutrients 

exported to estuaries are probably of equal or greater 

importance than are the total amounts (Nixon, 1980).

In the Apalachicola River-wetland system, one 

effect of the wetland is to transform the nutrient load to 

one which favors secondary productivity and a detritusbased food web in the estuary. Primary productivity in 

estuarine systems is likely to be limited by bioavailable 

species of either nitrogen (Ryther and Dunstan, 1971) or 

phosphorus (Taft and Taylor, 1976). As was noted earlier, 

phosphorus would seem to be the more critical nutrient in 

the Apalachicola River-wetland system because of the 

shortage of soluble reactive phosphorus relative to inorganic nitrogen. No matter which nutrient is more 

critical, the inorganic forms of both nitrogen and 

phosphorus are only sparingly supplied to the estuary by 

riverine inflow. However, the river transports an abundant 

supply of detritus from the flood plain (Elder and 

Mattraw, 1982). The detritus provides an excellent substrate for bacterial growth (Fenchel, 1970) and a base for 

support of a thriving population of detrital feeders 

(Darnell, 1961), including many of the economically 

valuable shellfish species.

D30
FLOOD-PLAIN FUNCTION

0

X tons Flood plain Y tons 0

X=Y

Figure 3.1. Flood-plain function.

D31
3.0 OVERVIEW AND IMPLICATIONS Continued

3.2 Impact of River and Wetland on Apalachicola Bay

Research conducted for several years by scientists 

from Florida State University (Livingston, 1983) has 

shown conclusively that the productivity and general 

vitality of the Apalachicola Bay estuary is highly dependent 

on inflow from the river (fig. 3.2). Not only the nutrient 

and detritus inputs but also the salinity controls by the 

seasonal fluctuations of riverine input are crucial in 

maintaining the estuarine community, including the 

extremely valuable shellfish population.

If there were major changes in the present flooding 

cycle of the river or if large areas of the flood-plain 

community were removed, would the river still be able to 

maintain the estuary the way it does today? Information 

from the studies of this river basin, as well as others, 

suggests that there would be at least some appreciable 

changes in the estuarine community if the river were 

subject to such major alterations. The importance of the 

flood plain in propagating nutrient transformations has 

already been noted. The importance of salinity controls

has been extensively described by Livingston (1983). The 

fluctuating inflows of the river are important in maintaining a community of species that are either euryhaline 

(tolerant to a wide salinity range) or migratory. Without 

such pulsations, species with a lower tolerance to salinity 

variation could immigrate, producing an inevitable change 

in the community structure.

In addition to the control of nutrient quality by 

flood-plain processes and to the effects of pulsating 

riverflow on estuarine salinity, there are other impacts of 

the river-wetland system on the estuary. One wetland 

function which may become of greater importance in the 

Apalachicola basin in future years is the filtration of 

potentially toxic substances. This process has been shown 

to be of such efficiency that wetlands can be utilized for 

waste water purification (Sloey and others, 1978; Tilton 

and Kadlec, 1979). Other wetland functions which are less 

directly related to the estuary are flood detention, aquifer 

recharge, and utilization as a fish and wildlife habitat.

D32
DETRITUS

RIVER 

FLOW

FRESHWATER

( MICROBIAL 

VCOLONIZATION

( DETRITIVORES )

FILTER 

FEEDERS

&

(CONSUMERS)

Figure 3.2. Riverflow controls on the estuarine food web.

PRIMARY A 

PRODUCERS J

GRAZERS)

D33
3.0 OVERVIEW AND IMPLICATIONS Continued

3.3 Trace Substances

The fourth objective of the Apalachicola River 

Quality Assessment, to determine the accumulation of 

potentially toxic elements and organic substances in 

benthic organisms and sediments, was addressed by 

conducting a survey of trace element and synthetic organic 

compounds in bottom materials. Data were collected 

from five sites, all on the main river channel. Four of the 

sites were the same as sites 1 -4 identified earlier, and the 

fifth site was 6 miles from the river mouth.

Substances analyzed included trace elements (predominantly heavy metals), organochlorine insecticides, 

organophosphorus insecticides, chlorinated phenoxy-acid 

herbicides, and polychlorinated biphenyls. Three kinds of 

materials were surveyed: fine-grained sediments, wholebody tissue of the Asiatic clam Corbicula manilensis, and 

bottom-load organic detritus.

Some of the results of the survey are shown in figure 

3.3. The predominant metals and organic compounds are 

included, although a large number of other substances 

were analyzed. More details of the study are available in 

the report by Elder and Mattraw (1984).

The concentrations shown in figure 3.3 do not 

signify hazardous levels for any of the substances. Concentrations in the fine-grained sediments and clams were 

generally at least 10 times lower than maximum limits 

considered safe for biota of aquatic systems (National 

Academy of Sciences and National Academy of Engineering, 1972; Walshand others, 1977). Further data analysis 

did not identify any trends, either with time or from 

upstream to downstream reaches of the river.

A comparison of trace-substance data from the 

Apalachicola River with data from Lake Seminole 

(upstream) and Apalachicola Bay (downstream) showed 

lower concentrations in riverine clams. Sediment concentrations in all parts of the system were comparable.

The principal use of the results of this survey is as a 

baseline for comparison with future water quality. At 

present, there are no major point discharges of these 

substances in the Apalachicola basin (although there are 

such sources in the Chattahoochee and Flint basins). If 

future development were to create additional sources, the 

impacts of those sources might be assessed on the basis of 

predevelopment conditions.

D34
1 UUU

I

0

UJ

g 100

DC

O

DC

UJ

0.

CO

C 10

O

O

DC

O

2

Z

^

z

o

H- 1

DC

Z 

UJ

o

z

o

o

n 1

i

(

-

<

i

'

_ «

" "

\ '

I

< >

(

s

J

r

t

r

-1-

r

i

1 '

K.CY

range J o median range j J« median 

[ 1 f Lower value be ow

Concentration Concentr

100

CO

5

< K

§2

oc ^ 10

o >

5 >

2 O

i!

t- 0

< o

OC -1

z * 1

UJ rr 

O uj

Z Q. 

O

0

n 1

_

_

? t \ 

i .

_

i

<

-

"

i

>

4

detection mil

ation

/tensis

_

t

h

1

] [ 

 * ~

_

-

-

<?

METALS ORGANICS

Figure 3.3. Concentration ranges and medians of metals and organic substances in fine-grained sediments and Corb/cu/a 

manilensis in the Apalachicola River, August 1979 through May 1980. Where no median is shown, it was at or below detection 

limit. Dieldrin in sediments was below detection limit in all samples.

D35
3.0 OVERVIEW AND IMPLICATIONS Continued

3.4 Influence of Dams

At present, the Apalachicola River flows unimpeded 

by dams. At the headwaters of the river, however, Jim 

Woodruff Lock and Dam (fig. 3.44) impounds Lake 

Seminole, and further upstream, 15 additional dams 

regulate the flow of the Chattahoochee and Flint Rivers.

Leitman and others (1983) conducted an analysis of 

long-term stage and discharge records for the Apalachicola 

River at Chattahoochee. The records represented the 

period 1929-79. Although the 16 dams on the Apalachicola, 

Chattahoochee, and Flint Rivers were constructed at 

various times from 1834 to 1975, filling of both the largest 

reservoir, Lake Sidney Lanier, and the reservoir closest to 

the area of investigation, Lake Seminole, was completed 

in 1957. The second and third largest reservoirs were filled 

in 1975 and 1963, respectively. Thus, 1929-57 and 1958-79 

were the periods of record chosen for comparison.

Figure 3.45 shows that the predam and postdam 

periods were very similar in terms of the distribution of 

flow through the annual cycle. The principal difference 

was that the flow of the more recent period was higher. 

Examination of records from other rivers in north Florida 

for the same periods showed that the mean annual 

discharge in all of them was higher from 1958 to 1979 than 

in the 20 years prior to 1958. This was attributed to higher 

rainfall over the three-State area during the later period.

A more subtle difference between the two periods is 

shown in figure 3.4C. This graph shows flow duration, or 

the percentage of time that discharge exceeds any particular 

level. The curve is somewhat flatter for the period 1958-79 

than for 1929-57, indicating that the dams may have had 

an effect of dampening fluctuations or reducing the 

amount of time that the flow was at low extremes.

In short, the effect of dams on riverflow is to 

decrease expection of extreme low flow. There has been 

very little effect on either the amount or the seasonal 

distribution of discharge over an annual cycle.

Ecological changes are probably the most notable 

effects of dam construction. Most ecological changes 

result from the development of reservoirs in former 

terrestrial or wetland environments. A system which 

contains dams and their associated reservoirs is obviously 

very different than the system before the construction of 

the dams. Reservoirs, whatever their benefits, bring an 

entirely new set of management problems, as was 

previously discussed. Flood-plain area is diminished, and 

wildlife habitat is altered.

Erosion downstream of a dam can result from the 

channelized, turbulent flow of relatively clear water below 

the dam (Taylor, 1978). This could be manifested by 

degradation of the channel and erosion of streambanks in 

some reaches, with concomitant aggradation of the channel 

in others. In the Apalachicola River, scouring just below 

Jim Woodruff Dam has left the river bottom quite rocky 

and relatively free of sediments. In general, bank erosion is 

retarded by the heavy growth of rooted vegetation on the 

banks.

Proposals for the construction of dams on the 

Apalachicola River to facilitate navigation have been 

rejected in the past because it was the general consensus of 

policymakers that the benefits of such dams would be 

outweighed by losses of existing resources due to alterations to the system. These kinds of decisions are based on 

the perceived value of the existing conditions; the greater 

the value of the status quo, the greater the deterrence to 

introduced changes.

D36
100.000

o 

o

zuj -co

LUQC

o u

OUJ O) u.

50.000

20.000

10.000

\ I I I I I I I I I I T

f

MONTHS

B

Figure 3.4. (A) Jim Woodruff Lock and Dam and Lake 

Seminole, (B) average monthly flows at Chattahoochee, 

1929-57 and 1958-79, and (C) cumulative discharge curve at 

Chattahoochee, 1929-57 and 1958-79.

«oog_

.512 5 W 90 95 »8 99

PERCENT OF TIME INDICATED 

DISCHARGE IS EQUALED OR EXCEEDED

D37
3.0 OVERVIEW AND IMPLICATIONS Continued

3.5 Effects of Channel Modifications

The amended River and Harbor Act of 1946 

authorizes the U.S. Army Corps of Engineers to maintain 

a channel in the Apalachicola River 100 ft wide and 9 ft 

deep that is navigable 95 percent of the time from the 

mouth of the Apalachicola River to Bainbridge, Ga., on 

the Flint River and to Columbus, Ga., on the Chattahoochee River. The main purpose of the Jim Woodruff 

Lock and Dam was to help sustain this channel. However, 

the dam alone is not enough, and channel maintenance 

requires a considerable amount of dredging (fig. 3.5/1) and 

snagging each year. The average annual volume of 

dredging since 1956 has been 350,000 yd 3 /yr. In the past, 

dredged material was placed at 131 locations along the 

river (fig. 3.55), many of which were undiked flood-plain 

disposal sites used on a one-time basis. Most of the 151 

disposal sites currently in use are between the banks of the 

river rather than on the flood plain (Harry Peterson, U.S. 

Army Corps of Engineers, oral commun., 1980).

In a study of 11 dredged material disposal sites from 

mile 6.5 to mile 42.5, Eichholz and others (1979) found 

that deposition on the flood-plain forest averaged 4 acres 

per disposal area. Dredged material was deposited most 

often in the mixed bottom-land hardwood forest of the 

riverbank levee and frequently blocked flood-plain sloughs 

and creeks. In only one instance was dredged material 

placed in the tupelo-cypress forest behind the riverbank 

levee. The depth of deposition ranged from less than 3 ft to 

over 30 ft. Clewell and McAninch (1977) found that tree

vigor was reduced when only 1.5-5 in of fill was deposited 

on Apalachicola River flood-plain trees. Most trees were 

killed by 2.5 ft or more of fill.

Dredging of the river might be expected to have 

some effect on the trace-substance concentrations in 

bottom materials. Disturbance of bottom sediments due 

to dredging is likely to cause some resuspension of fine 

materials, resulting in altered rates of adsorption or 

release of associated metals and organic substances. It is 

also likely to change the benthic community and physical 

environment which is involved in uptake and release of the 

substances.

Other effects of dredging and snagging have been 

pointed out by Livingston (1978). The disturbance of the 

natural habitat for benthic organisms and fish is included 

among these. If spoils are disposed on banks, destruction 

of some wildlife habitat will also occur.

Channelization may entail construction of levees 

which could have a long-term effect of decreasing the 

extent of the flood plain. The loss of flood-plain area 

would very likely have an impact on the composition of 

nutrient and detritus yield to the estuary, as was previously described. A significant amount of channel 

modification, including construction of levees and cutoffs, 

ditching, draining, or filling wetlands, could also change 

the influx of freshwater to the system and therefore change 

the natural salinity distribution in the estuary.

D38
Figure 3.5. (A) Dredging operation and (B) dredge spoil site.

D39
4.0 CONCLUSIONS OF THE APALACHICOLA RIVER QUALITY ASSESSMENT

The essence of the findings of the Apalachicola 

River Quality Assessment is diagrammatically shown in 

figure 4.0. The Apalachicola River Quality Assessment 

dealt with interrelations among hydrodynamics, the floodplain community and nutrient and detritus flow in the 

system, and the overall yield to the estuary (fig. 4.0). 

Important conclusions of the study are as follows:

 Flooding plays a critical role in the combined set of 

processes which support the existing estuarine productivity. The extent and duration of floods have 

major influence on the species composition and 

productivity of the flood-plain plant community. The 

extent and velocity of floods are important in 

determining the amount of detritus which can be 

moved through the system. Leaf-litter decomposition, 

which produces most of the detritus, is also accelerated 

by flooding.

 The Apalachicola water budget is heavily streamflow 

dominated; water volumes involved in precipitation 

within the basin, ground-water flow, surface-water 

runoff, and evapotranspiration are relatively minor in 

comparison with main-stem flow. As is indicated in 

figure 4.0, however, rainfall in the upper basins of the 

Chattahoochee and Flint Rivers is the primary control 

on waterflow in the Apalachicola, especially in the 

winter when rainfall input is not rapidly taken up by 

vegetation.

 The flood-plain community is very productive, more 

so than most warm temperate systems and even more 

than many tropical systems. Forest-litter fall amounts 

to about 7,100 Ib/acre annually. The fraction of this 

material that is transported each year to the estuary 

depends on flooding. In addition to the extent, 

duration, and velocity of the flood, timing is also 

important. If the flood occurs very early, more 

material may be deposited directly on the water 

surface, but there is less opportunity for decomposition 

before transport.

 The role of the flood plain in nutrient transport 

through the system should not be considered as a 

source or as a sink but more as a transformer. On an

annual basis, the quantities of nutrients which enter 

the headwaters of the Apalachicola are not greatly 

different from the amounts that exit to the estuary. 

However, there is a tendency for soluble inorganic 

nutrients to undergo substantial net import to the 

flood plain, while there is a net export of particulate 

organic material. This is important in sustaining a 

detritivore-based estuarine community. 

Because of the dependence of the forest-community 

structure on flood characteristics, it should be expected 

that if the normal flooding cycle is significantly and 

permanently altered, the flood-plain forest will 

gradually change in structure and character. This may 

or may not affect productivity and yield to the 

estuary, depending on the nature of the change. 

Because of the high litter production of the floodplain community and the mobilization of littergenerated detritus by inundation, it should be expected 

that substantial reductions in flood-plain area will 

result in decreased detritus yield to the estuary. 

Dam construction and other channel modifications 

cause moderate to severe changes in the aquatic and 

wetland environments. Analysis of long-term hydrologic records, including periods prior to and following 

construction of the Jim Woodruff Dam, indicates that 

dams do not significantly alter the total annual flow or 

the monthly distribution of flow. However, dams do 

have an effect of dampening the low-flow extremes. 

Channelization practices such as dredging and 

snagging may have a significant effect on benthic 

organisms and fish by destroying habitats. If dredge 

spoils are deposited in the flood plain, they will also 

alter the habitat in that environment. Dredging also 

causes increased mobilization of substances associated 

with bottom sediments.

Toxic substances are present in Apalachicola sediments and benthic organisms, but their concentrations 

are well below hazardous levels. Future development 

of industry or agriculture in the basin should be 

accompanied by monitoring of toxic substances which 

could be introduced from the new sources.

D40
RAINFALL

FLOOD-PLAIN ^EXTENT^^^ TREE 

INUNDATION DURATION COMMUNITIES

DETRITUS

LEAFLITTER 

S1TION PRODUCTION

NUTRIENT AND ESTUARINE

DETRITUS ^^^^M» E5TUAKINE

UtlKIIUS ^^^^^^ PROniirTIVITY TRANSPORT PRODUCTIVITY

Figure 4.0. Flood-plain processes.

D41
5.0 SUMMARY

During 1979-81, the U.S. Geological Survey conducted a large-scale study of the Apalachicola River in 

northwest Florida. The Apalachicola River Quality 

Assessment emphasized the interrelations among hydrodynamics, the flood-plain forest, and the nutrient-detritus 

flow through the river system to the estuary.

The Apalachicola River is a waterway for shipping; 

hence, there is an economic incentive for modification to 

facilitate movement of barge traffic. The river is also 

recognized as an important supplier of detritus, nutrients, 

and freshwater to the Apalachicola Bay. The importance 

of this input to the bay creates an incentive to keep the 

river basin in a natural state. Questions about the most 

beneficial management strategies for the Apalachicola 

River result from these diverse values and possible uses of 

the system. Some uses call for mechanical or physical 

alteration of the natural system to maximize utility of the

system for commercial benefit. Other uses need limited 

intervention in the natural system. The benefits are largely 

controlled by physical, chemical, and biological features 

of the system, and they can best be maintained by scientific 

understanding of those features.

The primary purpose of this report is to provide 

information that will aid those who are involved, either 

directly or indirectly, in implementing best management 

practices for the Apalachicola River basin. The more 

management decisions can be based on scientific knowledge, the more likely such decisions will be beneficial to 

the stability of the system and to users of this valuable 

natural resource. The authors hope that the information 

in this report will help to maximize the possibility that 

decisions can be made which suit the needs of all users of 

the river basin.

6.0 SCENES OF THE APALACHICOLA RIVER

"Apalachicola Doin' Time"

When she leaves the dam at Chattahoochee, 

Winding in a southern flow, 

Easy on her way, another night and day, 

She'll finally reach the Gulf of Mexico.

Apalachicola, let her wind; 

Apalachicola, flowing fine; 

Apalachicola, strong in mind; 

Apalachicola, doin' time.

Crider and Crider (1981)

D42

SELECTED REFERENCES

Cairns, J., Jr., 1978, Waterway recovery: Water Spectrum, v. 10, 

no. 4, p. 26-32.

Clewell, A. F., 1977, Geobotany of the Apalachicola River 

region: Conference on the Apalachicola drainage system, 

Gainesville, Florida, April 1976, Proceedings, p. 6-15.

Clewell, A. F., and McAninch, Helen, 1977, Effects of a fill 

operation on tree vitality in the Apalachicola River floodplain, Florida: Conference on the Apalachicola drainage 

system, Gainesville, Florida, April 1976, Proceedings, p. 

16-19.

Crider, Dale, and Crider, Linda, 1981, Apalachicola doin1 time, 

in Crider, Linda, ed., The water song book: Gainesville, 

Anhinga Roost Music Company, p. 51.

Cummins, K. W., and Spengler, G. L., 1978, Stream ecosystems: 

Water Spectrum, v. 10, no. 4, p. 1-9.

Darnell, R. M., 1961, Trophic spectrum of an estuarine community based on studies of Lake Pontchartrain, Louisiana: 

Ecology, v. 43, no. 3, p. 553-568.

de la Cruz, A. A., 1979, Production and transport of detritus in 

wetlands, in Greeson, P.E., Clark, J.R., and Clark, J.E., 

eds., Wetland functions and values The state of our 

understanding: National Symposium on Wetlands, Lake 

Buena Vista, Florida, 1978, Proceedings, p. 162-174.

Eastman, S. E., 1980, Fuel efficiency in freight transportation: 

The American Waterways Operators, Inc., Arlington, Va., 

17 p.

Eichholz, N. F., Bailey, D. B., and McGehee, A. V., 1979, An 

investigation of dredged material disposal sites on the lower 

Apalachicola River: Tallahassee, Fla., Florida Game and 

Freshwater Fish Commission, Office of Environmental 

Services, 115 p.

Elder, J. F., 1983, Riverine transport of nutrients and detritus to 

Apalachicola Bay, in Andree, Scott, ed., Apalachicola 

Oyster Industry Conference: Apalachicola, Fla., October 

6-7, 1982, Proceedings, Report No. 57, Florida Sea Grant 

College, p. 28-30.

 1985, Nitrogen and phosphorus speciation and flux in a 

large Florida river-wetland system: Water Resources 

Research, v. 21, no. 5, p. 724-732.

Elder, J. F., and Cairns, D. J., 1982, Production and decomposition of forest litter fall on the Apalachicola River 

flood plain, Florida: U.S. Geological Survey Water-Supply 

Paper 2196-B, 42 p.

Elder, J. F., and Mattraw, H. C., Jr., 1982, Riverine transport of 

nutrients and detritus to the Apalachicola Bay estuary, 

Florida: Water Resources Bulletin, v. 18, no. 5, p. 849-855.

 1984, Accumulation of trace elements, pesticides, and 

polychlorinated biphenyls in sediments and the clam 

Corbicula manilensis of the Apalachicola River, Florida: 

Archives of Environmental Contamination and Toxicology, 

v. 13, no. 5, p. 453-469.

Fenchel, Tom, 1970, Studies on the decomposition of organic 

detritus derived from the turtle grass Thallassia testudinum: 

Limnology and Oceanography, v. 15, no. 1, p. 14-20.

Greeson, P. E., ed., 1978, River-quality assessments: American 

Water Resources Association Symposium, Tucson, 1977, 

Proceedings, 191 p.

Hosner, J. F., 1960, Relative tolerance to complete inundation of 

fourteen bottomland tree species: Forest Science, v. 6, no. 3, 

p. 246-251.

Hosner, J. F., and Boyce, S. G., 1962, Tolerance to water 

saturated soil of various bottomland hardwoods: Forest 

Science, v. 8, no. 2, p. 180-186.

Kurz, Herman, and Godfrey, R. K., 1962, Trees of northern 

Florida: Gainesville, University of Florida Press, 311 p.

Leitman, H. M., 1978, Correlation of Apalachicola River floodplain tree communities with water levels, elevation, and 

soils: Florida State University Master's Thesis, 57 p.

 1984, Forest map and hydrologic conditions, Apalachicola River flood plain, Florida: U.S. Geological Survey 

Hydrologic Investigations Atlas HA-672, 1 sheet.

Leitman, H. M., Sohm, J. E., and Franklin, M. A., 1983, 

Wetland hydrology and tree distribution of the Apalachicola 

River flood plain, Florida: U.S. Geological Survey WaterSupply Paper 2196-A, 52 p.

Livingston, R. J., 1978, The Apalachicola dilemma: Wetlands 

priorities, developmental stress, and management initiatives, 

in U.S. Fish and Wildlife Service, Proceedings of the 

National Wetland Protection Symposium, Reston, Va., 

June 6-8, 1977: Biological Services Program FWS/OBS78/97, p. 163-177.

 1983, Resource atlas of the Apalachicola Estuary: 

Florida Sea Grant Report No. 55, 64 p.

Livingston, R. J., and Loucks, O. L., 1979, Productivity, trophic 

interactions, and food-web relationships in wetlands and 

associated systems, in Greeson, P.E., Clark, J.R., and 

Clark, J.E., eds., Wetland functions and values The state 

of our understanding: National Symposium on Wetlands, 

Lake Buena Vista, Florida, 1978, Proceedings, p. 101-119.

Livingston, R. J., Iverson, R. L., Estabrook, R. H., Keys, V. E., 

and Taylor, John, Jr., 1974, Major features of the 

Apalachicola Bay system Physiography, biota, and resource management: Florida Scientist, v. 37, no. 4, p. 

245-271.

Mattraw, H. C., Jr., and Elder, J. F., 1980, Nutrient yield of the 

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D44
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045
CONVERSION FACTORS

For those readers who may prefer to use International System (SI) units rather than inch-pound units, the conversion factors for 

the terms used in this report are listed as follows:

Multiply inch-pound unit By To obtain SI unit

inch (in)

foot (ft)

square foot (ft2)

mile (mi)

square mile (mi2)

acre

acre

cubic mile (mi3)

ton

pound (Ib)

ounce (oz)

parts per million (ppm) 

foot per second (ft/s) 

cubic foot per second (ft3 / s) 

pound per acre per year

(Ib/acre/yr) 

pound per acre

(Ib/acre)

ton per hour (ton/hr) 

parts per billion (ppb) 

cubic yard per year

(yd3 /yr) 

0 C (degree Celsius)

25,4 millimeter (mm)

0.3048 meter (m)

0.09294 square meter (m2)

1.609 kilometer (km)

2.590 square kilometer (km2)

4,047 square meter (m2)

0.4047 hectare (ha)

4.168 cubic kilometer (km3)

0.9072 metric ton

453.6 gram (g)

28.35 gram (g)

0.0000353 milligram (mg)

1.0 milligram per liter (mg/ L)

0.3048 meter per second (m/ s)

0.283 cubic meter per second (m3 / s)

0.1122 gram per square meter per year

	(g/m2/yr) 

1.1208 kilogram per hectare

	(kg/ha) 

907.2 kilogram per hour (kg/hr)

1.0 microgram per kilogram (ug/ kg)

0.7646 cubic meter per year

	(m3/yr) 

1.81(+ 32) °F (degree Fahrenheit)

D46