Sediment Transported by 

Georgia Streams

By VANCE C. KENNEDY

GEOLOGICAL SURVEY WATER-SUPPLY PAFER 1668

Prepared in cooperation with the 

Georgia Department of Mines, 

Mining, and Geology

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1964
UNITED STATES DEPARTMENT OF THE INTERIOR 

STEWART L. UDALL, Secretary

GEOLOGICAL SURVEY

The U.S. Geological Survey Library has cataloged this publication as follows:

Kennedy, Vance Clifford, 1923--

Sediment transported by Georgia streams. Washington, 

U.S. Govt. Print. Off., 1963.

v, 101 p. maps, diagrs., tables. 24 cm. (U.S. Geological Survey. 

Water-supply paper 1668)

Prepared in cooperation with the Georgia Dept. of Mines, Mining, 

and Geology.

Bibliography: p. 97-98.

1. Sedimentation and deposition. 2. Sediments (Geology) Georgia. 

3. Stream measurements Georgia. I. Georgia. Dept. of Mines, Mining 

and Geology. II. Title. (Series)

For sale by the Superintendent of Documents, U. S. Government Printing Office 

Washington, D.C. 20402
CONTENTS

Page

Abstract__ _____________________________________________________ 1

Introduction ______________________________________________________ 2

Economic aspects of sediment study_____________-_.____-______.___-_ 4

General factors affecting sediment yield ______________________________ 6

Precipitation_ _______________________________________________ 7

Runoff ___--_-__-__-_----__-_-_-_-_-_-----_--__-_-_-_-_-___--_ 9

Temperature. _________________________________________________ 9

Topographic features._________________________________________ 9

Soils________.-_---__________________-___-_-___-._ 10

Cover.._-____--_-_____-__-____-_-_-___-_---_-___-___________- 12

Detention reservoirs___________________________________________ 13

Channel characteristics.____________________________________________ 17

Physiographic provinces and their characteristics______________________ 18

Blue Ridge.__________-______-_____--_____--_____-___-_-_-____ 18

Valley and Ridge_-__-_--__-_-_--_-__-__________-_---________ 18

Cumberland Plateau section of Appalachian Plateau_______________ 19

Piedmont___________________________________________________ 19

Coastal Plain_________________________________________________ 20

Methods and accuracy of sampling,_________________________________ 20

Suspended load____-______-___----_____-______-----_-___--_-- 20

Total sediment load__________________________________________ 21

Data from sampling sites.__________________________________________ 22

Sites of frequent sampling._____________________________________ 22

Broad River near Bell, Ga______________._______________._ 22

Ogeechee River near Eden, Ga______________________________ 32

Slash Creek near Mclntyre, Ga_ ____________________________ 35

Flint River near Culloden, Ga_____________________________ 39

Ichawaynochaway Creek at Milford, Ga____________________ 43

Etowah River at Canton, Ga____ ___________________________ 50

Oostanaula River at Calhoun, Ga__________________________ 60

Sites of occasional sampling_____________________________________ 66

Brier Creek at Millhaven, Ga.______________________________ 66

Rocky Comfort Creek near Louisville, Ga____________________ 67

Ogeechee River near Louisville, Ga __________________________ 68

Canoochee River near Claxton, Ga__________________________ 69

Ocmulgee River at Macon, Ga___________________________._- 69

Ocmulgee River at Lumber City, Ga________________-________ 70

Little Ocmulgee River at Towns, Ga________--_________.____- 71

Oconee River near Greensboro, Ga_________________________ 71

Oconee River at Milledgeville, Ga___________________________ 72

Commissioner Creek at Toomsboro, Ga ______________________ 73

Oconee River near Mount Vernon, Ga__ _____________________ 73

Ohoopee River near Reidsville, Ga_________________________ 74

Altamaha River at Doctortown, Ga________________________ 75

Satilla River at Atkinson, Ga_ ______________________________ 76
IV CONTENTS

Data from sampling sites Continued

Sites of occasional sampling Continued Page

Alapaha River near Alapaha, Ga_________________----_-_-___ 78

Little River near Adel, Ga_____________________--------___ 79

Ochlockonee River near Thomasville, Ga_____________________ 80

Chattahoochee River near Leaf, Ga_---__-__---_-----------__ 82

Chestatee River near Dahlonega, Ga.________________________ 83

Chattahoochee River at Atlanta, Ga_ _____________-_------__- 84

Chattahoochee River at West Point, Ga______________________ 85

Flint River near Griffin, Ga-_____________________-_-___----_ 86

Whitewater Creek below Rambulette Creek near Butler, Ga _ _ _ _ 87

Flint River at Montezuma, Ga_________-_______-____-------- 88

Coosa River near Rome, Ga-_--_------_-_-_-_-_-_---------__ 89

Chattooga River at Summerville, Ga_________________-----___ 89

Data from other sources____________________________________________ 90

Significance of data._______________________________________________ 92

Variation in concentration and particle-size distribution of suspended

sediment- _ __________________________________________________ 93

Variation in sediment load._____________________________________ 96

References cited-__________________________________________________ 97

Index-______________________________________________.__ 99

ILLUSTRATIONS

Page 

FIGUEE 1. Total precipitation during 1958__--____________-_-_---___ 7

2. Total precipitation during 1959__________________________ 8

3. Average relief per square mile_________________--------_ 11

4. Surface soils.__________________________________________ 12

5. Percent of land classified as cropland_________-___--_-___ 14

6. Percent of land classified as harvested cropland.___________ 15

7. Map of Georgia showing percent of land area from which runoff

passes through ponds __________________________________ 16

8. Reservoirs with drainage area greater than 100 square miles__ 17

9. Index map showing locations of sampling sites _____________ 23

10. Relation of stream discharge to concentration, Broad R: ver

near Bell, Ga________________________________________ 26

11. Suspended-sediment concentration-frequency curve, Broad

River near Bell, Ga___________________________________ 27

12. Variation of discharge and concentration, Broad River near

Bell, Ga_____________________________________________ 29

13. Suspended-sediment transport curve, Broad River near P<?11,

Ga_ _____________________________________ 30

14. Suspended-sediment load-distribution curves, Broad River

near Bell, Ga_-__-_-_______________________. 33

15. Relation of stream discharge to concentration, Ogeechee River

near Eden, Ga_______________________________---__-__ 34

16. Relation of stream discharge to concentration, Flint River

near Culloden, Ga____________________________________ 40

17. Relation of stream discharge to concentration, Ichawaynochaway Creek at Milford, Ga.____________________________ 44

18. Suspended-sediment concentration-frequency curve, Ichawaynochaway Creek at Milford, Ga______________-___--__-_ 46
CONTENTS

FIGURE 19. Suspended-sediment transport curve, Ichawaynochaway Creek

at Milford, Ga____________________________________ 47

20. Suspended-sediment load-distribution curve, Ichawaynochaway Creek at Milford, Ga____________________-__--_-_- 48

21. Relation of stream discharge to concentration, Etowah River

at Canton, Ga_______________________________________ 51

22. Variation in gage height and concentration, Etowah River at

Canton, Ga., January 1959_-_-_--___-_-_-------------- 52

23. Variation in gage height and concentration, Etowah R'ver at

Canton, Ga., March 1959____________________________ 53

24. Suspended-sediment concentration-frequency curve, Etowah

River at Canton, Ga________________________________ 54

25. Suspended-sediment transport curve, Etowah River at Canton, Ga_____________________________________________ 57

26. Suspended-sediment load-distribution curve, Etowah River

at Canton, Ga., 1959 water year_______________-________ 58

27. Relation of stream discharge to concentration, Oostanaula

River at Calhoun, Ga_______-_______________----_----_ 61

28. Suspended-sediment concentration-frequency curve, Oostanaula River at Calhoun, Ga_________________________ 63

29. Particle-size distribution in samples from selected Georgia

rivers ________-________________-________-_---_.,--__-- 96

TABLES

Page

TABLE 1. Sites within or on the boundary of Georgia at which sediment 

data had been collected prior to June 1959 (exclusive of 

data in this report) _________________________--_---__-- 3

2. Georgia reservoirs for which sediment data are available.-.-. 4

3. Long-term mean monthly precipitation for various parts of

Georgia _____________________________________________ 9

4. Drainage area and physiographic province(s) above each

sampling site_____-__-_______--_-_--___-___-__-______ 24

5. Concentration of suspended sediment in samples from the

Broad River near Bell, Ga___________________________ 25

6. Particle-size analyses of suspended sediment, Broad River

near Bell, Ga_ _______________________________________ 28

7. Daily suspended-sediment concentration and load, Broad

River near Bell, Ga., Dec. 16, 1958, to May 15, 1959. ____ 31

8. Concentration of suspended sediment in samples from the

Ogeechee River near Eden, Ga_________________________ 34

9. Daily suspended-sediment concentration and load, Ogeechee

River near Eden, Ga., Dec. 16, 1958, to May 15, If59____ 36

10. Particle-size distribution of bed material from the Ogeechee

River near Eden, Ga., Feb. 9, 1959---___-__---__--___-_ 37

11. Concentration of suspended sediment in samples from Slash

Creek near Mclntyre, Ga______________________________ 38

12. Concentration of suspended sediment in samples from Slash

Creek near Gordon, Ga___ ____________________________ 39

13. Concentration of suspended sediment in samples from the

Flint River near Culloden, Ga__________________________ 41
VI CONTENTS

Pag« 

TABLE 14. Particle-size analyses of suspended sediment, Flint River near

Culioden, Ga._______________________________________ 42

15. Particle-size distribution of bed material from the Flint E: ver

near Culioden, Ga., Mar. 4, 1959___________________ 43

16. Concentration of suspended sediment in samples from Ichawaynochaway Creek at Milford, Ga__ __________________ 45

17. Daily suspended-sediment concentration and load, Ichav^aynochaway Creek at Milford, Ga., Dec. 16, 1958, to May 15, 

1959________________________________________________ 49

18. Concentration of suspended sediment in samples from the

Etowah River at Canton, Ga_______-___-____--_____--_ 50

19. Particle-size analyses of suspended sediment, Etowah R: ver

at Canton, Ga______________________________-____--__ 55

20. Daily suspended-sediment concentration and load, Etowah

River at Canton, Ga., Dec. 16, 1958, to May 15, 1959---. 59

21. Concentration of suspended sediment and particle-size distribution of bed material from the Etowah River at Canton, 

Ga., Mar. 6, 1959_________________________.____ 60

22. Concentration of suspended sediment in samples from the

Oostanaula River at Caihoun, Ga______________________ 62

23. Particle-size analyses of suspended sediment, Oostanrula

River at Caihoun, Ga_________________________________ 65

24. Particle-size distribution of bed material from the Oostanf.ula

River at Caihoun, Ga., Mar. 7, 1959________________ 66

25. Concentration of suspended sediment in samples from B"ier

Creek at Milihaven, Ga_______--___--__-_---_-_--_---_ 67

26. Concentration of suspended sediment in samples from Ro^ky

Comfort Creek near Louisville, Ga____________________ 68

27. Concentration of suspended sediment in samples from the

Ogeechee River near Louisville, Ga.___________________ 68

28. Concentration of suspended sediment in samples from the

Canoochee River near Claxton, Ga______-____-____-__- 69

29. Concentration of suspended sediment in samples from the

Ocmulgee River at Macon, Ga________________________ 70

30. Concentration of suspended sediment in samples from the

Ocmulgee River at Lumber City, Ga__________________ 71

31. Concentration of suspended sediment in samples from the

Little Ocmulgee River at Towns, Ga__________________ 72

32. Concentration of suspended sediment in samples from the

Oconee River near Greensboro, Ga____________________ 72

33. Concentration of suspended sediment in samples from the

Oconee River at Miiiedgeville, Ga____________________ 73

34. Concentration of suspended sediment in samples from the

Oconee River near Mount Vernon, Ga________________ 74

35. Concentration of suspended sediment in samples from the

Ohoopee River near Reidsville, Ga____________________ 75

36. Concentration of suspended sediment in samples from the

Altamaha River at Doctortown, Ga__________________ 75

37. Concentration of suspended sediment in samples from the

Satilla River at Atkinson, Ga_____--____---___-______ 76

38. Data from sampling verticals, Satilla River at Atkinson,

Ga., and Alapaha River near Aiapaha, Ga____________ 77

39. Concentration of suspended sediment in samples from the

Alapaha River near Alapaha, Ga______________________ 78
CONTENTS VII

Fast 

TABLE 40. Concentration of suspended sediment in samples froir the

Little River near Adel, Ga________._______-__.._..___ 79

41. Data from sampling verticals, Little River near Adel, Ga. T

and Ochlockonee River near Thomasville, Ga__________ 81

42. Concentration of suspended sediment in samples from the

Ochlockonee River near Thomas ville, Ga ________________ 82

43. Concentration of suspended sediment in samples from the

Chattahoochee River near Leaf, Ga____._____-_-_-___--_ 83

44. Concentration of suspended sediment in samples fron the

Chestatee River near Dahlonega, Ga____________________ 84

45. Concentration of suspended sediment in samples from the

Chattahoochee River at Atlanta, Ga ____________________ 85

46. Concentration of suspended sediment in samples fron the

Chattahoochee River at West Point, Ga-_________-___--_ 86

47. Particle-size analyses of suspended sediment, Chattahcochee

River at West Point, Ga_._.________________________ 86

48. Concentration of suspended sediment in samples from the

Flint River near Griffin, Ga___._______-_-_-___-__-_-___ 87

49. Concentration of suspended sediment in samples from "\vhitewater Creek below Rambulette Creek near Butler, Ga_ _ _ _ _ 88

50. Concentration of suspended sediment in samples from the Flint

River at Monte/uma, Ga_ _____..__-_-___--_--_-.________ 88

51. Concentration of suspended sediment in samples fro*n the

Coosa River near Rome, Ga_______-______-__--_-_-_-_- 89

52. Concentration of suspended sediment in samples froTi the

Chattooga River at Summerville, Ga_______________-____ 90

53. Suspended-sediment data from streams originating in northern

Georgia _____________________________________________ 91

54. Sediment deposited in reservoirs in northern Georgia and

western North Carolina_______________________________ 91

55. Sediment deposited in Georgia reservoirs-_________________ 92

56. Sediment characteristics of Georgia streams as related to the 

physiographic province in which the drainage basin is located -_____-_____-____-______-_____-_-__-__.__-__--- 94
SEDIMENT TRANSPORTED BY GEORGIA STREAMS

By VANCE C. KENNEDY

ABSTRACT

A reconnaissance investigation of the sediment transported by selected 

Georgia streams during the period December 1957 to June 1959 was made to provide a general understanding of the physical quality of stream water in Georgia 

and to supply facts needed in planning more detailed work.

The investigation was made by studying the variation of sedimert concentration and sediment load with stream discharge at 33 sites and by relating the 

available data to topographic, geologic, climatic, and soil conditions in the State.

In the Blue Ridge Mountains area of northern Georgia the great relief, 

moderately heavy precipitation, fast runoff, and loamy soils cause sediment concentrations and sediment loads which are above average for the State. During 

periods of moderate to low streainflow, the concentration of suspended sediment 

ranges from 1 to 25 ppm (parts per million). After heavy rainfall, sediment 

concentration increases rapidly as water discharge rises, and occasionally exceeds 

1,000 ppm before decreasing again. The concentration may reach a maximum 

and decrease before the discharge peak is reached. A major part of the annual 

sediment load can be carried during a short period of time because of the 

great increase in both water discharge and sediment concentration during floods.

The lower Coastal Plain differs from the mountainous areas in several respects. 

The topography is gently rolling to almost level, precipitation anrl runoff are 

less than average for the State, and topsoils generally consist of sard and loamy 

sand. Concentration of suspended sediment in streamflow commonly ranges 

from 1 to 20 ppm during periods of low to moderate discharge and increases to 

15 to 60 ppm at high discharge. Because of the small increase in concentration 

with increasing stream discharge, the sediment load varies approximately in 

proportion to the discharge.

The sediment characteristics of streams in the Piedmont, the Valley and 

Ridge area, and the upper Coastal Plain are intermediate between those of the 

Blue Eidge area and the lower Coastal Plain.

Comparison of suspended load with estimated bed load in a few Georgia 

streams suggests that bed load is less than 20 percent of the susperded load for 

most streams.

Factors which appear to be most important in causing variation in sediment 

yield in Georgia are topographic relief, soil texture, and locatHn of dams. 

Variations in other factors such as precipitation, runoff, covering vegetation, 

drainage area, and channel types serve to modify the effects cf the major 

factors.

In general, Georgia stream water is of good quality. Water of some streams 

is of exceptionally fine quality and contains less than 30 ppm combined dissolved 

and suspended solids during at least 90 percent of the time. Knowledge of the 

nature and cause of variation in water quality will permit the most effective use 

of Georgia streams.

1
2 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

INTRODUCTION

A reconnaissance investigation of the sediment transported by selected Georgia streams was made during the period Decenber 1957 

to June 1959 to provide some understanding of the physical quality 

of stream water in Georgia and to supply facts needed in planning 

more detailed work.

The investigation was made by studying the variation of sediment 

concentration and sediment load with stream discharge at 3§ sites and 

by relating the available data to the topographic, geologic, climatic, 

and surface soil conditions in the State.

Because of the reconnaissance nature of the study, corsiderable 

extrapolation from meager data was necessary, and conclusions, especially regarding sediment load and concentration-frequency relations, 

must necessarily be tentative.

Little information concerning sediment transported by the larger 

Georgia streams is available from previous work. About the only detailed earlier work is the sampling done by the U.S. Army Corps of 

Engineers and the Tennessee Valley Authority in connection with 

dam construction. The U.S. Geological Survey, as early as 1906, 

analyzed water samples for suspended matter, but the samples were 

collected primarily for chemical analysis and the suspended matter 

reported probably represented only the finer particles in suspension. 

A summary of the data available in June 1959, exclusive of the data 

in this report, concerning suspended sediment in Georgia streams and 

in streams deriving most of their flow from Georgia is presented in 

table 1.

In addition to the suspended-sediment sampling listed in table 1, a 

few sedimentation surveys have been made either of reservoirs in 

Georgia or of reservoirs getting much of their sediment from Georgia. 

The data obtained by such surveys are valuable in estimating both 

the sediment yield from the drainage basin above the reservoir and 

the length of time required to fill the reservoir with sediment. A summary of available information on sedimentation in Georgia reservoirs 

is presented in table 2.

Some information from the studies listed in tables 1 and 2 is incorporated in this report.
INTRODUCTION

TABLE 1. Sites within or on. the boundary of Georgia at which sediment data 

had been collected prior to June 1959 (exclusive of data in this report)

[Dates of sampling indicate only the years in which some sampling was done; sampling may not have been 

done throughout the year. Agency collecting data: CE, U.S. Army Corps of Engineers; USGS, U.S. 

Geol. Survey; SCS, Soil Conservation Service of U.S. Department of Agriculture; TVA, Tennessee 

Valley Authority]

Site

Downstream 

order

1

2 

3 

4

5

6

7

8 

9 

10 

11 

12

13 

14

15 

16 

17

18 

19 

20 

21 

22 

23 

24

25 

26

 ^7 

28 

29 

30

31 

32 

33

34 

35 

36 

37

Stream

 ..do....... .........

 ..do............ .

 . .do................

.. do...............

Tributary to North 

Fork of Broad 

River.

Little Kiver... __ ...

Savannah River ......

 ..do...............

 . .do.. . ....

 -do. .... ...

 .do-.... ...........

. .do...............

 do._ ........ .

 do . ... _ .

Satilla River . ...

Chattahoochee River. 

 .do. .... ...

.....do ............

 .do...... ..........

.....do .............

Flint River... __ ...

 do-.-. ..

Ichawaynochaway 

Creek. 

Flint River .____._.

Conasauga River __._. 

Oostanaula River. . . .

Chattooga River - __ 

Nottely River. 

South Chickamauga 

Creek.

Location

2 miles below Yonah 

Lake. 

Near Fair Play, S.C. ... 

Junction with US 29 -. 

Junction with Georgia 

Route 181. 

Junction with Georgia 

Route 82. 

Near Calhoun Falls, S.C.

Near Bell, Ga _ . ....

At Clark Hill dam 

At New Savannah Bluff, 

Ga. 

At Bur tons Ferry bridge, 

near Millhaven, Ga.

Near Savannah, Ga __

At Lumber City, Ga __ 

At Milledgeville, Ga _ .

At West Point, Ga_ 

At Fort Gaines, Ga_. 

At Montezuma, Ga. ....

At Bainbridge, Ga 

AtTilton, Ga 

Near Cartersville, Ga_ 

Dates of 

sampling

1956-59

1956-59 

1956-59 

1956-59

1956-59

1950-51 

1956-59

1950-51 

1950-51 

1949-59 

1906-07 

1949-50

1949-50

1938-39 

1949-59 

1931-33 

1937-38 

1906-07 

1937-38 

1945-46 

1937-38 

1906-07 

1937-38 

1937-38 

1937-38 

1906-07 

1956-59 

1940-41 

1956-59 

1951-59 

1943-44 

1906-07 

1944-45

1941-42 

1952-59 

1942-43

1906-07 

1941-42 

1938-39 

1946-47 

1934-42 

1937-38

Agency collecting data

CE _ . ...

CE. __ ....

CE... .

CE _ ...

CE _ ...

CE._ .

USGS for

SCS.

CE-. ......

CE _ ......

CE.

USGS... ....

CE...... ...

CE ...

USG8.._ 

CE-__ 

CE _. . 

USGS..._.

USGS ....

USGS 

USGS 

USGS.......

USGS 

USGS... 

USGS... ....

USGS 

USGSCE-- 

USGS-. 

CE- - ...

CE ___ ...

USGS.-. ...

USGS.- 

USGS.- 

USGS--... .

CE...... ...

USGSUSGS.- .

USGS.. 

USGS 

USGS. 

TVA 

TVA 

Reference

Unpublished data.

Do. 

Do. 

Do.

Do.

Do. 

Do.

Do. 

Do. 

Do.

Dole (1909). 

Unoublisheddata.

Do.

Lamar(1944). 

Unpublished data. 

Do. 

Lamar (1944). 

Do'eClQOQ). 

Lamar (1944) . 

Unpublished data. 

Lamar (1944). 

Do'e(1909). 

Lamar (1944). 

Do. 

Do. 

Do1 " (1909). 

Unpublished data. 

Lamar (1944). 

Unpublished data. 

Do. 

US ^S (1947). 

Do'ra(1909). 

USGS (1949).

Lamar (1944). 

Unpublished data. 

Howard and Love 

(1945). 

Dole (1909). 

La-nar (1944). 

Do. 

Unpublished data. 

Do. 

Do.
SEDIMENT TRANSPORTED BY GEORGIA STREAMS

TABLE 2. Georgia reservoirs for which sediment data are available

[TVA, Tennessee Valley Authority; SOS, Soil Conservation Service, U.S. Department of AgricutlureJ

Reservoir

Lloyd Shoals .....

Newnan .- ___

White 

Manganese 

No. 6... .--__ 

Nottely. - ..____

Blue Rirtge-_____

Carrol Lake ......

Stream

Toccoa River.... ..- ...

Tributary to Chattahoochee 

River in White County. 

Tributary to Tallapoosa 

River. 

 . .do-.... ... _ ... .

Accumulation time 

of sediment 

measured

1910-35

1924-45 

1929-39

1929-38 

1942-54 

1942-55 

1944-54 

1925-56

1949-57 

1954-57

Agency 

collecting 

data

TVA 

TVA 

TVA 

SCS

scs

SCS

Reference

Federal Inter-Agency Committee on Water Resources 

(1957). 

Do. 

Do.

Do. 

Do. 

Do. 

Do. 

Unpublished data.

Do. 

Do.

Most of the determinations of sediment concentration and" size distribution for this report were made in the Ocala, Fla., laboratory of 

the U.S. Geological Survey by B. J. Sanders, L. M. Teboe, C. L. Cole, 

H. L. Weisner, and D. E. Shattles. Some size determinations were 

made in the U.S. Geological Survey Quality of Water laboratory at 

Raleigh, N.C., by H. E. Eeeder and M. D. Edwards. Mary of the 

sediment samples were collected by personnel of the Geological Survey 

Surface Water Branch during routine visits to sampling sites.

ECONOMIC ASPECTS OF SEDIMENT STUD^

When soil is eroded, land values are reduced and there is an increase 

in the amount of sediment transported and deposited by streams. 

High concentrations of suspended sediment interfere with the use of 

stream water by industries and municipalities. Excessive concentrations also harm fish and wildlife. Stream sediment is deposited in 

reservoirs and reduces their capacities. Irrigation canals, highway 

structures, and navigable streams often are adversely affected by sediment deposits.

Ordinarily, two separate but related types of sediment data are 

needed. Many users of stream water are concerned almost exclusively 

with variation in concentration of suspended sediment; otherr are concerned only with the magnitude of the sediment load. For example, 

most industries and municipalities are interested in the concentration 

of suspended sediment in the water which they withdraw from a 

stream. They are not concerned about the total sediment load carried 

by the stream. Groups engaged in dam construction, however, are not 

as much interested in concentration data as they are in the potential 

loss of reservoir capacity due to the sediment load transported by the 

stream.
ECONOMIC ASPECTS OF SEDIMENT STUDY 5

Information regarding the relation of concentration and particle 

size of suspended sediment to stream discharge is helpful in selecting 

the best time and place to withdraw water from a stream. The knowledge also enables a factory to discharge industrial wastes into a stream 

at times when it will be least damaging to water quality. In the Piedmont and Blue Ridge sections of Georgia, sediment concentration 

commonly increases rapidly as stream discharge increases, and then decreases again while the discharge is still high. When sedim ent concentration is high, the release of industrial wastes is least harmful, for 

fine-grained mineral and organic matter remove some dirsolved material from solution. After the concentration of suspended sediment 

has decreased, but while the discharge is still high, large quantities of 

good-quality water are available.

The concentration of suspended sediment usually is lowest near the 

water surface in a slow-moving part of the stream cross section, but is 

highest near the bottom in a swiftly flowing part of the section. 

Water can be withdrawn from the stream where sediment concentration is relatively low, and waste disposal can be made where sediment 

concentration is highest.

A detailed study of the time variation in concentration of suspended 

sediment permits the construction of curves showing tl n probable 

frequency of occurrence of various concentrations. Water users can 

combine this information with particle-size data and estimate the 

cost of water treatment required to remove the sediment. Such a 

study of sediment concentration also provides information necessary 

in predicting when high or low concentrations can be expected.

The total sediment load carried by a stream can be calculated from 

discharge data, suspended sediment concentration, and estimates of 

the amount of material moving along or near the bottom of a stream. 

Sediment-load data is helpful in identifying areas in which the rate of 

erosion is great and in determining which streams are supplying most 

of the sediment that fills reservoirs and clogs stream cl 'vnnels and 

estuaries.

A partial list of activities in which sediment data are useful is 

given below: 

Concentration data needed for:

1. Treatment of domestic water supplies

2. Treatment of industrial water supplies

3. Fish and wildlife studies

4. Recreational uses of water

5. Pollution studies

6. Hydrologic studies

7. Hydroelectric power generation

8. Industrial and radioactive waste disposal

9. Control of infiltration losses during irrigation
6 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

10. Maintenance of stream and canal channels

11. Canal design 

Sediment-load data needed for:

1. Reservoir design

2. Maintenance of stream and canal channels

3. Erosion control

4. Industrial and radioactive waste disposal

5. Flood control

6. Canal design

7. Dredging in navigable streams

The value of streams containing water of excellent quality has 

not always been emphasized in sediment studies. Although it is 

known that Georgia generally has a plentiful supply of good water, 

that information alone is not as effective in attracting potential users 

as is a description of the quality of the water in quantitative terms. 

Whitewater Creek in Taylor County can be used as an example of a 

stream whose waters are of exceptionally good quality. The total 

content of dissolved plus suspended solids probably does not exceed 

30 ppm (parts per million) more than 5 to 10 percent of the time. 

The water discharge varies little throughout the year and exceeded 

100 cfs (cubic feet per second) even during the drought period in 

1954. Industries in need of a dependable supply of exceptionally 

good water might become interested in using water from a stream like 

Whitewater Creek if quantitative data concerning its quality and 

quantity were brought to their attention. Thus it seems probable 

that information about the physical as well as the chemical quality 

of Georgia streams can be very helpful in the industrial development 

of the State.

In summary, facts concerning the amount and source of stream 

sediment are helpful in planning programs which will reduce the 

quantity of soil that is eroded and transported by stream waters. 

Knowledge of variations in quantity and characteristics of stream 

sediment permits the most efficient use of streams as sources of water 

and as transporting agents for waste products. Streams of unusually 

good quality can be identified, their characteristics determined, and 

their advantages publicized.

GENERAL FACTORS AFFECTING SEDIMENT YIELD

The amount and type of sediment transported by a stream at any 

point is the net result of the interaction of all the many factors 

capable of affecting sediment movement. Glymph (1954, p. 180) has 

listed eight factors which are important in estimating sediment yield. 

(Sediment yield is defined as the total sediment outflow from a 

watershed or drainage basin.) The factors listed are: soils, covering vegetation, precipitation, drainage-area and topographic fea-
GENERAL FACTORS AFFECTING SEDIMENT YIELP

tures, channel types, runoff, soil and cover management practices, and 

conservation practices and watershed treatment measures. These 

causal factors can be considered the result of the interaction of 

geology, climate, and man's activities. Glymph's study war concerned 

mainly with sediment yields in small watersheds, whereas the present 

study is concerned almost completely with large watersheds; there is, 

therefore, some variation in the importance attributed to particular 

causal factors in the two studies. Some factors influencing sediment 

yield in the State of Georgia are discussed below.

PRECIPITATION

The distribution of precipitation in Georgia in 1958 and 1959 is 

shown in figures 1 and 2. The precipitation during 1958 was below

TENNESSEE 1 p-\ --< t--i 

\ /^Cumberland. 

» y Plateau/

V- '~:J VfV-'jP^ f,,;^^-^^*

NORTH CAROLINA

EXPLANATION

County lines

Boundary lines of physiographic 

provinces and sections

 40 

Lines of equal precipitation, 

>. in inches

F L O R 1 D x -> A 

FIGURE 1. Total precipitation in Georgia during 1958. (From U.S. Weather Bureau,1959.)
8 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

EXPLANATION

County lines

Boundary lines of physiographic 

provinces and sections

 50 

qua! pr?ci 

in inches

. &

 50 

 c^ Lines of equal precipitation, 

in inches

TENNESSEE & I NORTH CAROLINA n;n7i~ iruYT23r:~ J

i\WJ

ir //i i r / *f ~T~-"'

' /' ' \J ( f\ Plu rAiJd M^Vij

20 0 20 

I I I I I

FLORIDA ^ *^ 'J 

FIGUBE 2. Total precipitation in Georgia during 1959. (From U.S. Weather Bureau, 1960.)

normal and that in 1959 was above normal. Although figures 1 and 2 

show the amount of precipitation received, they do not show the form, 

seasonal occurrence, or relative intensity. A snowfall which melts 

slowly, for example, will cause much less sediment yield than a hard 

spring rain after the fields have been plowed. The long-term monthly 

mean precipitation for various parts of the State is shown in table 3; 

most precipitation is received in the winter and early spring ri northwest Georgia, and during the summer in southeast Georgia. Snow is 

rather common in the mountainous area of northern Georgia, during 

the winter but is rare in southern Georgia.
GENERAL FACTORS AFFECTING SEDIMENT YIELD

TABLE 3. Long-term monthly mean precipitation, in inches, for various parts

of Georgia

[From U.S. Weather Bureau (1959). Based in part on the period 1921-50 and in part on tl» period 1931-55]

Part of State

North central ______

Northeast... _______

Central __________

Southwest ________

South central. ............

Jan.

5.49

5.13

5.20

4.33

3.96

3.09

3.82

3.26

2.50

Feb.

5.29

4.98

4.87

4.53

4.07

3.67

4.14

3.51

2.93

Mar.

5.96

5.63

5.81

5.71

5.03

a on

5.24

4.56

3.64

Apr.

4.51

4.57

4.52

4.64

4.23

3.63

4 66

4.03

3.01

May

3.74

3.61

3.57

3.36

3.44

3.24

3.69

3.24

3.13

June

3.88

3.93

3.07

3.95

3.68

3.77

4.33

4.27

5.0

July

4.75

4.98

5.20

5.77

5.29

4.74

6.30

6.18

6.78

Aug.

4.39

4.13

4,85

4.61

4.36

4.71

5.59

5.56

6.46

Sept.

2.90

2.90

3.29

3.14

3.08

3.59

3.81

3.96

6.61

Oct.

2.66

2.78

3 06

2.09

2.27

2.26

1,82

2.10

3 16

Nov.

3.39

3.26

3.53

3.86

2.61

2.24

2.63

1.98

1,78

Dec.

5.30

5.23

5.33

4.63

4.34

3.62

4.25

3.40

2.87

BUNOFF

Average runoff reported for Georgia streams (Thomson and others, 

1956) ranges from a low of 0.39 mgdsm (million gallons per day per 

square mile; 1.0 mgd=1.547 cfs) in the Coastal Plain to a high of 

1.86 mgdsm in the Blue Ridge area. This difference is due in part 

to the greater precipitation, in. the mountains; however, variation in 

runoff depends also upon soil type, covering vegetation, topography, 

and other factors.

The amount of sediment carried is dependent upon the rate of flow 

as well as upon the volume of the water which runs off tH land. A 

short period of heavy rainfall causes a greater sediment yield than 

a longer period of gentle rainfall even though the runoff or total 

rainfall may be the same for the two periods.

Runoff data quoted at various places in this report were taken from 

Thomson and others (1956).

TEMPEBATUBE

The viscosity of water increases with decreasing temperature. The 

increased viscosity of the water during cold weather enable? it to move 

more sediment and thus to increase sediment yield. Temperature, as 

a factor in sediment transport, is critical only when the particles are 

of sand size or coarser. The natural turbulence of streamflow is more 

than sufficient to transport silt and clay sizes, especially in the normal 

range of water temperatures. In the major rivers of Georgia the 

temperature range during the year is usually between 40 °F and 85 °F 

(Thomson and others, 1956, p. 228). Rivers in the mountainous 

regions show a larger range and rivers in the Coastal Plain a smaller 

range. This temperature variation causes a change in the water viscosity by a factor of about two. In the smaller streams the water temperature probably ranges from freezing to about 100 °F.

TOPOGRAPHIC FEATURES

The amount of relief (difference in elevation between the high and 

low points 011 a land surface) and the nature of the topography are of

695-903 64 2
10 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

considerable importance in determining how much of the material dislodged from the land surface by rainfall will be carried, away by 

water. The topography results mostly from the effect of climate on 

the rocks of the region. The relief in a particular area is s measure 

of the potential energy available for moving sediment. The way in 

which that relief is expressed in the topography also influences sediment movement. The relief may be the same in two different areas, 

but the potential energy may not be utilized as efficiently in moving 

sediment in one area as in another.

Figure 3 is a map of Georgia showing the average relief p°>r square 

mile in each county. The data were obtained by determining the 

highest and lowest elevations for each county, as shown on maps prepared by the Army Map Service, Corps of Engineers, U.S. Army, 

and dividing the difference in elevation, expressed in feet, by the square 

miles of area in the county. In a few counties the relief per square 

mile does not accurately indicate the average energy available for 

erosion. For example, in the Valley and Kidge province in rorthwest 

Georgia, the relief shown is that from the ridge crests to the river bottoms. However, very little of the land area is at or near the elevation 

of the ridge crests; furthermore, the cultivated land is mostly in the 

valleys, and there is very little elevation difference between this highly 

erodible land and the streams. Hence, relatively little sediment is 

removed from the valley areas. In some areas of the Piedmont 

province, a few isolated mountains standing high above the snrrounding region give a distorted picture of the normal relief. In general, 

however, figure 3 does indicate the amounts of potential energy available for moving sediment in various parts of Georgia.

SOILS

The characteristics of the soil in an area are always significant in 

determining the amount of erosion from the land. Sandy soils absorb 

precipitation rapidly and reduce the water available for transportation of soil particles. Clayey soils, on the other hand, tend to shed 

water, and thereby cause a large part of the rainfall to run off the 

land surface. Figure 4 shows the types of surface soils in Georgia. 

Most of the information in this report regarding soils in Georgia was 

obtained from Carter and Giddens (1953).

The grain-size distribution of soil particles is important in determining how effective surface runoff will be in transporting material 

from the land and out of a drainage basin. Coarse-grained sand, 

granules, pebbles, and large rock fragments commonly move by rolling 

or slumping downslope under the influence of surface runoff. Because 

these materials move at velocities which are much less thar that of 

the water, they travel downslope only short distances dur; ng each 

period of rainfall. The fine-grained fraction of the soil, however,
GENERAL FACTORS AFFECTING SEDIMENT YIELF 11

can be held in suspension in water draining off the land surface and 

hence will move at or near the velocity of the water. Grains which 

are intermediate in size will move partly in suspension and partly by 

rolling and bouncing.

EXPLANATION

Count'' lines

'Undary lines of physiographic 

provinces ?nd sections

 1.0 

Lines of ecual relief, 

n feet per square mile

N

FLORIDA

FIGURE 3. Average relief per square mile in Georgia.

Clay and silt-sized particles can be carried into the strerms and out 

of a local drainage basin during one storm period, and it is this type 

of material which constitutes much of the suspended load in Georgia 

streams. Thus, large concentrations of suspended sedimert are found 

only in stream waters that run off soils containing a sigrificant proportion of fines.
12 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

It should be emphasized that the grain size of particles tH.t can be 

carried in suspension will vary with the velocity and turt ilence of 

a stream. In mountain areas coarse sands may be carried in suspension, but on the Coastal Plain even coarse silt may move mainly as 

bed load.

EXPLANATION

County lines

Boundary lines of physiographic

provinces and sections

see /Yff 1)

j__NORTH CAROLINA

SANDY LOAM, ' 

0

>v--\ ^

-~-i_t^_t___

FLORIDA 

FIGUEB 4. Surface soils in Georgia. The first name given is that of the most common soil 

type; other names show range of types present. Adapted from Carter and Giddens 

(1953).

COVER

The type of vegetation covering the land influences greatly the force 

with which rainfall strikes the ground. The presence of rootlets 

which cling to soil particles is also a factor in holding the soil in place. 

Although no detailed information is available concerning the type of
GENERAL FACTORS AFFECTING SEDIMENT YIELD 13

cover in various parts of Georgia, areas in which bare soil is exposed 

at least part of the year and areas which are covered throughout the 

year have been distinguished on maps (figs. 5, 6) showing distribution 

of "croplands" and "harvested croplands" in Georgia. The maps are 

based on data published by the U.S. Bureau of the Census (1956). 

Figure 5 shows the distribution of total cropland as a percent of the 

land area; this figure was prepared by calculating the percent of 

cropland in each county and plotting these percentages at the center 

of each county. The resulting map was contoured to emphasize the 

continuity and trends of the croplands in Georgia. (Croplands are 

those farmlands from which crops are harvested, those used only for 

pasture, and those not harvested and not pastured. Excluded are 

woodlands and rough or brush lands.) Figure 6 shows the percentage 

of harvested cropland during 1954. Much of the harvested cropland 

is cultivated and exposed to erosion during at least part of the year; 

hence, the harvested cropland can be considered as a measure of the 

"credible farmland." The term "harvested cropland," as used here, 

includes land from which crops were harvested, land from which hay 

was cut, and land in small fruits, orchards, vineyards, nurseries, and

greenhouses.

DETENTION RESERVOIRS

The presence of dams and reservoirs in a drainage basin can be a 

major factor in the control of sediment yield from the basin. One 

or more dams have been built on most major Georgia rivers, and there 

are more than 27,000 farm ponds on the small streams (Thomson 

and others, 1956, p. 197). The efficiency with which the various reservoirs trap sediment is related to the ratio of the reservoir capacity to 

the rate of inflow. Brune (1953) has shown that the trap efficiency 

for large reservoirs is in the .ranges 30 to 57, 78 to 94, and 94 to 100 

percent for capacity to annual-inflow ratios of 0.01, 0.1, and 1.0, respectively. Preliminary studies by H. P. Guy and others (written 

communication, 1958) suggest that trap efficiency for reservoirs on 

small watersheds generally is in the range 50 to 98 percent.

Thomson and others (1956, p. 192) have indicated that the average 

farm pond in the Piedmont region contains 2.7 million gallons. If 

the average runoff in the Piedmont region is 0.8 mgdsm and the average drainage area of the farm ponds is in the range 50 to 200 acres 

(estimated), then the capacity to annual-inflow ratio for the average 

farm pond ranges from 0.03 to 0.12. Brune's (1953) data indicate 

that, under these conditions, trap efficiency would range from 57 to 94 

percent. Therefore, based upon the studies by Brune and Guy, a 

reasonable estimate for the trap efficiency of Georgia farm ponds is 

probably about 80 percent.
14 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

TENNESSEE / NORTH CAROLINA ~/>^y,"- r*r^.tt**»?jf*-jff* J -, 7 ' ~ ' T1 ' ~ ~ -

ir>Fi ^ EXPLANATION

r~~~ PERCENT County lines CROPLAND

^Boundary lines ef physiographic NX\N

provinces and sections fVvVS

(see fig. 1) 45.50

30-45

15-30

0-15

20 0 20 40 60 MILES 

I I I I I ____ j ____ | ____ |

FLORIDA

FIGURE 5. Percent of land in Georgia classified as cropland. From U.S. Bureau of

Census (1956).

According to Brune (1953), the trap efficiency of Lloyd Shoals 

Reservoir on the Ocmulgee River is about 81 percent and that of Hiwassee Reservoir on the Hiwassee River is about 98 percent. It seems 

probable that the trap efficiency of most other large reservoirs in Georgia is in the same range.
GENERAL FACTORS AFFECTING SEDIMENT YIELD

EXPLANATION 

County lines

15

nr~7T7T TENNESSEE I NORTH CAROLINA - J-T 

Boundary lines of physiographic

provinces and sections

(sec fig. 1)

PERCENT HARVESTED 

CROPLAND

FIGURE 6. Percent of land in Georgia classified as harvested cropland. From U.S. Bureau

of Census (1956).

An estimate of the proportion of runoff which passes through farm 

ponds can be made by using data supplied by Thomson, and others 

(1956, p. 198-203) concerning the number of farm ponds in each 

county and by assuming an average drainage area per farm pond. To 

prepare figure 7, the drainage area of each farm pond was assumed 

to be 100 acres and the percentage of land in each county upstream 

from a pond was calculated. If the estimate of 100 acres for the 

average drainage area is nearly correct, in most parts of Georgia only 

a minor proportion of the runoff passes through farm ponds.
16 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

EXPLANATION

PERCENT OF AREA FROM 

WHICH RUNOFF PASSES 

THROUGH FARM PONDS

FIGUEE 7. Map of Georgia showing percent of land area from which runoff passes through 

farm ponds. An average of 100 acres upstream assumed for each pond.

The locations of dams on streams with drainage areas of 100 square 

miles or more are given on figure 8. There are also many dams on 

streams having drainage areas of less than 100 square miles but 

greater than that of a single farm pond. Little up-to-date information 

is available concerning the location and number of these intermediatesize dams.

In summary, it seems probable that the sediment deposited in 

Georgia farm ponds does not greatly exceed 10 percent of the total 

carried by Georgia streams. Because one or more large dams are 

located on many of the major rivers, perhaps as much as 50 percent 

of the stream sediment is trapped in reservoirs and is not carried out 

of the State.
CHANNEL CHARACTERISTICS 17

SAVANNAH

FIGURE 8. Reservoirs on streams in Georgia having a drainage area greater than 100

square miles.

CHANNEL CHARACTERISTICS

The sediment yield from a drainage basin represents the material 

eroded from the land surface as modified by the effects of gains or 

losses in the stream channel. If a stream is near equilibrium, about 

as much sediment will leave a drainage basin annually as is washed 

into the stream channels. However, many streams are net in equilibrium, either because changing conditions alter the volume of sediment 

supplied to the stream or because the sediment-carrying capacity of 

the stream is varied.

Soil conservation practices have reduced land erosion in Georgia, 

in recent years and the supply of stream sediment has decreased. 

Streams which previously had been in equilibrium or were depositing 

sediment along their channels now may tend to erode their beds. Such
18 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

a condition can result in a measured-sediment yield greater than the 

amount of sediment presently being washed into the channel system.

Similarly, dam construction can temporarily overload the sedimentcarrying capacity of a stream, but, after a dam is completed, most 

sediment will be deposited in the reservoir and the stream will be 

capable of eroding its bed downstream from the dam.

Even very large floods which tend to deepen stream charnels may 

cause streams to be out of equilibrium for several years Hiile bed 

material is being deposited again. Thus, over a period of years the 

sediment yield from a drainage basin may equal the sediment carried 

into the stream channel system, but on a short-term basis equilibrium 

conditions probably are uncommon.

PHYSIOGRAPHIC PROVINCES AND THEIR 

CHARACTERISTICS

Topography, climate, soils, and other factors affecting sediment 

yield vary considerably throughout Georgia. However, the State can 

be divided into areas within whch these factors are fairly uniform. 

For the purpose of this study the physiographic provinces and sections 

defined by Fennemau (1938) and Thomson and others (1956, p. 68-70) 

have been considered to be such areas. The boundaries of tH.se areas 

are shown on figure 1 and each is described below.

BLUE RIDGE

The Blue Ridge province is mountainous and has deep narrow 

valleys. The topography is mature. Rocks underlying the area include slate, quartzite, conglomerate, biotite gneiss, phyllite, schist, 

granite gneiss, and smaller amounts of granite, marble, and hornblende 

gneiss. On weathering, these rocks form soils ranging from sandy 

loam to clay loam. Where covering vegetation is removed, the soil 

erodes easily and supplies considerable quantities of fine particles 

which are carried away in suspension. The great relief and abundant 

rainfall result in high water velocities and great sediment-transporting 

capacity in the streams. The low percentage of land which is under 

cultivation, however, means that relatively little of the soil h exposed 

to direct rainfall. There are several large reservoirs in the Blue Ridge 

province but comparatively few farm ponds.

VALLEY AND RIDGE

The folded beds of shale, sandstone, and carbonate which characterize the Valley and Ridge province resulted from the thrust of forces 

from the east against the more stable area of the Cumberland Plateau 

(Butts and Gildersleeve, 1948, p. 56). Solution and erosion of carbonate and shale beds have produced gently rolling to almost level
PHYSIOGRAPHIC PROVINCES AND THEIR CHARACTERISTICS 19

valleys between ridges of resistant sandstone and quartzite. Some 

streams flow across the area from the Blue Ridge and the Cumberland 

Plateau; others originate within the province. Many of the streams 

are only a fe\y feet below the level of the valley floor, and there is 

relatively little potential energy available for transporting sediment 

off the valley lands. Ridges rise as much as several hundred feet 

.above the valley bottoms, but most are covered with vegetation so that 

comparatively little land is exposed to rapid erosion. The sharp 

change in slope from ridge flank to valley floor probably causes deposition of much of the sediment that is removed from the ridge slopes. 

Soils in the Valley and Ridge province range from very fine sandy 

loam to silt-clay loam, and can be easily transported by flowing water. 

Average annual rainfall is 54 to 56 inches and runoff is approximately 

1.0 mgdsm. The number of farm ponds is about average for the State, 

but large dams are few. About 25 percent of the area is cropland.

CUMBERLAND PLATEAU SECTION OF APPALACHIAN PLATEAU

Only the extreme northwestern corner of Georgia lies ^ithin the 

Cumberland Plateau. The area is underlain by beds of sandstone, 

shale, coal, and limestone which show very little folding, in contrast to 

the rocks of the Valley and Ridge province. Average annual rainfall is about 54 inches and runoff is a little more than 1 mgdsm. As 

indicated by the name, the region is a plateau which is cut by narrow 

valleys. Soils consist of sandy loam and silt loam. Only about 11 

percent of the area is in cropland and 7 percent is harvested cropland. 

Drainage in the province is mainly to the north and west. No sediment samples from this area were collected by the writer.

PIEDMONT

The Piedmont province includes about one-third of Georgia. Average annual rainfall ranges from 46 to 60 inches and runoff from much 

of the area is in the range 0.70 to 0.90 mgdsm. The topography is 

gently rolling to very hilly, and relief is great enough to provide the 

energy needed for transportation of sand, silt, and clay. The soil 

ranges from sandy loam to clay loam and is easily eroded when the 

covering vegetation is removed. The proportion of land under cultivation varies considerably throughout the province, depending upon 

topography and soil type (see fig. 6). A zone trending southwestward 

from Hart County contains more cultivated land than other areas in 

the Piedmont. The number of farm ponds is about average for the 

State; however, most of the major dams in Georgia are on rivers in the 

Piedmont, and therefore much of the Piedmont sediment yield is 

trapped in reservoirs and not carried out of the province.
20 SEDIMENT TRANSPORTED BY GEORGIA STREAMP

COASTAL PLAIN

The Coastal Plain can be conveniently divided into upper and lower 

sections as shown on figure 1. In the northern part of the upper 

Coastal Plain, the "sandhills" region, the topography is rolling to 

hilly, the soils are very sandy, and little farming is done. South of 

the sandhills region, the topography is rolling to nearly level, and the 

soils range from sandy loam to clay loam, the sandy soils being most 

common in the southern part of the upper Coastal Plain. Large areas 

of the upper Coastal Plain are suitable for mechanized large-scale 

farming operations. Much of the lower Coastal Plain is nearly level, 

and some of the land is poorly drained. A part of the area is covered 

by forests, and little of the sandy soil in the southeastern part of the 

lower Coastal Plain is farmed. Average annual rainfall ranges from 

46 to 54 inches in the upper Coastal Plain and from 48 to 50 inches in 

the lower Coastal Plain. Runoff is generally 0.5 to 0.8 mgdsm in the 

upper Coastal Plain and 0.4 to 0.6 mgdsm in the lower Cosstal Plain. 

A few dams have been built on the Flint and Chattahoochee Rivers 

where they lie on the upper Coastal Plain, but no major reservoirs are 

present in the lower Coastal Plain of Georgia.

METHODS AND ACCURACY OF SAMPLING

SUSPENDED LOAD

Most of the samples of suspended sediment were taken vdth a U.S. 

DH-48 or D-43 sampler. In a few instances a U.S. D-49 sampler 

was used. All these samplers, when lowered to the stresmbed and 

raised again at a constant speed, collect a quantity of wate^-sediment 

mixture which is a depth-integrated representation of the streamflow 

at the time and place sampled.

The concentration of suspended sediment varies from point to point 

across a stream, but the magnitude of the variation is dependent both 

upon the size distribution of suspended sediment (coarser sediment 

causes greater variation) and upon the nature of the individual 

stream. Ideally, a large number of samples should be collected at 

different points across a stream to determine its average sediment concentration but, practically, only three to five samples could be collected. Thus the concentration determined is an approximation of 

the true average suspended-sediment concentration. The range in concentration among the samples collected was considered an indication 

of the magnitude of the variation present across the stream and, 

hence, an indication of the probable accuracy of the measurements.

At most sites selected for sampling, the actual sampling points were 

determined by estimating, either visually or from stream-discharge 

measurement notes, the position of imaginary lines which would divide the stream into six parallel substreams of equal discharge.
METHODS AND ACCURACY OF SAMPLING 21

Samples were collected at points dividing the first and second substreams, the third and fourth substreams, and the fifth and sixth 

substreams. If five samples were desired, the stream was divided 

into 10 imaginary substreams of equal discharge and samples taken 

between the first and second, third and fourth, fifth and sixth, seventh 

and eighth, and ninth and tenth substreams. Samples taken as described above are said to have been taken at three or five centroids of 

discharge.

Suspended-sediment data from five Georgia rivers obtained at single 

verticals showed that during at least 80 percent of the tim?- any one 

sample could be expected to have a concentration within 40 percent 

of the average of samples collected at three centroids. These data 

indicate that at a given time there is considerable variation in concentration of suspended sediment within the cross section in Georgia 

streams. Thus, a measurement of suspended-sediment concentration 

made at only one vertical can deviate appreciably from an average 

of three or more measurements.

TOTAL SEDIMENT LOAD

Though the sediment transported along or within 0.3 foot above 

the streambed is not sampled when suspended sediment is collected, 

the suspended-sediment load is calculated by multiplying the suspended-sediment concentration by the total water discharge; this 

computation accounts for a part of the sediment transported in the 

lower 0.3 foot of the stream. The difference between the total sediment 

load and the calculated suspended load consists of particles moving in 

substantially continuous contact with the streambed and of particles 

which progress by a bouncing action just above the streambed. The 

sediment which moves by bouncing is probably an insignificant fraction of the total load (Benedict, 1957, p. 897; Kalinske, 194-2, p. 641- 

643). For the purposes of this study the total sediment load will be 

considered to be composed of just two parts, bed load and suspended 

load.

No method of direct measurement of bed load is available which 

is practical for general use in a study of this type. However, estimates 

of instantaneous bed load can be made using the modified Einstein 

method as described by Colby and Hembree (1955), if the following 

date are available for a particular time:

1. Stream width, average depth, and mean velocity.

2. Average concentration of suspended sediment.

3. Size analyses of the suspended sediment.

4. Average depth at the verticals where suspendei 

sediment samples were collected.

5. Size analyses of the bed material.

6. Water temperature.
22 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

The modified Einstein method has been checked for accuracy on 

sand-bed streams in the western United States where the stream characteristics may be different from those of Georgia streams. Therefore, 

the probable accuracy of this method when applied in Georgia cannot be stated. However, the modified Einstein method has been used 

in this report because it is probably the best method nov available 

for an estimate of either the total load or bed load.

DATA FROM SAMPLING SITES

Sediment data from Georgia streams were collected with a view to 

obtaining detailed information concerning a few streams and some 

general information about many streams. By applying knowledge 

gained about the relation of sediment concentration to water discharge 

in the detailed studies to streams for which only sparse data were 

available, it was possible to draw conclusions about sediment conditions throughout the State.

The locations of all the sampling sites are shown on figure 9; other 

information regarding the streams studied is given in tam 4.

Sites designated on table 4 as frequently sampled are tl ose where 

local observers were asked to collect suspended-sediment samples at 

least once every 5 days during periods of little change in discharge. 

When the discharge was changing rapidly, samples were to be collected with every foot of rise or fall in gage height. Although all the 

desired information was not obtained, it was still possible to gain some 

understanding of the relation of suspended-sediment concentration 

to water discharge at these sites.

At other sites listed in table 4, water samples were obtained at less 

frequent intervals, commonly when a Survey representative visited 

the station in connection with other dutes.

SITES OF FREQUENT SAMPLING 

BROAD RIVER NEAR BELL, GA.

The Broad River (see fig. 9) lies entirely within the Piedmont 

province and drains an area of rolling to hilly topography. About 

30 percent of the area is cropland and 20 to 25 percent is harvested 

cropland. Topsoils range from sandy loam to clay loam of the Cecil, 

Lloyd, Appling, and Madison series which have developed en granite, 

gneiss, and schist of varied composition. Farm-pond capacity averages 0.6 to 0.7 mgsm, and average daily runoff is 0.74 mgdsra.

Suspended-sediment concentration. Water samples were obtained 

from the Broad River during the period December 1957 to May 1959. 

The variation in sediment concentration across the Broad River was 

studied by averaging the concentrations of the samples collected at 

three centroids of discharge and determining for each sample set the
DATA FROM SAMPLING SITES 23

maximum percentage deviation of any one sample from tH average. 

This study showed that, of the 60 sample sets suitable for the study, 

67 percent of the sets contained no samples differing from the average 

concentration by more than 23 percent, and 95 percent differed by 

no more than 40 percent. The study showed, furthermore, that samples taken at the south centroid contained the lowest suspendedsediment concentration 65 percent of the time and those trken at the 

middle centroid had the highest concentration 52 percent of the time. 

These figures indicate that the measured variation in suspended sediment is not entirely due to random sampling errors but, rather, that 

the concentration normally is lower than average at the sou^h centroid 

and higher than average at the middle centroid.

EXPLANATION

FIGURE 9. Index map of Georgia showing location of sampling sites.
24 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

TABLE 4. Drainage area and physiographic province(s) above each sampling site

No. (fig. 9)

1

2

3

4

5

6

7

8

9

10

11

12 

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

Sampling site

Name

Brier Creek at Millhaven _____

Louisville.

ville. 

Ogeechee River near Eden J _

ton.

City.

Towns.

f""if*impp T? i VPT* n POT* {"TTPPTICI 

boro.

ville. 

Slash Creek near Mclntyre L_

Toomsboro.

Vernon.

ville.

town.

Little River near Adel __

Thomasville.

Leaf.

nega.

lanta.

Point. 

Flint River near Griffin

bulette Creek near Butler.

Milford. 1

Coosa River near Rome____ _

ville.

Drainage area above

sampling site 

(sq mi)

1,430-- 

646 

286 

800 

2,650 - 

555 

o 94.0

5,180--- 

329 

1,090_- -__ ___

2,950-.. 

Not determined191 

5,110 . 

1,110.--- -

13,600-._---___

2,790-----.----

663. -- -

547 - -

550 -- 

150 

153_-----------

1,450 _. __ .-

3,550-_--------

272

1,850---. 

93.4_.--__ 

2,900---. 

620- -_ _ - --_

1,625 2 -.-. 

605____-__-----

4,040.---------

193 . 

Physiographic prov ince(s) containing major part of drainage area above sampling site

Piedmont.

Coastal Plain.

Do.

Do.

Do.

Do.

Piedmont.

Coastal Plain, Piedmont. 

Coastal Plain.

Piedmont.

Do.

Coastal Plain. 

Do.

Coastal Plain, Piedmont. 

Coastal PI? in.

Coastal Plain, Piedmont. 

Coastal Pip in.

Do.

Do.

Do.

Blue Ridge, Piedmont. 

Do.

Piedmont, Blue

Ridge. 

Piedmont.

Do.

Do.

Coastal Plain.

Piedmont.

Coastal Plain.

Valley and Ridge,

Piedmont. 

Piedmont.

Valley and Ridge,

Piedmont. 

Valley and Ridge.

1 Station sampled frequently.

2 Approximate.
DATA FROM SAMPLING SITES 25

Average concentrations of suspended sediment at sampling dates 

during 1957-59 are given in table 5. Average discharge for the periods 

1928-31 and 1937-57 was 1629 cfs (U.S. Geological Survey, 1959a).

TABLE 5. Concentration of suspended sediment in samples from the Proad River

near Bell, Ga.

Date

1957 

Dec. 11 . _ . ___ .....

1958

Jan, 14..... ___ .. __ .

Jan. 29. ___________

Feb. 11.... ___ ... __ .

Feb. 27 __ . __ ... .....

Mar. 6_.__...__--_.._._...

Mar. 12.... ___ .... __ .

Mar. 25 ... ____ . _ ..

Apr. 15. __ . ..... _ ..

Apr. 23. __ . _ . _ . .....

Aug. 27 

Sept. 21... .. _____ .

Oct. 31...... _ . _ . __ .

Nov. 17. . ______ ...

Dec. 16..... _ . __ . _ .

Dec. 19 ___________

Dec. 26..... __ .. .. 

Dec. 29 ___________

Dec. 30 . __ . .........

Dec. 31... ................

1969

Jan. 11...... _ . __ . ...

Jan. 18... ................

Jan. 22........ ____ . ...

Jan. 23. -....- ..-... .

Jan. 26... .... ... .

Feb. 1 .................

Feb. 4....... .............

Feb. 4... _ ........... ...

Feb. 5 .............

Feb. 6 ......

Feb. 7... .

Feb. 8. __ ........ ......

Feb. 9 .................

Feb. 11... ............. ...

Feb. 13 .. _ ... .....

Feb. 13.......... .

Feb. 13..... ...........

Instantaneous 

discharge 

(cfs)

2,450

1,750

1,200

2,000

1,950

8,400

1,700

2,650

5,500

2,800

3,000

940

440

460

565

605

680

640

620

670

1,990

1,980

1,240

955

925

795

780

930

760

1,300

1,660

2,520

2,150

1,300

1,000

910

1,820

2,600

2,750

1,630

1,250

1,300

1,300

4,200

5,500

6,450

Suspendedsediment 

concentration (ppm)

116

43

19

72

82

510

36

56

122

96

89

29

26

9

14

10

15

11

10

13

227

158

111

57

415

23

25

34

20

165

185

335

405

160

60

40

154

234

199

137

76

51

37

46

226

277

389

Date

1959 (continued)

Feb. 13 .. 

Feb. 14 ___________

Feb. 14 __________ .

Feb. 15 _____ . ........

Feb. 16. . _ ....

Feb. 21 __ . _ . .........

Feb. 26 __ . ______ .

Mar. 6 ___ . .............

Mar. 6 . 

Mar. 6 __ . _______

Mar. 7. ................

Mar. 8.. .................

Mar. 9 __________

Mar. 12 _____ . ........

Mar. 15 __________

Mar. 16 __________

Mar. 16 

Mar. 17.. .................

Mar. 18 . ...............

Mar. 19. ______ ...

Mar. 21- ______ ....

Mar. 26.. _____ . _ ...

Mar. 27 ..... ...... .....

Mar. 27 . ..............

Mar. 30..._._. ._ .

Mar. 30 

Mar. 31 ..............

Apr. 1 _ . ______ . ...

Apr. 2. ______ . .......

Apr. 3 ... 

Apr. 11 _ . ___ . ........

Apr. 13 ...-.._.. ...-...

Apr. 13...- ...............

Apr. 14 _____ ..

Apr. 14 

Apr. 15 _ . ...............

Apr. 16 __ . ............

Apr. 21 __ . _ . ___ ...

Apr. 23 ...................

Apr. 27 __ . __ __ -

May !._.__ ____ .... ...

May 12- _ . _ . __ . ...

May 13 ____ . __ .

May 13. __________

May 14. _____ ..... ...

Instantaneous 

discharge 

(cfs)

7,600

8,450

8,200

6, 3DO

3,100

l,2i?0

1,030

ftJO

3,180

3,730

4, 2oO

4,150

2, 550

l,5fO

1,6'0

2, 400 4,4^>0

5, 000

4, 200

2,4)0

1,750

1,4'Q

1,100

1,8110

1,9'0

2, 8*0

3, 100

3,010

2, 100

2,7oO

2, 5^0

1, 8'0

1,410

1, 110

4,120

4,810

5, 3-0

4,5)0

2,2fO

1,710

1,600

1,310

1,010

950

730

610

1,430

2,210

1,410

1,390

Suspendedsediment 

concentration (ppm)

450

466

300

231

187

42

33

35

153

158

174

211

105

64

56

118

236

360

285

116

57

45

34

113

103

84

108

95

75

102

96

73

51

31

487

565

354

226

111

88

72

59

33

51

27

42

248

187

107

108

The relation of stream discharge to concentration of suspended 

sediment is shown in figure 10. The position of the solid line was 

obtained by inspection. The line represents the median of concentration for a given water discharge, and points falling on this line are 

presumed to represent the most probable concentration for a given 

water discharge rather than the average concentration. Combination 

of the data in figure 10 with flow-duration curves (cumulative frequency curves that show the percent of time during which specified

695-903 64 3
26 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

discharges were exceeded or equaled in a given period, Searcy, 1959) 

for the Broad Kiver during the periods 1950-55 and 1958-59 permits 

the preparation of two concentration-frequency curves. Although 

these curves differ somewhat, they are of value in determining the 

percent of time that the concentration of suspended sediment is equal 

to or less than any certain value. For example, figure 11 shows that, 

for the 1959 water year, the concentration of suspended sediment was

600

500

400

300

z

o

3 200 

I

IE

ff 150 

w

or 

<

0.

S 100

£ 90

g 80

S 70 

w

S 60

a

5 50

I 30

PO O

 

Ol

I

400 600 800 1000 2000 4000 6000 8000 10,000

DISCHARGE, IN CUBIC FEET PER SECOND, AT THE TIME OF SAMPLING

FIGURES 10. Relation of stream discharge to concentration of suspended sediment in 

samples from the Broad River near Bell, Ga.
DATA FROM SAMPLING SITES 27

less than 16 ppm during 40 percent of the time and less than 84 ppm 

during 90 percent of the time. Because the character of the flowduration curve changes from year to year and the relation of water 

discharge to concentration of suspended sediment shows considerable 

variation, a concentration-frequency curve for any one year is only 

an approximation of a long-term curve.

Size distribution of suspended sediment. Particle-siz*. analyses 

were made for 18 samples of suspended sediment taken during 16 

river observations (table 6). Three of the samples were analyzed in 

native water and the others were dispersed and analyzed in distilled 

water. The analyses in native water were made to indicate the degree 

of flocculation which might be expected during deposition under natural conditions. Analyses in distilled water containing a dispersing 

agent were made to show the ultimate particle-size distribution in the 

samples under conditions of no flocculation. Samples 3 to 11 were 

taken at various times during and after the storm of Feb. 13,1959, to 

determine whether there was a systematic change in particle size with 

stream discharge.

5

o

w

LU 80

20

I I

Based upon a flow-duration f 

curve for 1959 water year "v

- Based upon a flow-duration 

curve for 1950-55 water years

I I I I

5 10 20 50 100 200

CONCENTRATION OF SUSPENDED SEDIMENT. IN PARTS PER MILLION

FIGURE 11. Suspended-sediment concentration-frequency curve for the Brord River near

Bell, Ga.
TABLE 6. Particle-size analyses of suspended sediment, Broa

[Method of analysis: B, bottom withdrawal tube; N, in native water; W, in distilled water; C, che

Sample

1

2

3 

4

5 

6 

7

8 

9 

10 

11 

12

13 

14 

15 

16 

17 

18

Date of collection

1958 

Feb. 27

1959 

Feb. 13 

Feb. 13 

Feb. 13

Feb. 13... 

Feb. 13 

Feb. 14 

Feb. 14 

Feb. 15

Feb. 16 

Mar. 7 -

Mar. 15 

Mar. 16

Mar. 18 .

Mar. 19 

Apr 13

Apr. 14

Time

12:50 p.m. 

12:50

8:00 a.m. 

1:00 p.m. 

1:00 

4:30 

9:30

8:30 a.m. 

7:00 p.m. 

7:00 

7:00 

10:15 a.m.

3:30 p.m. 

3:30 

7:50 a.m. 

7:15 

10:00 

7:00

Discharge 

(cfs)

8,400 

8,400

4,200 

5,500 

5,500 

6,450 

7,600

8,450 

8,200 

6,300 

3,100 

4,150

2,400 

4,480 

2,400 

1,750 

4,120 

5,350

Water 

temperature 

(°F)

53 

53

47

48 

48 

49 

49

49 

53 

51 

54 

48

54 

51 

48 

48 

59 

52

Suspend

Concentration of 

sample 

(ppm)

422 

502

245 

320 

258 

454 

388

538 

363 

209 

156 

261

112 

461 

140 

67 

535 

391

Concentration of 

suspension 

analyzed 

(ppm)

443 

453

208 

297 

271 

361 

327

463 

342 

154 

162 

245

129 

538 

169 

86 

686 

455

Perc

0.004

70

49

46 

48 

36 

40 

36

32 

38 

35 

38 

51

42 

56 

52 

33 

44 

50

0.008

76 

67

54 

56 

52 

48 

50

44 

47 

43

49 

62

60 

64 

60 

47 

57 

54

0
DATA FROM SAMPLING SITES 29

The variation in concentration of suspended sand, silt, and clay 

with water discharge from February 13 to 16,1959, is shown in figure 

12. All samples, with the exception of the one collected at 9: 30 p.m. 

011 February 13, were taken at the middle centroid of discharge 

(samples analyzed in native water for particle-size distribution are 

not shown in fig. 12). The concentration of suspended clay was 

considerably higher than that of sand or silt during the early part 

of the rise in discharge. As the discharge continued to rise, however, 

the proportion of suspended sand increased rapidly and was probably 

about equal to that of the clay just prior to the discharge peak. The 

silt concentration lagged behind that of both the sand and clay during 

the early part of the discharge rise, but probably equaled or exceeded 

the sand and silt near the discharge peak.

EXPLANATION

® 9

Sand Clay

Silt

0

Discharge

10,000

6000

4000 O

2000

12p.m. 12m. 12p.m. 12m. 12p.m. 12m. 12p.m. 12m. 12p.m. 

FEBRUARY 13 FEBRUARY 14 FEBRUARY 15 FEBRUARY 16

FIGURE 12. Variation of water discharge and concentration of suspended sand, silt, and 

clay in Broad River ne&r Bell, Ga., Feb. 13-16, 1959.

The concentration of suspended sediment in a sample collected at 

9: 30 p.m., February 13 at the south centroid of discharge apparently 

would not plot on a curve of sediment concentration for the middle 

centroid of discharge. The difference in concentration of suspended 

sediment at the two sampling points is believed to result from differences in flow characteristics and from the fact that an important 

tributary enters the river from the south approximately 1 mile 

upstream from the sampling site.

Suspended-sediment load. Water samples were collectei from the 

Broad Eiver during the period Dec. 16, 1958, to May 15, 1959, in 

sufficient number to permit an estimate of the suspendei-sediment 

load. The daily sediment loads are shown in table 7, and a sediment 

transport curve showing the relation of daily mean discharge to daily 

suspended load is given in figure 13. The calculated total suspendedsediment load of the Broad River during this period was about 75,000 

tons. Size analyses of suspended sediment indicated that the sediment
30 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

10,000

8000

6000

4000

2000

1000

800

600

400

200

100

80

60

40

20

15

10

 t.

500 1000 2000 4000 6000 10,000

MEAN DAILY DISCHARGE, IN CUBIC FEET PER SECOND 

FIGURE 13. Suspended-sediment transport curve for the Broad River near Bell, Ga.
DATA FROM SAMPLING SITES 31

TABLE 7. Daily suspended-sediment concentration and load, Broad River near 

Bell, Ga., Dec. 16,1958, to May 15,1959

[Suspended-sediment concentration estimated from curve shown on fig. 10 except r^here otherwise

indicated]

Day

1.. .....

2 __ - .....

3

4. ...

5. .........

6...... ....

7. . .....

8 .......

9..........

10 .

11.... ..

12.... _ ..

13.... __ .

14. 

15..-. __ .

16.. ___ .

17. .

18.. ___ .

19 

20 ____ .

21 

22...... ...

23..... _ .

24..... ....

25... ......

26...- ....

27...- __

28 

29 _ 

30.. ....

31- . .

Total ...

1....... ...

2 _ . ......

3... _ ....

4 

5 ...

6 ...

7.. __ ....

8.. ___ ..

9 .....

10. __ . _

11 __ . ...

12 __ .....

13 ....

14 

15... ......

16 

17 

18 __ -

19 

20 .... .

21... ......

22 _

23. 

24... __ ..

25 .....

26 ......

27 ......

28- 

29

30.. ___ .

31... ......

TotalMean 

discharge 

(cfs)

Suspended sediment

Mean 

concentration 

(ppm)

Load 

(tons)

December

680 

640 

640 

640 

620 

600 

600 

600 

620 

680 

680 

640 

820 

1,700 

1,430 

1,020

12, 610

 16 

13 

11 

«11 

11 

 10 

10 

10 

11 

12 

 12 

11 

24 

 163 

 148 

 76

..........

29 

23 

19 

19 

18 

16 

16 

16 

18 

22 

22 

19 

 54 

 810 

 602 

209

1,913

March

945 

920 

895 

870 

1,370 

3,480 

4,060 

2,620 

1,820 

1,400 

1,250 

1,640 

2,140 

1,640 

1,900 

4,510 

3,720 

2,300 

1,700 

1,520 

1,460 

1,430 

1,280 

1,200 

1,120 

1,120 

1,640 

2,140 

1,640 

2,860 

2,860

59, 450

31 

 31 

30 

30 

51 

 159 

 197 

 105 

 57 

50 

38 

 61 

87 

53 

 87 

 284 

 259 

 104 

 57 

51 

 45 

42 

42 

41 

38 

 34 

 86 

112 

69 

 89 

 93

78 

77 

73 

71 

 252 

 1,500 

 2,140 

 750 

280 

189 

128 

270 

503 

234 

 515 

 3,100 

 2,700 

 686 

262 

209 

177 

162 

145 

133 

115 

103 

 438 

 652 

 314 

 673 

 740

17,669

Mean 

discharge 

(cfs)

Suspended sediment

Mean 

concentration 

(ppm)

Load 

(tons)

January

920 

1,200 

1,340 

1,070 

945 

845 

795 

770 

845 

895 

820 

770 

745 

720 

700 

895 

1,170 

970 

845 

795 

795 

1,430 

1,520 

1,520 

1,170 

1,040 

970 

920 

870 

845 

870

30,005

 47 

59 

66 

48 

33 

 22 

20 

19 

24 

31 

 25 

24 

24 

25 

25 

32 

50 36 

28 

25 

 21 

 142 

 335 

 227 

126 

 56 

50 

44 

39 

28 

33

117 

 191 

239 

139 

84 

50 

43 

40 

55 

 74 

55 

50 

48 

49 

48 

77 

 160 

94 

64 

54 

45 

 600 

 2, 070 

 956 

398 

157 

132 

109 

92 

64 

78

6,436

April

2,140 

2,780 

2,460 

1,820 

1,520 

1,400 

1,280 

1,220 

1,170 

1,120 

1,100 

1,280 

3,810 

5,080 

2,780 

1,760 

1,520 

1,400 

1,400 

1,700 

1,580 

1,400 

1,280 

1,170 

1,120 

1,040 

1,020 

970 

1,040 

1,070

 77 

 103 

 94 

 76 

66 

 53 

50 

45 

40 

36 

 31 

54 

 467 

 383 

 140 

 101 

85 

72 

60 

80 

 79 

67 

 62 

57 

49 

42 

 35 

32 

41 

60

50,430

 464 

 777 

 634 

373 

271 

201 

173 

148 

126 

109 

93 

 199 

 5,040 

5,280 

 1,160 

480 

349 

272 

227 

 368 

337 

253 

214 

180 

148 

118 

97 

84 

 127 

173

18, 475

Mean 

discharge 

(cfs)

Suspended sediment

M°.an 

concentration 

(ppm)

Load 

(tons)

Feb-uary

945 

870 

870 

1,340 

3,100 

2,620 

1,640 

1,220 

1,280 

1,310 

1,280 

1,400 

5,270 

8,200 

6,350 

3,480 

2,380 

1,820 

1,580 

1,430 

1,250 

1,200 

1,120 

1,120 

1,100 

1,040 

995 

970

57,180

 35 

31 

23 

 97 

 216 

 133 

 86 

 53 

 42 

42 

 43 

63 

 285 

 394 

 239 

 195 

168 

138 

101 

67 

 45 

39 

38 

34 

32 

 32 

32 

32

89 

73 

64

 502 

 1, 810 

 990 

381 

174 

146 

149 

149 

 257 

 4,700 

 8,950 

 4,120 

 1, 870 

1,080 

678 

431 

259 

152 

126 

115 

103 

95 

90 

86 

84

27, 712

May

920 

870 

845 

795 

770 

745 

720 

700 

700 

680 

700 

700 

1,400 

1,520 

1,020

13,085

 49 

43 

34 

31 

27 

26 

 25 

24 

22 

20 

29 

 43 

 128 

 108 

60

122 

101 

78 

66 

56 

52 

49 

45 

42 

37 

55 

81 

 675 

 483 

165

2,107

 At least one water-sediment sample was collected on this date and used in estimating the suspendedsediment load.

 Computed by subdividing day.
32 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

was composed of about 24 percent sand, 32 percent silt, and 44 percent 

clay (all percentages by weight). Such material, when deposited in 

a reservoir and kept under water, would weigh approximately 45 Ib 

per cu ft at the end of 1 year and 60 Ib per cu ft at the end of 10 

years (calculated by the method of Lane and Koelzer, 1943). If a 

weight of 50 Ib per cu ft is assumed, the suspended sediment transported would occupy a volume of 3 million cubic feet or about 69 

acre-feet when deposited.

It is unfortunate that sediment sampling on the Broad Kiver was 

discontinued on May 15,1959, for the largest flows by far of the 1959 

water year (October 1958 through September 1959) occurred in the 

period May 26 to June 5,1959. Extrapolation of data obtained from 

Dec. 16,1958, to May 15,1959, indicated that the amount of suspended 

sediment transported during the period May 26 through June 5 was 

from 100,000 to 150,000 tons. Thus, probably more sediment was carried in these 11 days than during the previous 5 months. This fact 

emphasizes the importance of floods in transporting suspended sediment in the Broad Kiver. About two-thirds of the total water discharge for the 1959 water year flowed past the sampling station between Dec. 16,1958, and June 5,1959. Because much of the remaining 

one-third of the total flow passed when stream level and sediment concentration were low, it seems probable that more than 90 percent of 

the sediment load for the water year was carried during the period 

Dec. 16,1958, through June 5,1959.

If approximately 200,000 tons of suspended sediment v^as transported by the Broad River during the 1959 water year, tin average 

amount of sediment removed from the Broad River drainage basin 

was about 140 tons per square mile. Of this tonnage, 52 tons was 

measured and 88 tons was estimated.

The fact that much of the annual sediment load is transported in 

a relatively short period of time is shown by suspended-sedinent loaddistribution curves (fig. 14). Although the load-distribution curve 

based upon the 1959 water year differs from that based upon the 

1950-55 water years, it is evident that about 90 percent of the annual 

suspended-sediment load is carried during only 20 percent of the time, 

and 50 percent or more is carried during 2 percent of the time.

OGEECHEE KIVER NEAR EDEN, GA.

The Ogeechee River heads in the rolling hills of Greene and Taliaferro Counties above the Fall Line and flows southeastward across 

the Coastal Plain. Only about 10 percent of the Ogeecl °-e River 

drainage area is in the Piedmont; the remainder is in the very gently 

rolling to almost level Coastal Plain. Although many names are given 

to soils of the basin, practically all the soils are of sand, lor.my sand, 

or sandy loam. Average runoff is 0.60 mgdsm. Harvested cropland
DATA FROM SAMPLING SITES 33

Based upon a flow-duration,^ 

curve for 1950-55 water years^ /

Z 60 /

/ Based upon a flow-duration 

/ curve for 1959 water year

-J30

10

0.1 0.5 2 5 10 20 30 40 50 60 70 80 90

PERCENT OF TIME

FIGURE 14. Suspended-sedimeat load-distribution curves for the Broad River near Bell, Qa.

is nearly 20 percent of the total land area, and total cropland is 25 

percent. Most of the cropland is in the almost level, ^ell-drained 

middle part of the drainage basin. Less land is farmed in the hilly 

areas above the Fall Line and in the low, poorly drained areas along 

the coast.

Suspended-sediment concentration. The concentration of suspended sediment was 13 ppm or less (and averaged 7.5 ppm) in 

26 samples collected during the period July 7, 1958, to Apr. 24, 1959. 

Average discharge for the period 1937-57 was 2,037 cfs (U.S. Geol. 

Survey, 1959b). The suspended-sediment concentration and instantaneous stream discharge are shown in table 8 and are plotted graphically in figure 15. Correlation between the suspended-seiiment concentration and water discharge is poor. The suspended-sediment 

concentration also shows no consistent variation in the etream cross
34 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

section. Because of the very low concentration of suspended sediment, insufficient material was available for a particle-size analysis. 

The fact that the suspended-sediment concentration does net vary appreciably across the stream, despite considerable variation of stream 

velocity, suggests that the suspended sediment is mostly s: lt or clay 

and that the streambed is composed of coarse-grained material.

Suspended-sediment load. Daily suspended-sediment loads for the 

period Dec. 16,1958, to May 15, 1959, were calculated and are shown

20

200 400 600 800 1000 2000 4000 6000 80.00 10,000

DISCHARGE, IN CUBIC FEET PER SECOND, AT THE TIME OF SAMPLING

FIGUHB 15. Relation of stream discharge to concentration of suspended sediment in 

samples from the Ogeechee River near Eden, Ga.

TABLE 8. Concentration of suspended sediment in samples from the Ogeechee

River near Eden, Ga.

Date

1958 

July 14._____________.__._

Sept. 24 __ .... ___ ....

Dec. 5... _______ ....

Dec. 11 ___________

Dec. 22 ___________

Dec. 27 ...................

1959

Jan. 4.... ________ .

Jan. 11 __ . ___ . __ .

Jan. 17..... . ______ .

Jan. 23 _ ________ .

Jan. 30 __________ .

Instantaneous 

discharge 

(cfs)

2,030

950

345

430

460

630

770

1,050

1, ISO

1,260

1,120

1,270

Suspendedsediment 

concentration (ppm)

10

6

3

6

5

8

6

4

3

4

8

9

Date

1959 Continued 

Feb. 4 _ ... ________

Feb. 5 __ . _________ Feb. 7 ___ . __ . _ . ...

Feb. 9....................

Feb. 16 _ ..... __

Mar. !. . ........ _ . ....

Mar. 6 ... _ ...........

Mar. 10. ........ .......

Mar. 29 ...............

Apr. 24 ______ . .......

Instantaneous 

discharge 

(cfs)

1,670

2 280

4,030

4,31C

4,180

5,860

6.71C

6,98C

6,400

8,450

8.45C

6,33C

5,910

3,110

Suspendedsediment 

concentration (ppm)

13

g

11

8

10

4

8

8

11

10

6

4

9

6
DATA FROM SAMPLING SITES 35

in table 9. The total suspended-sediment load is about 10,000 tons for 

the sampled period but, because the stream discharge during the period 

was approximately 75 percent of the discharge for the ^ater year, 

the total suspended-sediment load for the period October 1958 to September 1959 is estimated at 12,000 to 15,000 tons. This suspendedsediment load corresponds to an annual sediment yieT d for the 

Ogeechee River basin of about 5 tons per square mile.

Size distribution of bed material. Samples of bed material were 

collected from the Ogeechee River on Feb. 9,1959, when th^ discharge 

was 4,000 cfs, or almost twice the average discharge of the river. 

Suitable samples were obtained at only 4 of the 10 stations in the 

cross section selected for sampling. Fortunately, however, these four 

stations were near the middle of the stream where current velocity 

was greatest. The size distribution of particles in the four samples is 

shown in table 10. The sample collected at station 499 may be slightly 

affected by currents swirling about the base of a pier 11 feet away, 

for the particle-size distribution is different from that in the other 

three samples. The average depth of water between stations 455 and 

488 was 12.2 feet, the average velocity 2.87 ft per second, r.nd the discharge approximately 30 percent of the total stream disci arge. Suspended-sediment concentration was 8 ppm.

An estimate of the approximate magnitude of bed lo^d between 

stations 455 and 488 was made by the modified Einstein method 

(Colby and Hubbell, 1957). In the part of the stream studied, the 

bed load was about 13 tons per day and the suspended sediment about 

25 tons per day. It should be emphasized that this estimate of bed 

load may be in error by a factor of two or more because, ar previously 

pointed out, the modified Einstein method has not been tested in deep 

streams in the eastern United States.

SLASH CREEK NEAR McINTYRE, GA.

Although the major purpose of this study was to determine sediment concentration and load in streams which were not markedly polluted, one greatly polluted stream, Slash Creek, was investigated at 

the request of the Georgia Department of Mines, Mining and 

Geology.

Slash Creek (Little Commissioner Creek), a tributary to Commissioner Creek in Wilkinson County, drains an area of rolling to hilly 

topography. Clay mines and clay-processing plants are located in 

the basin and contribute varying quantities of clay to Slash Creek. 

Samples were collected from Slash Creek at a point about 2 miles west 

of Mclntyre, Ga., where a wooden bridge crosses the stream. Two 

samples were collected on alternate days from December 16, 1958, to 

Apr. 1, 1959. A discharge measurement was made at less than average flow on Dec. 16, 1958, and the sample collector was instructed 

to measure the water level each time a sample was collected thereafter.
36 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

TABLE 9. Daily suspended-sediment concentration and load, Ogeetihee River 

near Eden, Ga., Dec. 16, 1958, to May 15, 1959

[Suspended-sediment concentration estimated from curve shown on fig. 15 except wl ere otherwise

indicated]

Day

I....... 

3.. .....

4 .......

5.... ......

6 __ ___

7 . -----

8 

9 ... -

10 

11 

13 

14 

15 - .

16. .

17 

18.- .

19 

20 

21 

22 

23 

24 

25. -

27 

28 

29 

30 

31 

Total 

1 ... 

3 ..... ._

4 

6 

7. ....

8 

9 

10 

11 

12 

13 

14 1 <=,

16 

17 

la

19

20 

21 

22 _____

*>^l

25 __ .

26 

28 

on

30 

31 

TotalMean 

discharge 

(cfs)

Suspended sediment

Mean 

concentration 

(ppm)

Load 

(tons)

December

540 

540 

540 

555 

555 

570 

585 

600 

630 

630 

655 

655 

680 

705 

760 

790

9,890

7 

7 

7 

8 

8 

8 8 

8 

7 

7 

6 

«6 

6 

6 

5 

5

10 

10 

10 

12 

12 

12 

13 

13 

12 

12 

11 

11 

11 

11 

11 

11

182

March

5,180 

5,000 

4,820 

4,480 

4,480 

5,900 

6,200 

7,350 

7,850 

7,850 

7,600 

7,100 

6,900 

7,350 

7,850 

7,650 

7,350 

7,350 

7,000 

6,800 

6,600 

6,300 

6.200 

6,500 

6,800 

6,800 

6,600 

6,300 

6,100 

5,800 

5,300

197, 360

«8 

8 

9 

10 

11 

"11 

11 

11 

10 

«10 

10 

9 

9 

8 

8 

7 

7 

6 

«6 

6 

6 

6 

5 

5 

5 

5 

4 

4 

«4 

4 

4

..........

112 

108 

117 

121 

133 

175 

187 

218 

212 

212 

206 

172 

168 

159 

170 

145 

139 

119 

113 

110 

107 

102 

84 

88 

92 

92 

71 

68 

66 

63 

57

4,186

Mean 

discharge

(cfs)

Suspended sediment

Mean 

concentration 

(ppm)

Load 

(tons)

January

820 

820 

880 

910 

970 

1,000 

1,030 

1,030 

1,000 

1,030 

1,030 

1,060 

1,090 

1,120 

1,120 

1,120 

1,200 

1,200 

1,100 

1,100 

1,000 

1,000 

1,000 

1,100 

1,100 

1,200 

1.200 

1,300 

1,300 

1,300 

1,400

33, 530

5 

4 

4 

 4 

4 

4 

4 

3 

3 

3 

 3 

3 

3 

4 

4 

4 

 4 

4 

5 

6 

7 

8 

 8 

8 

8 

8 

8 

9 

9 "9 

9

11 

9 

10 

10 

11 

11 

11 

8 

8 

8 

8 

8 

9 

12

12 

13 

13 

15 

18 

19 

^2

24 

24 

26 

26 

32 

32 

32 

34

511

April

5,200 

6,000 

6,600 

7,000 

7,000 

7,100 

7,100 

7,200 

7,000 

6,700 

6,400 

6.200 

6.100 

5.720 

5,540 

5,000 

4,480 

4,180 

3,920 

3,700 

3,510 

3,330 

3,150 

2,990 

2,830 

2,690 

2,620 

2,480 

2,360 

2,300

146, 400

4 

5 

5 

6 

6 

7 

7 

7 

8 

8 

9 

8 

 9 

9 

9 

9 

8 

8 

7 

7 

7 

6 

6 

«6 

6 

6 

6 

6 

6 

6

56 

81 

89 

113 

113 

134 

134 

136 

151 

145 

156 

151 

148 

139 

135 

108 

97 

90 

74 

70 

66 

54 

51 

48 

46 

44 

42 

40 

38 

37

2,786

Mean 

discharge 

(cfs)

Suspended sediment

Mean 

concentration 

(ppm)

Load 

(tons)

February

1,400 

1,500 

1,600 

1,800 

2,200 

2,600 

3,100 

3,700 

4,000 

3,900 

4,200 

4,300 

4,480 

4,820 

5,180 

5,540 

6,100 

6,700 

7,100 

7,350 

7,100 

6,700 

6,500 

6,300 

5,900 

5,720 

5,540 

5,180

130, 610

10 

11 

12 "13

«8 

9 11 

10

 8 

8 

7 

6 

6 

5 

4 

«4 

4 

5 

5 

6 

6 

7 

 8 

8 

8 

8 

8 

8

38 

45 

52 

67 

46 

63 

92 

100 

86 

84 

79 

70 

73 

65 

56 

60 

66 

81 

96 

119 

1,150 

127 

140 

136 

127 

124 

120 

112

2,449

May

2,080 

1,980 

1,880 

1,740 

1,620 

1,500 

1,390 

1,250 

1,150 

1,030 

940 

850 

790 

760 

760

19, 720

6 

6 

6 

6 

5 

5 

5 

5 

5 

5 

5 

5 

5 

5 

5

34 

32 

30 

28 

22 

20 

19 

17 

16 

14 

13 

12 

11 

10 

10

287

 At least one water-sediment sample was collected on this date and used In estimating the suspendedsediment load.
DATA FROM SAMPLING SITES 37

TABLE 10. Particle-size distribution of bed material from the Ogiechee River 

near Eden, Qa., Feb. 9, 1959

[Station number indicates distance, in feet, from a reference point on the bridge which crosses the river

at the sampling site]

Size range (mm)

>4-...___________________.__ ...........................

2-4............... __ .... _ . ____ .... _____ ..

1-2......... ___ . _ ....................... ___ ..

0. 5 -1 .... ... _____ ........ _ ............... __

0.25 -0.5 _ . __________________ . ___ ........

0. 125-0. 25...... __ .............. _____ ..... _ . .....

0.062-0. 125. ............................................

<. 062............................. .....................

Weight percent

Station 455

<0. 1 

.21 

4.9 

35.9 

54.4 

4.6 

<.l 

<.l

Station 471

0.04 

.9 

13.2 

47.4 

37.0 

1.5 

<.l 

<.l

Station 488

C.I 

1.32 

11.02 

51.5 

35.2 

.9 

<.l 

<.l

Station 499

7.6 

24.6 

36.1 

23.7 

7.5 

.6 

<.l 

<.l

These data made possible an estimate of the minimum average daily 

sediment load in Slash Creek and permitted determination of the relation of suspended concentration to water stage.

Smpended-sediment concentration. The suspended-sediment concentration of samples taken from Slash Creek Apr. 9,1958, to Apr. 1, 

1959, are given in table 11. The average concentration during the last 

half of December 1958 was 1,650 ppm; in January 1959, 1,620 ppm; 

in February, 495 ppm; and in March, 365 ppm. Although the sharp 

drop in concentration in February may be due only to a change in the 

amount of clay put into the stream, it is possible that other factors 

are important. Much of the clay carried by Slash Creek appears to 

be contributed by factories in the town of Gordon, about 7 miles upstream from the sampling point; the clay tends to be deposited in the 

streambed, during periods of low flow. As the stream riees, this deposited clay is flushed out. In the case of Slash Creek, sampling was 

begun after about 3 months of low rainfall and corresponding low 

streamflow. Moderate amounts of rain fell in the latter part of December 1958 and January 1959, and the resultant runoff probably 

caused erosion of some clay from the stream channel. O.^ Feb. 3-5, 

1959, about 2.5 inches of rain fell, and Slash Creek rose to 2,5 feet from 

a normal gage height of about 1.1 feet. This rise probably was accompanied by the flushing out of much of the accumulated clay. Following this heavy rain, sediment concentration was low, possibly because most of the accumulated clay had been removed. As the streamflow decreased,, the concentration of suspended sediment slowly increased. This relation suggests that there was less dilution of the 

clay by clear water derived from the drainage basin upstream from 

Gordon. During the last part of February and all of March, the 

suspended-sediment concentration varied in a rather erratic fashion, 

but the average concentration was well below, and the average discharge was higher than, that observed prior to the flood of early 

February.
38 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

TABLE 11. Concentration of suspended sediment in samples from Slash Creek

near Mclntyre, Ga.

[Gage height, based on arbitrarily assumed reference, obtained by measuring between the water surface 

and a particular point on the bridge crossing Slash Creek]

Date

1958 

Apr. 9 _____ . _____

Apr. 30.. .......... .......

Dec. 16 _____ .... ......

Dec. 17 ______ . ......

Dec. 18... .. .... _ ....

Dec. 20 __ ...............

Dec. 22.. __ . _ ... __ .

Dec. 24 __ . _ . ___ ....

Dec. 26 ________ . ...

Dec. 28... _ ........ _ ..

Dec. 30 ...................

1959

Jan. 1 _ ......... __ ....

Jan. 3 _ . ______ ....

Jan. 5 ...................

Jan. 7. __ ._-.... ___ .

Jan. 9. ...................

Jan. 11...................

Jan. 13...................

Jan. 15.. .................

Jan. 17. ........ __ ......

Jan. 19-.. ................

Jan. 21 __ . ____ :...

Jan. 23......... ___ ....

Jan. 25. __ .... _ .......

Jan. 27 ______ ___ .

Jan. 29 ...................

Jan. 31. _________ .

Feb. 2... ........ __ ....

Gage 

height 

(feet)

1.1

.9

.7

1.0

1.1

1.5

1.3

1.2

1.5

1.2

1.2

1.2

1.1

1.0

1.0

1.6

1.4

1.4

1.5

1.4

1.1

1.1

1.2

1.5

Suspendedsediment 

concentration (ppm)

276

843

1,583

1 493

4,310

1,516

1,972

496

936

1,712

744

1,526

596

5,300

380

524

1,998

563

2,171

1,535

1,002

875

1,764

1,114

877

449

Date

1959 (continued) 

Feb. 4... ........_. .......

Feb. 5 

Feb. 6 . 

Feb. 8 _.. . 

Feb. 10... ___ .........

Feb. 12 ____ ............

Feb. 14. ______ . __ .

Feb. 16. ___ ............ Feb. 18 

Feb. 20 . 

Feb. 22...... _ ..........

Feb. 24. ......... __ ..

Feb. 26.. ... .... _ .

Feb. 28. 

Mar. 6.. __ ...........

Mar. 8....... ... .

Mar. 14........ ....... Mar. 16 

Mar. 18 

Mar. 18.... __ 

Mar. 22. __ . _

Mar. 24 . .

Mar. 26 

Mar. 28 

Apr. 1..... _ ........

Gage 

height 

(feet)

2.1

2.5

2.5

2.1

2.3

2.1

2.1

2.1

2.1

1.6

1.2

1.0

2.0

1.3

l.f

3.0

2.3

1.8

1.7

l.f

l.f

1.8

l.f

1.P

l.f

1.6

1.P

2.0

Suspendedsediment 

concentration (ppm)

520

400

565

284

264

238

246

253

340

36

510

801

779

1,294

519

422

404

200

410

299

251

371

352

796

428

326

165

335

197

218

Suspended-sediment load. Estimates of the suspended sediment in 

Slash Creek are based on measurements of concentration and on a discharge measurement of 33 cfs made at a gage height of 1.1 feet. The 

average suspended-sediment concentration for the sampling period 

was approximately 950 ppm. The daily suspended-sediment load was 

calculated as 85 tons for a discharge of 33 cfs and a concentration of 

950 ppm. However, the average discharge during the sampling period 

was greater than 33 cfs by an unknown amount. Although an accurate 

determination of the average load cannot be made, the data available 

suggest than an estimate of 125 tons per day is reasonable.

The great changes in concentration from one day to the next or 

even during one day show that the suspended load is highly variable. 

(See table 11, Jan. 5-11 and Mar. 18,1959.) The instantaneous load 

at the time of sampling on Jan. 9, 1959, was approximately 530 tons 

per day. By comparison, the instantaneous load on Mar. 24,1959, was 

perhaps 30 tons per day.

Source of clay particles. A thorough study of the source of the 

clay carried by Slash Creek was beyond the scope of this stud7, but the 

major source of the clay was determined. Samples were collected
DATA FROM SAMPLING SITES 39

three times from Slash Creek above and below the town of Gordon; 

the suspended-sediment concentration was found to increa^ greatly 

because of clay derived from mills in the town of Gordon. The data 

obtained are shown in table 12.

TABLE 12. Concentration of suspended sediment in samples from Slash Creek

near Gordon, Ga.

Date

1958

Dec. 17................ . .... . ......

1959 

Jan. 20 . ....... ........... 

Apr. I.........................................

Suspended-sediment 

concentration (ppm)

At bridge 

south of

Gordon on

Georgia

Route 18

4

8

9

At bridge

southeast

of Gordon

2,340

1,160

270

FLINT RIVER NEAR CUIXODEN, GA.

The headwaters of the Flint River are located near Hapeville just 

south of Atlanta. From there the river flows southward across the 

Piedmont and Coastal Plain until it leaves Georgia at the southwest 

corner of the State. The Flint River was sampled just a few miles 

above the Fall Line. The drainage area above this site is r.bout 1,890 

square miles.

Upstream from the sampling site the terrane is characteristic of 

much of the Georgia Piedmont. The land is hilly, and tl <\ soils are 

of gray-brown to reddish-brown sandy to clay loam. The more common soils include the Cecil, Lloyd, Appling, and Madison series. 

Average runoff is 0.73 mgdsm. Cropland constitutes about 25 percent 

of the drainage basin and, of this, about one-half is harvested cropland. No large reservoirs are located upstream from the sampling 

point, and it can be assumed that the sediment yield is not greatly 

affected by dams.

Suspended-sediment concentration. Water-sediment samples were 

collected from the Flint River near Culloden, Ga., during the period 

Dec. 18, 1958, to May 15, 1959. Only 25 samples were collected during the sampling period. The suspended-sediment concentration is 

shown in table 13 and plotted against instantaneous discharge in 

figure 16. The graph demonstrates the increase of sediment concentration with increasing discharge. Average discharge during the periods 1911-22,1928-31, and 1937-57 was 2,341 cfs (U.S. Geol. Survey, 

1959b).
40 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

350

Z 

0

_l

I

ce i cn

0.

V) 125 

a 

%. 100

z

H -...

LJ

0

LJ

w 50

Q 4 c

0 An

Z w

UJ

W 

D qo

(rt du

fe ,c

| 20

CChU z 15io 

O

0 *" 

O

10

s;

-//

7

^

/\

/

:

A

/

 /

/

/ ,

/

/

/

*

-A

/

'

/

/

/

.

*

-//

400 800 1200 1600 2000 4000 6000 8000 12,000 16,000 

DISCHARGE, IN CUBIC FEET PER SECOND, AT THE TIME OF SAMPLING

FIGURE 16. Relation of stream discharge to concentration of suspended sediment in 

samples from the Flint River near Culloden, Ga.

Samples were taken at three centroids of discharge, and^ in 14 

of the 17 groups of three samples that were suitable for study, the 

sample collected at the middle centroid had the highest concentration. 

The sample from the south centroid contained the lowest concentration of sediment 65 percent of the time. Thus, it is apparent that suspended sediment is unevenly distributed in the river cross section.

Size distribution of suspended sediment. Size analyses were made 

on 11 samples from the Flint Elver; the data are presented in table 

14. Six of these samples were collected at the middle centroid of 

discharge during periods of above-normal flow and were dispersed
DATA FROM SAMPLING SITES 41

TABLE 13. Concentration of suspended sediment in samples from the Flint 

River near Oulloden, Ga.

Date

1968

Dec. 18...- ..... _ 

1969

Jan. 14...................

Jan. 17. ___ . ______

Jan. 18. __ . _ . _ - ....

Jan. 22. _ ________

Jan. 25...................

Feb. 1 __ ... ......

Feb. 5......... ___ ....-

Instantaneous 

discharge 

(cfs)

850

680

750

850

2,740

2,300

3,260

1,690

8,720

Suspendedsediment 

concentration (ppm)

7

11

8

9

118

70

141

60

43

267

Date

Feb. 8 

Feb. 11.. ............ .-

Feb. 14 _ . _______ ...

Feb. 16. .......... ... 

Feb. 21 

Mar. 4.. _____ . __ ...

Mar. 5- __________

Mar. 6 ___________

Mar. 8... ...

Mar. 16..... ...... _ .

Mar. 30..... _ -.-_. 

May 13.. _

May 16.... _

Instantaneous 

discharge 

(cfsl

4 530

4480

6 580

6 140

2.340

1,690

7,000

9 390

11.100

5 230

3 220

3 380

1.300

1.690

1.630

Suspendedsediment 

concentration (ppm)

95

98

115

106

28

14

339

436

302

99

39

61

36

42

39

before analysis. The six samples were similar in their particle-size 

distribution and averaged 35 percent sand, 35 percent silt, and 30 

percent clay. In one instance, size analyses of dispersed sediment were 

made on samples collected at both the south and the middle centroids 

of discharge (samples 2 and 3, table 14). The sample at the middle 

centroid had a higher suspended-sediment concentration and a higher 

percentage of sand. In two instances, a sample collected at the middle 

centroid was analyzed in a dispersed condition and a sample collected 

at the same time from the north centroid was analyzed in rative water 

(samples 6-9, table 14). In both instances the sample collected at the 

middle centroid had a higher suspended-sediment concentration and 

a somewhat higher percentage of sand. The samples analyzed in 

native water showed very little tendency to flocculate. This fact agrees 

with previous findings by K. N. Cherry (oral communication) that 

turbidity is persistent in the water of some Piedmont streams. The 

failure to flocculate is probably related to the low concentration of 

dissolved solids in the water.

A sample collected at relatively low flow (sample 11, table 14) 

had a particle-size distribution quite different from that of the samples 

collected at higher flows. The suspended sediment contained very 

little sand and a high percentage of clay.

Suspended-sediment load. The estimate of the suspended-sediment 

load transported by the Flint River must necessarily be only an 

approximation because of the small munber of samples collected. If 

the discharge-sediment concentration curve shown in figure 16 is used 

in estimating sediment concentration at times of no sampling, the 

suspended-sediment load during the period Dec. 15, 1958, to May 15, 

1959, is calculated to be about 80,000 tons.

695-903 64
TABLE 14. Particle-size atialyses of suspended sediment, Flint 

[Method of analysis: B, bottom withdrawal tube; N, in native water; W, in distilled water; C, ch

Sample

l 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11

Date of collection

1959

Feb. 5. __ - -._._-.-..

Feb. 6-.-... ...........

Feb. ll...................

Mar. 6. _____ ........

Mar. 6 ...................

Mar. 6 ______ . __ -.

Mar. 9 __ - ____ - ...

May 13...... .........

Time

5:30 p.m. 

6:15 

6:15 

7:00 

11:30 

2:00 a.m. 

2:00 

10:40 

10:40 

8:00 p.m. 

9:45 a.m.

Discharge 

(cfs)

3,270 

8,720 

8,720 

4,010 

7,000 

9,430 

9,430 

11, 100 

11, 100 

4,400 

1,300

Water 

temperature 

(°F)

38 

42 

42 

43 

40 

46 

46

44 

73

Suspen

Concentration of 

sample 

(ppm)

155 

335 

223 

88 

433 

535 

395 

331 

285 

175 

40

Concentration of 

suspension 

analyzed 

(ppm)

127 

250 

263 

74 

371 

497 

389 

260 

294 

145 

137

Perc

0.004

30 

25 

54 

28 

28 

30 

32 

34 

32 

30 

73

0.008

46 

39 

60 

40 

36 

37 

40 

41 

41 

40 

83
DATA FROM SAMPLING SITES 43

On June 2,1959, after sampling was discontinued, the Flint River 

reached a discharge slightly greater than 30,000 cfs. This discharge 

is much greater than the 11,000 cfs maximum reached during the 

sampling period. Sediment concentration rises with increasing discharge as shown in figure 16, so the sediment concentration probably 

exceeded 2,000 ppm on June 2 and the daily sediment load may have 

exceeded 150,000 tons. Because the sediment load carried on June 2 

was probably not more than one-half of the load carried during the 

period June 1-4, a reasonable estimate of suspended sediment transported during the whole flood would be at least 300,000 tons. Thus 

the suspended-sediment load estimated for the period De".. 15, 1958, 

to May 15,1959, is small compared to the load transported June 1-4, 

1959. If the total suspended-sediment load for the 1959 water year 

is assumed to have been 400,000 tons, the sediment yield ws approximately 200 tons per square mile.

Size distribution of bed material. Bed material was collected on 

Mar. 4,1959, near each of three centroids of discharge. Si^e distribution of samples is shown in table 15. The discharge at the time of 

sampling was only 1,680 cfs and the size distribution determined may 

not represent equilibrium conditions at this discharge. Nevertheless, 

the size analyses are of value in indicating the approximate size 

 distribution of bed material in the Flint River near Cullo'len, Ga.

TABLE 15. Particle-size distribution of bed material from the Flw-t River near 

Culloden, Ga., Mar. 4, 1959

Size range (mm)

S.A

2-4.___._..._.._....._. __ .... __ ..............

1-2... _________ . _________________

0.5-1.. ___ . ___________________ . ........

0.25-0.5. __ ..... .................................

0.125-0.25. ____________________ . __ . ...

0.062-0.125. ___________ . ___ . __ . _____

<0.062.._.__. ________________________

Weight percent

North 

centroid

0.1

.7 

3.6 

26.8 

59.9 

8.8 

.2 

<.l

Middle 

centroid

0.2 

.7 

7.4 

50.0 

40.3 

1.4 

<.l 

<.l

South 

cintroid

9.7 

13.7 

29.2 

43.0 

4.0 

.4 

.1

<a

ICHAWAYNOCHAWAY CREEK AT MILFORD, G/ ,

Ichawaynochaway Creek is a tributary to the Flint Piver in the 

Ooastal Plain of southwestern Georgia. The topograpl y is gently 

rolling to almost level but, in general, the land is well drained. Soil 

is sandy loam of the Greenville, Magnolia, Faceville, and Carnegie 

series. Average runoff is 0.83 mgsm. Cropland constitutes about 40 

percent of the land area and harvested cropland about 28 percent. 

Oordrays Pond in northeastern Calhoun County causes the deposition 

of much of the sediment from approximately 40 percent cf the drainAge area above Milf ord.
44 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

Suspended-sediment concentration. Instantaneous valuer of suspended-sediment concentration for Ichawaynochaway Creek during 

the period Nov. 3, 1958, to May 15, 1959, are given in table 16. Average discharge for the period 1939-57 was 762 cfs (U.S. Geol. Survey, 

1959b). Data given in table 16 are plotted against stream discharge 

in figure 17. At least a part of the scatter of points in figure 17 is 

due to the fact that, during floods, the peak in sediment concentration 

precedes the discharge peak.

60

=1 50

40

30

« 20

t 10

V.

200 400 600 800 1000 2000 3000 4000 5000

DISCHARGE, IN CUBIC FEET PER SECOND, AT THE TIME OF SAMPLING

PIGUEB 17. Kelation of stream discharge to concentration of suspended sediment in 

samples from Ichawaynochaway Creek at Milford, Ga.

Suspended-sediment concentration data, collected at three centroids 

of discharge, showed no consistent tendency to be higher at any particular centroid. Of the 35 sample sets suitable for study, 67 percent 

contained no samples differing from the average by more than 33 percent, and 95 percent contained no samples differing by more than 61 

percent. The correlation between suspended-sediment concentration 

and discharge permits an estimate of the percent of the time that sediment concentration is equal to or less than certain values (fig. 18). 

If the years 1950-55 inclusive are considered as normal and the discharge-sediment concentration relation for the sampling period is
DATA FROM SAMPLING SITES 45

typical, the suspended-sediment concentration is less than 7 ppm about 

50 percent of the time and less than 15 ppm during 90 percent of the 

time.

TABLE 16. Concentration of suspended sediment in samples from Icfnwaynochaway Creek at Milford, Ga.

Date

1958 

Nov. 3.. _ _______ .

Dec. 19 ___________

Dec. 21 _______ .....

Dec. 31 ___ . ___ .....

19S9

Jan. 9_ _______ . ...

Jan. 14...................

Jan. 18 . . .. __ ..

Jan. 28. _ ..............

Feb. 3.................... Feb. 5 ___ . __ .... __

Feb. 7....................

Feb. 8........... _ ...... Feb. 9.. _ . _____ . ...

Feb. U....... ............

Feb. 18....... ............ Feb. 23.. _ ___ . ....

Feb. 27- ..............

Mar. 3 .. . .........

Mar. 6 ................

Mar. 6... . ............

Mar. 7. __ .... .... ....

Mar. 7. _

Instantaneous 

discharge 

(cfs)

300

400

380

585

515

460

700

700

630

980

1,600

2,480

2,490

2,220

1,270

1,200

745

955

825

785

1,350

1,745

2,125

2,780

Suspendedsediment 

concentration (ppm)

8

9

6

7

10

8

12

9

10

22

35

46

30

31

30

21

20

8

7

33

34

38

53

Date

1959 Continued

Mar. 8... .. - . 

Mar. 8.. _________

Mar. 9 ___________

Mar. 10 ___ .. _ ........

Mar. 11.... ___ .. .....

Mar. 12.... ........ __ .

Mar. 15..-. ____ . _

Mar. 16. __ . _____ ..

Mar. 18 __ ..............

Mar. 20. ____ . ........

Mar. 21 ___ . ______

Mar. 25.. ........... _ ..

Mar. 28... .... ... .....

Mar. 30 __ . ........

Mar. 30-. ... ... 

Apr. 13. _ ..... _

Apr. 28 __ ...... ___ ...

May 15 __ .... .....

Instartaneor<« 

discharge 

(cfs)"

3,739

4,160

3,610

2,740

2,200

1,650

1,515

1,960

2,360

1,860

1,520

1,280

1,120

1,700

2,050

1,800

1,600

980

860

830

550

530

440

360

500

Suspendedsediment 

concentration (ppm)

48

43

37

36

23

28

14

10

24

18

17

13

12

37

29

13

11

11

12

11

13

17

12

9

9

Suspended-sediment load. Daily suspended-sediment loads were 

computed from discharge and sediment-concentration data for the 5- 

month period Dec. 15, 1958, to May 15, 1959, and are shov^n in table 

17. Daily suspended-sediment load is plotted against average daily 

discharge in figure 19. The part of the annual suspended-sediment 

load carried during a particular part of the time can be estimated 

from figure 20. Because data are available for just a short period, the 

relation shown in figure 20 can only be a first approximation. Apparently, about 50 percent of the annual load is carried during only 10 

percent of the time and 90 percent of the load is carried during 50 

percent of the time.

The suspended-sediment yield from the drainage basin above Milford during the 1959 water year is estimated to be approximately 

11,000 tons. The water from about 40 percent of the drainage basin 

above Milford passes through a reservoir, and much sediment is removed from it. If the reservoir is considered, the average yield for 

the 620 square miles in the drainage basin was about 30 tons per square 

mile during the 1959 water year.
46

O 80

O «

LJ -^

SI 60

OXO \-

LJ CO

40

20

Based on a flow-duration 

curve for 1950-55

5 10 20 30

CONCENTRATION OF SUSPENDED SEDIMENT,

IN PARTS PER MILLION

FIGURE 18. Suspended-sediment concentration-frequency curve for Ichawaynochaway Creek

at Mllford, Ga.
DATA FROM SAMPLING SITES 47

600

500

400

300

200

150

1009°

80

70

"

50

.20

V,

^

300 400 600 800 1000 2000 3000 4000 5000 

MEAN DAILY DISCHARGE, IN CUBIC FEET PER SECOND

FIOUBB 19. Suspended-sediment transport curve for Ichawaynochaway Creek at

Milford, Ga.
48 SEDIMENT TRANSPORTED BY GEORGIA STREAMS 

100

90

80

9 70

< 60

50

40

30

20

10

/^ Based upon the flow-duration 

for the period 1950-55

0.5 1 2 5 10 20 40 60 80 90

PERCENT OF TIME

FIGURE 20. Suspended-sediment load-distribution curve for Ichawaynochawiy Creek at

Milford, Ga.
DATA FROM SAMPLING SITES 49

TABLE 17. Daily suspended-sediment concentration and load, IchawaynocJiaway 

Creek at Milford, Ga., Dec. 16, 1958, to May 15,1959

[Suspended-sediment concentration estimated from curve shown on fig. 17 except where otherwise

indicated]

Day

1

2 

3... __ ..

4.. ___ ..

5 ..........

6. ____ ..

7... _ . ...

8..........

9.. ........

10.........

11. ........

12. ........

13.........

14 ____ ..

15-- 

16.........

17 ____ ..

18 

19 ____ 

20.. .......

21.. .......

22.........

23 

24 .........

25 .........

26 .........

27 .........

28

29 ____ ..

30 __ . ....

31. .

Total ...

1.. ........

2 .......

3... .......

4 ..........

5.. ........

6.. ....

7 ..........

8. __ ....

9... .......

10.. ___ -

11.... _ ..

12 

13 . _ ..

14. ........

15 ...

16.. .......

17 __ ....

18.. __ ...

19 . ...

20- .......

21. ____ .

22 ......

23 ___ .

24 __ 

25 . _ 

26 .........

27- ___ .

28. _ ..

29 .........

30. ........

31.. ___ ..

Total. ..

Mean 

discharge 

(cfs)

Suspended sediment

Mean 

concentration 

(ppm)

Load 

(tons)

December

741 

706 

618 

537 

465 

410 

390 

385 

385 

385 

421 

448 

454 

513 

579 

604

8,041

11

11 

10 

 9 

8 

 6 

6 

6 

6 

6 

6 

7 

7 

7 

7 

 7

22 

21 

17 

13 

10 

6 

6 

6 

6 

6 

7 

8 

9 

10 

11 

11

169

March

958 

892 

825 

769 

826 

1,580 

2,400 

3,870 

3,730 

2,900 

2,150 

1,710 

1,500 

1,350 

1,540 

1,950 

2,200 

2,350 

2,250 

1,800 

1,540 

1,450 

1,450 

1,400 

1,300 

1,240 

1,240 

1,120 

1,270 

1,900 

2,000

53,459

15 

11 

 8 

 7 

10 

 32 

 44 

 45 

 38 

 35 

 25 

 27 

24 

19 

 14 

 10 

18 

 22 

21 

 18 

 17 

17 

15 

14 

 13 

12 

12 

 12 

17 

 31 

26

39 

27 

18 

15 

22 

183 

285 

471 

883 

331 

145 

125 

97 

69 

58 

53 

107 

140 

127 

88 

71 

67 

59 

53 

46 

40 

40 

36 

58 

159 

140

3,552

Mean 

discharge 

(cfs)

Suspended sediment

Mean 

concentration 

(ppm)

Load 

(tons)

January

573 

561 

604 

650 

678 

678 

604 

555 

525 

531 

525 

507 

471 

443 

426 

477 

604 

706 

783 

790 

706 

692 

685 

699 

720 

706 

650 

618 

567 

531 

543

18,808

7 

8 

8 

8 

9 

9 

9 

10 

 10 

10 

9 

9 

8 8 

8 

9 

11 

 12 

12 

11 

10 

10 

9 

 9 

9 

9 

10 

 10 

10 

10 

10

11 

12 

13 

14 

16 

16 

15 

15 

14 

14 

13 

12 

10 

10 

9 

12 

18 

23 

25 

23 

19 

19 

17 

17 

18 

17 

18 

17 

16 

14 

15

482

April

1,850 

1,800 

1,850 

1,850 

1,710 

1,540 

1,300 

1,090 

990 

892 

860 

825 

860 

860 

825 

790 

762 

720 

706 

790 

892 

925 

892 

825 

741 

664 

611 

573 

561 

543

30, 097

20 

 14 

12 

12 

11 

 11 

10 

10 

«10 

11 

11 

12 

 12 

12 

11 

11 

11 

10 

10 

10 

11 

11 

11 

 10 

10 

11 

12 

 13 

13 

15

100 

68 

60 

60 

51 

46 

35 

29 

27 

27 

25 

25 

26 

26 

25 

23 

23 

19 

19 

21 

27 

27 

27 

22 

20 

20 

20 

20 

20 

19

957

Mean 

discharge 

(cfs)

Suspended sediment

Mean 

concentration 

(pom)

Load 

(tons)

February

618 

706 

925 

1,220 

1,540 

1,900 

2,400 

2,500 

2,300 

1,950 

1,670 

1,540 

1,400 

1,270 

1,180 

1,150 

1,150 

1,180 

1,150 

990 

892 

825 

762 

734 

741 

825 

925 

958

35,401

11 

17 

 22 

27 

 33 

40 

 45 

 40 

 32 

30 

30 

30 

30 

 30 

27 

25 

22 

 20 

18 

16 

13 

11 

 8 

8 

8 

10 

 17 

18

18 

32 

55 

89 

137 

205 

292 

270 

199 

158 

136 

125 

113 

103 

86 

78 

68 

64 

56 

43 

31 

25 

16 

16 

16 

22 

42 

47

2,541

May

519 

537 

495 

465 

448 

438 

421 

385 

375 

360 

356 

360 

421 

477 

513

6,570

16

 17 

15 

15 

13 

 12 

12 

11 

10 

 9 

9 

9 

9 

9 

 9

22 

25 

20 

19 

16 

14 

14 

11 

10 

9 

9 

9 

10 

12 

12

212

 At least one water-sediment sample was collected on this date and used in estimating the suspendedsediment load.
50 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

ETOWAH RIVER AT CANTON, GA.

The Etowah River drains an area of hilly to mountainous topography. Approximately 15 percent of the drainage basin is cropland 

and, of this, about one-half is harvested cropland. Topsoils are of 

loam and sandy loam of the Ashe, Habersham, and Porters series 

which have formed on gneiss, schist, quartzite, slate, and marble. The 

relief is great and the streams have much transporting power, but the 

high proportion of the land covered by permanent vegetation limits 

the amount of material available for transport. A dam on the Etowah 

River east of Dawsonville regulates the streamflow from about 15 

percent of the drainage area upstream from Canton. No other dams 

are known which would significantly affect the sediment trg nsported 

by the Etowah River at Canton.

Suspended-sediment concentration. The concentration of suspended sediment in samples collected from the Etowah River ranged 

from about 10 ppm to more than 1,900 ppm, as shown in table 18. 

Average discharge for the period 1937-57 was 1,059 cfs (U.S. Geol.

TABLE 18. Concentration of suspended sediment in samples from tl-? Etowah

River at Canton, Ga.

Date

1957

1958

Jan. 14 ___________

Feb. 18 __ . _______

Feb. 24 ___________

Mar. 5... _________

Mar. 17... ____ . __ ...

Apr. 8 ___________

May 10 __________

Sept. 11 __ . __ ... __ ..

Nov. 15 __________

1959

Jan. 15 __________

Jan. 16 _ ... _ . __ .....

Jan. 18. __ . _____ ...

Jan. 21..... 

Jan. 21.. _________

Jan. 22 __________

Jan. 23 ___________

Jan. 26 __________

Feb. 5.. ____ . __ . _

Feb. 13 _____ . ____

Feb. 13 __ . ______ 

Feb. 14 _____ . ........

Mar. 5..... ____ . _ ....

Mar. 5 ____ .... .......

Mar. 6...... __ . _ .....

Instantaneous 

discharge 

(cfs)

860

900

1,290

1,010

800

950

1,220

1,290

3,500

1,650

2,060

1,250

405

480

470

490

590

740

870

610

640

1,240

3,050

3,300

4,200

2,070

1,000

1,290

4,600

5,900

7,000

830

940

1,520

Suspendedsediment 

concentration (ppm)

11

10

53

70

13

40

64

65

350

93

120

58

13

27

9

21

24

39

41

16

14

92

1,920

1,406

997

55

90

810

807

363

48

60

141

Date

1959 (continued)

Mar. 6..... ___ .........

Mar. 7.-.. . ............

Mar. 7. ____ .. ......

Mar. 8... _____ .

Mar. 9. . .. ..........

Mar. 11...... _ . _ . .....

Mar. 12.. ............ ..

Mar. 12. ____ ..... ...

Mar. 13..... .. _ ...

Mar. 14 . _____ . ....

Mar. 15 ... .. .

Mar. 15 - ___ . ........

Mar. 15 . ...............

Mar. 15 . _ .. __ ...

Mar. 16 __ .. ....

Mar. 16 ...... __ ....

Mar. 17 . _ . __ ..

Mar. 18 .. __ . ___

Mar. 21 _ ...... __ ..

Mar. 26 .. . 

Mar. 31 . _.. 

Apr. 2............... _ ..

Apr. 3. __ ..........

Apr. 11.. __ .. _ .. __ .

Apr. 12...... _ ..........

Apr. 14 .... ....... .....

Apr. 21..-. .... _ -

Apr.26 

TWftV (5

May 11.. .. ..... ..... . .

Instantaneous 

discharge 

(cfs)

2,440

2,770

2,000

1,530

1,310

1,200

1,030

1,410

1,850

1,600

1,230

1,850

2,380

3,750

4,000

3,650

2,300

1,700

1,420

1,230

1,020

1,280

1,980

2,150

1,690

1,400

1,250

1,380

2,200

2,900

2,040

1,830

1,290

1,100

930

895

900

Suspendedsediment 

concentration (ppm)

318

370

230

132

68

68

47

111

167

132

52

252

551

830

683

525

211

128

81

53

48

79

386

302

178

98

71

127

183

327

171

139

82

73

47

49

40
400 6081000 2 4000' 60080 

DISCHARGE, IN CUBIC, FEET PERSECOND, ATTHE TIMEOFSAMPLING

CONCENTRATION OF SUSPENDED SEDIMENT, IN PARTS PER MIL

>- ro (» 

-> ro -t. en co o o o 

3 O OOOO O O

^-\

 "^

.

L^

Sk^^

^ ^

.

. '^

'^

Xj

^\

f '

t

^s\

 *

.

^

* 

 ^v

^
52 SEDIMENT TRANSPORTED BY GEORGIA STEEAMS

centration generally increases with increasing water discharge, the 

correlation is affected particularly during floods by the tendency 

of sediment concentration to reach a maximum before the discharge 

peak and then to decrease rapidly. This tendency is demonstrated 

by samples collected during the period Jan. 21-23, 1959, and Mar. 15- 

17,1959. (See figs. 22, 23.)

Z 6 < 1200

4 Q 800

0

12 m.

\ ,Gage height

 Sedimer t concentration

12 p. m. 12m. 12p.m. 12m. 12p.m. 12m. 12 p. m.

JANUARY 21 JANUARY 22 JANUARY 23 JANUARY 24

FIGURE 22. Variation in gage height and concentration of suspended sediment in the 

Etowah River at Canton, Ga., during the period Jan. 21-24, 1959.

Sediment concentration also shows a variation which is related to 

the position in the cross section at which the sample was collected. 

At the south centroid, the sediment concentration was equal to or 

less than that in samples collected at the other two centroids 36 times 

out of 52, or in 69 percent of the observations. At the middle centroid, 

the sediment concentration equaled or exceeded that at the other
DATA FROM SAMPLING SITES 53

centroids 39 times out of 52, or in 75 percent of the observations. 

Thus, there is apparent a well-defined tendency for sediment concentration to be highest near the middle of the stream and lowest on the 

south side.

Of the 52 sets of samples from the three centroids, 67 percent contained no samples which deviated from the average concentration by 

more than 28 percent. In 95 percent of these sample sets, no sample 

differed from the average by more than 52 percent. This variation 

is an indication of what to be expected in samples collected a.t the same 

time but at different places in the cross section of the Etowah River 

at Canton.

10 1000

7 O 700

I- 6

300

V

.Gage heigit

S sdiment concentration

12 p. m. 12 p. m. 12m. 

MARCH 17

12m. 12p.m. 12m. 12 p. m.

MARCH 15 MARCH 16

FIGURE 23. Variation in gage height and concentration of suspended sediment in the 

Etowah River at Canton, Oa., during the period Mar. 15-17, 1959.
54 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

Although relatively high concentration of suspended sediment is 

characteristic of the Etowah Eiver during floods, the concentration 

is moderate to low most of the time (fig. 24). During the 1959 water 

year the concentration was less than 36 ppm during about f 0 percent 

of the time and less than 100 ppm during about 90 percent of the 

time. If the flow-duration curve for 1950-55 and the conc^.ntration80

O

O 60

2 20

Based upon the flow-duration curve _, 

for the 1959 water year \ ff*

Based upon the flow-duration curv; 

for the 1950-55 water years

I I I I

10 20 50 100 200 500

CONCENTRATION OF SUSPENDED SEDIMENT, IN PARTS PER MILLION

FIQDBH 24. Suspended-sediment concentration-frequency carve for the Btovah River at

Canton, Ga.

discharge curve for the 1959 water year be combined, as shown in 

figure 24, the resulting concentration-frequency curve is displaced in 

the direction of higher concentrations.

Size distribution of suspended sediment. Size analyses were made 

on 15 samples from the Etowah Kiver at Canton (table 19). Samples 

collected on Jan. 22,1959, and Feb. 13, 1959, were high in suspended 

sediment and the percent of sand was low. Samples taken on Mar. 5-8, 

1959, had only moderate sediment concentration and the percent of 

sand was high. No well-defined trends in size distribution were noted 

during this rise and fall of the river. Size determinations in native 

water were not markedly different from those made using a dispersing 

agent.
TABLE 19. Particle-size analyses of suspended sediment, Etow

[Method of analysis: B, bottom withdrawal tube; N, in native water; W, in distilled water; C, ch

Sample

1 

2 

3 

4 

5

6 

7 

8 

9 

10

11 

12 

13 

14 

15

Date of collection

1959 

Jan. 22 ___________

Jan. 22... ________

Feb. 13........ ...........

Mar. 5... ..........

Mar. 6... .... ... ...

Mar. 7..... 

Mar. 7 . ..... 

Mar. 7. 

Mar. 8... ................

Time

12:10 p.m. 

9:45 

8:00 

2:00 

9:00

4:45 a.m. 

4:45 

11:45 

5:20 p.m. 

5:50

6:10 

9:00 a.m. 

9:00 

11:20 p.m. 

2:15

Discharge 

(ob)

3,350 

4,200 

3, 980 

800 

942

1,550 

1,550 

2,420 

2,770 

2,770

2,770 

2,000 

2,000 

1,530 

1,310

Water 

temperature 

(OF)

47 

47 

48 

44 

45

44 

44 

44 

46 

46

46 

45 

45 

45 

47

Suspen

Concentration of 

sample 

(ppm)

1,385 

1,045 

831 

148 

66

154 

161 

351 

310 

422

375 

192 

285 

127 

59

Concentration of 

suspension 

analyzed 

(PPm)

1,610 

1,090 

685 

148 

253

294 

190 

315 

330 

312

318

287 

177 

101 

175

Perc

0.004

36 

34 

31 

11 

25

18 

20 

18 

26 

24

20 

20 

20 

32 

22

0.008

49 

47 

39 

20 

33

27 

35 

23 

38 

33

27 

26 

26 

39 

32
56 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

Intense rainfall, which may wash much fine-grained material into 

a river, can cause an increase in the proportion of clay in the mspended 

sediment, and apparently does so on the Etowah River; a rapid rise 

on Jan. 22 and Feb. 13, 1959, indicated heavy rainfall, and the suspended sediment consisted of 30 to 35 percent clay. Rainfall of moderate to low intensity on Mar. 5 and 6 caused a slower irse in the 

river and the suspended sediment contained 20 to 25 percent clay.

The increased proportion of suspended clay in stream wr.ter after 

intense rainfall reflects the fact that fine-grained material is derived 

mainly from the land surface during storms and that coarro-grained 

material already in the streambed is the source of much of the sand. 

Thus the concentration of sand in suspension is related much more 

to water velocity, which increases with increasing discharge, than to 

the intensity of rainfall.

A tendency for the proportion of suspended sand to vary with position in the stream cross section is shown by size analyses of samples 

collected on Mar. 6 and 7, 1959. Samples 9 and 12 (table 19) were 

obtained at the south centroid of discharge, whereas sample 10 and 

13 were collected at the middle centroid. In both instances the concentration of suspended sediment and the proportion of suspended 

sand were less at the south centroid than at the middle centroid.

Suspended-sediment load. Daily sediment loads for the period 

Dec. 16, 1958, to May 15,1959, are presented in table 20. The relation 

of the daily load to the daily mean discharge is shown in figure 25. 

By use of this suspended-sediment transport curve and a flow-duration 

curve for the 1959 water year, an estimate of approximately 120,000 

tons can be made for the suspended-sediment load during the entire 

year. This load corresponds to a sediment yield for the Etowah drainage basin of about 200 tons per square mile. A suspended-sediment 

load-duration curve (fig. 26) indicates that more than 75 percent of 

the annual suspended load is carried during 10 percent of tH time.

Total-load estimation computed ~by the modified Einstein method. 

Suspended sediment and bed material were collected at peak discharge on March 6 following rainfall on March 5 and 6. Suspendedsediment concentration in samples taken at nine points in the stream 

cross section were determined. Size analyses were made for three 

suspended-sediment and eight bed-material samples. The particlesize distribution of the suspended sediment is given in tabls 19 for a 

gage height of 7.40 feet (discharge, 2,770 cfs). The concentration 

of suspended sediment and the particle-size distribution of the bed 

material are shown in table 21.
SUSPENDED SEDIMENT LOAD, IN. TO

400 10002

MEAN DAILYDISCHARGE, INCUB

FIGURE 25. Suspended-sediment 

the Etowah Riverat C

§ i q

§ s § a i 8

i-* ?O G> ^ Cl 00 

 » K5 -t> CT> 00 O OOOOOO 

3 O OOOO OOOOOO 

>^\ .

 ^

M

^*^-^^1..

"S^

~-^,_

^ M 7~^>^

1 

.

*-1 4,

'.«.

^*">>^ -. -

'-

^*^

 . >< *».

- « "^
58 SEDIMENT TRANSPOKTED BY GEOKGIA STKEAMS

The concentration of suspended sediment demonstrates the variation found in the cross section. The size analyses of bed material show 

most of the material to be in the 0.5 to 1.0 mm size range and therefore 

of relatively uniform size.

Inasmuch as the average depth of the stream at the time of sampling 

was 8.05 feet and the average sampled depth was about 7.75 feet, 96 

percent of the depth, corresponding to about 98 percent of the flow, 

was sampled. The instantaneous load in the sampled zone was 2,800 

tons per day and the total load estimated by the modified Einstein 

method (Colby and Hembree, 1955) was 3,200 tons per day. Thus 

the estimated load in the unsampled zone was equal to 15 percent of 

the load in the sampled zone.

100

90

80

70

60

Ill

V)

S 50 Q

tu

0.

u. 40 

O

tu 

o 

a: tu 

a. 30

20

EJased on the flov-duration 

curve for 1959 water year

10

0.1 0.5 2 5 10 20 30 40 50 60 70 80

PERCENT OF TIME

FIQUBB 26. Suspended-sediment load-distribution curve for the Etowan River at Canton, 

Ga., for the 1959 water year.
DATA FROM SAMPLING SITES 59

TABLE 20. Daily suspended-sediment concentration and load, Etowah River at 

Canton, Ga., Dec. 16, 1958, to May 15, 1959

[Suspended-sediment concentration estimated from curve shown on fig. 21 except where otherwise

indicated]

Day

1... _ ...

2

3... ___ .

4... __ ...

5... __ ...

6..........

7.. __ ...

8- ......

9_. __ ....

10 

11. ... .....

12 

13 

14.........

15.........

16.. 

17 

18 

19.. 

20 ......

21... __ ..

22. _ ..

23 

24 ...

25. ____ .

26... __ ..

27 

28. __ ...

29.. 

30. ___ ..

31- 

Total...

1 

2. ____ ..

3 . 

4 . 

F -

6... . 

7 .... 

8 . .

n

10 ___ -

11. ____

12. 

13 ......

14 

16 

16.. .

17.- .

18. 

19.. 

20.. __ ...

21 .........

22 .........

23. .

24.. 

25.. __ ...

26.. 

27 

28. __ ....

9Q

30 

31

Total ...

Mean 

discharge 

(cfs)

Suspended sediment

Mean 

concentration 

(ppm)

Load 

(tons)

December

490 

474 

474 

490 

474 

474 

458 

458 

554 

656 

554 

522 

990 

1,300 

895 

728

9,991

21 

20 

20 

15 

15 

10 

10 

10 

16 

20 

14 

13 

57 

90 

41 

26

........ ..

28 

26 

26 

20 

19 

13 

12 

12 

22 

35 

21 

18 

162 

316 

99 

51

870

March

876 

857 

838 

819 

857 

2,220 

1,890 

1,350 

1,180 

1,100 

1,030 

1,580 

1,480 

1,220 

2,740 

3,010 

1,800 

1,480 

1,300 

1,220 

1,220 

1,220 

1,100 

1,070 

1,030 

1,030 

1,140 

1,220 

1,070 

1,260 

1,260

41,467

38 

36 

34 

32

 40 

"275 

 212 

 87 

 66 

58 55 

 130 

 105 

 51 

 488 

 362 

 143 

 94 

74 

65 

 53 

51 

51 

51 

50 

 48 

62 

75 

56 

71 

 75

..... .....

90 

83 

77 

71 

92 

 1, 740 

 1,030 

317 

210 

172 

153 

 594 

421 

168 

 4,300 

 3, 240 

695 

386 

260 

214 

175 

168 

152 

148 

139 

134 

198 

247 

162 

241 

255

16,332

Mean 

discharge 

(cfs)

Suspended sediment

Mean 

concentration 

(ppm)

Load 

(tons)

January

710 

952 

914 

764 

692 

603 

603 

620 

710 

656 

586 

670 

554 

654 

570 

782 

800 

656 

620 

638 

728 

4,300 

2,370 

1,350 

1,100 

990 

876 

819 

764 

764 

800

28,415

25 

43

40 

35 

30 

25 

20 

20 

30 

25 

20 

20 

20 

20 

 22 

 42 

40 

 20 

15 

16 

 62 

 1,220 

 357 

140 

100 

 60 

40 

35 

30 

25 

30

48 

111 

99 

72 

56 

41 

32 

33 

67 

44 

32 

31 

30 

30 

34 

89 

86 

35 

25 

26 

 29 

 10, 750 

 2, 670 

510 

297 

160 

95 

77 

62 

52 

65

15, 778

April

1,220 

1,980 

1,620 

1,350 

1,220 

1,180 

1,140 

1,100 

1,070 

990 

1,440 

2,320 

2,680 

1,940 

1,620 

1,440 

1,350 

1,350 

2,170 

2,320 

1,840 

1,620 

1,480 

1,350 

1,300 

1,220 

1,180 

1.140 

1,180 

1,100

44,910

81 

 309 

 165 

 95 

 70 

65 

61 

56 

53 

47 

 162 

 233 

 370 

 165 

120 

109 

96 

90 

295 

270 

 140 

107 

93 

89 

85 

 83 

81 

81 

79 

76

266 

 1, 670 

722 

346 

267 

207 

195 

166 

153 

126 

630 

 1, 510 

 2, 690 

 884 

526 

630 

350 

328 

 1,800 

1,690 

696 

469 

372 

324 

298 

273 

268 

259 

262 

226

18,583

Mean 

discharge 

(cfs)

Suspended sediment

Mean coicentration 

(I nm)

Load 

(tons)

Fel ruary

746 

728 

728 

838 

1,180 

1,030 

857 

800 

800 

819 

1,070 

1,070 

4,400 

4,940 

2,420 

1,840 

1,530 

1,400 

1,260 

1,100 

1,030 

990 

990 

1,100 

990 

933 

914 

876

37,379

30 

26 

25 

40 

 78 

60 

40 

30 

30 

30 

56 

40 

 464 

 320 

215 

145 

100 

90 

80 

73 

66 

67 

48 

47 

46 

43 

40 

39

60 

49 

49 

91 

248 

167 

92 

66 

65 

66 

159 

116 

 6,800 

4,880 

1,400 

720 

413 

340 

272 

217 

184 

162 

128 

140 

123 

109 

99 

93

16,297

May

1,070 

1,070 

1,030 

990 

952 

914 

914 

876 

857 

876 

895 

876 

990 

1,070 

895

14, 275

 73 

69 

64 

60 

54 

 49 

48 

47 

44 

43 

 48 

45 

43 

50 

 40

211 

199 

178 

160 

139 

121 

118 

111 

102 

102 

116 

107 

115 

145 

97

2,021

 At least one water-sediment sample was collected on this date and used in estimating the suspendedsediment load.

 Computed by subdividing day.
60 SEDIMENT TRANSPORTED BY GEORGIA STREAMS,

TABLE 21. Concentration of suspended sediment and particle-size distribution 

of bed material from the Etowali River at Canton, Qa., Mar. 6, 1959

Station

I5i.. ............................

ns.. ............................

183... ________________

192..............................

202.. . _-. - ._-.. ..--

209. - 

216 ___ . _____ . _____ ....

223

240 _ . .

Percent of bed material in each size fraction (size range in mm)

0.0625- 

0.125

2.6 

.1 

.1 

.1 

.1 

.1 

.1

.1

0.125- 

0.25

6.5 

.5 

1.1 

1.7 

3.1 

1.4 

1.3

.8

0.25- 

0.5

14.1 

5.0 

16.5 

24.8 

36.6 

22.4 

18.4

15.0

0.5-1.0

60.6 

59.8 

50.0 

47.5 

42.8 

57.9 

48.5

7.0

1.0-2.0

15.2 

31.8 

27.3 

19.5 

14.0 

16.5 

20.9

10.9

2.0-4.0

0.9 

2.2 

3.8 

4.5 

2.6 

1.4 

7.1

1.1

>4.0

0.1 

.6 

1.2 

l.fl 

.8 

.3 

3.7

.1

Suspendedsediment 

concentration (ppm)

318 

310 

417 

373 

422 

451 

375 

343 

317

OOSTANAULA KIVEB AT CAU3OTJN, GA.

The drainage basin of the Oostanaula River lies partl^ in the 

mountainous Blue Ridge province and partly in the Valley and Ridge 

province. Near the head of the Oostanaula drainage basir, valleys 

are narrow and stream gradients are high. After the streams leave 

the mountains, valleys are wide, the streams meander, and gradients 

are relatively low. The soils in the Blue Ridge province are commonly 

of loam on the slopes and of silt loam in the valley bottoms. In the 

Valley and Ridge province most soils are of silt loam, but the soils 

on the ridges tend to be more rocky than those of the vrlleys.

Runoff from the drainage basin above Resaca, Ga., 6.5 miles upstream 

from Calhoun, averages 1.06 mgdsm.

Cropland constitutes only 4 to 7 percent of the area in the upper 

drainage basin and harvested cropland 2.5 to 5 percent. In the lower 

drainage basin, where river valleys are broad and the relief is less, 

15 to 25 percent of the area is cropland and. 10 to 15 percent is 

harvested cropland.

Although there are a few small dams on tributaries to tl ^ Oostanaula, no large reservoirs are located upstream from Calhoun. Thus, 

very little sediment is removed from the water by deposition in 

reservoirs. Average discharge for the period 1937-57 is estimated as 

1,149 cfs (U.S. Geol. Survey, 1959b).

/Suspended-sediment concentration. Water-sediment samples were 

collected from the bridge over the Oostanaula River on Georgia Route 

143 at Calhoun during the period Nov. 16, 1958, to May 15, 1959. 

Samples were collected at three stations in the cross section near the 

centroids of discharge corresponding to a gage height of 3 feet. At 

gage heights above 4 feet, the distribution of water discharge in the 

channel changed considerably, and sampling was also done at a fourth 

station in the cross section.

The suspended-sediment concentration determined in 43 samples is 

shown in table 22; the concentrations are plotted against discharge in 

figure 27. No samples were obtained during the rising stage of the
DATA FROM SAMPLING SITES 61

Apr. 19-23, 1959, flood, so a comparison between rising and falling 

stages cannot be made. However, during the flood of Feb. 13-15,1959, 

the suspended-sediment concentration reached a maximum before the 

discharge peak and then decreased. Probably the sediment concentration also peaked before the discharge maximum during the flood of 

April 19-23; if so, samples collected on the rising stage would have 

plotted on figure 27 more nearly in line with the other data. The

500

00 O O

IO OO

gJ 100 

r/i 90

vj O

m O

S .50

CO O

IO O

M I"

i-" 

O

©

55

500 1000 2000 3000 4000 5000 10,000 15,000 

DISCHARGE, IN CUBIC FEET PER SECOND, AT THE TIME OF SAMP-ING

FIGDRE 27. Relation of stream discharge to concentration of suspended sediment In 

samples from the Oostanaula River at Calhoun, Ga. Points enclosed In circles designate 

samples collected after the crest of the flood of Apr. 19-23, 1959.
62 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

concentration in samples collected during smaller floods does not show 

this great deviation from the median line. It seems possible that the 

larger the flood and the longer the water is high, the farther the points 

will plot from the line extrapolated from smaller floods.

22. Concentration of suspended sediment in samples from the 

Oostanaula River at Galhoun, Go.

Date

1968 

Nov. 16..... ________

Dec. 15 .....

Dec. 26 

1959

Jan. 6.. __________

Jan. 17. _ . ________

Jan. 18.. _________

Jan. 19. _ . __ . __ . ...

Jan. 21.. _______ . ...

Jan. 22... ________

Jan. 23.. ......... ........

Feb. 10-... _ 

Feb. 11........ __ 

Feb. 13. __ ... __ ......

Feb. H... ........... .....

Feb. 26....... ... _ ......

Mar. 5 . ________ ..

Mar. 5 .............

Mar. 6 _ ... ....

Mar. 6- _________

Instantaneous 

discharge 

(cfe)

700

790

920

995

A finfl

3,300

2,120

1,680

i Qfift

10,500

10,250

2,350

1,680

2,000

7,600

10,200

1,800

1,640

1,980

2,800

3,800

Suspendedsediment 

concentration (ppm)

6

4

20

22

991

Oft

ttfl

28

387

394

314

4310

56

979

243

20

90

54

63

121

Date

1959 Continued

Mar. 6- ...... ___ . ...

Mar. 7.. .... .... ...... .

Mar. 8 .... .....

Mar. 10-. ___ ... ...

Mar. 12 . 

Mar. 13.. .. _ .......

Mar. 16.......... ..... ....

Mar. 17 

Mar. 18- _ ....... .....

Mar. 20- ... ... .. ....

Mar. 23.......... ___ ..

Apr. 14....... _ .........

Apr. 20.. ... ..... ..... .

Apr. 21...... __ 

Apr. 21 _ . _ ..... __ ..

Apr. 22....... ..... _ ....

Apr. 23....... .... _ .. ...

Apr. 24..... ..............

Apr.24__. ___. 

May 15 ... ... ..... .

Instantaneous 

discharge 

(cfe)

5,050

5,100

3,200

2,820

2,330

3,400

3,100

7,220

5,350

3,180

2,320

2,220

8,350

12,200

11,700

11,500

11,500

11,600

10,800

7,400

5,450

1,620

Suspendedsediment 

concentration (ppm)

135

124

36

24

25

59

45

168

83

36

19

40

84

90

98

82

54

47

27

29

34

30

The distribution of suspended sediment across the width of the 

Oostanaula at Calhoun is fairly uniform. Of the 29 sets composed 

of at least three valid samples, 67 percent contained no samples which 

deviated from the average concentration by more than 22 percent, and 

95 percent of the sets contained no samples deviating by more than 50 

percent.

If the median line of figure 27 is assumed to represent the normal 

relation of concentration to discharge, curves can be drawn to estimate 

the percent of time that the concentration is equal to or les^1 than a 

given value. In figure 28 the concentration-discharge relation has 

been combined with flow-duration data for the 1959 water year to 

give a concentration-frequency curve. If the average flow-duration 

curve for the 1950-55 water years is used, a different concentrationfrequency curve results. Because data from a few months' sampling 

cannot be expected to be exactly typical of much longer periods, these 

curves permit only a rough estimate of the frequency of occurrence of 

certain suspended-sediment concentrations. In general, the estimated 

frequency of occurrence of a given concentration will be most accurate 

if it is near the middle part of the curve. Accurate data for the upper 

and lower ranges of the concentration-frequency curves can be obtained 

only by sampling over a long period of time.
101 5000 20 105

PER OF PARTS SUSPENDED INMILLION CONCENTRATION SEDIMENT, 

 Elver atQa. curve for Oostanaula theFIGOEB 28.Calhoun, Suspended-sediment concentration-frequency 

EQUAL IS CONCENTRATION TIME OF PERCENT 

SHOWN VALUE THAN LESS OR TO 

c CQ en -P* ro 

C O O O O 3 

\

to

en

8

the flow-durat upon 

the for1959 water y

curve on

ear

\\

^

/\

\

N co 

0>

the flow-duratic 950-55 water y

>n curveears

^ - * 

\ 

\

\\

V 

'
64 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

Size distribution of suspended sediment. Suspended-sediment samples collected during five different floods were subjected to size analysis. 

The particle-size distribution is shown in table 23. Little sand is carried by the Oostanaula at Calhoun compared to the Etowah Eiver at 

Canton. The upper part of the Oostanaula drainage basin resembles 

the Etowah basin, so the character of the stream sediments in the two 

basins might logically be expected to be similar. However, t^ie Oostanaula flows through the Valley and Eidge province after leaving the 

mountains, and changed stream gradients and addition of fun-grained 

sediments may cause a decrease in the proportion of sand in the stream 

sediments.

Samples 8 through 16 (table 23) were collected at various times during the rise and fall of the river in the period March 6-8. It is probable that the river crested between 7 and 8 a.m., March 7, at a discharge 

of about 5,300 cfs. No consistent changes in grain-size distribution 

were noted as the stream rose and fell. Considerable variation in 

size distribution was found in samples 8 through 11, wHch were 

collected between 2 and 3 p.m., March 7, at various points in the cross 

section. This variation suggests that, on river rises of only a few feet, 

the range in grain-size distribution may be as great in the cnrs section 

at any one time as it is throughout the period of the rise and fall of the 

river.

The average size distribution of the suspended sediment in samples 

analyzed was as follows: 6 percent sand, 36 percent silt, and 58 percent clay.

Suspended-sediment load. The suspended-sediment load for the 

5-month sampling period was calculated by using a discharge versus 

load (sediment-transport) curve. Approximately 150,000 tons of 

sediment was carried from Dec. 15, 1958, to May 15, 1959. During 

this period about 63 percent of the annual discharge occurred and an 

estimated 75 percent of the annual suspended-sediment load was carried. It seems probable, therefore, that the suspended-sediment load 

for the 1959 water year was about 200,000 tons. This load corresponds 

to an average sediment yield of 125 tons per square mile of drainage 

area. The estimate is only an approximation because no samples were 

collected during several floods.

Size distribution of bed material. Bed-material samples- "wfp 

collected on Mar. 7, 1959, when the discharge was 5,100 cfs. An 

attempt was made to get samples at 12 points in the cross section, but 

sand was found at only three points. The particle-size distribution in 

the three samples of bed material is given in table 24. Th^ lack of 

sufficient bed-material samples makes it impossible to calculate a bed 

load for the Oostanaula River; however, the fact that sandy material 

was present on the bed at only 25 percent of the points tested suggests 

either that not much sand was available for transport or that the stream
TABLE 23. Particle-size analyses of suspended sediment, Oosta

[Method of analysis: B, bottom withdrawal tube; N, in native water; W, in distilled water; O, c

Date of collection

1959 

Jan. 21 _______________

Jan. 22.. ______________

Jan. 22.. ______ . _______

Jan. 23 _______________

Feb. 13.. ............ .... 

Feb. 14. . . ............

Mar. 6 _____ . ___ .. _ . ___ .

Mar.6.......--...- .............

Mar. 7... __.. .._ ....__ .____.

Mar. 1... ............ ..............

Mar. 7 _____ . ___ . ...........

Mar. 1.. ...........................

Mar. 7. __ .. ___ . _____ . ....

Mar. 8-._ _ ....................

Mar. 16. ______________

Apr. 20 . .... ..... _ . ...

Apr. 21. ____ . __ . ............

Apr. 22.. ....... __ ... ...........

Time

8:45 p.m. 

5:30 

5:30 

5:30 

4:45

6:00 

3:30 

7:00 a.m. 

2:30 p.m. 

11:45

2:10 

2:35 

2:55 

3:00 

7:00

10:00 a.m. 

4:30 p.m. 

10:45 

9:10 a.m. 

9:30

Discharge 

(cfs)

4,900 

10, 600 

10,600 

10,600 

10,300

7,400 

10, 300 

2,800 

3,850 

5,000

5,100 

5,100 

5,050 

5,050 

4,800

3,900 

7,100 

12,200 

10,800 

10, 700

Water 

temperature 

(°F)

49 

47 

47 

47 

45

50 

57 

46 

47 

44

47 

53 

47 

47 

44

46 

53 

63 

61

 >0

Su

Concentration of 

sample 

(ppm)

459 

407 

358 

416 

310

222 

187 

51 

148 

116

130 

150 

126 

152 

119

90 

139 

92

81 

51

Concentration of 

suspension 

analyzed 

(ppm)

654 

546 

521 

473 

447

302 

212 

90 

520 

307

141 

245 

147 

156 

119

211 

132 

319 

201 

150

Perc

0.004

56 

60 

62 

60 

66

44 

46 

56 

38 

47

59 

54 

62 

68 

68

48 

68 

68 

59 

54

0.008

72 

74 

74 

68

75

56 

60 

69 

46 

61

73

77 

72 

79 

88

64 

78 

75 

71

79
66 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

velocity was high enough to sweep the bed clear of sand. If not much 

sand was available, the bed load was probably a small fraction of the 

total load. If the velocity of the water was sweeping the bed clean, 

then the sand should have been in suspension or bouncing along the 

bottom. Most of that in suspension would be sampled b7 the suspended-sediment sampler and measured. Therefore, it seems probable 

that bed load did not constitute an appreciable fraction of the total 

load at the time of sampling.

TABLE 24. Particle-size distribution, of bed material from the OostarauJa River 

at Calhoun, Ga., Mar. 7, 1959

Size range (mm)

>4. - _..._.._._...____.____.___.___ - ~.

2-4. . _______ . ____ .... _ . __ . ......

1-2. ____ . _____ . ____ . ___________

0.5-1.... ______________ . ________ ...

0. 25-0. 5.____ ___ . ____ . ___________ .....

0.125-0.25. _________________________

0.082-0.125.... _ . _______ ..... ______ . _ .

<0.062- .... _ . _ .. ______ . _______

Weight percent

Station 107

0.1 

.1 

4.9 

53.4 

39.4 

1.5 

.5 

.1

Station 127

<0.1 

.4 

20.6 

55.9 

21.4 

1.4 

.3 

<.l

Station 206

2.3 

14.7 

54.2 

18.7 

9.2 

.9 

<.l 

<.l

SITES OF OCCASIONAL SAMPLING 

BRIER CREEK AT MILLHAVEN, GA.

Brier Creek originates just above the Fall Line in Warren and 

McDuffie Counties. It flows southeastward through the upper Coastal 

Plain and into the lower Coastal Plain before joining the if<wannah 

River. Relief is low, and soils are sandy in the drainage basin.

Suspended-sediment concentration. Suspended-sediment data collected from Brier Creek during the period Dec. 21, 1957, to Sept. 30, 

1959, are shown in table 25. It is apparent that there is little correlation between sediment concentration and stream discharge. With 

three exceptions, all samples contained less than 9 ppm. It seems reasonable to conclude, therefore, that the suspended-sediment concentration is less than 10 ppm most of the time.

Particle size of suspended sediment. One sample of suspended sediment (Sept. 30,1959) was subjected to size analysis. The amount of 

sediment available was very low (16 ppm in the stream) and the 

analysis is accordingly only semiquantitative. Of the sediment present, approximately 85 percent was finer than 0.0039 mm. The remaining sediment was in the size range 0.0039 to 0.0156 mm.

Suspended-sediment load. The sediment load can be only approximated with the limited available data. The average concentration 

of suspended sediment in Brier Creek is probably about 15 ppm. 

Such an estimate is based on the assumption of a slight increase in 

sediment concentration with increasing stream discharge. The an-
DATA FROM SAMPLING SITES 67

nual suspended-sediment load is approximately 9,000 tons, based on 

the above estimates of discharge and load. This load corresponds to 

an annual suspended-sediment yield of 14 tons per square mile.

TABLE 25. Concentration of suspended sediment in samples from, Brier Creek

at Millhaven, Go,.

[Average discharge: 1937-56, 613 cfs (U.S. Geol. Survey, 1958, p. 294)1

Date

1957 

Dec. 21.... ................. .............

1958 

Jan. 14. .................................

Feb. 4... _.-................ .............

Feb. 25.. ....... . .... . .. .

Feb. 27................ _ . ....... .. .

Mar. 10....... ................ _ ........

Mar. 12..... ._..... ......................

Mar. 21......... ....

Apr. 1.. ................... .. _ .. ..

Apr. 14................................ .

Apr. 25.. ..-...-........_...... ..........

July 14..................................

Aug. 6............................... _ .

Sept. 23-____. _ .. ___ ........... .. .

Dec. 5...................................

1959 

Jan. 13_. ........ ............... .

Feb. 9...................................

Feb. 9...................................

Feb. 13............. .....

Mar. 12............................ ...

May 13. _ ..............................

Sept. 30 _______ . _ ........ _ .....

Time

10:45 a.m.

1:30 p.m.

1:15

3:30

11:05 a.m.

11:55

11:50

10:55

1:00 p.m.

12:30

11:30 a.m.

5:20

10:45 a.m.

2:15 p.m.

10:50 a.m.

8:00 p.m.

10:30

Qaee 

height 

(feet)

6.05

5.45

6.13

5.00

6.30

7.30

7.36

6.55

6.72

7.00

6,81

5.20

1.90

1.99

2.70

4.00

6.65

6.58

7.31

8.62

2.20

4.88

Instantaneous 

discharge 

(cfs)

903

831

1,042

710

1,101

1,511

1,535

1,192

1,263

1,377

1,295

762

218

228

306

491

1,233

1,205

1,516

2,232

250

680

Susperiedsedirrent 

concentration (pr>m)

4

3

4

3

6

3

4

5

7

7

7

8

17

7

6

6

6

4

4

12

5

16

Ratio of instantaneous 

discharge 

to average 

discharge

1.47

1.35

1.71

1.16

1.80

2.46

2.50

1.94

2.06

2.25

2.11

1.24

.36

.37

.50

.80

2.01

1.97

2.47

3.64

2.04

1.11

No samples of bed material were collected during high water on 

Brier Creek. However, Brier Creek is believed to be a sand-bed 

stream, and the sandy soils of the drainage basin, when eroded, would 

be expected to contribute mostly sand to the stream sediment load. 

Thus it is possible that bed load constitutes the major part of the 

total sediment load carried by Brier Creek.

ROCKY COMPORT CREEK NEAR IXJUISVXLIJEJ, GA.

The headwaters of Rocky Comfort Creek lie in Warren County just 

above the Fall Line. The stream flows through the roFing hills of 

the upper Coastal Plain in an area of predominantly sandy soils before flowing into the Ogeechee River near Louisville. A small dam, 

about 6 miles upstream from the sampling site, probably causes deposition of some of the sediment load.

Suspended-sediment concentration. Information obtained during 

the period December 1957 to December 1958 is tabulated in table 26. 

The data are very similar to those obtained for Brier Creek, and 

therefore it can reasonably be expected that the sediment-transport 

characteristics are similar to Brier Creek. No gaging station is maintained on Rocky Comfort Creek and discharge data are not available.
68 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

TABLE 26. Concentration of suspended sediment in samples from Rocky Comfort 

Creek near Louisville, Ga.

[Rainfall data from U.S. Weather Bureau (1958)]

Date

1957 

Dec. 10 ...................

1968

Jan. 13 __ ............

Feb. 4- ________ . ...

Feb. 25. ..................

Mar. 6- ..................

Mar. 10- .................

Mar. 12 __________

Time

11:30 a.m.

1:35

4:15

1:05

4:00

Suspendedsediment 

concentration (ppm)

5

5

4

8

6

9

6

Date

1958 Continued

Mar. 21 ___ .. .....

Apr. 1-.. ............ .... .

Apr. 14- .................

Apr. 15- ____ ...... _

May 27- ..................

Dec. 8 .................

Time

1:05

1:50

1:30

12:00 m.

12:20 p.m.

2:40

2:05

Suspendedsediment 

concentration (ppm)

4

5

6

'11

7

a 12

»52

10

' 2.75 inches of rain fell in Louisville this date.

»Less than 0.01 inch of rain fell in Louisville, May 25-28,1958.

8 About 2 inches of rain fell in the drainage basin on this date.

OGEECHEE RIVER NEAR LOUISVILLE, GA.

The Ogeechee River originates in Green and Taliaferro Counties 

above the Fall Line and flows southeastward across the Coastal Plain. 

The topography is gently rolling, and soils are generally sandy.

Suspended-sediment concentration. Suspended-sediment data collected for the Ogeechee River near Louisville during the period December 1957 to December 1958 are shown in table 27. No stage recorder is operated at this station, and gage heights are available for 

only a few samples; discharge data are not available. Examination of 

the data indicates that suspended-sediment concentration is less than 

10 ppm most of the time and that there is no well-defined correlation 

between gage height and, suspended-sediment concentration.

TABLE 27. Concentration of suspended sediment in samples from t7ie Ogeechee

River near Louisville, Ga.

[Rainfall data from U.S. Weather Bureau (1958)]

Date

1967 

Dec. 10. ... . _.. .......

Dec. 21 ____ .... _______ .... ......

1958 

Jan. 13 ...................................

Jan. 22 ........ ...........................

Feb. 25. __ . _________ .... .......

Mar. 6... _ . __ . __ . __ ... _ ....

Mar. 10 - ___ ... __ ... __ . _ ....

Mar. 12...... ________ . __ . _ ....

Mar. 21.......... ______ .. __ . __

Apr. 14.... _ . ___ .... _____ .. __ ..

Apr. 15.. ______ . _ ....... ___ .....

Apr. 25 .- ___ ... ... _____ ........

May 27- __ . ____________ ...

July 9 _-_..__..__.__._..

Aug. 12...................................

Sept. 16...... . ____ . _______ . ...

Sept. 22.... _ .. _ ......... _____ ..

Dec. 8 .. ________ .... __ ..

Time

3:30

4:10

A,] K

1:50

2:20

2:00

12:45 p.m.

19 -<in

11:50 a.m.

12:30

12:15

Suspendedsediment 

concentration (ppm)

6

3

14

5

4

14

3

g

7

5

'4

6

18

249

20

23

6

3

Gage 

height 

(feet)

10.1

9.0?

8.18

10.8

12.00

3.95

1 2.75 inches of rain fell in Louisville on this date.

3 About 2 inches of rain fell ia the drainage basin on this date.
DATA FROM SAMPLING SITES 69

CANOOCHEE RIVER NEAR CI^AXTON, GA.

The Canooch.ee Kiver drainage lies entirely within the lower Coastal 

Plain in an area of low relief and generally well-drained sandy soils.

Suspended-sediment concentration. Information obtained during 

the period December 1957 to May 1959 is presented in tab1 ** 28. The 

relation of stream discharge to suspended-sediment concentration is 

not consistent, but the sediment concentration is probably less than 10 

ppm at least 50 percent of the time.

Suspended-sediment load. If the average suspended-sediment concentration is estimated to be 20 ppm, the average annual load would 

be about 8,000 tons, which corresponds to a suspended-sediment yield 

of 14 tons per square mile.

TABLE 28. Concentration of suspended sediment in samples from the Canoochee

River near Claxton, Ga.

[Average discharge: 1937-57,397 cfs]

Date

1957 

Dec.22... _______ . _________

1968 

Mar.l2...__...___..._.______.___.___._..

Mar. 13 _______________ . ....

Apr. 25 _______ .... _________

July 14.. ............................

Dec. 6 ___________________

1959 

Feb. 5.............. ___ .............

Feb. 9_--._______. __ . _ _. _. .

Feb. 10- __ ........... __ ............

Feb. 13................ ___ ............

Mar. 13 __________________

May 12 ___________________

Time

10:25 a.m.

8:00

12:00 m.

10:15 a.m.

4:10 p.m.

4:30

9:45 a.m.

10:10

11:35

10:15

12:20 p.m.

8:50 a.m.

height 

(feet)

5.08

11.90

11.50

7.39

5.62

2.18

1.69

8.24

10.00

10.40

9.80

9.80

1.70

Instantaneous 

discharge 

(cfs)

690

3,400

3,010

1,060

735

111

27

1,265

1,930

2,140

1,840

1,840

27

Suspendedsediment 

concentration 

(ppn)

4

6

29

10

34

10

4

27

5

5

5

6

10

Ratio of instantaneous 

discharge to 

average 

discharge

1.74

8.56

7.58

2.67

1.85

.28

.07

3.20

4.86

5.39

4.63

4.63

.07

OCMTTLOEE RIVER AT MACON, GA.

The Ocmulgee Eiver heads in DeKalb and Gwinnett Counties and 

flows southeastward across the Piedmont and part of the Coastal Plain 

before joining the Oconee Eiver to form the Altamaha Piver. The 

topography in the drainage basin above Macon is rolling to hilly, and 

soils range from sandy loam to clay loam. Lloyd Shoals dam lies 

about 42 miles upstream from Macon and probably traps much of the 

sediment from the upper part of the drainage basin. Tl ^ drainage 

area above Macon is approximately 2,240 square miles (U.S. Geol. 

Survey, 1959b, p. 21), and the drainage area above the Lloyd Shoals 

dam is about 1,400 square miles.

Suspended-sediment concentration. Data collected during the period December 1957 to January 1959 are shown in table 29. These data 

indicate that there is a poorly defined positive correlation between
70 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

stream discharge and suspended-sediment concentration. Samples 

were not obtained at high stages, so prediction of suspended-sediment 

concentration under such conditions is not possible. Sediment concentration was less than 30 ppm in samples collected when the discharge 

was less than average.

TABLE 29. Concentration of suspended sediment in samples from the Ocmulgee

River at Macon, Oa.

[Average discharge: 1893-1911 and 1931-57, 2,591 cfs (U.S. Geol. Survey, 1959b, p. 2D]

Pate

1957 

Dec. 16. __ 

1958

Feb. 24.................. .............

TWftr 7

Mar. 20.-... _. .. --_ - 

Mar. 31.- _........ ..... .... . 

Apr. 7.................-. ....... ...

Apr. 24........ ..._ .. 

Aug. 11... . 

Oct. SO......... ....-.- 

1959 

Jan. 26 __ .. ... __ ...... 

Time

5:10 p.m.

1:10

4:00

10:30 a.m.

1:25 p.m.

2:45

3:40

10:00 a.m.

12:45 p.m.

4:30

12:30

3:00

10:10 a.m.

3:00 p.m.

Gage 

height 

(feet)

5.27

9.21

9.44

10.56

10.60

11.34

12.54

13.40

10.92

4.41

4.1

3.80

4.26

6.74

Instantaneous 

discharge 

(cfe)

1,430

3,600

3,780

4,550

4,600

5,100

6,200

6,900

4,800

1,040

890

760

960

2,170

Suspendedsediment 

concentration 

(ppm)

28

37

40

111

26

24

84

107

44

16

10

3

7

26

Ratio of instantaneous 

discharge to 

average 

discharge

0.55

1.39

1.46

1.75

1.77

1.97

2.39

2.66

1.85

.40

.34

.29

.37

.84

Suspended-sediment load. The information available does not permit an accurate estimate of the annual load at Macon. However, the 

sediment accumulation in Lloyd Shoals reservoir for the period December 1910 to March 1935 is known (Federal Inter-Agency Committee on Water Kesources, 1957, p. 6), and the sediment yield for the 

drainage basin upstream from the dam has been calculated. The sediment deposited in the reservoir during that period was equal to an 

average annual sediment accumulation of 533 tons per square mile of 

drainage area. Soil conservation measures and changes in land use 

in the period after 1935 have probably resulted in considerate reduction of the sediment yield, and the present average annual sediment 

yield may be considerably less than 500 tons per square mile.

OCMULGEE BIVER AT LUMBER CITY, GA.

From Macon to Lumber City the Ocmulgee Kiver flows through the 

upper Coastal Plain and part of the lower Coastal Plain. T^ e topography near Macon is characterized by low hills, but the relief gradually decreases southeastward. In the Lumber City region the topography is gently rolling. Sandy soils are characteristic of the 

Ocmulgee Kiver basin below Macon.

Suspended-sediment concentration. Data collected during the period January 1958 to March 1959 are shown in table 30. Th*. concen-
DATA FROM SAMPLING SITES 71

tration of suspended sediment tends to increase with increasing discharge, but the range of concentration is less than at Mr con. The 

surface water of the Coastal Plain generally has a low concentration 

of suspended sediment, even during floods. It seems probs ble, therefore, that the clear streams of the Coastal Plain serve mainly to dilute 

the muddy streams from the Piedmont. The average discharge at 

Macon is almost exactly half that at Lumber City. Thus it may not 

be fortuitous that the maximum suspended-sediment corcentration 

observed at Macon is about twice that observed at LumHr City.

TABLE 30. Concentration of suspended sediment in samples from t\e Ocmulgee 

River at Lumber City, Qa.

[Average discharge: 1937-57, 5,251 cfs (U.S. Oeol. Survey, 1959b, p. 28)]

Date

1958 

Feb. 3.. ..- 

Feb. 25 _________ . _________

Mar. 13 __ . ______ .... ____ . ...

Mayl . ~

JulyU. ... .. . ..

Dec. 8.... ...

1969

Feb. 10 ..-. - .

Feb. 11. ... ... ... ... ... ...

Feb. 12 ___ . _ . . .

Mar. 12.., ____ . _____ . _ _

Mar.31 . 

Time

10:45 a.m.

12:45 p.m.

11:15 a.m.

9:30

8:55

3:30 p.m.

12:05

ll:10a.m.

2:40

1:55

3:45

5:10

Gage 

height 

(feet)

8.68

9.21

13.85

11.92

4.45

5.20

1.10

2.30

10.88

11.45

11.18

12.39

12.35

Instantaneous 

discharge 

(cfs)

8,420

9,150

19,400

13,750

4,180

4,800

1,980

2,700

11,700

12,800

12,260

14,950

14, 820

Suspendedsedimmt conceit ratten 

(ppnr)

29

16

61

13

27

21

12

15

21

24

26

20

11

Ratio of instantaneous 

discharge to 

average 

discharge

1.60

1.74

3.69

2.61

.80

.91

.38

.51

2.23

2.44

2.34

2.85

2.82

LITTLE OCMULGEE RIVER AT TOWNS, GA.

The drainage basin of the Little Ocmulgee River lies entirely in the 

lower Coastal Plain. The topography is gently rolling and the soils 

are sandy. Seven samples were collected during the period February 

1958 to January 1959. The concentration of suspended sediment in 

these samples is shown in table 31. No stage recorder is maintained 

at this site, so the average stream discharge is not available. However, 

the character of the drainage basin and the concentration of suspended 

sediment determined indicate that the annual sediment yi°ld may be 

similar to that of Brier Creek near Millhaven, that is, about 14 tons 

per square mile.

OCONEE RIVER NEAR GREENSBORO, GA.

The Oconee River originates in the hilly country of the upper Piedmont and flows southeastward across the Piedmont and Coastal Plain 

until it joins the Ocmulgee River. Soils in the Oconee Riv?.r drainage 

above Greensboro are mainly of sandy to clayey loam, anc\ where exposed to erosion, contribute considerable amounts of fine-grained sediment to the stream. Several dams (including the Barnett Shoals dam 

only 12 miles upstream) trap sediment above the sampling site.
72 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

TABLE 31. Concentration of suspended sediment in samples from the Little 

Ocmulgee River at Towns, Go,.

Date

1958 

Feb. 3.... __ ....... ........ ....................

Mar. 13. _ ............. _. .................

TVTnv 1CJ

July 14...............................................

Aug. 1... ....................................... .

1959

Time

10:15

9:45 a.m.

1:00

4:40

Gage 

height 

(feet)

9.59

4.17

4.12

1.80

2.38

Instantaneous 

discharge 

(cfs)

150

145

Suspendedsediment 

concentration (ppm)

13

8

9

13

9

2

4

Suspended-sediment concentration. Information obtained during 

the period December 1957 to December 1958 is presented in table 32. 

It is apparent that suspended-sediment concentration tends tc increase 

with increasing stream discharge. Concentration at moderately low 

flows ranges from 15 to 30 ppm and at medium flows from 60 to 120 

ppm. Samples were not obtained at high flows, but it seems probable 

that under such conditions much fine sediment would bo carried 

through the upstream reservoirs, and would cause relatively high concentration of suspended sediment in the Oconee River near Greensboro.

TABLE 32. Concentration of suspended sediment in samples from the Oconee 

River near Oreensooro, Ga.

[Average discharge: 1903-13, 1914-31, and 1937-57, 1,425 cfs (U.S. Geological Survey, 1959b, p. 31)]

Date

1957 

Dec. 2 ___ . ___ ...... __ ... _ .....

1958 

Jan. 6 __________________ .

Feb.3...................................

Feb. 8. __ . _ . __ . _______ .....

Feb. 24..................................

Mar. 3. ................................

Mar 11-- .. ...-............-.......

Mar. 19 _ . _____ ... ___ . _ . __

Mar. 31-....... . .. ..........

Apr. I........... ........................

Apr. 22..................................

May 1 _______ . ________

Julyl _____ . ____________

Sept. 2 ____ . _ ...... __ ........ _ .

Dec. 31 .. ... .............

Time

11:30

10:20

11:40

11:00

11:10

11:00

9:50

11:55

12:50 p.m.

2:35

1:50

3:00

12:00 m.

11:30 a.m.

1:20

Gage 

height 

(feet)

6.15

3.34

4.41

13.27

4.04

6.88

8.09

6.90

6.32

6.45

5.88

4.96

3.40

2.10

2.34

1.45

1.30

3.34

Instantaneous 

discharge 

(cfs)

2,070

900

1,310

5,720

1,170

2,400

2,950

2,405

2,145

2,200

1,945

1,530

920

480

555

310

275

815

Suspendedsediment 

concentration 

(ppm)

100

39

42

99

25

94

115

88

72

54

65

60

14

31

44

20

16

70

Ratio of instantaneous 

discharge to 

average 

discharge

1.45

.63

.92

4.00

.82

1.68

2.07

1.69

1.50

1.54

1.37

1.07

.65

.34

.40

.22

.19

.57

OCONEE RIVER AT MILLiEDGEVIIJLiE, QA.

The sampling site at Milledgeville is near the Fall Line and is 4 

miles downstream from Sinclair Dam. Much of the fine-grained, and 

nearly all the coarse-grained, sediment carried by the Oconee probably 

is deposited in the reservoir. Regulation of the streamflow results
DATA FROM SAMPLING SITES 73

in very rapid changes in stage at Milledgeville, and high gage heights 

cannot be used as an indication of intense rainfall.

Suspended-sediment concentration. Data collected during the period December 1957 to September 1958 are shown in table 3^. No consistent relation between discharge and concentration is evident from 

the data obtained.

TABLE 33. Concentration of suspended sediment in samples fron. the Oconee 

River at Milledgeville, Ga,

[Average discharge: 1906-08,1909-16,1918-31, and 1937-57, 3,355 cfs (U.S. Geol. Surver, 1959b, p. 36)]

Date

1967 

Dec. II..................................

1968 

Jan. 22 ________ . _______ . ....

Feb. 24 ________ . ______ . ......

Mar. 6 ...................................

Mar. 6 ____________________

Mar. 20..................................

Mar. 31.-.. ____________ . .......

Apr. 14 ___ . ___________ . _ ...

Apr. 28 _______________ . ......

May 27 __________________

Aug. 12..................................

Sept. 19 _________________

Time

10:30 a.m.

3:10 p.m.

2:15

8:50 a.m.

10:25

10:45

11:55

2:35 p.m.

10:30 a.m.

8:00

7:20

11:35

Gage 

height 

(feet)

13.5

8.20

10.89

13.3

13.20

13.22

13.52

9.7

12.07

6.00

5.80

7.0

Instantaneous 

discharge 

(cfs)

7,150

1,760

4,300

6,930

6,820

6,840

7,170

3,100

6,580

325

265

910

Suspendedsedlirent 

concentration 

(ppm)

39

78

42

102

27

22

17

21

66

31

32

53

Eatio of instantaneous 

discharge of 

average 

discharge

2.13

.52

1.28

2.07

2.03

2.04

2.14

.92

1.66

.10

.08

.27

COMMISSIONER CREEK AT TOOMSBORO, GA.

The headwaters of Commissioner Creek lie above the Fall Line in 

Jones County, but most of the drainage basin above Toomsboro is 

in the sandhills region just below the Fall Line. Here the soils are 

generally very sandy because of the Cretaceous and Eocene sandstones 

underlying the area. Lenses of kaolin are interbedded with the sandstone, however, and some of this kaolin is being mined by open-cut 

methods. Wash water from some clay-processing plant? is dumped 

into the streams and greatly increases the suspended-sediment concentration. Slash Creek, which was discussed above, is a tributary to 

Commissioner Creek above Toomsboro. Most of the clay in Commissioner Creek appears to be due to inflow from Slash Creek. Three 

samples were collected in 1958 from Commissioner Creek prior to the 

sampling of Slash Creek. The data are tabulated below.

Date of 

sampling 

Apr__. 

Apr_. 

Dec_.

Suspended-sediment 

concentration (pirn)

.__ 58

.__ 32

.__ 62

OCONEE RIVER NEAR MOUNT VERNON, GA.

Below Milledgeville the Oconee River flows southeastward through 

the low hills of the upper Coastal Plain and then through the gently

695-903 64-
74 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

rolling to almost-level land of the lower Coastal Plain. Moit of the 

soils downstream from Milledgeville are sandy and provide little 

fine-grained sediment. The average flow of the Oconee River prior 

to 1955 was 3,385 cfs at Milledgeville and 4,977 cfs (U.S. Geological 

Survey, 1959b, p. 36) near Mount Vernon, so approximately 32 percent of the flow at Mount Vernon is derived from the Coastr.l Plain. 

Suspended-sediment concentration. The concentrations of suspended sediment in samples collected during the period March 1958 

to March 1959 are shown in table 34. Samples were taken durng 1959 

at three to six places in the cross section. The suspended concentration 

was highest in samples taken on the east side of the river four out of 

five times. The fifth time the concentration was highest near the 

middle of the river.

TABLE 34. Concentration of suspended sediment in samples from tl.e Oconee 

River near Mount Vernon, Ga.

[Average discharge: 1937-55,4.977 cfs (U.S. Qeol. Survey, 1957, p 36)]

Date

1958

Mar. 13. ___ . _ . _ ....... __ . _ ..

Mayl - ___ . ____ . __ . _

1959 

Feb. 10 __________________

Feb. 11... -.. ... ..... .-.......

Feb. 12-_.-.-.._-....-.__._ .-.__....

Mar. 12. _____ . ______ . ____

Mar. 31 ___________________

Time

8:45

11:55

12:55

3:00 p.m.

4:40

7:00

Gage

height

(feet)

16.84

11.21

13.14

13.79

14.30

14.84

11.24

Instantaneous

discharge

(cfs)

24,200

8,230

11,650

13,250

14,640

16,200

8,280

Suspendedsediment

concentration

(ppm)

62

48

42

41

37

34

28

Ratio of instantaneous

discharge to

average

discharge

4.86

1.65

2.34

2.66

2.94

3.26

1.66

Suspended-sediment load. The suspended-sediment concentration 

in the samples collected during high discharge did not exceed 62 ppm. 

An estimate of 40 ppm for the average concentration of su^ended 

sediment is probably reasonable. In sampling a river which is 15 or 

more feet deep at high discharges, about 99 percent of the f ow will 

be sampled by the method employed in this study. It is probable, 

therefore, that the unsampled suspended load constitutes an insignificant part of the total load. If the average discharge is taken as 

4,980 cfs and the average concentration as 40 ppm, then the average 

annual suspended-sediment load may be estimated at about 200,000 

tons.

OHOOPEE RIVER NEAR REIDSVILLJE, GA.

The drainage basin of the Ohoopee River lies in the lower Coastal 

Plain. The topography near the headwaters is rolling but where the 

Ohoopee River empties into the Altamaha River it is almc^t level. 

The surface soils are of sand and loamy sand.

Suspended-sediment concentration. Data collected durng the 

period March 1958 to February 1959 are reported in table 35. Except
DATA FROM SAMPLING SITES 75

in the samples collected on Mar. 11 and 12,1958, the suspended-sediment concentration is similar to that of other Coastal Pla in streams. 

It is uncertain whether the unusually high sediment concertration observed on March 11 and 12 is the result of scooping bed material with 

the suspended-sediment sampler or is the true concentraticn resulting 

from the movement of large amounts of sand at very high floodflows.

TABLE 35. Concentration of suspended sediment in samples from the Ohoopee 

River near Reidsville, Ga.

[Average discharge: 1903-07 and 1937-57, 888 cfs (U.S. Geol. Survey, 1959b, p. 42)]

Date

1958 

Mar. 1....... ........ __ ......... _ ...

Mar. 11..-....... .__.-_ _ _. 

Mar. 12..... .-. ___ _-._-.- 

Mar. 14......... -__-_._ . - 

July 14........... .......................

1959

Feb. 5... ... __. .. - _

Time

11:45 a.m.

4:00

12:00 m.

12:45

12:00 m.

10:00 a.m.

Gage 

height 

(feet)

9.82

16.00

16.00

15.00

4.44

2.25

1.04

1.86

8.82

Instantaneous 

discharge 

(cfs)

2,500

8,000

8,000

6,900

660

195

44

135

2,050

Suspendedsediment 

concentratiin 

(ppn)

10

»352

»724

66

12

5

7

5

33

Ratio of instantaneous 

discharge to 

average 

discharge

2.82

9.01

9.01

7.77

.74

.22

.05

.15

2.31

1 Only one sample was analyzed for this date. The accuracy of the data, therefore, is uncertain. 

ALTAMAHA RIVER AT DOCTORTOWN, GA.

The Altamaha River is formed by the confluence of th.3 Ocmulgee 

and Oconee Rivers south of Charlotte, Ga., in the lower Ccastal Plain. 

Approximately 60 percent of the drainage basin above Doctortown 

is in the Coastal Plain, and 50 percent of the discharge is derived 

from Coastal Plain streams.

Suspended-sediment concentration. Two samples were collected 

in March 1958 and one in January 1959. The concentration of suspended sediment in these samples is shown in table 36. Although the 

concentration is about the same, the small number of samples involved 

does not permit generalizations. Variations in the proportion of

TABLE 36. Concentration of suspended sediment in samples from the Altamaha 

River at Doctortown, Ga.

[Average discharge: 1931-57,12,420 cfs (U.S. Geol. Survey, 1959b, p. 43)]

Date

1958 

Mar. 11.. __________________

Mar. 14 __ . ___ . _______ . _______

1959 

Jan. 12. -. __________________

Time

Gage 

height 

(feet)

7.9

8.32

.20

Instantaneous 

discharge 

(cfs)

44,300

51,700

4,520

Suspendedsediment 

concentrat'on 

(pp-n)

16

17

16

Ratio of instantaneous 

discharge to 

average 

discharge

3.57

4.16

.36
76 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

floodwaters derived from the Piedmont should have a major effect 

on suspended-sediment concentration, and conclusions regarding 

probable concentration must take into account the source of tl 3 stream 

water.

SATTT.T.A RIVER AT ATKINSON, OA.

The Satilla Eiver drainage is entirely within the lower Coastal 

Plain. Topography is almost level and much of the area is poorly 

drained. Soils are of sand and loamy sand.

Suspended-sediment concentration. Information obtained during 

the period February-May 1959 is presented in table 37. Orly a few 

samples were collected, but the range of discharge at the time of 

sampling was great.

TABLE 37. Concentration of suspended sediment m samples from t^e Satilla

River at AtJcinson, Ga.

[Average discharge: 1931-57,1,915 ofs (U.S. Geol. Survey, 1959b, p. 50)]

Date

1959

Feb. 8...................................

Feb. 13 _______________ . ....

Mar. 12 _________ . ...............

Mar. 13 ___________________

Time

3:40

6:00

11:15 a. m.

Gage

height

(feet)

9.71

12.82

19.00

19.09

6.61

Instantaneous

discharge

(cfs)

2,280

4,900

29,000

30, 000

990

Suspendedsediment

concentration

(ppm)

17

12

24

17

19

Katio of instantaneous

discharge to

average

discharge

1.18

2.66

15.1

15.7

.52

/Suspended"sediment load. The suspended-sediment concentration 

appears to show little variation with discharge, so an estimate of the 

average annual suspended-sediment load can be computed from discharge data. If the average suspended-sediment concentration is 

estimated as about 20 ppm, the calculated average annual suspendedsediment load is approximately 38,000 tons. This figure corresponds 

to an average suspended-sediment yield for the Satilla River drainage 

of 13 tons per square mile.

Size distribution of suspended sediment. A particle-size analysis 

was made of one sample collected at station 223 (see table 38) on 

Mar. 12,1959, when the gage height was 19.00 feet. The low sediment 

concentration in this sample permitted only a semiquantitative analysis 

of particle-size distribution. However, the analysis indicated that 

about 98 percent of the suspended sediment was finer than 0.0312 mm 

and 80 percent was finer than 0.0039 mm.

Size distribution of bed material. Bed material was collected from 

the Satilla River on Mar. 12,1959. The suspended-sediment concentration and particle-size distribution of bed material in samples collected at five points in the cross section are shown in table f 8.
TABLE 38. Data from sampling verticals, Satilla River at AtJcinson, Ga., 

[Station number indicates distance, in feet, from a reference point on tne bridge wnlcn 

Station Depth 

(feet)

Average 

velocity 

(fps)

Velocity 

Ifoot 

above 

stream bed 

(fps)

Suspendedsediment 

concentration 

(ppm)

Particle-size distributi

less than 

0.062

0. 062-0. 125 0. 125-0. 25 

Satilla River at Atkinson, Ga. Mar. 12,1959

197......................

223...... ________ ...

251..... _______ . .....

278. ________ . _ . ...

306......................

20.2 

22.9 

20.7 

16.5 

15.1

2.26 

3.48 

3.54 

3.83 

3.29

0.80 

2.35 

2.06 

2.21 

2.45

19 

47 

36 

14 

51

0.4 

<.l 

<.l 

<.l 

<.l

4.4 

.2 

.3 

.1 

<.l

27.9 

9.8 

18.7 

18.3 

9.5

Alapaha River near Alapaha, Ga. Feb. 12, 1959

465 _______ . ____ ...

485 ______ ... ........

505 .. ....... .

535... ___ ........ .....

12.5 

13.5 

13.7 

11.4

1.31 

2.08 

2.43 

1.55

7 

7 

7 

7

1.4 

<.l 

<.l 

.2

4.3 

.2 

.4 

1.6

16.2 

14.8 

5.9 

30.0

46.4 

60.1 

41.2 

54.9
78 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

Bed, load. If the bed load be computed for the section of the stream 

between stations 223 and 251, some indication of the relation of the 

bed load to the suspended-sediment load can be obtained. The bed 

load was calculated as approximately 30 tons per day, by use of the 

method described by Colby and Hubbell (1957). The suspendedsediment load in the same section was about 240 tons per day. If 

these conditions are representative of the Satilla River at high discharges, the major part of the sediment load is carried as enspended 

sediment.

ALAPAHA RIVER NEAR ALAPAHA, GA.

The Alapaha River drains an area of low relief in the south-central 

part of the Georgia Coastal Plain. Soils are of sand and sandy loam 

and, in the low areas, are poorly drained.

/Suspended-sediment concentration. The concentration of suspended 

sediment in seven samples collected during the period March 1958 

to April 1959 is shown in table 39. The observed concentrp.tions did 

not exceed 17 ppm despite the fact that all samples except one were 

collected when streamflow was at least 4.7 times greater thar average. 

These data are insufficient to define the relation of suspended-sediment 

concentration to stream discharge, if any exists.

TABLE 39. Concentration of suspended, sediment in samples from the Alapaha

River near Alapaha, Ga.

[Average discharge: 1937-57, 446 cfs (U.S. Qeol. Survey, 1959b, p. 165)]

Date

1958

M&r.lS.............. ....................

Jaly 15.. ................................

1959

Feb. 11. _ . ___ - .. ..--_ 

Feb. 12 _ ..... ___ . __ ...............

Mar. 12.... __ ... __________ .

Apr. I...................................

Time

2:15

6:35

Gage

height

(feet)

10.67

11.42

5.48

11.77

12.14

13.22

12.39

Instantaneous

discharge

(cfs)

2,100

2,820

382

3,200

3,720

5,330

4,070

Suspendedsedimen*

concentration

(ppm)

7

6

17

11

7

171«

Ratio of instantaneous

dscharge of

average

discharge

4.71

6.32

.85

7.18

8.34

11.95

9.12

Suspended-sediment load. An estimate of the average annual suspended-sediment load carried by the Alapaha River was made from 

stream-discharge records because there appears to be little vs/riatioii in. 

the concentration of suspended sediment. The average discharge from 

1937 to 1957 was 446 cfs. The average suspended-sediment concentration is estimated as 12 ppm. From these data the average annual suspended load is calculated to be approximately 5,000 tons. This load 

corresponds to an annual suspended-sediment yield for the drainage 

basin of 8 tons per square mile.

Size distribution of bed material. Bed material was collected from 

the main channel of the Alapaha River on Feb. 12,1959, wher the river
DATA FROM SAMPLING SITES 79

was at a high stage. The suspended-sediment concentration and particle-size distribution of the bed-material samples are shewn in table 

38. The bed material is well sorted, for 65 to 78 percent of it falls in 

the 0.25 to 1.00 mm size range.

Bed load. The very low concentration of suspended sediment in the 

Alapaha Eiver and the fact that the river lias a sandy bed suggest 

that a significant part of the sediment load may be transported as 

bed load. Therefore, an estimate of the bed load for February 12, 

1959, was made from the data available. (See table 38.)

The section between statipns 485 and 505 was in the deepest part 

of the main stream channel, and water velocity was highest there. The 

bed load in this section was calculated by the method of Colby and 

Hubbell (1957) and was approximately 4 tons per day. The suspended-sediment load was about 12 tons per day for the same section. 

The main stream channel of the Alapaha River is the mopst favorable 

section for bed-material movement, for vegetation prevents much bedmaterial movement on the flood plain. Because the bed load is calculated to be only about one-third as great as the suspended load in 

the main stream channel, it is probable that, at the time of sampling, 

the bed load constituted only a minor proportion of the total sediment 

load.

L.ITTUE3 RIVER NEAR AJXESL, GA.

The drainage basin of the Little River lies in the lower Coastal Plain 

in an area of gently rolling topography. Soils are of san d or loamy 

sand and have numerous iron-and-clay-cemented concretions.

Suspended-sediment concentration. Data collected during the period March-May 1959 are shown in table 40. The concentration of 

suspended sediment tends to increase with increasing discharge, but 

the highest suspended-sediment concentration determined was only 59 

ppm, despite the fact that the river was sampled during periods of 

very high discharge.

TABLE 40. Concentration of suspended sediment in samples frcm the Little

River near Adel, Oa.

[Average discharge: 1940-57, 448 cfs (U.S. Geol. Survey, 1959b, p. 167)]

Date

1959 

Mar.6._. _ ........ _ . ____

Mar. 8-.- _ ........ _____ ..... 

Mar. 11............. _ ... ___ ........

Mar. 12......... _ . _ ........... _ ...

Mar. 13., . _________.-_- 

Mar. 13... ___ . ____ .... ___ .....

Mar. 20 _______ . __ . ___ ... .....

Apr. 2 ____________________

Apr. 30 ____________________

May 26.. ______ . _ .. ____ . ....

Time

2:25

2:20

10:20 a.m.

2:20 p.m.

6:45

2:00

Gage 

height 

(feet)

16.5

17.6

15.9

14.6

13.3

13.1

15.7

14.4

4.83

13.1

Instantaneous 

discharge 

(cfs)

5,070

8,300

4,070

2,920

2,100

2,020

3,800

2,820

240

2,020

Susperdedsedtaent 

concontratnn 

(ppn)

59

32

26

48

14

13

24

14

14

25

Ratio of instantaneous 

discharge to 

average 

discharge

11.31

18.52

9.09

6.51

4.69

4.51

8.48

6.30

.54

4.51
80 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

Suspended-sediment load. The annual suspended-sediment load 

can be estimated if an average concentration is assumed. T"^ available data indicate that an estimate of 30 ppm would be reascnable for 

the average suspended-sediment concentration. The average discharge for the period 1940-57 was 448 cfs. The average annual load, 

therefore, is probably about 13,000 tons. This average corresponds to 

an annual suspended-sediment yield in the drainage basin cf 24 tons 

per square mile.

Size distribution of ~bed material. A series of bed-material samples 

were collected from the Little River on Mar. 13,1959, when the gage 

height was 13.3 feet. The concentration of suspended sediment and 

the particle-size distribution of bed-material samples are given in 

table 41.

Bed load. The data presented in table 41 can be used to estimate 

the bed load of the Little River for Mar. 13,1959. In the section between stations 108 and 141, the velocity and depth of water show little 

variation. The bed load computed for this section was about 1 ton per 

day. The suspended load for the same section at the same time was 38 

tons per day. The bed-load to total-load ratio is greater for tl i s stream 

section than for the stream as a whole, because vegetation or the flood 

plain prevents the movement of much bed material outside the main 

stream channel. These results indicate, therefore, that the bed load 

was a minor part of the total load carried by the Little River at the 

time of sampling.

The sampling was done during the falling stage of the r;ver after 

a flood, and some of the finer grained sediment may have been removed 

from the bed material by the more rapidly moving water at the peak 

of the flood. This condition could be partially responsible for the low 

proportion of bed load, because the median diameter of bee1 material 

is 0.78 mm (table 41). Observation of four other streams in the lower 

Coastal Plain shows a range in median diameter of bed material from 

0.38 to 0.64 mm.

OCETLOCKONEE RIVER NEAR THOMASVmLE, GA.

The Ochlockonee drains an area in the southwestern pp.rt of the 

Georgia Coastal Plain. The topography is gently rolling to almost 

level. Soils are of sand and loamy sand.

Suspended-sediment concentration. Sample data from the Ochlockonee River during the period February to April 1959 are given in 

table 42.

Suspended-sediment load. Although insufficient data are available 

from the Ochlockonee River alone to permit generalizations concerning average suspended-sediment concentration, the data ir table 42, 

when combined with information about concentrations in oth?.r Coastal 

Plain streams, indicate that 20 ppm would be a reasonable approxima-
TABLE 41. Data from sampling verticals, Little River near Adel, Ga., and O

[Station number indicates distance, in feet, from a reference point on the bridge which 

Station Depth 

(feet)

Average 

velocity 

(fps)

Velocity 

Ifoot 

above 

stream bed 

(fps)

Suspendedsediment 

concentration 

(ppm)

Particle-size distributio

<0.062 0.062-0.125 0. 125-0. 25 

Little River near Adel, Ga., Mar. 13, 1959

97 

108.. _____ . _ ....

119. ...

130...... ___ ... __ . ...

141... _______ . ...

13.7

13.2

12.6

13.0

13.7

1.52

2 28

2.54

2.37

2.15

1.26

2.10

1.93

1.48

1.36

14

14

14

16

14

<01

^ j

^ j

^ ^

^ j

0.1

^ j

<- j

.2

1.0

.4

.1

.1

.3

Ochlockonee River near Thomasville, Ga., Feb. 13, 1

900..--.....-......... 

100 ___ ...... ..........

110. _____ . ____ ....

120. . ____ . __ .....

17.6

16.9

16.6

15.4

2.91

2.68

2.28

1.76

15

15

41

14

0.0

.0

.0

.0

0.4

.0

.2

3.0

4.6

4.7

2.6

31.2
82 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

tion for average suspended-sediment concentration. The avorage discharge for the period 1937-57 was 426 cfs. On the basis of these data 

the average annual load of suspended sediment is estimated to be 

approximately 8,500 tons per year. This figure correspords to an 

annual suspended-sediment yield of 15 tons per square mile.

Size distribution of bed material. Samples of bed material were 

collected from the Ochlockonee River on Feb. 13,1959, when the gage 

height was 14.39 feet. The concentration of suspended sediment and 

the particle-size distribution of bed-material samples are shown in 

table 41. Other data pertaining to the sampling stations also are in 

table 41.

TABLE 42. Concentration of suspended sediment in samples from the Ochlockonee River near Thomasville, Ga.

[Average discharge: 1937-67,426 cfs (U.S. Qeol. Survey, 1959b, p. 182)]

Date

1959

Feb. 13.. _____ . __ . _______

Mar. 2.. ______________ . ...

Mar. 12.... ............................

Apr. 3. .... _ . ________ . ......

Time

10:40 a.m.

11:00 a.m.

8:15

Gage

height

(feet)

14.39

9.62

12.78

12.61

Instantaneous

discharge

(cfs)

3,610

1,310

2,430

2,340

Suspendec1 -

sediment

concentration

(ppm)

15

12

28

3G

Ratio of instantaneous

discharge to

average

discharge

8.34

3.08

5.75

5.52

Bed load. An estimate of the bed load for Feb. 13,1959, v^as made 

from the data in table 41. Approximately 4 tons of sediment per day 

moved through the section between stations 90 and 110 as bed load 

and about 35 tons passed the section as suspended load. Bed load 

probably represents a higher percentage of the total load ir the section studied than in the stream as a whole because vegetation obstructs movement of sediment on the flood plain. These data, therefore, suggest that the bed load constituted a minor fraction of the total 

load at the time of sampling. The flood reached its peak 2% days before the sampling was done, and it is possible that considerably larger 

amounts of sediment were transported as bed load during tH period 

of higher stream discharge.

CBtATTAHOOCHEE RIVER NEAR £BAF, OA.

The headwaters of the Chattahoochee Kiver lie in White County 

in the Blue Ridge province. The topography is mountainous and 

runoff is rapid. Soils range from fine sandy loam to clay loim.

Suspended-sediment concentration. The concentration of suspended sediment in samples collected during the period November 1957 

to April 1959 is shown in table 43. Samples were not obtained during 

periods of high discharge because the flow increases and decreases so 

rapidly that it is difficult for distant observers to reach this stream 

in time to collect samples before and during peak discharge. The
DATA FROM SAMPLING SITES 83

data indicate that the concentration of suspended sediment tends to 

increase with increasing discharge but that the relation is not a 

linear one.

TABLE 43. Concentration of suspended sediment in samples from the Chattahoochee River near Leaf, Ga.

[Average discharge: 1940-57,380 cfs (U.S. Geol. Survey, 1959b, p. 191)]

Date

1957 

Nov. 1... ___________________

Dec. 2 ___________________

Dec. 9..___...._...... ._.-._..__ __ .. ...

1958 

Jan. 2. ..................................

Jan. 24.. ................................

Feb. 18 ... . . _ ..... ......

Mar. 3...................... .............

Mar. 4....... _ .........................

Mar. 18... .... .. ....... ............

Mar. 28. ._ .. ........ ......

Apr. I.................. .................

Apr. 16 .. __ ._ .. 

July 1. ........ ..... .... _ ....... _ .

Aug. 2... ........ _ .....................

Aug. 9...................................

Oct. 1.. .......... ___ .................

Nov. 3...... .......... _ ................

Dec. 1.. .................................

1959 

Jan. 2.. .................................

Mar. 11..................................

Apr. IS .... ........................

Apr. 20.......... _ ........ _ ..........

Time

3:50

3:20

3:50

4*nn

4:45

12:45 p.m.

11:00

11:50

3:45

6:30

3:07

2:35

Gage 

height 

(feet)

1.87

2.31

2.68

2.34

2.42

3.26

2.47

2.51

2.48

2.83

2.79

2.62

3.00

2.32

1.98

1.88

1.81

2.64

1.79

1.75

2.25

2.17

3.30

2.91

Instantaneous 

discharge 

(cfs)

197

384

580

400

450

950

465

485

470

665

635

545

775

390

235

200

180

560

170

160

355

320

379

718

Suspendidsedimert 

concentration 

(ppm)

5

7

34

35

18

114

9

7

5

25

34

10

30

22

14

10

11

10

166

9

5

37

5

68

30

Ratio of Instantaneous 

discharge to 

average 

discharge

0.52

1.01

1.53

1.05

1.18

2.50

1.22

1.28

1.24

1.75

1.67

1.43

2.08

1.03

.62

.53

.47

1.47

.45

.42

1.47

.84

1.00

1.8P

It was not possible to estimate suspended loads or bed loads from 

available data.

One analysis for particle-size gradation of suspended sediment was 

made; the results are shown below. The sample was collected April 18, 

1959, at 1:00 p.m.; discharge was 379 cfs.

Percent in 

Sisefraction sizefraction

>0.0625 mm (sand)______________________ 17

0.0039-0.0625 mm (silt)__----__._-___----- 51

<0.0039 mm (clay)__________________ 32

CHESTATEE RIVER NEAR DAHLONEGA, GA,

The Chestatee River originates in White and Lumpkin Counties in 

the Blue Ridge province. The topography is mountainous and the 

soils are of sandy loam to clay loam. The character of str^arnflow is 

much like that of the Chattahoochee River near Leaf.

Suspended-sediment concentration. Data collected from the Chestatee River near Dahlonega during the period December 1957 to April 

1959 are given in table 44. There is a well-defined tenderly for the 

concentration of suspended sediment to increase with increasing dis-
84 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

charge, but data were not obtained, at high discharges to confirm, the 

validity of such a correlation for the complete range of flow.

TABLE 44. Concentration of suspended sediment m samples from the Chestatee 

River near Dahlonega, Ga.

[Average discharge: 1929-31 and 1940-57, 331 cfs (U.S. Oeol. Survey, 1959b, p. 112)]

Date

1957 

Dec. 23 ____________________

195S 

Jan. 15 __________________

Jan. 31 __________________

Feb. 13 ____________ . ______

Mar. 4 __________________

Mar. II..................................

Mar. 18.. _____________ .. ......

Mar. 28 _______ . _____ .... ......

Apr. 16..................................

Apr. 21..................................

JuneS ...................................

July 15..................................

Aug. 28.................... ...........

Sept. 10....-...-........... .........

Oct. 6 ___________________ . ...

Dec. 18 ____________________

1969 

Apr. 19........ ...... _ ............

Apr. 20 __ . _________________

Time

12:15

2:30 p.m.

4:25 p.m.

11:15 a.m.

9:10

1:00 p.m.

5:40

8:30 a.m.

12:30 p.m.

2:50

2:20 p.m.

2:20

Gage 

height 

(feet)

2.25

1.75

1.73

1.92

1.92

1.95

2.74

2.41

3.02

2.17

1.58

2.28

1.31

1.06

1.19

1.01

3.65

2.88

Instantaneous 

discharge 

(cfe)

471

315

310

366

366

375

642

525

748

444

267

481

197

136

168

126

1,020

694

Suspendedsedimert 

concentration 

(ppm)

16

12

4

5

10

12

64

25

75

21

15

50

14

8

16

2

IF*

49

Ratio of instantaneous 

discharge to 

average 

discharge

1.42

.95

.94

1.10

1.10

1.13

1.94

1.59

2.26

1.34

.81

1.45

.60

.41

.51

.38

3.08

2.10

The available data are also not sufficient for the calculation of 

sediment loads. One particle-size analysis of suspended sediment was 

made, however, and the results are given below. The sample was 

collected at 2:20 p.m., Apr. 19,1959; discharge was 1,020 cfs.

Size fraction 

>0.062 mm (sand)_________

0.0039-0.062 mm (silt) _ . _ 

<0.0039 mm (clay)__....

Percent in 

size fraction

34

42

24

CHATTAHOOCHEE RIVER AT ATLANTA, GA.

The Chattahoochee Eiver at Atlanta is formed by streams from 

the Blue Ridge and upper Piedmont provinces. The topography in 

the drainage basin is hilly to mountainous and soils are of sandy loam 

to clay loam.

Suspended-sediment concentration. Data concerning the Chattahoochee Eiver at Atlanta during the period November 1957 to December 1958 is presented in table 45. Flow at this site is controlled by 

release of water from Lake Sidney Lanier, by action of Morgan Falls 

hydroelectric plant, and by rainfall. The suspended-sedinent concentration may increase greatly or only moderately with increasing 

flow, depending upon the cause of rise in discharge. Approximately 

3 inches of rain fell during the period Nov. 23-25,1957. The sediment
DATA FROM SAMPLING SITES 85

in the sample taken November 25, therefore, probably resulted from 

erosion during the rainy period. Similarly, heavy rains fcU on Feb. 

6, 1958, and caused high sediment concentrations. However, release 

of water from storage upstream was responsible for the above-normal 

flow on Sept. 13,1958, and the resulting suspended-sediment concentration was relatively low. Determination of the sediment load and 

estimation of suspended-sediment concentration at this site cannot be 

made without sampling several times a day during period^1 of rapid 

change in concentration. Data would also be needed for several storm 

events occurring throughout the year.

TABLE 45. Concentration of suspended sediment in samples from the Chattahoochee River at Atlanta, Oa.

[Average discharge: 1928-31 and 1937-57, 2,413 cfs (U.S. Geol. Survey, 1959b, p. 197)]

Date

1967 

Nov. 25 ____ . ____ . _____ . ......

1968 

Jan. 3 ____________________

Jan. 7-_ __________________

Jan. 16 _____________ . ...........

Feb. 6 _______________ , .....

Feb. 6.................... ............

Feb. 18..................................

Mar. 5 ............... .......

Mar. 17 _ . _ .._______._____,____....._

Mar. 27 ____ . ______ . ...........

Mar. 28. ................................

Apr. 18 ........ ..._................._. 

May I............. ........ . ....

JuneS ___________________

Sept. 13 .................................

Dec. 30 ..................................

Time

2:05 p.m.

1:40

1:30

1:05

10:20 a.m.

3:00 p.m.

10:40 a.m.

10:10

9:10

10:10

12:15 p.m.

12:20

3:20

2:00 p.m.

10:20 a.m.

Gage 

height 

(feet)

5.00

2.55

2.57

2.87

3.61

4.20

2.38

2.56

2.77

4.06

3.33

3.62

4.00

1.25

4.90

4.65

Instantaneous 

discharge 

(cfs)

3,600

715

730

970

1,690

2,370

610

720

885

2,190

1,400

1,700

2,120

<200

3,440

3,040

Suspend 3dsedi inert 

concentratior 

(ppm)

1T7

18

5

14

530 i,<r<9

12

12

10

58

60

60

14

23

38

Ratio of instantaneous 

discharge to 

average 

discharge

1.49

.30

.30

.40

.70

.98

.25

.30

.37

.91

.58

.70

.89

<.08

1.43

1.26

CHATTAHOOCHEB RIVER AT WEST POINT, GA.

The Chattahoochee Eiver at West Point drains an arer, of about 

3,550 square miles, most of which is in the Piedmont physiographic 

province. Topography is mountainous at the headwater?, but the 

relief decreases downstream. Buford Reservoir causes deposition of 

much of the sediment derived from the area above it. However, more, 

than 1,000 square miles of the Piedmont drains into the channel system 

between Buford Eeservoir and West Point. The soils in the Piedmont 

upstream from West Point are of sandy to clay loam.

Suspended-sediment concentration. Data collected during the period December 1957 to May 1959 are given in table 46. Concentration 

of suspended sediment definitely tends to increase with increasing discharge, but data are insufficient to permit an estimate of the normal 

limits of variation in sediment concentration.

Siae distribution of suspended sediment. Analyses of fi^e samples 

of suspended sediment for particle-size distribution (table. 47) indi-
86 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

cate that silt and clay are about equal in amount and together represent almost 90 percent of the suspended sediment.

TABLE 46. Concentration of suspended sediment in samples from the Chattahoochee River at West Point, Ga.

[Average discharge: 1896-1910 and 1912-57, 5,539 cfs (U.S. Geol. Survey, 1959b, p. 201)]

Date

1957

1958

Jan. 27 ______ ..... ____ ....

Feb. 7. _.. _.

Feb.17. .. 

Feb. 28 _ _ - _ 

Mar. 13... __ ... __ .. _ ..............

Mar. 24.. .................... ......

Apr. 2 _ . _____ .... __ .............

Apr. 17...... .. . __.

July 21.. . -. __ ...

Sept. 15 __ .................. _ .. __ .

Nov. 24. ___ . .........

Dec. 26 . ______ . _ . ..............

1959

Mar. 7. ............ ........ .............

Mar. 23.. ...............................

May 13. .. .. .............

Time

3:40 p.m.

2:10

11:30 a.m.

2:00

12:20

12:30

7:30

6:30

11:55 a.m.

3:00

2:15

1:55

10:20 a.m.

4:00 p.m.

4:45

Gage 

height 

(feet)

3.85

2.62

3.78

16.30

4.70

10.56

5.55

4.66

4.95

13.15

4.64

2.87

5.86

3.65

2.87

3.20

4.37

7.92

9.35

4.57

4.22

Instantaneous 

discharge 

(cfs)

3,280

1,380

1,585

33, 200

4,720

16,500

6,190

4,640

5,150

22,950

4,620

1,710

6,750

2,950

1,720

2,230

3,990

10, 550

13,500

4,500

3,900

Suspendedsedimert 

concentration 

(ppm)

81

16

142

6)0

50

557

61

32

34 3'"5

41

12

202

25

15

13

111

228

278

67

67

Ratio of instantaneous 

discharge to 

average 

discharge

0.59

.25

.29

6.00

.85

3.00

1.12

.84

.93

4.15

.83

.31

1.22

.53

.31

.40

.72

1.90

2.44

.81

.70

TABLE 47. Particle-sise analyses of suspended sediment, Chattahoochee River

at West Point, Ga.

[All samples mechanically and chemically dispersed before analysis. Station number indicates distance, 

in feet, from a reference point on the bridge across the Chattahoochee River]

Date

1958 

Feb. 28......

1959

Mar. 7 . 

Mar. 7... .

Averagf

Time

11:55 a.m.

2:15 p.m. 

2:15 

9:50 a.m. 

9:50

Gage 

height 

(feet)

10.56

7.92 

7.92 

9.35 

9.35

Instantaneous 

discharge 

(cfs)

16,500

10, 550 

10, 550 

13, 500 

13, 500

Station

190

210 

270 

210 

270

Suspendedsediment 

concentration 

(ppm)

572

244 

243 

310 

303

5---- _

Percent in size range (mm)

>0.082

12

14 

11 

16 

14

13

0.00*)- 

0.062

34

44 

40 

43 

48

42

<0.0039

54

feS

42 

48 

41 

38

45

FLINT RIVER NEAR GRIFFIN, GA.

The Flint Elver above Griffin is in the Piedmont in an area of hilly 

topography and sandy-loam to clay-loam soils. The headvaters are 

in Fulton County in a well-populated area on the outskirts of Atlanta, 

Ga.
DATA FROM SAMPLING SITES 87

Suspended-sediment concentration. The concentration of suspended sediment in samples collected during the period December 

1957 to November 1958 is shown in table 48. There is som^ tendency 

for the concentration to increase with increasing discharge; however, no samples were collected during very high flows, so the normal 

range of concentrations to be expected was not determined. The 

highest concentration found was 88 ppm. This concentration is considerably less than the highest measured in samples from the Flint 

Kiver near Culloden, and indicates either that the drainage basin 

above Griffin is yielding little sediment or that no sample^ were obtained during periods of high sediment load.

TABLE 48. Concentration of suspended sediment in samples from the Flint River

near Griffin, Oa.

[Average discharge for the period 1937-57 was 315 cfs (U.S. Qeol. Survey, 1959b, p. 203)]

Date

1957 

Dec. 2 ___________________ .

Dec. 27 ___________________

1958 

Jan. 11. _____________ . _ ......

Jan. 27. _______ .... _____ .......

Feb. II..................................

Feb. 28 _________ . ______ ....

Mar. 13..................................

Mar. 18.... _____ . ______ .......

Mar. 24 ___________________

Aor. 2 _______________

Aor. 17.. ______ ..... ________

Aor. 29.. _________ . _________

June 13.. __________________

July 23 ____ ... _ .... ___ ____ .

Sect. 14 _______ ..... _____ ......

Oct. 15. _____ . ___ . _____ .. ....

Nov. 25.... _______ . _____ .. ....

Time

2:25 a.m.

1:45

12:45

3:00

11:00 a.m.

3:35 p.m.

11:30 a.m.

2:30

2:45

4:00

3:50

2:00

5:45

3:00

Gage 

height 

(feet)

6.52

6.18

4.63

8.18

8.84

9.49

8.15

7.50

6.19

6.39

9.08

5.61

3.13

7.47

2.96

2.91

Instantaneous 

discharge 

(cfs)

404

350

168

743

932

1,215

732

585

350

382

1,015

268

69

580

70

58

Suspenc'edsediment 

concentration 

(ppm)

68

13

5

22

25

34

11

15

9

9

21

12

15

88

13

18

10

Ratio of instantaneous 

discharge to 

average 

discharge

1.28

1.11

.55

2.36

2.96

3.86

2.32

1.86

1.11

1.21

3.22

.85

2.19

1.84

.22

.18

WHITEWATEB CREEK BELOW RAMBTTLETTE CREEK NEAR BUTLER, GA.

Whitewater Creek drains an area in the upper Georgia Coastal 

Plain. The topography is hilly, but the topsoils are of clean sand 

and absorb water rapidly. This water percolates down to the water 

table and helps supply the surface streams which show fairly constant 

discharge even during dry periods.

Suspended-sediment concentration. Data collected during the 

period March 1958 to March 1959 are reported in table 49. The concentration of suspended sediment is uniformly low and s^ows little 

tendency to change with discharge.

The water from Whitewater Creek is exceptionally low in dissolved 

and suspended mineral matter. K. N. Cherry (oral communication, 

1960) states that four samples which he collected contained dissolved 

solids in the range 15 to 18 ppm. The available data suggest that combined dissolved and suspended solids rarely exceed 30 ppm.
SEDIMENT TRANSPORTED BY GEORGIA STREAMS

Surf ace-water records indicate that Whitewater Creek shows little 

variation in discharge. Even during the low-flow period of 1954 (U.S. 

Geol. Survey, 1956, p. 168), the discharge was not less than 100 cfs.

TABLE 49. Concentration of suspended sediment in samples from Whitewater 

Creek below Ramoulette Creek near Butler, Ga.

[Average discharge: 1951-57,160 cfs (U.S. Geol. Survey, 1959b, p. 212)]

Date

1958

M.a,T.28............... ...................

May 5-... _______________

Aug. 13- . -. __ - ..._.-_..._ ._

Sept. 16 . ____ . ..............

Nov. 4.... _________ . ____ . ......

Dec. 22 __________________

1959

Jan. 27. _______________ . ...

Mar. 3 . ________________

Mar. 7 ................................

Time

11:05 a.m.

11:00

2:30

3:30

6:30

Gage

height

(feet)

2.13

1.71

1.69

1.87

1.54

1.49

1.49

1.59

1.80

3.48

3.14

Instantaneous

discharge

(cfs)

189

152

150

165

138

134

134

142

159

370

316

Suspendedsediment

concentration

(ppm)

4

8

13

14

6

4

2

5

5

12

4

Ratio of instantaneous

discharge to

average

discharge

1.18

.95

.94

1.03

.86

.84

.84

.89

1.00

2.31

1.98

Suspended-sediment load. If the average concentration of suspended sediment be estimated as 10 ppm, the annual suspended-sediment load is approximately 1,600 tons. This annual load corresponds to 

an average annual sediment yield per square mile of 17 tons.

FLINT RIVER. AT MONTEZUMA, GA.

The station at Montezuma is located about 58 miles downstream 

from the station near Gulloden. The intervening drainage area is 

almost entirely in the upper Coastal Plain where topography is gently 

rolling to hilly and soils are generally sandy.

Suspended-sediment concentration. Information obtained during 

the period November 1957 to January 1959 is reported in table 50.

TABLE 50. Concentration of suspended sediment in samples from the Flint River

at Montezuma,, Ga. 

[Average discharge: 1930-32,1934-57,3,500 cfs (U.S. Geol. Survey, 1959b, p. 213)]

Date

1957 

Nov. 22.. ...............................

1958 

Mayl.. _ . __ .........................

July I-....... . .._..... _..

July 22 ..................................

Aug. 13..................................

Sept. 17...-.......-.-. ...............

Nov. 3..... ..........................

1959 

Jan. 28 ..................................

Time

9:00

12:00 m.

12:00

4:00 p.m.

1:30

Gage 

(feet)

11.64

6.22

3.77

9.77

3.70

1.9

2.00

2.89

5.38

Instantaneous 

discharge 

(cfs)

8,800

3,650

2,100

6,700

2,050

1,140

1,180

2,600

3,100

Suspendedsediment 

concentration 

(ppm)

154

45

32

188

32

21

14

11

64

Ratio of instantaneous 

discharge to 

average 

discharge

2.52

1.04

.60

1.92

.59

.33

.34

.74

.89
DATA FROM SAMPLING SITES 89

The concentration of suspended sediment shows a positive correlation 

with discharge, probably because of suspended sedimert from the 

Piedmont rather than sediment from the Coastal Plain. The data 

suggest that the normal concentration of suspended sediment is 10 to 

20 ppm during periods of low flow and more than 150 ppm during 

high flows.

COOSA RIVER NEAR ROME, GA.

The Coosa River is formed by the confluence of the E'towah and 

Oostanaula rivers. The Etowah River originates in the Blue Ridge 

and flows across the upper Piedmont to the Allatoona reservoir where 

much of the sediment load is deposited. Below the Alls.toona dam, 

mining activity contributes an undetermined amount of sediment to 

the Etowah River. The Oostanaula River also originates in the Blue 

Ridge but flows through the Valley and Ridge province before joining 

the Etowah River near Rome. No major dams cause deposition of the 

sediment load from the Oostanaula.

Suspended-sediment concentration. The concentration of suspended sediment in samples collected during the period December 1957 

to January 1959 are reported in table 51. There is a positive but 

poorly defined correlation between stream discharge and suspendedsediment concentration. Concentration during periods of low flow 

probably ranges from 10 to 40 ppm and at high flows exceeds 100 ppm.

TABLE 51. Concentration of suspended sediment in samples from the Coosa

River near Rome, Ga.

[Average discharge, 1928-31 and 1937-57, 6,104 cfs (U.S. Oeol. Survey, 1959b, p. 268)]

Date

1957 

Dec. 5. ____________ . __ . .....

1958

Jan. 17..... __ . ___ . _ . __ . .....

Feb. 5.. ........ ......................

Feb. 26. _ . _ . _ .... _ ..--.---.. .....

Apr. 21... ...... .........................

July 29. ____ ..- ..... ____ . .........

1959 

Jan. 13. _______ .. ________ ...

Time

3:00 p.m.

6:30

1:15

12:20

12:20

2:20

2:15

Gage 

height 

(feet)

5.82

3.66

6.60

4.61

4.15

8.45

9.48

5.80

2.90

4.50

2.40

Instantaneous 

discharge 

(cfs)

6,130

4.100

6,910

4,960

4,550

8,940

10, 220

6,110

3,150

4,860

2,970

Suspendedsediment 

concentrat'on 

(PP"1)

79

49

39

28

25

86

109

25

36

70

11

Ratio of instantaneous 

discharge to 

average 

discharge

1.00

.67

1.13

.81

.75

1.46

1.67

1.00

.52

.80

.49

CHATTOOGA RIVER AT STTMMERVHJLiE, GA.

The Chattooga River drains a part of the Valley and Ridge province 

in northwest Georgia. Soils are of silt loam to sandy loam on the 

ridges and of silt loam to silty clay loam in the valleys. More than 

80 percent of the flow of the Chattooga River at the sampling site is

695-903 64 7
90 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

controlled by a dam at Trion, and an undetermined part of the sediment load, is deposited in the reservoir.

Suspended-sediment concentration. Data collected during the 

period December 1957 to January 1959 are shown in table 52. In general, the concentration of suspended sediment is low and shows little 

increase with increasing discharge.

TABLE 52. Concentration of suspended sediment in samples from the Chattooga 

River at Summerville, Ga.

[Average discharge, 1937-57,341 cfs (U.S. Geol. Survey, 1959b, p. 270)]

Date

1957 

Dec.ll ._. -._ _-..

1958

3emA&.. ................................

Jan. 28... ________________

Feb. 14.. .. ..... .. ........

Mar.3 _ ... ... 

Mar. 14... .. _____ . __ ... _____ .

Mar. 26 ... ..... __ ...... ___ . _ ...

Apr. 1 ._. ._ 

Apr. 21. _._.. .... .-.________..._

May 13... ____ . _____ . _ .

July29_ ... ..

Sept. 9........ . .

Sept. 12.............. __ .......... _ .

Dec. 2 __________________ .

1959 

Jan. 13 __________________

Time

12:10 p.m.

11:30 a.m.

11:00 a.m.

10:45

5:00

Gage 

height 

(feet)

4.66

3.21

3.92

4.42

3.70

4.01

5.57

6.01

4.16

3.91

4.35

2.47

2.60

2.18

2.22

2.13

2.24

Instantaneous 

discharge 

(cfs)

540

259

392

494

353

410

740

845

442

392

480

130

150

88

93

80

95

Suspended - 

sediment 

concentration 

(ppm)

8

3

5

11

13

36

20

6

11

82

5

12

4

3

16

11

Ratio of instantaneous 

discharge to 

average 

discharge

1.58

.76

1.15

1.45

1.03

1.20

2.17

2.49

1.30

1.15

1.41

.38

.44

.26

.27

.24

.28

DATA FROM OTHER SOURCES

Several agencies other than the U.S. Geological Survey 1 ave collected information concerning the sediment transported by Georgia 

streams. Some of the data are tabulated below.

The Hydraulic Data Branch of the Tennessee Valley .Authority 

made a comprehensive investigation of the suspended-sediment load 

in a number of Tennessee Valley streams during the period 1934-42 

(Albert S. Fry, written communication 1959). Later, after reservoirs 

had been built on some of these streams, surveys were made to determine how much sediment had accumulated during known time intervals. Some of the data obtained by the Tennessee Valley Authority 

pertained to Georgia streams. These data are presented in tables 

53 and 54.

Information concerning sediment deposited in other Georgia reservoirs has been collected by the Federal Inter-Agency Committee on 

Water Resources (1957). A summary of available data on sedimentation in reservoirs (other than that reported in tables 53 and 54) is 

given in table 55.
DATA FROM OTHER SOURCES 91

Comparison of the average annual suspended-sediment load in the 

Nottely and Hiwassee Rivers (measured prior to construct'on of Nottely and Chatuge dams) with the sediment deposited in reservoirs 

formed after dams were built indicates that most of the sediment load 

is transported in suspension. The contrast between the minimum and 

maximum suspended-sediment concentrations is extreme and shows 

the great increase in sediment concentration caused by erosion during 

storms.

TABLE 53. Suspended-sediment data from streams originating in northern

Georgia

[From records of the Tennessee Valley Authority]

Description

Drainage area (sq mi):

Daily mean concentration (ppm):

Monthly mean concentration (ppm) :

TWfjYimiiTn

Minimum

Monthly mean load (tons) :

Minimum

Annual load (tons) : 

Total __ ......... __ . ___ .....

South Chickamauga 

Creek, McCarty, 

Tenn.

458

400

Jan. 1937-June 1938

1,550

2

745

35

116,400

527

1251,000

550

Sampling site

Nottely River, 

Ranger, N.C.

272

200

Aug. 1934-May 1942

6,950

1

2,010

6

196, 120

68

» 189, 000

700

Hiwassee River, 

Murphy, N.C.

421

150

Aug. 1934-May 1942

8,740

1

1,235

4

231, 100

82

» 219, 000

520

1 Calendar year 1937.

2 Average for calendar years 1935-41.

TABLE 54. Sediment deposited in reservoirs in northern Georgia and western

North Carolina

[From data collected by the Tennessee Valley Authority]

Location of reservoir

Description

Drainage area: 

Net sediment-contributing area. __ ..sq mi.. 

Approximate sediment-contributing area in

Ratio of original capacity to watershed 

ac ft per sq mi.. 

Date of sediment investigations:

Average annual sediment yield. tons per sq mi..

Blue Ridge dam 

on Toccoa River

227 

227

851 

April 1944

August 1954 1839

Nottely dam on 

Nottely River

207 

207

825

April 1955 2677

Chatuge dam on 

Hiwassee River

178 

130

1,282 

February 1942

August 1954 3444

1 Average for 10.3 years.

2 Average for 13.3 years, 

s Average for 12.5 years.

The annual sediment yield from the drainage basins above the reservoirs ranges from 444 to 2,638 tons per square mile. In general, the 

higher sediment yields were found in the small drainage basins. All 

the reservoirs for which sediment data are available receive their water
92 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

from hilly or mountainous parts of Georgia, hence the sediment yields 

to be expected from areas of low relief can be estimated only from 

sediment-concentration measurements.

TABLE 55. Sediment deposited in Georgia reservoirs

[Data from Federal Inter-Agency Committee on Water Resources (1957) and from records of the U.S 

Department of Agriculture Soil Conservation Service]

Reservoir

Carroll Lake.. 

Lloyd Shoals .

Seguoyah ..... 

Sky Lake .....

White Manganese No. 

6.

County

Butts, Jasper, 

and 

Newton.

Pic kens

White.........

Sedimentcontributing 

area 

(sq mi)

6.91 

1,407

1.34

1.51 

2.31 

.61 

11.0

Time of 

sediment 

accumulation

1949-57 

1910-35

1924-37 

1937-45 

1929-39 

1925-56 

1954-57 

1929-38

Number 

of years sediment 

accumulated

8.6 

24.3

13.4 

7.3 

10 

31 

3 

9.2

Original 

reservoir 

capacity (acrefeet 

per sq 

mi of 

drainage 

area)

202 

79.6

] 276

556 

93.3 

104 

72.2

Total sediment 

volume 

(acrefeet)

122.6 

13,960

f 26 

i 4 

25 

41.9 

5.0 

121

Average arnual 

sediment accumulation par sq 

mi of sedirientcontributing 

area

Acrefeet

2.07 

.408

1.45 

.41 

1.66 

.58 

2.74 

1.20

Tons

1,916 

533

1,580 

446

846 

2,638 

1,660

Density 

of 

deposit 

(Ib per 

cuft)

42.5 

160

150 

ISO

67 

44.2 

63.7

i Density is assumed.

SIGNIFICANCE OF DATA

Information obtained during this study is summarized in table 56. 

In general, streams draining from mountainous areas show great 

changes in sediment concentration and sediment load with changes in 

discharge and especially with periods of intense rainfall. In areas of 

very low relief, suspended-sediment concentration changes little with 

discharge, and sediment load is believed to increase approximately in 

proportion to the increase in discharge. Annual sediment yields range 

from about 10 tons per square mile on the Coastal Plain to more than 

1,000 tons per square mile in the Blue Ridge province.

Consideration of the information gained in this study emphasizes 

the fact that the sediment yield from a drainage basin is appreciable 

only if the following conditions exist:

1. Rainfall is great enough, and of sufficient intensity, tl at a significant amount of surface runoff occurs.

2. Covering vegetation is sparse enough that the runoff has opportunity to erode the land surface.

3. The surface soil contains an appreciable proportion of fin^-grained 

particles.

4. The topographic relief is such that water velocity and turbulence 

are great enough to transport at least silt and clay pr.rticles.

5. The streams are free of major obstructions to streamflow which 

reduce water velocity and cause deposition of sediment.
SIGNIFICANCE OF DATA 93

The influence of these various factors can be illustrated with information available from this study. On the Coastal Plain the topographic relief is low, and many of the surface soils are very sandy. 

Thus, even though some areas have much open cultivated land, comparatively little sediment is transported by the streams. In the Piedmont region, loamy soils, intensive cultivation of land in some areas, 

and moderate relief tend to increase sediment yields, whereas the 

presence of many dams on the larger rivers causes deposition of sediment in reservoirs. The net sediment yield from the Piedir ont, nevertheless, is perhaps 5 to 20 times that of the Coastal Plain.

The great relief, loamy soils, and few clams in the mountainous 

Blue Ridge area encourage sediment transportation. Th?, fact that 

there is little open cultivated land apparently does not prevent considerable erosion. It is possible, however, that the amount of cultivated 

land is not a good measure of open areas in the mountains. Many of 

the smaller watercourses have cut through the veneer of surface vegetation and laid bare the underlying soil. The soil so exposed can be 

rapidly eroded. The sediment yield from the mountain ar?,as is large 

because of the many factors which combine in favoring erosion and 

transportation of sediment.

VARIATION IN CONCENTRATION AND PARTICLE-SIZE 

DISTRIBUTION OP SUSPENDED SEDIMENT

The concentration of suspended sediment shows large variations in 

the Blue Ridge mountain areas. During periods of low to average 

discharge, the concentration usually ranges from 5 to 25 ppm. After 

heavy rains the suspended-sediment concentration increases very 

rapidly with increasing discharge and may reach 10,000 ppm in areas 

of greatest relief. Available evidence indicates that the concentration 

reaches a maximum before the stream discharge does ard that the 

concentration then decreases rapidly while the discharge reaches a 

peak and decreases slowly. As the suspended-sediment concentration 

increases, there is a tendency for the proportion of clay-size material 

to increase also. This rapid rise in concentration, followed by an 

almost equally rapid fall, may take place in 12 hours o^ less even 

though the water discharge may be great for 2 to 3 days. Sediment 

concentration is lowest near the surface of the stream in slow-moving 

parts of the cross section and is highest near the bottom in the fastest 

moving part of the cross section.

In the Piedmont province, the characteristics of the stream sediments are much like those of the Blue Ridge province, but suspendedsediment concentration and water discharge do not change so rapidly 

and probably only rarely does the concentration in the larger streams 

exceed 1,000 ppm. Concentration at low to average flowr is 5 to 25 

ppm, about the same as in the Blue Ridge area. Many daim have been
TABLE 56. Sediment characteristics of Georgia streams as related to the physioffraph

of Engineers or Soil Conservation Service. The bed loads of the streams sample

Physiographic province 

or section

Cumberland Plateau, 

Valley and Ridge.

Blue Ridge, Valley and 

Ridge.

Blue Ridge, Piedmont.

Blue Ridge, Piedmont, 

Valley and Ridge.

Piedmont, Coastal 

Plain.

Location of sampling site

South Chickamauga Creek at McCarty, 

Tenn.

Chattahoochee River at West Point, Ga._

Rocky Comfort Creek near Louisville, Ga.

Commissioner Creek near Toomsboro, Ga. 

Oconee River near Mount Vernon, Ga ....

Flint River at Montezuma, Ga .

Sediment concentration 

(ppm)

Low

2

3

4

1 

1 

5 

2 

9 

11

9 

3 

14 

17 

5 

12 

5 

7 

3 

3 

11 

32 

28 

16 

11

High

1,550

36 

394

8,740 

6,950 

166 

138 

1,920 

109

565 

111 

115 

102 

1,028 

690 

88 

436 

52 

i9 

61 

62 

62 

17 

188

Ratio of instantaneous to average discharge

Low

0.24

.25

.42 

.38 

.38 

.49

.27 

.29 

.19 

.08 

<.08 

.25 

.18 

.29

.38

1.65 

.40 

.33

High

2.49 

4.38

2.50 

3.08 

6.61 

1.67

5.11 

2.66 

4.00 

2.14 

1.49 

6.00 

3.86 

4.74

3.69

4.86 

3.57 

2.52

Approxi

mate 

annual 

sedimen

yield per 

square 

mile 

(tons)

550

125

520 

700

200

140

200
Coastal Plain- Brier Creek near Millhaven, Qa_____ 

Ogeechee River near Eden, Qa..____.. 

Canoochee River near Claxton, Qa____ 

Little Ocmulgee River at Towns, Ga___ 

Slash Creek near Mclntyre, Qa...___ 

Ohoopee River near Reidsville, Qa ___ 

Satilla River at Atkinson, Qa_______ 

Alapaha River near Alapaha, Qa____.. 

Little River near Adel, Qa______.... 

Ochlockonee River near Thomasville, Qa. 

Whitewater Creek near Butler, Qa__ .. 

Ichawaynochaway Creek at Milford, Qa._

3

3

4

fifi

5

17 

fi

13

2

6

17

13

34

13

5,300

724

24 

17

59

30

14

53

.36

.17

.07

.05

.52 

.85

.54

3.08

.84

.39

3.64

4.15

8.56

9.01

15.7 

11.95

18.52

8.34

2.31

5.46

14

5

14

13

8

24

15

17

30

 Sediment-concentration range and approximate annual sediment yield are from 

table 53.

*> Dam 6 miles upstream stops some sediment.

c One particle-size analysis made.

A Lloyd Shoals reservoir 48 miles upstream stops much sediment.

6 Barnett Shoals dam 12 miles upstream stops some sediment.

' Sinclair dam 4 miles upstream stops some sediment.

e Much sediment is p

h No stage recorder h

' Stream is polluted b

i The high concentra

tamination of the samp

k Only one sample an
96 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

constructed on rivers in the Piedmont, and presumably these serve to 

trap all the coarse-grained and some of the fine-grained sediment. 

Stream water just below these dams can be expected to contain less 

sediment than normal for Piedmont streams.

Streams which derive all their flow from the Coastal Plain show 

little change in suspended-sediment concentration with ir creasing 

discharge. The normal concentration is 10 to 20 ppm and only rarely 

does the concentration exceed 100 ppm.

The sediment characteristics of streams which derive their water 

from more than one physiographic province are intermediate between 

those of the provinces concerned.

Particle-size analysis of suspended sediment indicates that sand 

constitutes 6 to 38 percent, silt 30 to 42 percent, and clay 25 to 58 

percent of most samples. The average particle-size distribution of 

suspended sediment in five Georgia rivers is shown on a trilinear diagram in figure 29.

Clay 

«0.0039 mm diameter)

O0.062 mm diameter) (0.0039-0.062 mm diameter)

FIGURE 29. Average particle-size distribution of suspended sediment in samples from

selected Georgia rivers.

Curves showing discharge-concentration and concentrationfrequency relations are very helpful in summarizing the data and can 

profitably be used if sufficient information is available.

VARIATION IN SEDIMENT LOAD

The rate of transportation of sediment varies greatly between physiographic provinces. In the Blue Ridge area the great increase in 

suspended-sediment concentration, combined with increasing water
REFERENCES CITED 97

discharge, results in an extremely rapid increase in sediment load 

during storms. More than 75 percent of the annual sediment load 

may be transported during only 10 percent of the time, hence a good 

estimate of the annual sediment load can be made from -rater samples collected during only the larger floods. Data obtained by the 

Tennessee Valley Authority suggest that the average arnual sediment yield per square mile in the Blue Eidge area ranges from 200 

to 1,000 tons per square mile.

The rate of sediment transport in the Piedmont also increases rapidly with increasing discharge. For example, it is probable that more 

than half of the sediment load for the 1959 water year v^as carried 

by the Broad River between May 26 and June 5, 1959. Sampling 

to estimate sediment load in the Piedmont also need be done- only during the larger floods. Available data indicate that sediment yields in 

the Georgia Piedmont ranges from 100 to 500 tons per square mile 

per year.

The sediment load carried by streams in the Georgia Coastal Plain 

is relatively small and probably ranges from 5 to 30 tons per square 

mile per year. The suspended-sediment load can be estimated by 

detailed sampling during the larger floods and by occasional sampling 

at other times.

Sediment-transport curves and load-distribution curves are helpful 

in summarizing sediment-load information and may be used where 

sufficient data make them feasible.

Data obtained during the present study suggest that the bed load 

is not a major part of the total sediment load. However, this hypothesis is not proven and more data are needed, especially for streams 

on the Coastal Plain.

REFERENCES CITED

Benedict, P. C., 1957, Fluvial sediment transportation: Trans. Amer. Geophys. 

Union, v. 38, p. 897-902.

Brune, G. M., 1953, Trap efficiency of reservoirs: Trans. Amer. Gecphys. Union, 

v. 34, p. 407-418.

Butts, Charles, and Gildersleeve, Benjamin, 1948, Geology and mineral resources 

of the Paleozoic area in northwest Georgia: Georgia Dept. Mines, Mining, 

and Geology Bull. 54,176 p.

Carter, R. L., and Giddens, Joel, 1953, Soils of Georgia: Agricultural Experiment Station Bull. 2, 68 p., Athens, Ga.

Colby, B. R., and Hembree, C. H., 1955, Computation of total sediment discharge, 

Niobrara River near Cody, Nebr.: U.S. Geol. Survey Water-JTnpply Paper 

1357, 187 p.

Colby, B. R. and Hubbell, D. W., 1957, Simplified methods for computing total 

sediment discharge with the modified Einstein procedure: U.S. Geol. Survey 

open-file report, 35 p.

Dole, R. B., 1909, Quality of surface waters in the United States, pt. 1, Analyses 

of waters east of the one hundredth meridian: U.S. Geol. Survey WaterSupply Paper 236, p. 54-99.
98 SEDIMENT TRANSPORTED BY GEORGIA STREAMS

Federal Inter-Agency Committee on Water Resources, 1957, Summary of reservoir sedimentation surveys made in the United States through 1953: Sedimentation Bull. 6, U.S. Government Printing Office, Washington 25, D.G.

Feneman, N. M., 1938, Physiography of Eastern United States: New York, N.Y., 

McGraw-Hill Book Co.

Glymph, L. M., Jr., 1954, Studies of sediment yields from watershed?: Internat. 

Assn. Sci. Hydrology, Rome assembly, Pub. 1, p. 178-191.

Howard, C. S., and Love, S. K., 1945, Quality of surface waters of the United 

States, 1943: US. Geol. Survey Water-Supply Paper 970,180 p.

Kalinske, A. A., 1942, Criteria for determining sand-transport by svface-creep 

and saltation: Trans. Amer. Geophys. Union, v. 23, p. 641-643.

Lamar, W. L., 1944, Chemical character of surface waters of Georgia: U.S. GeoL 

Survey Water-Supply Paper 889-E, p. 350-377.

Lane, E. W., and Koelzer, V. A., 1943, Density of sediments deposited in reservoirs, in A study of methods used in measurement and analysis of sediment 

loads in streams: Federal Inter-Agency River Basin Comm. Rpt. 9, p. 60.

Searcy, J. K., 1959, Flow duration curves: U.S. Geol. Survey Water-Supply 

Paper 1542-A, p. 1-33.

Thomson, M. T., Herrick, S. M., Brown, Eugene, and others, 1956, The availability 

and use of water in Georgia : Georgia Dept. Mines, Mining, and Geology Bull. 

65,329 p.

U.S. Bureau of the Census, 1956, United States census of agriculture, 1954, 

Georgia : v. 1, pt. 17, 380 p.

U.S. Geological Survey, 1945, Quality of surface waters of the United States, 

1940: U.S. Geol. Survey Water-Supply Paper 1030, 355 p.

 1947, Quality of surface waters of the United States, 1944: U.S. GeoL 

Survey Water-Supply Paper 1022, 311 p.

 1956, Surface water supply of the United States, 1954: U.S. G«?ol. Survey 

Water-Supply Paper 1334.

 1957, Surface water supply of the United States, 1955: U.S. Geol. Survey 

Water-Supply Paper 1384.

 1958, Surface water supply of the United States, 1956: U.S. Geol. Survey 

Water-Supply Paper 1433.

 1959a, Surface water supply of the United States, 1957: U.S. G?ol. Survey 

Water-Supply Paper 1503.

1959b, Surface Water supply of the United States, 1957: U.S. Geol. Survey

Water-Supply Paper 1504. 

U.S. Weather Bureau, 1958, Climatological data, Georgia: v. 62, nos. 1-12.

 1959, Annual Summary 1958, Climatological data, Georgia: v. 62, no. 13, 

p. 191.

 1960, Annual Summary 1959, Climatological data, Georgia: v. 63, no. 13.

p. 187.
INDEX

[Where several page numbers appear, major references are in italic]

A Page

Alapaha Eiver near Alapaha, sampling site.- 78 

Altamaha Eiver at Doctortown, sampling site. 75 

Analyses, particle-size__ 28, 42, 55, 65, 83, 84, 86 

Appalachian Plateau, Cumberland Plateau

section- 19

Bed load, Alapaha River_.__........

factors effecting measurement.. .......

Little Eiver near Adel. _._........

Ochlockonee River near Thomasville.

Satilla River at Atkinson.___ 

Bed material, Alapaha River near Alapaha.

Brier Creek at Millhaven-.............

Etowah River at Canton.__........

Flint River near Culloden__. .

Little River near Adel______.- 

Ochlockonee River near Thomasville--

Ogeechee River near Eden.............

Oostanaula River at Calhoun 

Satilla River at Atkinson___.. 

Blue Ridge province__ __..........

Brier Creek at Millhaven .............

Broad River near Bell, sampling site.......

Canoochee River near Claxton, sampling site.. 

Capacity to annual-inflow ratios. ____..... 

Channel characteristics___________.... 

Chattahoochee River at Atlanta, sampling

site__ ......................

Chattahoochee River at West Point, sampling

site .. _... 

Chattahoochee River near Leaf, sampling

site.______._..............

Chattooga River at Summerville, sampling

site.................._

Chestatee River near Dahlonega, sampling

site ......... .................

Clay particles, Slash Creek.______......

Coastal Plain province.......................

Commissioner Creek at Toomsboro, sampling

site....... .....................

Conservation, soil...-______________ 17

Coosa River near Rome, sampling site__ _ 89

Cordrays Pond__________________ 43

Cover__ ..... ...... ......._ ... 12,13

Cropland, Broad River area__________ 22

defined________.___.______ 13 

distribution. . _......._.... 13,14,15

Etowah Eiver area____________ 50

Flint River area___________... . 39

Ichawaynochaway Creek area____ __ 43

Ogeechee Riverarea_____.______ 33

Oostanaula River area____.______ 60

Cumberland Plateau_____ ________ 19

D Page

Dams, effect on sediment-carrying capacity of

streams..... __.. __ 18

Data, other sources .. 90

sampling sites . .. 22

significance._________________ 92

Depth of water, Etowah River.... ....__ 58

Ogeechee River. _ .... 35

Detention reservoirs__ ___.. ...... 13

Discharge (average), Alapaha River..____ 78 

Brier Creek.__._..__. ....._._ 67

Broad River_____.____._.....__ 25

Canoochee River . .. 69 

Chattahoochee River-____.____ 83,85,86 

Chattooga River. ______.______ 90 

Chestatee River___________..... 84

Coosa River._______________ 89 

Etowah River.________.______ 50 

Flint River....... ..........._...._ 39,87

Ichawaynochaway Creek-_________ 44 

Little River.._________.... .. 79

Ochlockonee River.____._____.... 82

Ocmulgee River__.___ .. 70,71 

Oconee River____________.... 72,73,74

Ogeechee River ___._ 33 

Ohoopee River___.___..... .. 75

Oostanaula River .________...... 60

Satilla River_.__________ ... 76 

Slash Creek_____________.___ 38 

Whitewater Creek _._________ 88 

Discharge-suspended-sediment concentration

relation, Broad River near Bell.. 25

Flint River near Culloden-____.. 39

Ichawaynochaway Creek at Milford 44

Ogeechee River near Eden._____ ... 32

Oostanaula River at Calhoun .. 61

Dissolved solids, Whitewater CreeV... -... 87

Drainage area, average per farm pciid--.--.._ 15

Drainage area, sampling sites. ________ 24

E

Economic aspects of sediment study.__ .. 4 

Einstein method, modified..______..... 21,56 

Erodible farmland-.____________..... 13 

Erosion, by physiographic province. _ .. 18 

Etowah River at Canton, sampling site. _.... 50

Farm ponds, average drainage area _ .. 15

Farm-pond capacity, Broad River area____ 22 

Piedmont..-..______._______ 13

Flint River sampling site, Culloden..____ 39 

Griffin ...__....__.....______ 86 

Montezuma-..-.. __... 88

Floods, effects on suspended sedrnent transported. --.......... . 18,32,61

99
100 INDEX

Geology, by physiographic province. 

Grain-slze distribution________

H

Harvested cropland, defined__________ 13

See also Cropland.

Hiwassee Reservoir, trap efficiency______ 14 

Hlwassee River. .........__ ____ 14,91

Ichawaynochaway Creek at Milford, sampling

site..___.__..__.___-._ 43

Kaolin._.___.________._.____ 73

Little Commissioner Creek____ ........... 35

Little Ocmulgee River at Towns, sampling

site. - - .. 71 

Little River near Adel, sampling site.-------- 79

Lloyd Shoals Reservoir, trap efficiency...__ 14,70 

Load estimation, total, Etowah River at

Canton___________..___ 56

M

Methods and accuracy of sampling. 

Modified Einstein method___...

N

Nottely River.

20

21,56

91

O

Ochlockonee River near Thomasville,

sampling site_._______. __ 80

Ocmulgee River sampling site, Lumber City. 70

Macon...-.__________....__.. 69

Greensboro...-.-_...............__.. 71

Milledgeville.-- . ..-......_..__.. 72

Mount Vernon.____________. 73

Eden__....________________ 32

Louisville.__-----_____-----_.._. 68

Ohoopee River near Reidsville, sampling site. 74

Oostanaula River at Calhoun, sampling site-. 60

Particle size. See Suspended-sediment particle

size. 

Physiographic provinces___.____......

Piedmont province._________.......

Ponds. See Farm ponds.

Precipitation__________.......... 7,19,

Previous investigations_____...__.....

18

19

20,37

Quality of water.

Q

R

Relief-.-_____________________ 9,11 

Reservoirs, detention..,.._.........._..._.. 13

sediment deposited in. ____ _. ____ 91 

Rocky Comfort Creek near Louisville, sampling site....________.__ 67

Runoff, Broad River area.

Flint River area. _____ _ 

general.. .. _ 

Ichawaynochaway Creek area

Page

22

- __ 39 

.. 9 

43

Ogeechee River area . 32 

Oostanaula River area. ___________ 60 

physiographic provinces.. _________ 19,20 

proportion passing through farm ponds _ 15

Sampling, methods and accuracy.._..___ 20

sites of frequent sampling_______ _ 22

sites of occasional sampling.. _______ 66

Sampling sites, drainage area..._._____. 24

Satilla River at Atkinson, sampling she___ 76

Sediment, percent trapped in reservoirs___ 16

Sediment load, economic aspects. .. .. 4

measurement of total____..______ 21

variation.__________________ 96

Sediment yield, factors affecting.............. 6,92

Piedmont province_____________ 19

Significance of data ____.. 92

Sinclair Dam. ......__.... 72

Slash Creek near Mclntyre, sampling s'te. _. 35

Soil conservation______________. 17

Soils .............................-...--...- 10

Stream equilibrium, effect on sediment yield.. 17

Summary..._._________............... 92

Suspended load, methods and accuracy of

sampling.______..._ ..... 20

Suspended-sediment concentration, Alapaha

River near Alapaha 78

Altamaha River at Doctortown____ 75

Brier Creek at Millhaven.-...-._____ 66

Broad River near Bell.._____..___ 22

Canoochee River near Claxton........... 69

C hattahoochee River at Atlanta _____ 84

Chattahoochee River at West Poir t_.._ 85

C hattahoochee River near Leaf___ -... 82

Chattooga River at Summerville.____ 90

Chestatee River near Dahlonega.____ 83

Commissioner Creek at Toomsboro___ 73

Coosa River near Rome __________ 89

economic aspects____________ 4

Etowah River at Canton_ _ _______ 50

Flint River at Montezuma________ 88

Flint River near Culloden_________ 39

Flint River near Griffin.... ._.._ 87

Ichawaynochaway Creek at Milford__. 44

Little Ocmulgee River at Towns_____ 71

Little Rher near Adel_._ ________ _ 79

Ochlockonee River near Thomasville-.- 80

Ocmulgee River at Lumber City.......... 70

Ocmulgee River at Macon..________ 69

Oconee River at Milledgeville______ 73

Oconee River near Greensboro______ 72

Oconee River near Mount Vernon____ 74

Ogeechee River near Eden_________ 33

Ogeechee River near Louisville_______ 68

Ohoopee River near Reidsville______ 74

Oostanaula River at Calhoun.__.___ 60

Rocky Comfort Creek near Louisville__ 67

Satilla River at Atkinson_________ 76

Slash Creek near Mclntyre-------____. 37

variation. ................................ 21,93

Whitewater Creek below Rambulette

Creek near Butler____ ____ 87
INDEX 101

Suspended-sediment concentration-discharge 

relation, Broad River near Bell...

Etowah River at Canton.. .... ..

Flint River near Culloden________

Ichawaynochaway Creek at Milford ....

Ogeechee River near Eden,_______ 32

Oostanaula River at Calhoun_ ....

Suspended-sediment data, streams in northern

Georgia . 

Suspended-sediment load, Alapaha River

near Alapaha___________ 78

Brier Creek at Millhaven_..............

Broad River near Bell....__ .

Canoochee River near Claxton __.....

economic aspects________.__....

Etowah River at Canton_______....

Flint River near Culloden ..............

Hiwassee River...........................

Ichawaynochaway Creek at Milford ....

Little River near Adel______........

Nottely River_.__ .__ .....

Ochlockonee River near Thomasville.....

Ocmulgee River at Macon_____.__.

Oconee River near Mount Vernon........

Ogeechee Rivernear Eden________ 34

Oostanaula River at Calhoun-._ ...

Satilla River at Atkinson.................

Slash Creek near Mclntyre...............

Whitewater Creek below Rambulette 

Creek near Butler..........._..._

Suspended-sediment particle size, Brier Creek 

at Millhaven.....................

Broad Rivernear Beil....................

Chattahoochee River at West Point___

ge

M

50

39

44

32

m

91

Do

4 

56 

41

45

80 

70 

74

76 

38

88 

66

28 

85

Suspended-sediment particle size Con.

Suspended-sediment size distribution, Broad

T

V

Viscosity of water, relation to temperature 

W 

Whitewater Creek, quality and cuantity of

sampling site below Rambulitte Creek 

near Butler ________ 

Page

83

44

82

54

64

76

93

27

85

54

40

64

76

9

9,18

96

13, 14

18

12

35

9 

6

87

o