Water-Resources Investigations Report 92-4082 

RECENT SEDIMENTATION AND 

SURFACE-WATER FLOW PATTERNS ON 

THE FLOOD PLAIN OF THE NORTH FORK 

FORKED DEER RIVER, DYER COUNTY, 

TENNESSEE 

Prepared by the 

U.S. GEOLOGICAL SURVEY 

in cooperation with the 

TENNESSEE WILDLIFE RESOURCES AGENCY 
Cover photograph. South side outlet of Tigrett Wildlife Management Area, Dyer County, Tennessee. Note roots of old cypress 

stump and roots of small tree on top of stump. Photograph by 

Bradley A. Bryan, U.S. Geological Survey. 
RECENT SEDIMENTATION AND 

SURFACE-WATER FLOW PATTERNS ON 

THE FLOOD PLAIN OF THE NORTH FORK 

FORKED DEER RIVER, DYER COUNTY, 

TENNESSEE 

By William J. Wolfe and Timothy H. Diehl 

U.S. GEOLOGICAL SURVEY 

Water-Resources Investigations Report 92-4082 

Prepared in cooperation with the 

TENNESSEE WILDLIFE RESOURCES AGENCY 

Nashville, Tennessee 

1993 
U.S. DEPARTMENT OF THE INTERIOR 

MANUEL LUJAN, JR., Secretary 

U.S. GEOLOGICAL SURVEY 

Dallas L. Peck, Director 

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

purposes only and does not constitute endorsement by the U.S. 

Geological Survey. 

For additional information write to: Copies of this report can be purchased from: 

District Chief 

U.S. Geological Survey 

810 Broadway, Suite 500 

Nashville, Tennessee 37203 

US. Geological Survey 

Books and Open-File Reports Section 

Federal Center, Box 25425 

Denver, Colorado 80225 
Abstract 1 

Introduction 1 

Purpose and scope 2 

Previous studies 2 

Acknowledgments 4 

Study area 4 

Flood-plain stratigraphy and recent sedimentation rates 5 

Flood-plain materials 5 

Recent sedimentation rates 8 

Surface-water flow patterns 10 

Location and condition of the natural channel 10 

Primary flow path--the North Fork Forked Deer ditch 13 

Present location of flood-plain flow paths 13 

Flow paths between Doakville Creek and Parker Ditch 13 

Flow paths between Stokes Creek and U.S. Highway 412 16 

Flow paths between Parker Ditch and U.S. Highway 412 17 

Condition of tributaries 17 

Channel evolution in the study area 18 

Summary and conclusions 19 

References cited 21 

FIGURES 

l-3. Map showing: 

1. Location of the study area near Dyersburg, Tennessee 3 

2. Location of radiocarbon and tree-ring sampling sites in Dyer County, Tennessee 6 

3. Hydrography of the eastern part of the study area, Dyer County, Tennessee 11 

4. Longitudinal profile along the natural channel, north of the main ditch of the North Fork 

Forked Deer River, in Dyer County, Tennesee 12 

5. Map showing hydrography of the western part of the study area, Dyer County, Tennessee 

6. Longitudinal profile along the natural channel, south of the main ditch of the North Fork 

Forked Deer River, in Dyer County, Tennessee 15 

14 

TABLES 

1. Radiocarbon ages, sampling locations, and depths of burial of cypress stumps (Tarodium distichum) 

2. Tree ages and calculated sedimentation rates based on tree-ring analyses 9 

3. Number of trees sampled for tree-ring analysis, by sampling site and species 9 

8 

Contents iii 
CONVERSION FACTORS AND VERTICAL DATUM
RECENT SEDIMENTATION AND SURFACE-WATER 

FLOW PATTERNS ON THE FLOOD PLAIN OF 

THE NORTH FORK FORKED DEER RIVER, 

DYER COUNTY, TENNESSEE 

By William J. Wolfe and Timothy H. Diehl 

ABSTRACT 

Sedimentation in the 19th and 20th centuries has had 

a major effect on surface-water drainage conditions along 

a 7-mile section of the North, Fork Forked Deer River flood 

plain, Dyer County, Tenn. During the century prior to 1930, 

5 to 12 feet of sediment were deposited over much of the 

flood plain, resulting in channel obstruction and widespread 

flooding. The estimated bankfull capacity of the natural 

channel before it was channelized in 19 16 was comparable 

to the base flow of the river during the 1980’s. 

Ditching of the ci.va between 191i6 and 1;9,21 was 

folfowed by ceductims ia sedimentation rates. over parts of 

the flood plain. HoweverWthaeftectsofr sed’i’mentation have 

persisted. Occlusions along tie natuml’ channeli of the river 

have divided this stream reach into a series of sloughs. 

These sloughs continue to fill with sediment and are 

surrounded by ponds that have expanded since 1941. 

Degradation of the North Fork Forked Deer ditch may 

eventually reduce ponding over much of the flood plain. 

Active incision of headcuts in both banks of the ditch is 

enhancing the drainage of widespread ponded areas. These 

headcuts likely will have limited effect on drainage of most 

tributaries. 

The highest recent sedimentation rates, in places more 

than 0.2 foot per year, are concentrated near the flood-plain 

margin along tributary streams. In conjunction with beaver 

dams and debris, ongoing sedimentation has blocked flow 

in several tributaries, posing a flood hazard to agricultural 

land near the flood-plain margin. The occluded tributaries 

likely will continue to overflow unless they are periodically 

dredged or their sediment loads are reduced. 

INTRODUCTION 

Obstructed surface-water drainage is a recurrent 

problem in the flood plains of most major streams in West 

Tennessee (Ashley, 1910; Tennessee State Planning 

Commission, 1936; Robbins and Simon, 1983). Little 

information isavaikable onvalley-bottom drainage conditions 

at the time of initial. European settlement in the early and 

mi&t8t%Xs, but by the late 1800’s many channels in West 

Ibmressee were choked by sediment and debris (Ashley, 

1910; Morgan and McCrory, 1910). Land clearing and 

row-crop agriculture in upland parts of drainage basins 

during the 19th century greatly accelerated upland erosion 

and valley-bottom sedimentation over their pre-settlement 

rates (Happ and others, 1940; Trimble, 1976; Knox, 1987; 

Bamhardt, 1988a, 1988b). Subsequent flooding ofthe valley 

bottoms hampered logging and farming operations. This led 

local landowners to seek engineering solutions to drainage 

problems in the early 1900’s (Ashley, 1910). 

Efforts to improve drainage focused on increasing channel capacity through such means as straightening, dredging, 

and snagging the channels, and clearing the banks of vegetation (Robbins and Simon, 1983). Such measures were commonly effective over the short term, but improvement of 

Introduction 1 
drainage was often temporary or accompanied by unforeseen 

and undesirable side effects. Commonly, the dredged channels tilled quickly with sediment, or became deeper and 

wider, damaging adjacent forest and agricultural land in the 

process (Robbins and Simon, 1983). 

In some instances, channel modifications may impede, 

rather than encourage, drainage on the flood plain adjacent 

to the channel. Spoil banks are generally too low to keep 

flood water from entering the flood plain. Natural levee 

deposits and sand splays may accumulate along the spoil 

banks, further isolating the flood plain from the channel and 

promoting ponding. These effects resemble the problems 

that channel modifications are intended to correct, and 

complicate efforts to understand and alleviate drainage 

problems in the flood plains of modified channels. 

The Tigrett Wildlife Management Area (WMA), and 

adjacent areas of the flood plain of the North Fork Forked 

Deer River, near Dyersburg, Term. (fig. l), are characterized by drainage conditions typical of the valley bottoms of 

many modified streams in the region. Large areas of the 

flood plain are ponded throughout the year, and substantial 

tracts of cypress (Taxodium distichum) and bottomland 

hardwoods are dead or dying. Owners of agricultural land 

adjacent to the WMA have complained of increased flooding 

along tributary streams (J.W. Johnson, Tennessee Wildlife 

Resources Agency, written commun., 1991). 

Management of drainage in the WMA and similar areas, 

whether for wildlife, timber, or agriculture, requires an 

understanding of the present surface-water flow patterns. 

Because flood-plain drainage is partly determined by the 

distribution and accumulation of sediment, such understanding requires knowledge of the flood-plain sediments and 

the factors that control their deposition. 

The U.S. Geological Survey (USGS), in cooperation 

with Tennessee Wildlife Resources Agency (TWRA), conducted a study to identify the major surface-water flow paths 

in the flood plain, to assess their relation to recent 

sedimentation, and to improve understanding of the effects 

of recent sedimentation on surface-water drainage conditions 

in the flood plain of the North Fork Forked Deer River. 

The study was conducted in and near the Tigrett WMA 

(fig. 1) in 1991. 

Purpose and Scope 

This report describes the results of the study of the 

North Fork Forked Deer River flood plain. The study 

focused on two major objectives: (1) the determination of 

recent (since about 1800) sedimentation rates; and (2) the 

identification and location of major surface-water flow paths 

and determination of their relation to recent sedimentation. 

The study objectives were accomplished in several 

stages. 

1. Literature on sedimentation and drainage problems in 

the study area was reviewed. 

2. Stratigraphic relations of the upper 20 feet of floodplain sediments were established through field investigations 

and examination of the logs of soil borings. 

3. Recent rates of flood-plain sedimentation were determined at selected sites by radiocarbon dating and tree-ring 

analysis. 

4. Locations and approximate dimensions of major 

surface-water flow paths in the study area were determined 

by field surveys and analysis of survey records, bridge 

plans, and aerial photographs. 

Fieldwork was accomplished between May and 

September 1991, and was largely confined to the flood plain 

of the North Fork Forked Deer River along a reach 2.5 to 

10 miles upstream from Dyersburg, TeM. (fig. 1). Data 

collection included radiocarbon dating of buried tree stumps, 

tree-ring analysis, calculation of sedimentation rates, and 

measurement of channel-bed and water-surface elevations. 

Published and unpublished reports, maps, survey records, 

and aerial photographs provided background for this study. 

Previous Studies 

Accounts of drainage problems in West Tennessee were 

published in the early 1900’s. Ashley (1910) outlined the 

organization and financing of drainage districts in 1910, and 

reported that the obstruction of some channels by sediment 

and debris was a relatively recent phenomenon. He attributed channel and valley sedimentation to agricultural practices in the uplands and noted that long-term solutions to 

valley drainage problems must encompass entire drainage 

basins (Ashley, 1910). 

2 Recent Sedimentation and Surface-Water Flow Patterns on the Flood Plain 

of the North Fork Forked Deer River, Dyer County, Tennessee 
Figure 1 . Location of the study area near Dyersburg, Tennessee.
Morgan and McCrory (1910) described drainage prob- in the Upper Mississippi Valley (Happ, 1944; Trimble, 

lems in Gibson County, including that part of the North Fork 1976; Magilligan, 1985; Knox, 1987) and northern MissisForked Deer River flood plain immediately upstream from sippi (Happ and others, 1940; G&singer and Murphey, 

the present study area. They reported conditions on the 1982; G&singer and others, 1982; Schumm and others, 

North Fork Forked Deer River flood plain similar to those 1984). These topics have received relatively little attention 

observed in this study: channel segments tilled with in West Tennessee. Bazemore and others (1991) investisediment and debris, numerous depressions and secondary gated post-1900 flood-plain sedimentation near 11 highway 

channels, and tributaries that “disappear when they reach the crossings in West Tennessee. They reported mean sedimenbottoms, becoming ponds and sloughs” (Morgan and tation rates of -0.002 to 0.039 foot per year (ft/yr) and 

McCrory, 1910, p. 33). They also identified the threat of concluded that sedimentation at these sites is largely 

upland erosion to the long-term stability of constructed determined by local topography. 

drainage channels. 

Barnhardt (1988a, 1988b) provided radiocarbon dates 

Although the drainage ditches proposed by Morgan and for flood-plain deposits in West Tennessee, and described 

McCrory (1910) were constructed, their recommendations stratigraphic cross sections in incised gullies about 50 miles 

for on-farm sediment stabilization and erosion control were south of the study area. The cross sections show about 

apparently not implemented. Within 20 years of ditch con- 3 feet of post-settlement alluvium deposited at an average 

struction along the North Fork Forked Deer River, the rate of about 0.03 ft/yr. The post-settlement alluvium is unTennessee State Planning Commission (1936) reported derlain by 3 to 4 feet of Holocene alluvium deposited during 

deteriorating channel conditions throughout the Obion and the 5,000 years before European settlement at rates ranging 

Forked Deer River basins, This deterioration included from 0.0007 to 0.003 ft/yr (Bamhardt, 1988a, 1988b). 

obstructed channels, increased ponding, and the death of 

bottomland trees. The Tennessee State Planning Commission (1936) attributed the recurrence of drainage problems Acknowledgments 

to a lack of coordination among drainage districts and the 

failure of the districts to obtain adequate environmental data The authors acknowledge the assistance of several 

on which to base designs. individuals and agencies in carrying out this research. The 

Memphis District, U.S. Army Corps of Engineers (COE), 

Recent studies of channelized streams in West Tennessee provided logs of soil borings and topographic survey data 

(Robbins and Simon, 1983; Simon and Hupp, 1986) indi- relevant to the study site. Mr. John M. Cook of Continental 

cated that a second cycle of channelization of streams Engineering, Inc., provided channel profiles and cross secthroughout the region, in the 1930’s and 1940’s, provided tions of the North Fork Forked Deer River in the vicinity of 

only temporary improvement of flood-plain drainage prob- the study area. Messrs. Robert S. Bell and Earl L. 

lems. These recent studies focused on the adjustment of Willoughby, Jr., of Dyersburg, Term., were generous 

channel dimensions following channel modification. Robbins sources of information on local history, agriculture, and 

and Simon (1983) described six case studies in which they environmental change. Mr. Jimmy W. Johnson of Tennestraced the history of channelization, and presented available see Wildlife Resources Agency assisted with field work and 

data on changes in bed elevation and channel dimensions. provided aerial photographs and unpublished maps. 

They described the general evolution of straightened and 

dredged channels through stages of incision, widening, and 

filling with sediment (Robbins and Simon, 1983). Simon STUDY AREA 

and Hupp (1986) developed this generalization into an 

empirical model of channel response following widespread This study was conducted in and near the Tigrett 

channel modifications in the 1960’s and 1970’s. Wildlife Management Area in Dyer County, Tennessee 

(fig. 1). The study area lies within the Eastern Gulf Coastal 

Flood-plain sedimentation and its relation to land use Plain section of the Coastal Plain physiographic province 

and channel conditions were the focus of numerous studies (Fenneman, 1938). The subsurface geology of the area is 

4 Recent Sedimentation and Surface-Water Flow Patterns on the Flood Plain 

of the North Fork Forked Deer River, Dyer County, Tennessee 
dominated by mostly unconsolidated sediments of Tertiary 

age (Schreurs and Marcher, 1959; Cushing and others, 

1964). Those areas not directly affected by streams are 

generally capped by a layer of Pleistocene loess (winddeposited silt, clay, and fine sand), as thick as 100 feet in 

places (Schreurs and Marcher, 1959). The alluvial valleys 

of streams such as the Obion and Forked Deer Rivers and 

their larger tributaries are filled with Quatemary alluvium. 

Late Quatemary terraces, probably deposited 10,000 years 

ago or earlier (Saucier, 1987), form benches as wide as 

2,000 feet, with 10 to 20 feet of relief above the adjacent 

flood plain. 

At the downstream end of the study area, the North 

Fork Forked Deer River drains approximately 800 square 

miles in Dyer, Gibson, and Crockett Counties. Dyer and 

Gibson Counties were incorporated in 1823, and the area 

was rapidly settled. By the 1850’s, large tracts of the 

well-drained loess uplands had been cleared and planted with 

cotton, tobacco, maize, and other row crops (Greene, 1901; 

Hulme and Hulme, 1982). Commercial farming of row 

crops expanded and intensified throughout the 19th century 

and remains the mainstay of the local economy. 

Systematic channelization of the Forked Deer River 

began in the early 1900’s. Clearing of the valley bottoms 

for timber proceeded rapidly after about 1880 (E.L. 

Willoughby, Jr., Dyersburg, oral commun., 1991; D.L. 

Porter, Tennessee Valley Authority, oral commun., 1991), 

while high agricultural prices provided an economic 

incentive to cultivate marginal lands. Drainage districts 

were organized to drain the bottoms in order to exploit their 

agricultural potential (Ashley, 1910; Morgan and McCrory, 

1910). Planning for the construction of the North Fork 

Forked Deer ditch upstream from Dyersburg began around 

1916, and construction was completed in 1921 (D.L. Porter, 

Tennessee Valley Authority, oral commun., 1992). 

By the 1930’s, the North Fork Forked Deer ditch and 

other dredged channels in the region were partly or 

completely filled with sediment, leading to a program of 

basinwide drainage management and ditch maintenance 

(Tennessee State Planning Commission, 1936). Despite 

these efforts, another cycle of channel sedimentation 

followed, requiring widespread dredging and clearing in the 

1960’s and 1970’s (Robbins and Simon, 1983). 

The geomorphic instability of the North Fork Forked 

Deer River flood plain has been accompanied by ecological 

instability. Areas that were formerly well-drained forest are 

now (1991) shallow ponds containing dead or dying trees, 

water-tolerant shrubs, or aquatic vegetation. Formerly clear, 

open oxbow ponds several feet deep have been filled 

completely with sediment or have become shallow marshland 

covered with floating aquatic plants and smartweed 

(Polygonurn spp.). Local residents report a deterioration of 

fishing and waterfowl hunting since the 1950’s. Meanwhile, 

beaver, trapped out by the 1940’s, have become 

reestablished and their activities have further obstructed 

drainage over much of the flood plain (R.S. Bell, 

Dyersburg, Term., oral comrnun., 1991; D.L. Porter, 

Tennessee Valley Authority, oral commun., 1991). 

FLOOD-PLAIN STRATIGRAPHY AND RECENT 

SEDIMENTATION RATES 

The banks of the North Fork Forked Deer ditch are 

more than 12 feet high in many places, providing excellent 

exposures of flood-plain sediments. Fresh exposures also 

exist at the active headcuts into the north and south banks 

(sites 5 and 1, respectively, in figure 2). Field observations 

of flood-plain sediments focused on these exposures, and 

were made along the length of the study area. The scope of 

this study did not permit extensive cross-valley borings or 

excavations. However, a limited number of holes were 

augered by hand, and pits that had been dug in order to 

excavate trees were examined and logged. These field 

observations were supplemented by the logs of soil borings 

made along both sides of the North Fork Forked Deer ditch 

by the COE (Col. Clinton Willer, U.S. Army Corps of 

Engineers, written commun., 1991). 

Flood-Plain Materials 

The North Fork Forked Deer River flood plain is 

composed of 50 to 100 feet of Quatemary alluvium which 

unconformably overlies unconsolidated Tertiary sediments 

(Schreurs and Marcher, 1959). Only the upper 20 feet of 

flood-plain sediments are considered in this study. 

Soil borings by the COE (Col. Clinton Willer, U.S. 

Army Corps of Engineers, written commun., 1991) indicate 

that the entire study area is underlain by fine to medium, 

saturated sand, the upper boundary of which is generally 15 

Flood-Plain Stratigraphy and Recent Sedimentation Rates 5 
W

Figure 2. Location of radiocarbon and tree-ring sampling sites in Dyer County, Tennessee .
to 20 feet below land surface. This unit was not observed 

in the field. Its stratigraphic position and texture indicate an 

origin similar to that of channel-lag deposits described in 

northern Mississippi (Happ and others, 1940; Grissinger and 

others, 1982). 

Immediately above the sand is a layer of massive silts 

and clays about 10 feet thick. Only the upper 1 to 6 feet of 

this unit was examined in the field. The massive silts and 

clays range in color from light gray to green gray, 

depending on the depth to the water table. At some 

locations, this unit is homogeneous. Elsewhere, it contains 

sand lenses, wood and leaf fragments, or hard iron-oxide 

concretions 0.2 to 1 inch in diameter. The massive silts and 

clays are generally firm to hard, but can be soft when 

saturated. Some exposures exhibit moderate plasticity. The 

massive silts and clays, are fine-grained alluvial deposits, 

probably derived from reworked loess. 

The massive silts and clays are overlain by a layer of 

silty clay 0.5 to 1 foot thick. This layer is chiefly 

differentiated from the underlying material by abundant red 

mottles. The mottles are distinctly worm-like in appearance, 

and probably represent the former locations of plant roots. 

At some locations, the mottled silty clay contains elongate, 

tubular cavities, filled with sand and generally less than 

1 inch in diameter. These cavities are apparently remnants 

of former root channels or small animal burrows. 

At several locations throughout the study area, erosion 

of the ditch banks or incision of headcuts has exposed buried 

cypress stumps. The root systems of these trees generally 

are located within the mottled silty clay. Where the mottled 

clay is above the water table, it commonly exhibits a dark 

brown color which contrasts with the overlying and 

underlying materials; elsewhere, it is generally gray in color. 

Several observations suggest that the mottled silty clay 

is a buried soil. The presence of root-sized and shaped 

mottles and cavities in this layer and its dark brown color at 

some locations suggest the accumulation of organic matter. 

Although this supposition has not yet been confirmed 

through laboratory analysis, it is strongly supported by the 

presence of buried cypress roots exclusively in this layer at 

several locations throughout the study area. Thissoil shares 

the textural characteristics and relatively high cohesion of the 

massive silts and clays immediately beneath it, and is 

apparently a flood-plain soil developed on the surface of the 

massive silts and clays. 

The upper boundary of the mottled silty clay, generally 

5 to 12 feet below the present flood-plain surface, crops out 

on the North Fork Forked Deer ditch banks, forming a 

distinct line&ion traceable at least from the Gulf and Mobile 

Railroad bridge downstream past the U.S. Highway 412 

bridge (fig. 2). The association of exposed cypress root 

collars with the mottled silty clay is especially striking along 

this lineation. Together, the mottled silty clay and the 

underlying massive silts and clays represent the most 

cohesive materials in the upper 20 feet of the flood-plain 

sediments. These cohesive layers form resistant, steep-sided 

shelves or benches protruding into the channel several inches 

to several feet further than the upper banks. At one 

location, about 0.5 mile downstream of the abandoned Gulf 

and Mobile Railroad bridge (site 5, fig. 2), massive gray 

clay forms a broad shelf extending roughly 20 feet from the 

right (north) bank into the channel. 

The upper 5 to 12 feet of the North F&k Forked Deer 

River flood plain is composed of yellow, brown, and gray 

silts and clays with local lenses of sand. Though similar in 

texture, this material is generally softer and more friable 

than the underlying deposits, commonly breaking to fine 

crumbs between the fingers. At several locations, these 

sediments are stratified, with individual layers generally less 

than 1 inch thick. Commonly, identifiable remains of 

deciduous leaves separate the layers, particularly within 

3 feet of the flood-plain surface. Live roots, wood 

fragments, and occasional fragments of charcoal are found 

throughout this unit. Red mottles are far less common than 

in the underlying mottled silty clay, but are present in some 

places, generally at depths greater than 3 feet below land 

surface. 

Along the North Fork Forked Deer ditch, the stratified 

silts and clays are locally overlain with dredge spoil, a 

poorly sorted mixture of silt, clay, sand, and woody debris. 

Where dredge spoil is absent, a weakly developed organic 

soil commonly constitutes the top 3 inches of the flood plain. 

This soil is distinguished from the stratified silts and clays 

immediately below it primarily by its surface leaf litter and 

abundant fine roots. 

Flood-Plain Stratigrephy and Recent Sedimentation Rates 7 
Recent Sedimentation Rates

A central objective in this investigation was to determine

the rates and timing of sediment deposition in the upper part

of the North Fork Forked Deer River flood plain in the

study area. Flood-plain deposition offine-grained sediments

is a major geomorphic process along natural meandering

channels (Reineck and Singh, 1980). At the outset of this

study, it was unclear whether the top 5 to 12 feet of

stratified silts and clays that cover the North Fork Forked

Deer River flood plain had been deposited by natural

processes over several thousand years, or if their deposition

had been accelerated by human activity and occurred over

less than 150 years. Studies in West Tennessee (Barnhardt

1988a, 1988b) and northern Mississippi (Happ and others,

1940; Schumm and others, 1984; Grissinger and others,

1982) report post-settlement alluvium thicknesses ranging

from less than 1 foot to more than 10 feet . Because no

regional synthesis of Holocene stratigraphy has been

established for West Tennessee, examination of sediments in

the field was an insufficient basis to distinguish

pre-settlement from post-settlement alluvium.

Nonetheless, several observations indicated that the

upper 5 to 12 feet of stratified silts and clays in the study

area were deposited over the past few hundred years.

Preservation of stratification in the presence of abundant

roots and burrowing animals is unlikely over extended

periods of time. Most of these sediments are soft or friable,

and show little evidence ofpost-depositional weathering such

as iron-oxide concretions . Buried cypress stumps show a

general concordance in the elevations of their root collars

coinciding with a lithologic transition below which the clays

and silts are stiffer, more massive in structure, and contain

iron-oxide mottles and concretions . These observations

indicate an abrupt change in the properties of sediments

deposited on the flood plain or in the rate of deposition.

The lower boundary of the stratified silts and clays marks

this transition .

Radiocarbon dating of buried cypress stumps provided

a means of determining the maximum age of the stratified

silts and clays. Wood samples were collected from buried

stumps at three sites along or near the North Fork Forked

Deer ditch (sites 1, 2, and 5; fig . 2). Care was taken to

select upright stumps that appeared to be undisturbed . At all

a Recent Sedimentation and Surface-Water Flow Patterns on the Flood Plain

of the North Fork Forked Deer River, Dyer County, Tennessee

three sites, the root systems of these stumps coincided with

the mottled silty clay layer, and had been buried, until

recently, by about 7 feet of stratified silts and clays.

Radiocarbon ages for the three samples ranged from 80

to 170 years before 1950 with standard deviations of 60 to

70 years (table 1). Because of the limitations ofradiocarbon

analysis in precisely determining ages less than 300 years

before 1950, a conservative interpretation of the radiocarbon

dates is that the 6.9 to 7.5 feet of sediment burying these

trees was deposited after 1700. However, most or all of this

deposition probably occurred after European settlement in

the 1820's and 1830's .

Tree-ring analysis of living trees was used to determine

current (since about 1960) sedimentation rates at selected

sites on the flood plain. Ring counts reflect tree age, and

the depth of the root collar below the ground surface is a

useful estimate of sediment deposition since germination.

Fifty-seven cores were collected from 22 trees of 6 species

at 4 sites (tables 2 and 3) and examined to estimate tree age.

At sites 1, 2, and 3 (fig . 2), root collars of living trees were

not buried . The maximum age of trees without buried root

collars defines a lower limit for the age of the flood-plain

surface at these locations. Each of these sites includes trees

60 to 65 years old, indicating that accelerated sedimentation

in these areas ended before about 1930 (B.A. Bryan, U.S .

Geological Survey, written commun., 1991). Based on field

examination of bank exposures, however, recent

sedimentation in at least some parts of the flood plain

averaged about 10 feet . Most of this sediment was probably

Table 1 . Radiocarbon ages, sampling locations,

depths of burial of cypress stumps (Taxodium

distichum)

[Analysis by Murray Tanners, Beta Analytic, Inc ., 19911

C-14 age

and
deposited between 1830, when agricultural clearing was

rapidly expanding (Greene, 1901 ; Hulmeand Hulme, 1982),

and 1930. The sedimentation rate during this period,

therefore, probably averaged about 0.1 ft/yr. This rate is

about 4 to 16 times the modern sedimentation rates

(0 .006-0 .025 ft/yr) reported by Bazemore and others (1991)

along the Middle Fork Forked Deer River near the

Friendship-Eaton Road (fig . 1) .

At site 4, along Nash Creek (fig . 2), the root collars of

living trees were buried by sediment. Four trees, ranging in

age from 8 to 26 years (B.A. Bryan, U.S . Geological

Survey, written commun., 1991), were examined (table 2) .

The root collars of these trees were buried by 2 to 5 feet of

stratified silt containing abundant, horizontal, deciduous

leaves . Dividing depths of burial by tree ages gives local

recent sedimentation rates at this site of 0.17 to 0.24 ft/yr.

These extremely high sedimentation rates occur immediately

downstream of the point at which ditch maintenance on Nash

Creek ends. Sedimentation rates near other tributary streams

were not measured ; however, local residents report high

current sedimentation rates in similar settings elsewhere on

Table 3. Number of trees sampled for tree-ring analysis, by sampling site and species

Table 2. Tree ages and calculated sedimentation rates

based on tree-ring analyses

[Analyses by B.A . Bryan, U.S . Geological Survey . Sedimentation

rates calculated as depth of burial divided by age of tree]

f

the North Fork Forked Deer River flood plain (R.S . Bell,

Dyersburg, Tenn., oral commun., 1991) .

Radiocarbon dating of buried tree stumps and tree-ring

analyses indicate two distinct sediment sources whose

changing relative importance has largely determined the

9
spatial and temporal patterns of sedimentation on the North 

Fork Forked Deer River flood plain. Radiocarbon dating 

establishes a period of accelerated sedimentation, beginning 

after 1700 and probably triggered by agricultural clearing 

after about 1830. The source of this sedimentation appears 

to have been the basins of the North and Middle Forks, 

Forked Deer River upstream from the present study area. 

Based on the thick (5 to 12 feet) deposits of post-settlement 

alluvium near the natural North Fork Forked Deer River 

channel, sediment from upstream sources was delivered to 

the flood plain by overflow of the North Fork Forked Deer 

River. Analysis of living trees near the natural North Fork 

Forked Deer River channel and the North Fork Forked Deer 

ditch indicates that accelerated sedimentation in these areas 

had ended before 1930, possibly because the new ditch had 

a greater capacity to transport and store sediment than did 

the natural North Fork Forked Deer River channel. 

The second source of sediment in the study area is the 

drainage basins of Nash, Eliza, and Stokes Creeks, and other 

nearby tributaries. The overall contribution of tributary 

sedimentation (deposition of sediment near tributary channels 

without delivery to the main channel) to the historical sediment budget of the North Fork Forked Deer River flood 

plain has yet to be established. Field observations indicate 

that areas near the lower reaches of tributaries are currently 

the areas of sedimentation rates in the flood plain, at least in 

the present study area. Anecdotal evidence indicates that 

tributary sedimentation accelerated during the 1950’s and 

1960’s. One factor that may account for increased sediment 

delivery to the flood plain by tributaries during this period 

is consolidation of land holdings adjacent to the flood plain 

after 1950. This consolidation was accompanied by widespread removal of hedge rows (R.S. Bell, Dyersburg, Term., 

oral commun., 1991), possibly remobilizing previously 

deposited sediment from these sites. Probably, such 

increased sediment delivery to the flood plain has interacted 

with changes in the depositional environment, such as 

increased ponding by beavers, to accelerate sedimentation 

along the lower reaches of the tributaries. 

SURFACE-WATER FLOW PATTERNS 

The surface-water flow pattern in the study area reflects 

ongoing geomorphic evolution in response to multiple human 

disturbances. The natural channel was the dominant flow 

path in the study area until chamrelization. Natural-channel 

characteristics just prior to chamrelization are indicated by 

the characteristics of its least-disturbed sections, supplemented by aerial photographs and contemporary descriptions 

(Morgan and McCrory, 1910). As a result of channelization 

and repeated ditch maintenance, the North Fork Forked Deer 

ditch is the dominant flow path. Segments of the natural 

channel, tributary channels, and low areas of the flood plain 

act as flow paths during floods, and some of those flow 

paths remain ponded following floods. The North Fork 

Forked Deer ditch is actively degrading, as are several 

flood-plain flow paths that drain directly into it. The 

headward erosion of these flow paths is gradually reducing 

the extent and depth of ponding in several areas. 

Location and Condition of the Natural Channel 

The natural channel, defined as the main channel of the 

North Fork Forked Deer River immediately prior to construction of the North Fork Forked Deer ditch in about 

1916, can be traced through nearly all of the study area. 

Several maps (Thirteenth Surveyors District, 1819; Tennessee Valley Authority, 1936; C.S. Yelverton, Tennessee 

Wildlife Resources Agency, written comrnun., 1967) show 

part or all of the natural channel, with varying degrees of 

accuracy. Aerial photographs taken in 1941 and 1985 generally show the channel location in those sections where the 

maps disagree. The 1941 photographs include stereo coverage showing several sections of the natural channel at 

approximately bankfull stage, providing a basis for 

calculating the width of the natural channel. 

The elevations of the water surface, the bed, and the 

flood plain along most of the natural channel sections in the 

study area were surveyed in July and August 1991. Vertical 

control was provided by 1974 survey records (J.M. Cook, 

Continental Engineering Inc., written commun., 1991). At 

the time of the 1991 survey, flow in the ponded areas was 

negligible, and all water surfaces, except that in the North 

Fork Forked Deer ditch, were assumed to be level. The 

vertical precision of this survey was about 0.1 foot. 

The dimensions of the natural channel prior to 

channelization were estimated from soundings of the 

easternmost section of the natural channel in the study area 

(figs. 3 and 4). This section appears to be the one least 

10 Recent Sedimentation and Surface-Water Flow Patterns on the Flood Plain 

of the North Fork Forked Deer River, Dyer County, Tennessee 
Figure 3 . Hydrography of the eastern part of the study area, Dyer County, Tennessee .
12

Figure 4. Longitudinal profile along the natural channel, north of the main ditch of the North Fork Forked Deer River, in Dyer

County, Tennessee .

altered by sedimentation following channelization. The bed

of this channel section lies as much as 7 feet below the

surrounding flood plain; this depth was used as an estimate

of the depth of the natural channel . Analysis of 1941 aerial

photographs indicates the width ofthe natural channel ranged

from 40 to 50 feet along most sections, with some sections

as wide as 60 feet . Morgan and McCrory (1910) reported

that the natural channel in Gibson County, immediately

upstream from the study area, had a top width of 60 to

70 feet and as average bankfull depth of not more than

5 feet .

The sinuosity, slope, and roughness of the natural

channel were estimated on the basis of study area characteristics and typical conditions in West Tennessee channels.

The sinuosity of the natural channel was estimated to be 2.1,

based on the ratio of the length of the natural channel sections in the study area to the length of the corresponding

Recent Sedimentation and Surface-Water Flow Patterns on the Flood Plain

of the North Fork Forked Deer River, Dyer County, Tennessee

reach of the North Fork Forked Deer ditch (fig . 3 and 5) .

The slope of the North Fork Forked Deer ditch through the

study area is about 0.00027, and this slope divided by the

sinuosity ofthe natural channel is about 0.00013, which was

used as the estimated slope of the natural channel . This

slope is in the low end of the normal range for naturalchannel slopes in West Tennessee. The roughness

(Manning's n) of the natural channel was estimated to be

0.03, which would be typical of a smooth channel free of

woody debris .

The bankfull discharge of the natural channel before

ditch construction was estimated based on the following

assumed characteristics : a width of 50 feet, a depth of

7 feet, a slope of 0.00013, a roughness of 0.03, and a

rectangular cross section. The bankfull discharge was

calculated to be about 600 cubic feet per second. This
discharge is equivalent to a typical summer base-flow 

discharge of the North Fork Forked Deer River at 

Dyersburg (U.S. Army Corps of Engineers, 1981-89) under 

present conditions. The small bankfull capacity is consistent 

with statements by Morgan and McCrory (1910), which 

describe the river as incapable of carrying any sizable flood 

within its banks. 

The natural channel has been divided into discontinuous 

sections by sediment deposits (occlusions) that have nearly 

or completely filled it. The proximal source of most of the 

occlusions (A-D, fig. 3; A-C, fig 4; D-F, K, and L, fig. 5; 

and D-F and K, fig. 6) is probably the North Fork Forked 

Deer ditch. Other occlusions (G-J; figs. 5 and 6) are 

apparently the result of sedimentation at the outlets of 

tributary streams. 

Primary Flow Path--the North Fork Forked Deer Ditch 

The North Fork Forked Deer ditch is the main flow path 

in the study area. The top width of the ditch is about 

80 feet, and the bottom width is about 40 feet. Soundings 

of the North Fork Forked Deer ditch during base-flow 

conditions indicate water depths of 2 to 5 feet, with an 

average depth of about 3 feet. During floods, flow enters 

the flood plain from the ditch through tributary mouths and 

breaches in the spoil banks. Flow into the flood plain was 

observed at a river stage about 5 feet above base flow. At 

this stage, flow entered the flood plain through a breach in 

the spoil bank north of the North Fork Forked Deer River, 

about 2.3 miles upstream from the railroad bridge, and 

through the northernmost relief opening in the railroad 

causeway south of the North Fork Forked Deer River 

(fig. 3). Other breaches in the spoil banks have higher 

minimum elevations, ranging from about 8 to 13 feet above 

base-flow stage. 

The banks of the ditch are predominantly silt and clay. 

The upper banks consist of poorly consolidated, stratified 

silts and clays. The lower banks, and parts of the bed, are 

more cohesive, massive silts and clays. 

The bed of the ditch is predominantly sand, with shelves 

of silt or clay near the base of the banks in some locations. 

The bed is about 2 to 8 feet above the contact between the 

massive silts and clays and the poorly consolidated sand 

(Col. Clinton Willer, U.S. Army Corps of Engineers, 

written commun., 1991). The depth of the unconsolidated 

sand on the bed of the ditch was not measured; some of this 

sand is underlain by the massive silts and clays, and some 

may be in direct contact with the underlying sands. 

The location of the ditch has changed little since its 

original construction. At four points in the study area, substantial deviations from the original alignment were 

observed. Two of these deviations are at intersections of the 

ditch and the natural channel. The largest deviation is at the 

point where the natural channel intersects the ditch about 

0.6 mile downstream from the Gulf and Mobile Railroad 

bridge (fig. 3). Based on the available maps and aerial 

photographs, a meander in the ditch developed between 1941 

and 1967 and has changed little since 1967. A second, 

smaller meander is located at sampling site 1 (fig. 2), 

another intersection of the natural channel and the ditch. A 

small island 1.5 miles upstream from the U.S. Highway 412 

bridge has appeared since 1941. A small meander about 

1 mile upstream from the U.S. Highway 412 bridge was 

present in 1941 and has changed little since then. 

Present Location of Flood-Plain Flow Paths 

The North Fork Forked Deer ditch and Parker Ditch 

(fig. 1) divide the flood plain in the study area into areas that 

drain independently during base-flow conditions. Field investigations of flood-plain flow paths focused on three. areas: 

north of the North Fork Forked Deer ditch between Doakville Creek and Parker Ditch (fig. l), south of the North 

Fork Forked Deer ditch between Stokes Creek and U.S. 

Highway 412 (fig. l), and north of the North Fork Forked 

Deer ditch between Parker Ditch and U.S. Highway 412. 

Flow Paths between Doakville Creek and Parker Ditch 

The area between Doakville Creek and Parker Ditch is 

dominated by a single pond about 3 miles long and as much 

as 0.5 mile wide. This pond includes the deepest and most 

extensive area of ponded flood plain, and the longest and 

deepest section of natural channel in the study area. No 

significant tributaries enter this area of the flood plain, and 

the absence of sediment sources other than the North Fork 

Surface-Water Flow Patterns 13 
Figure 5. Hydrography of the western part of the study area, Dyer County, Tennessee .
Forked Deer ditch helps account for the large extent and

continuity of this pond.

Four breaches in the spoil bank admit water to the flood

plain from the North Fork Forked Deer ditch (fig . 3) .

These breaches are visible from the ditch as actively eroding

breaks in the levee. Several flow paths carry water across

the flood plain from the ditch to the natural channel, and,

particularly in the area of occlusion A, to a flow path along

the north side of the valley (fig . 3) that is visible in the 1985

aerial photographs.

The eastern section of natural channel, between occlusions A and B (fig . 3), has dimensions apparently little

altered since channelization . The average depth of this

section ranges from 3 to 5 feet below the nearby flood plain

(fig . 4) . The western section of the natural channel,

Figure 6. Longitudinal profile along the natural channel, south of the main ditch of the North Fork Forked Deer River, in Dyer

County, Tennessee.

between occlusions B and C (fig . 3), has been filled with

sediment to a depth of about 3 feet below the flood plain

(fig . 4) .

Much of the flood plain north and west of occlusion B

is ponded to depths of 3 to 4 feet during the summer

(fig . 4) . The flow paths bypassing occlusions B and C

through the flood plain (fig . 3) had a minimum water depth

of about 2 feet in July and August 1991 (fig . 4) . Field

observations and aerial photographs indicate that in 1991 the

water surface was close to its 1985 level, but about 3 feet

higher than the level in 1941 .

In this part of the ponded flood plain, a relation was

observed between water depth and dominant vegetation.

Ponded areas more than 3 feet deep generally were free of

aquatic vegetation . Areas between 2 and 3 feet deep were

Surface-Water Flow Patterns 15
dominated by floating aquatic plants, and areas less than 

2 feet deep were dominated by emergents, particularly 

StTWtWd. Where the depth is less than 1 foot, the 

emergents form a dense stand through which a canoe cannot 

be paddled. Water elm (Hunera aquatica) and buttonbush 

(Cephalanthus occidentalis) dominate the fringes of the 

ponded area. 

The main flow path draining the area north of the North 

Fork Forked Deer ditch and east of Parker Ditch passes 

south along the west pipeline clearing, through dense emergent vegetation, to the natural channel, which flows into the 

North Fork Forked Deer ditch about 0.6 mile downstream 

from the Gulf and Mobile Railroad bridge (fig. 3). This 

section of the natural channel is actively eroding. Another 

outlet at the east edge of the west pipeline clearing has been 

dammed by beavers. A small, actively eroding channel 

about 200 feet long flows into the North Fork Forked Deer 

ditch just downstream from the railroad bridge (fig. 3). 

Flow Paths between Stokes Creek and 

U.S. Highway 412 

The flow pattern in this area is more complex than in 

the other two flood-plain areas. Major surface-water features include nine sections of natural channel separated by 

occlusions, and sections of the lower reaches of Eliza Creek 

and Nash Creek (figs. 3, 5, and 6). The depth of most of 

the natural channel sections has been reduced by sedimentation (fig. 6). Water is ponded at four or more elevations in 

this area, and the connection between ponded areas is obscure in some cases. Beaver dams cross many of the floodplain flow paths, and control water levels in several ponds. 

The main flow inlet from the ditch to this area of the 

flood plain is Stokes Creek, Three relief openings in the 

railroad causeway allow water to flow westward out of 

Stokes Creek into the flood plain (fig. 3); the northernmost 

is about 100 feet wide, and is kept open by contraction 

scour. Based on their appearance in 1985 aerial photographs, the other two openings are similar in size, largely 

unobstructed, and probably undergo contraction scour, 

indicating that they convey flow during floods. 

A diffuse flow path begins west of the railroad causeway between the northern and middle relief openings and 

drains to the southwest (fig. 3), crossing an area that was 

mapped as a large pond in 1819 (Thirteenth Surveyors 

District, 1819). Based on 1985 aerial photographs, this flow 

path seems to mark the original location of Stokes Creek. 

The flow path crosses the Eliza Creek ditch at the pipeline 

clearings (fig. 3). The Eliza Creek ditch is largely occluded 

in this reach, and has been dammed by beaver. However, 

during floods, some flow follows the Eliza Creek ditch and 

enters the natural channel section known locally as “Brown 

Eddy” (figs. 3 and 5). 

Eliza Creek leaves its ditch, flows south and west from 

the easternmost pipeline crossing, and enters an area locally 

known as “Maple Flats” (fig. 5). Maple Flats includes two 

sections of the natural channel upstream and downstream 

from occlusion F (figs. 5 and 6). It also includes a ponded 

section of an older channel that apparently was a slough in 

1916 and now receives flow from Brown Eddy, Eliza Creek, 

and nearby areas of the flood plain. Water levels in the 

Maple Flats ponded areas did not differ significantly during 

the study period; these ponds seem to be hydraulically 

connected. 

Two ditches were dug from the Lamer Club to Brown 

Eddy and Maple Flats (fig. 5). These ditches coincide 

roughly with the natural channel location through occlusion 

E. They are separated by a low causeway (fig. 6) and do 

not carry flow except during floods, when most of the flood 

plain is inundated with westerly flowing water. 

During floods, flow passes south from the North Fork 

Forked Deer ditch to Brown Eddy through numerous 

breaches in the spoil bank. The minimum elevation of these 

openings near the Lamer Club (fig. 5) is about 9 to 10 feet 

above base-flow stage. A lower breach, just downstream 

from the Lamer Club, conducts flow from the North Fork 

Forked Deer ditch to the ditch from the Lanier Club to 

Maple Flats (fig. 5) when the river stage rises 8 feet above 

base-flow stage. This breach is partially blocked by a 

timber and rubber dam around which local scour is evident. 

Nash Creek drains west into the natural channel below 

occlusion H and receives outflow from Maple Flats (fig. 5). 

Flow in the area of occlusions G and H follows a complex 

pattern that includes some sections of natural channel. The 

many beaver dams in this area force most flow to cross the 

flood plain. 

16 Recent Sedimentation and Surface-Water Flow Patterns on the Flood Plain 

of the North Fork Forked Deer River, Dyer County, Tennessee 
The area west of and downstream from occlusion H is 

locally known as “Stowe Slough” (fig. S), and includes 

sections of the natural channel upstream and downstream 

from occlusion I. This area was a slough in 1941, with 

ponding limited almost entirely to the channel; water levels 

at that time were apparently about 2 feet lower than in 1991. 

Flow leaves the downstream end of this channel section to 

the north into an area of ponded flood plain, then flows west 

and northwest through a series of beaver ponds, bypassing 

occlusions I and J (fig. 5). 

The section of natural channel between occlusions J and 

K, and the ponded area adjacent to it, are accessible from 

the Beaver Dam Duck Club through an excavated ditch that 

carries no appreciable flow (figs. 5 and 6). The water depth 

in this area also has increased since 1941, at which time 

ponding was limited largely to the channel. This area has 

three outlets to the North Fork Forked Deer ditch. One 

outlet is a culvert 3 feet in diameter with a flap gate that 

drains this pond to the northeast into the North Fork Forked 

Deer ditch (fig. 5). This culvert is nearly plugged with 

woody debris and sediment. 

A second outlet follows the original course of the river. 

Flow bypasses occlusion K to the north and enters a section 

of the natural channel that drains to the North Fork Forked 

Deer ditch. The upper part of this channel section is stable, 

with cypress knees visible on its banks and beds. Near the 

North Fork Forked Deer ditch, north of occlusion K (fig. 5), 

this natural channel segment shows signs of deepening and 

widening, including collapsed banks and cypress roots 

exposed by erosion. 

The third outlet, west of occlusion L (fig. 5), is the 

largest and most actively eroding outlet. Flow leaves the 

ponded area to the northwest through the flood plain, 

bypassing occlusion K, and is eroding a channel through a 

cypress grove. It drops through an active headcut and enters 

the North Fork Forked Deer ditch through a short section of 

the natural channel. Downstream from the headcut, the 

incised channel has nearly vertical banks about 10 feet in 

height. Numerous buried cypress trees have been exposed 

by erosion of the banks, and trees growing on the flood plain 

near the channel are being undermined. This outlet seems 

to be passing an increasing share of the outflow from the 

pond. 

Flow Paths between Parker Ditch and 

U.S. Highway 412 

Overflow from the North Fork Forked Deer ditch 

enters this area during floods, and is the major source of 

flow. Tributary inflow from small ditches draining agricultural land north of the river probably occurs only 

immediately after rainfall. In contrast to the other two 

areas, the main impediments to flow across the flood plain 

are constructed levees rather than channel occlusions. 

Drainage of this area to the North Fork Forked Deer 

ditch was formerly provided by a constructed ditch. This 

ditch follows a zig-zag course from where Harrison Road 

enters the North Fork Forked Deer River flood plain 

(fig. 5). The tributary ditch has been dammed by beavers to 

the level of the flood plain at several points. The culvert 

intended to carry flow west under Harrison Road into this 

ditch is not effective. 

The main flow path draining this area is roughly parallel 

to the ditch, and apparently follows the pre-settlement 

location of the natural channel (Thirteenth Surveyors 

District, 1819). The upstream reach of this flow path is 

poorly defined and not confined to a channel. The levees 

that prevented water from flowing west and northwest to 

enter this flow path have been breached, but some of the 

breaches have been dammed by beavers. These beaver dams 

preserve the ponded conditions the levees originally were 

intended to create. An actively eroding gully about 500 feet 

long forms the section of this flow path immediately 

upstream from its confluence with the North Fork Forked 

Deer ditch. 

Condition of Tributaries 

The investigation of the condition of tributaries was 

based on field visits on foot and by canoe in the North Fork 

Forked Deer River flood plain, inspection of bridges outside 

the flood plain, and examination of aerial photographs. 

The Stokes Creek ditch is unobstructed from the 

northernmost relief opening in the railroad causeway to the 

North Fork Forked Deer ditch (fig. 3). Upstream from this 

opening, the Stokes Creek ditch is obstructed by beaver 

dams. The presence of deeply ponded water at the Green 

Hill Bottom Road crossing indicates that occlusions extend 

Surface-Water Flow Patterns 17 
upstream beyond the edge of the North Fork Forked Deer 

River flood plain. 

The Eliza Creek ditch originally entered the natural 

channel at Brown Eddy (fig. 5). Its downstream end is now 

nearly occluded. Flow in Eliza Creek eventually enters 

Maple Flats. 

Nash Creek is occluded at the boundary between cultivated fields and the forested flood plain near site 4 (fig. 2). 

At this point, flow has abandoned its original channel 

forming several new channels across a rapidly aggrading 

flood-plain surface. Backwater caused by this channel 

occlusion extends into the fields adjacent to Nash Creek. 

Doakville Creek and Parker Ditch seem to be unobstructed, and to carry substantially their entire flows to the 

North Fork Forked Deer ditch. Parker Ditch has steep, bare 

banks, indicating that it has recently undergone degradation. 

Other small tributaries, and the upstream reaches of 

Stokes, El&, and Nash Creeks, seem to have stable 

channels, and show little sign of rapid charmel evolution. 

Based on examination of Nash Creek, however, channel 

occlusions and abrupt changes in channel location are most 

likely where these streams enter the flood plain. 

Channel Evolution in the Study Area 

Observations of active erosion and deposition in the 

study area indicate that the flow pattern is changing, and 

indicate the direction of this evolutionary change. The 

history and stratigraphy of the study area and the observed 

pattern of channel evolution along other channel&d streams 

suggest the probable outcome of geomorphic evolution in the 

study area. This evolution is driven, however, by human 

actions in the North Fork Forked Deer River basin upstream 

from the study area, in small tributary basins that drain into 

the study area, and in the channel of the North Fork Forked 

Deer River downstream. Most of the trends discussed in the 

following paragraphs could be altered or reversed by 

changes in human activities outside the study area. 

The North Fork Forked Deer ditch seems to be 

degrading and widening. In 1974, its top width was 

typically 60 feet; its bottom width, 12 feet; and the depth of 

its bed below the flood plain, 10 feet (J.M. Cook, 

Continental Engineering Inc., written commun., 1991). 

Since then, the bed of the North Fork Forked Deer River 

has degraded by about 4 feet at the U.S. Highway 412 

bridge, by about 3 feet at the Parker Ditch access ramp, and 

by less than 1 foot at the Gulf and Mobile railroad bridge 

(fig. 2) based on 1991 surveys, the 1974 survey (J.M. Cook, 

Continental Engineering Inc., written commun., 1991), and 

bridge plans (Steve Hall, Tennessee Department of 

Transportation, written commun., 1991). 

Degradation is progressing in an upstream direction. 

The vertical distance between the channel bed and the flood 

plain increases in the downstream direction in the study area, 

and field observations of Lewis Creek and the North Fork 

Forked Deer River at Dyersburg (fig. 1) indicate active 

degradation downstream. If channel evolution follows its 

normal course, degradation will likely intensify in the 

Wildlife Management Area. Barring further ditch maintenance, continued downstream dredging, or a substantial 

reduction in sediment inputs upstream, the present episode 

of degradation will likely be followed by one or two decades 

during which sand will gradually fill the ditch. At the end 

of this period of aggradation, the river may abandon sections 

of the ditch in the study area and find its own course, which 

may or may not follow present flood-plain flow paths. 

The resistance of the massive silts and clays to erosion 

is the most important factor keeping the ditch close to its 

original alignment. If degradation penetrates these resistant 

materials to the underlying sands, bank stability may 

decrease, leading to accelerated widening and the development of meanders. Gn the other hand, should aggradation 

raise the level of the bed to the level of the poorly 

consolidated upper banks, the channel will be free to migrate 

laterally. 

Several flow paths draining the flood plain are 

undergoing degradation in response to the degradation of the 

North Fork Forked Deer ditch. All the headcuts in the study 

area appear to be active rather than healing. Most 

knickpoints have a vertical face, with a plunge pool at the 

base, indicating headward migration. Many exposed roots 

and recent failures on the steep banks of the headcuts 

indicate that the channels are downcutting and widening. As 

18 Recent Sedimentation and Surface-Water Flow Patterns on the Flood Plain 

of the North Fork Forked Deer River, Dyer County, Tennessee 
these headcuts continue to grow, they will lower the level of 

standing water in the ponded areas they drain. The entire 

ponded area north of the North Fork Forked Deer ditch 

(figs. 3 and 4) and east of Parker Ditch (fig. 5), the ponded 

area downstream from occlusion J (figs. 5 and 6), and the 

poorly drained area north of the North Fork Forked Deer 

ditch and west of Harrison Road (fig. 5) will likely be 

affected. 

Ponding along the lower reaches of several tributaries is 

apparently related to the deposition of fine-grained sediment 

delivered from their own basins, and occurs at elevations 

above those of the ponded water in the flood plain. These 

ponded areas and the depositional areas that cause them are 

relatively remote from the headcuts along the North Fork 

Forked Deer ditch, and consequently are not likely to be 

affected in the near future by the growth of these headcuts. 

The typical solution to such ponding is to excavate a ditch 

downstream to the next major ditch -- in this instance, the 

North Fork Forked Deer ditch. Such a tributary ditch will 

likely become ineffective with time unless regularly 

maintained and will have hydraulic effects on the flood plain 

it crosses, as exemplified by Stokes Creek. An ineffective 

ditch, or a ditch that does not extend downstream to the next 

larger ditch (for example, Eliza Creek), will likely deposit 

much of its sediment load at the edge of the flood plain, 

where the channel slope decreases. Sedimentation at that 

point could eventually lead to a restoration of ponded 

conditions in the fields upstream. 

SUMMARY AND CONCLUSIONS 

This report summarizes results of research conducted by 

the U.S. Geological Survey in cooperation with the 

Tennessee Wildlife Resources Agency to improve 

understanding of the relations between sedimentation and 

surface-water drainage conditions on the flood plain of the 

North Fork Forked Deer River near Dyersburg in West 

Tennessee. The research objectives were (1) to determine 

recent sedimentation rates in the study area, and (2) to 

identify and locate major surface-water flow paths and 

determine their relation to recent sedimentation. The 

objectives were accomplished by reviewing relevant 

literature, examining flood-plain sediments, age dating 

buried tree stumps and living trees, surveying water-surface 

and channel-bed elevations, and analyzing of maps, aerial 

photographs, survey records, and bridge plans. 

Previous studies show that impeded drainage on the 

North Fork Forked Deer River flood plain is not a new 

problem, and that it existed prior to channelization of the 

Forked Deer River. In the early 1900’s, and on several 

occasions since then, the North Fork Forked Deer River was 

charmelized to alleviate drainage problems caused by 

excessive upland erosion and valley sedimentation. The 

relation between upland erosion, valley sedimentation, and 

drainage conditions in, and adjacent to, the flood plains of 

many West Tennessee streams was identified by some of the 

earliest proponents of channelization in West Tennessee. 

The upper 15 to 20 feet of flood-plain sediments in the 

study area consist of fine-grained alluvium, underlain by 

sand. The fine-grained alluvium consists of several units, 

the lowest of which is a layer of massive silts and clays. 

This unit is overlain by a mottled silty clay which is 

probably a buried soil. These two cohesive units are more 

resistant to erosion than the overlying materials and form 

steep-sided benches along the banks of the North Fork 

Forked Deer ditch. Overlying the mottled silty clay is a Sto 1Zfoot thick layer of poorly consolidated, stratified silts 

and clays, overlain locally by dredge spoil or weakly 

developed soil. 

Radiocarbon analysis of buried cypress trees indicates 

that the stratified silts and clays were probably deposited 

near the North Fork Forked Deer River channel during the 

century prior to 1930 at rates on the order of 0.1 ft/yr. The 

cessation of flood-plain accretion before 1930 probably 

reflects the increased capacity of the North Fork Forked 

Deer ditch (completed in 1921) to transport and store 

sediment. 

The highest sedimentation rates measured during this 

study, about 0.2 ft/yr, occurred along Nash Creek near the 

flood-plain margin. Sedimentation near tributaries along the 

valley margins seems to be the major ongoing process of 

flood-plain accretion. 

The natural channel of the North Fork Forked Deer 

River, replaced as the primary flow path by the ditch 

constructed from 1916 to 1921, has been divided into a 

series of ponded sloughs by the ditch and by sediment 

Summary and Conclusions 19 
deposition. Twelve major occlusions of the natural channel 

were mapped in the study area. Nonetheless, the natural 

channel can be traced through nearly all of the study area, 

and its original dimensions estimated. The estimated 

bankfull capacity of the natural channel immediately before 

channelization is comparable to the present base flow of the 

North Fork Forked Deer ditch. 

There has been little change in the location of the North 

Fork Forked Deer ditch since its construction, because flow 

in the ditch is confined by cohesive lower banks. 

Degradation has the potential to destabilize the banks and to 

accelerate lateral migration of the channel by exposing the 

sands that lie below the present bed. Conversely, 

aggradation also could result in accelerated lateral migration 

by elevating the bed above the cohesive parts of the banks. 

The pattern of flow in the flood plain is complex. The 

natural channel provides an important path for flood flow 

and flood-plain drainage, but it has been plugged by 

sediment, woody debris, and beaver dams in many areas. 

Most of the sediment plugging the natural channel probably 

was delivered by the North Fork Forked Deer ditch, but in 

several locations the source of the sediment was tributary 

streams. Current or abandoned tributary channels and low 

areas of the flood plain also function as flow paths, although 

flow is impeded in these areas by dense vegetation and 

beaver dams. In the area north of the North Fork Forked 

Deer ditch and west of Parker Ditch, flow is impeded by 

beaver dams and levees on the flood plain. The spoil banks 

along the North Fork Forked Deer ditch impede drainage 

from small areas of the flood plain, but have been breached 

at points where sections of natural channel intersect the 

ditch. 

Of the tributaries entering the study area, only the two 

largest, Parker Ditch and Doakvilre Creek, have clear 

channels and provide effective drainage. The upstream 

reaches of these and other tributaries entering the study area 

seem to be generally stable, except for signs of bank retreat 

along Parker Ditch. The lower reaches of tributaries other 

than Parker Ditch and Doakville Creek are isolated from the 

North Fork Forked Deer ditch by occlusions of their 

channels, especially near the flood-plain margin, and by 

beaver dams and debris. Several of these streams are 

ponded, and inundate agricultural land adjacent to the flood 

plain. The sediment deposited in the occluded reaches seems 

to come from the watersheds of the tributaries themselves. 

Except for Doakville Creek and Parker Ditch, the tributaries 

that enter the Wildlife Management Area likely will not be 

affected by the channel evolution of the North Fork Forked 

Deer ditch in the near future. 

Clearing tributary streams of sediment and other 

obstructions would alleviate flooding over the short term. 

However, as long as the tributaries carry high sediment 

loads, such measures will continue to be temporary solutions 

whose continued effectiveness wilt require Periodic 

mafntenance of channels. The stability of the upstream 

reaches of tributaries could be disrupted, if the downstream 

occluded reaches are substantially modified. 

The North Fork Forked Deer ditch seems to be 

degrading and widening, and this degradation has stimulated 

rapid erosion of headcuts in the flow paths that drain the 

flood plain. Erosion of these headcuts has lowered water 

levels in the ponded areas immediateIy upstream from 

sampling site 1 and in the area north of the North Fork 

Forked Deer ditch and west of Parker Ditch, and has the 

potential to lower the water level in the ponded area north of 

the North Fork Forked Deer ditch and east of Parker Ditch. 

Degradation and widening of the North Fork Forked Deer 

ditch may continue for several years, but, in the absence of 

further ditch maintenance, is likely to be folIowed by a 

period of aggradation that could ultimately fill the ditch with 

sediment and divert flow into the flood plain. 

This report presents a reconnaissance-level evaluation of 

the interaction between recent sedimentation and surfacewater drainage in the Tigrett Wildlife Management Area and 

adjacent areas of the North Fork Forked Deer River flood 

plain. This evaluation has identified several areas where 

further research is needed. Two major issues not fully 

addressed in this study are (1) sedimentation patterns along 

such tributary streams as Stokes and Eliza Creeks, and 

(2) the frequency, duration, and magnitude of flooding of the 

North Fork Forked Deer River. Further investigation of 

these topics would aid managers in predicting hydroperiods 

and extent of flooding in various parts of the flood plain 

under different management alternatives. Additional studies 

of this type elsewhere in the Forked Deer River basin and in 

20 Recent Sedimentation and Surface-Water Flow Patterns on the Flood Plain 

of the North Fork Forked Deer River, Dyer County, Tennessee 
other drainage basins of West Tennessee also are needed to 

provide a framework in which to analyze local environmental problems such as those found in and around the 

Tigrett Wildlife Management Area. 

REFERENCES CITED 

Ashley, G.H., 1910, Drainage problems in Tennessee: 

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Barnhardt, M.L., 1988a, Historical sedimentation in West 

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no. 1, p. 1-18. 

1988b, Recent gully activity in Meeman-Shelby State 

Park, southwest Tennessee: Journal of the Tennessee 

Academy of Science, v. 63, p. 61-64. 

Bazemore, D.E., Hupp, C.R., and Diehl, T.H., 1991, 

Wetland sedimentation and vegetation patterns near 

selected highway crossings in West Tennessee: U.S. 

Geological Survey Water-Resources Investigations 

Report 91-4106, 46 p. 

Cushing, E.M., Boswell, E.H., and Hosman, R.L., 1964, 

General geology of the Mississippi embayment: U.S. 

Geological Survey Professional Paper 448-B, 28 p. 

Fennernan, N.M., 1938, Physiography of the eastern United 

States: New York, McGraw-Hill, 714 p. 

Greene, W.D., 1901, Gibson County, Tennessee: 

Nashville, Tenn., Press of Gospel Advocate, 154 p. 

Grissinger, E.H., and Murphey, J.B., 1982, Present 

“problem” of stream channel instability in the Bluff 

Area of northern Mississippi: Journal of the Mississippi 

Academy of Sciences, v. 27, p. 117-128. 

G&singer, E.H., Murphey, J.B., and Little, W.C., 1982, 

Late Quatemary valley-fill deposits in north-central 

Mississippi: Southeastern Geology, v. 23, no. 3, 

p. 147-162. 

Happ, S.C., 1944, Effects of sedimentation on floods in the 

Kickapoo Valley, Wisconsin: Journal of Geology, 

v. 52, p. 53-68. 

Happ, S.C., Rittenhouse, Gordon, and Dobson, G.C., 1940, 

Some principles of accelerated stream and valley 

sedimentation: U.S. Department of Agriculture 

Technical Bulletin 695, 71 p. 

Hulme, A.C., and Hulme, J.A., eds., 1982, A history of 

Dyer County: Dyersburg, Ten&, Dyer County 

Historical Society, 531 p. 

Knox, J.C., 1987, Historical valley sedimentation in the 

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American Geographers, v. 77, p. 224-244. 

Magilligan, F.S., 1985, Historical floodplain sedimentation 

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v. 75, p. 583-594. 

Morgan, A.E., and McCrory, S.H., 1910, Preliminary 

report upon the drainage of the lands overflowed by the 

North and Middle Forks of the Forked Deer River and 

the Rutherford Fork of the Obion River in Gibson 

County, Tennessee: Tennessee State Geological Survey 

Bulletin 3-B, p. 16-43. 

Reineck, H.E., and Singh, LB., 1980, Depositional 

sedimentary environments, with reference to terrigenous 

elastics (2d ed.): Berlin, Springer-Verlag, 549 p. 

Robbins, C.H., and Simon, Andrew, 1983, Man-induced 

channel adjustment in Tennessee streams: U.S. Geological Survey Water-Resources Investigations Report 

82-4098, 129 p. 

Saucier, R.T., 1987, Geomorphological interpretation of late 

Quatemary terraces in western Tennessee and their 

regional tectonic implications: U.S. Geological Survey 

Professional Paper 1336-A, 19 p. 

Schreurs, R.L., and Marcher, M.V., 1959, Geology and 

ground-water resources of the Dyersburg Quadrangle, 

Tennessee: Nashville, Tennessee Division of Geology 

Report of Investigations no. 7, 61 p. 

Schumm, S.A., Harvey, M.D., and Watson, C.C., 1984, 

Incised channels --Morphology, dynamics, and control: 

Littleton, Colo., Water Resources Publications, 200 p. 

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in modified Tennessee channels, in Federal Interagency 

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Council, v. 2, sec. 5, p. 71-82. 

Tennessee State Planning Commission, 1936, The Obion 

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drainage enterprises and land conditions within the area: 

Nashville, Term., 16 p. 

Tennessee Valley Authority, 1936, Map of Dyer County, 

Tennessee: Tennessee Valley Authority Map 8-4196-23, 

scale 1:63,000, 1 sheet. 

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as Map 3961, scale 1:80,000, 1 sheet. 

References Cited 21 
Trimble, S.W., 1976, Sedimentation in Coon Creek Valley, 

Wisconsin, in Federal Interagency Sedimentation 

Conference, 3rd, 1976, Proceedings: Washington, 

D.C., Water Resources Council, sec. 5, p. 100-112. 

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discharges of the Mississippi River and tributaries in the 

Memphis District: Washington, D.C., U.S. Govemment Printing Office, published annually [variously 

pw4. 

22 Recent Sedimentation and Surface-Water Flow Patterns on the Flood Plain 

of the North Fork Forked Deer River, Dyer County, Tennessee ‘USGPO 1993.750.232/80012