Fluvial-Sediment Discharge to 

the Oceans from the 

Conterminous United States 

.. GEOLOGICAL SURVEY CIRCULAR 67 

Fluvial-Sediment Discharge to 

the Oceans from the 

Conterminous United States 

By W. F. Curtis, J. K. Culbertson, and E. B. Chase 

G E 0 L 0 G I C A L S U R V E Y C I R C U l A R 670 

A contribution to the International 

Hydrologic Decade 

Washington J973 
Department of the Interior 

WILLIAM P. CLARK, Secretary 

U.S. Geological Survey 

Dallas L. Peck, Director 

First printing 1973 

Second printing 1984 

Free on application to Distribution Branch, Text Products Section, 

U. S. Geological Survey, 604 South Pickett Street, Alexandria, VA 22304 
CONTENTS 

Abstract 

Page 

1 

Introduction -----------------------------------------·-------------------- 1 

Explanation of data ----------------------------------------------------- 1 

Drainage area and water discharge ----------------------------------- 1 

Period of record ----------------------------------------------------- 4 

Suspended-sediment discharge ----------------------------------------- 4 

Suspended-sediment yield --------------------------------------------- 4 

Suspended-sediment concentration ------------------------------------- 5 

Sediment discharge to the Atlantic Ocean ---------------------------------- 5 

Sediment discharge to the Gulf of Mexico ---------------------------------- 6 

Gulf of Mexico drainage area ---------------------------------------- 6 

Mississippi River drainage basin -------------------------------------- 6 

Sediment discharge to the Pacific Ocean ----------------------------------- 8 

Pacific Ocean drainage area ------------------------------------------- 8 

Colorado River drainage basin ----------------------------------------- 8 

Comparison of present and previous estimates of suspended-sediment discharge_ 9 

Summary --------------------------------------------------------------- 10 

References cited ___ -----_----------------------------------------------- 11 

ILLUSTRATIONS 

COVER. Space photograph of the Colorado River Delta, Baja California, showing fluvial sediment entering 

the Gulf of California. Flight of Apollo 9, March 1969. From NASA color infrared photograph 

AS9-26D-3781. 

Page 

FIGURE 1. Map of the conterminous United States delineating drainage areas and location of sed~ment 

stations -------------------------------------------------------------------------- 2 

2. Section of river showing zones of sampled and unsampled sediment ------------------------ 5 

3. Sketch map of the lower Mississippi River drainage basin showing location of stations u~ed to 

compute sediment discharge for the Mississippi River --------------------------------- 7 

4. Hydrographs of water discharge and suspended-sediment discharge for the Colorado Rber at 

Yuma, Ariz., 1911-67 _________________________ ----_ _ _ ___ __ _ __ _ _ __ _ _ _ __ _ _ _ _ __ _ _ _ __ _ __ 9 

TABLES 

Page 

TABLE 1. Historical suspended-sediment discharge data for the lower Mississippi River --------------- 8 

2. Comparison between present and past estimates of sediment yields for selected rive1·s discharging to the oceans from the conterminous United States ------------------------- 10 

3. Summary of suspended-sediment discharge to the oceans from the conterminous United rtates_ 11 

4. Suspended-sediment discharge from the conterminous United States to the Atlantic Ocean, 

Gulf of Mexico, and the Pacific Ocean -------------------------------------------- 14 

5. Identification of river stations used to compute sediment data ----------------------------- 16 

III 

Fluvial-Sediment Discharge to the Oceans from 

the Conterminous United States 

By W. F. Curtis, J. K. Culbertson, and E. B. Chase 

ABSTRACT 

This report is a contribution to the UNESCOsponsored project of the International Hydrological 

Decade called the World Water Balance. Annual 

fluvial-sediment discharge from the conterminous 

United States averages 491,449,600 short tons, of 

which 14,204,000 is discharged to the Atlantic Ocean, 

378,179,000 to the Gulf of Mexico, and 99,066,600 to 

the Pacific Ocean. Data from 27 drainage areas were 

used to estimate the average annual discharge, yield, 

and concentration of fluvial sediment. The data may 

be used to extrapolate part of the total world sediment 

yield to the marine environment. 

INTRODUCTION 

Sediment is defined as fragmental material 

derived primarily from the physical and chemical disintegration of rocks from the earth's 

crust. Once the sediment particles are detached, 

they may be transported either by gravity, 

wind, or water, or by a combination of these 

agents. When the transporting agent is water, 

the sediment is termed "fluvial sediment." The 

terms "fluvial sediment" and "suspended sediment" are used synonymously in this report to 

mean inorganic material that is transported in 

suspension by streams and rivers. 

Knowledge of the amount of sediment transported by the various rivers of the world is important for many reasons. For example, reservoirs should be designed with enough space to 

store the sediment expected to accumulate in 

them and yet retain full effectiveness during 

their design life, and sediment yield can be an 

indication of the rate of erosion in the drainage 

basin. A summation of sediment yields by 

basins may indicate a regional, continental, and 

1 

even an approximate world rate of e.rosion (Holeman, 1968). This report, which i~· a contribution to the UNESCO-sponsored project of the 

International Hydrological Decade called the 

World Water Balance, summarizes the quantity 

of fluvial sediment discharged to the Atlantic 

and Pacific Oceans and the Gulf of Mexico from 

the conterminous United States. Tl'e data given 

here may be useful to obtain the present total 

of world sediment yield to the marine environment. 

The average annual amounts of suspended 

sediment discharged into the ocrans from 27 

major drainage areas were computed from suspended-sediment records from the files of the 

U.S. Geological Survey, the International 

Boundary and Water Commission. and the U.S. 

Army Corps of Engineers. These crainage areas 

and the location of selected sediment stations 

within the areas are shown in figure 1. The data 

for these areas are given in table 4 in the back 

of the report, and an explanation of the data is 

given below. 

EXPLANATION OF DATA 

DRAINAGE AREA AND WATER DISCHARGE 

The names, total drainage areas, and water 

discharges for the 27 drainage areas used in 

this report were taken from Wilson and Iseri 

(1967). Some of the data used in that report 

have since been revised (Alfonso Wilson and K. 

T. Iseri, oral commun., 1971) and the revised 

data are identified in table 4. vYater and sediment discharged into the Great Lakes from the 

United States are not included in this report. 
0 

I 

• 

a• -Daily sedi•ent station 

'V -Miscellaneous concentrations 

~-Noncontributing area (closed basin) 

ts]-Souris, Red, Rainy, Great Lakes, 

and St. Lawrence drainage 

not included in this report 

20-Drainage area nu•ber 

(See fable 4) 

-··--Drainage divide 

FIGURE 1 (above and right) .-Drainage areas and location of sediment stations. 

2 
FIGUREl .-Continued. 

3 
PERIOD OF RECORD 

To keep this report as up to date as possible, 

and yet provide a sufficient period of record for 

a meaningful average, the 1950-69 period was 

chosen. Although a longer period of record may 

be desirable, a 20-year period can be expected 

to span one or more extreme events, dry and 

wet years, and is a reasonable base for statistical summary. 

All sediment stations ( 43) selected for this 

study did not have records covering the full 20-

year period; however, all records available within this period were used. For those stations 

with relatively short periods of record that included one or more extreme floods, the average 

annual suspended-sediment discharge was revised downward to reflect conditions rr•ore compatible with the long-term discharge. For 

example, in 1969, three stations in California 

experienced a flood of approximately the 100-

year recurrence interval; thus, the 1969 sediment records for those stations were not used. 

Also, two other stations, Rouge River at Raygold, Oreg. (25c), and Skagit River near Mt. 

Vernon, Wash. (27d), each had only 1 year of 

record, 1912 and 1910, respectively (Van 

Winkle, 1914a, b) ; these records were used although they were outside the period f)f record 

selected for the report. For some of the drainage areas, no continuous records were available and the data presented in table 4 are estimates by the authors from misceJlaneous sediment samples, upstream sediment records, and 

(or) water-sediment relations for adjacent or 

similar basins ; thus, no period of record was 

given. 

SUSPENDED-SEDIMENT DISCHARGE 

The suspended-sediment discharge data presen ted in this report are based on analyses of 

samples collected with discharge-weighted suspended-sediment samplers used in the United 

States ([U.S.] Inter-Agency Committee on 

Water Resources, Subcommittee on Sedimentation, 1963). These samplers are used to collect 

representative samples of the entire depth of 

flow with the exception of a zoue (the unsampled zone) between the streambed and about 0.3 

to 0.5 foot (9 to 15 centimeters) above the 

4 

streambed. Most of the sedhnent moved by 

rivers and streams is held in suspension and is 

transported at about the mean velocity of flow. 

The remainder of the sediment moves more 

slowly on or near the streambe':l in the unsampled zone and generally is referred to as bedload plus saltation load, or simply unmeasured 

load. Computations of bedload or unmeasured 

load may be made using var~0u~ thMretical 

formulas; however, for long-term estimates, an 

unmeasured sediment discharg~ of 10 percent 

of the suspended-sediment discr arge frequently 

is used. Unmeasured load is not included in this 

report. Figure 2 shows the sampled and unsampled zones in sediment samplin~. 

Daily sediment discharge, in ton.s per day, is 

determined by multiplying water discharge, in 

cubic feet per second, by the concentration of 

suspended sediment, in milligrams per liter, 

times a coefficient and assuming a specific 

gravity of 2.65 for sediment. Tl'e daily records 

are then summed to give the annual sediment 

discharge. To determine the average annual 

suspended-sediment discharge at a station, the 

authors summed the annual sediment discharges and divided that sum by the number 

of years of record. When there were no longterm records (see "Period of Record") the 

average annual suspended-sedinent discharge 

for a drainage area was estimated All data 

are given in English units unless otherwise 

specified. 

For this report, the sediment records used 

were from the sediment station, in the flowing 

part of the river above tide, closest to the mouth 

of the chosen river. The latitud€. and longitude 

of the individual stations, the sources of the 

sediment-discharge data used in computing the 

average annual suspended-sediment discharge 

and concentration, and the station identification numbers used by the agency collecting the 

data and by the Office of Water Data Coordination (U.S. Geological Survey, O'lice of Water 

Data Coordination, 1971) are given in table 5 in 

the back of the report. 

SUSPENDED-SEDIMENT YIELD 

Average annual suspended-seiiment yields 

were computed for the 27 drainage areas and 

for the areas encompassed by tl'e 43 selected 
Suspended-sediment particles 

Flow 

Sampled zone 

---------,--

Unsampled zone 

Total 

Sampled depth 

h 

Suspended-sediment 

sampler (DH-48) 

FIGURE 2.-Section of river showing zones of sampled sediment and unsampled sediment (modified from Guy and 

Norman, 1970) . 

sediment stations. The sediment yields were 

determined by dividing the annual average suspended-sediment discharge by the total drainage area. In some instances, the values for 

sediment yield may be relatively meaningless in 

terms of the total drainage area because reservoirs and diversions within the area may trap 

75 to 95 percent of the sediment. (See "Colorado River Drainage Area.") 

SUSPENDED-SEDIMENT CONCENTRATION 

Average annual suspended-sediment concentrations for the 27 major drainages also were 

computed by dividing the daily average suspended-sediment discharge, in tons, by the daily 

average water discharge, in cubic feet per second (cfs), and using appropriate conversion 

factors. As an example, for area 1 where the 

average annual sediment discharge is 460,000 

short tons and the daily average water discharge is 23,500 cfs, the conversion factor is 

5 

0.0027, and average annual daily sediment concentration, in milligrams per liter (mg/ 1) is 

computed as follows: 

460,000 short tons 

20 mg/ 1. 

365 daysx23,500 cfsx0.0027 

In the metric system, the water discharge is 

665 cubic meters per second (ems), the sediment discharge is 417,000 metric tons, and the 

conversion factor is 0.0864; thus 

417,000 metric tons 

20 mg/ 1. 

365 daysX665 cmsx0.0864 

SEDIMENT DISCHARGE TO THE 

ATLANTIC OCEAN 

Sediment discharge to the Atlantic Ocean was 

determined for 10 major drainage areas (table 

4A). Of these 10 areas, no long-term sediment 

records were available for six of the areas, 

which represent about 46 percent of the total 

water discharged to the Atlantic Ocean. Thus, 

estimates of sediment discharge for these six 
areas were based on samples collected intermittently within the areas during 1950-69. Suspended-sediment discharges range from 134,000 

tons per year for area 10 to 5,800,000 tons per 

year for area 5. 

For the 10 areas, the average annual suspended-sediment yields range from about 12 

tons per square mile for area 10 to 73.2 tons 

per square mile for area 5, which contributes 

28.8 percent of the total water discharged and 

37.6 percent of the total sediment discharged 

to the Atlantic Ocean and contains the three 

river basins that have the highest sediment 

yields (Delaware River at Trenton, N.J., 111 

tons per square mile; Potomac River at Point of 

Rocks, Md., 81.4 tons per square mile; and Susquehanna River at Harrisburg, Pa., 81 tons per 

square mile) . 

The average annual suspended-~ediment concentrations for the 10 areas range from 20 mg/1 

for area 1 to 58 mg/1 for area 5. For the entire 

Atlantic Ocean drainage area the dischargeweighted average annual suspended-sediment 

concentration is 40 mg/1. 

SEDII\IENT DISCHARGE TO THE 

GULF OF MEXICO 

GULF OF MEXICO DRAINAGE AREA 

Sediment discharge to the Gulf of Mexico was 

determined for nine major drainage areas (table 

4B). Long-term sediment records were not 

available for four of these areas, and estimates 

of sediment discharge were based on miscellaneous samples collected at several locations within 

these areas. The suspended-sedin1ent discharges 

for the Gulf of Mexico area range from 37,000 

tons per year for area 11 to 326,468,000 tons 

per year for area 17. 

For the nine areas, the average annual suspended-sediment yields range from about 6 tons 

per square mile for area 11 to 259 tons per 

square mile for area 17. Interestingly, the single 

river basin with the highest sediment yield 

(Brazos River, Tex., 398 tons per square mile) 

is in area 19, whereas area 17, which has the 

highest annual tonnage, contains the river 

basin with the second highest sediment yield. 

The average annual suspended-sediment concentrations range from 15 mg/1 for areas 11, 

6 

12, and 13 to 820 mg/1 for area 19. Area 17, 

which has the highest average annual tonnage 

in the Gulf of Mexico drainage area, has an 

average annual suspended-sediment concentration of 510 mg/1. For the entire Gulf of Mexico 

drainage area the discharge-weighted average 

annual suspended-sediment concentration is 

433 mg/1. 

MISSISSIPPI RIVER DRAINAGE BASIN 

The Mississippi River drains 1,262,000 square 

miles (3,268,580 square kilometer~) or 47.4 percent of the total area covered in this report and 

contributes about 37 percent of the total amount 

of water and 66 percent of the suspended-sediment discharge from the conterminous United 

States. Sediment sampling had been carried on 

intermittently at different locations along the 

lower Mississippi River since 1838. At the beginning of the 1950 water year, the U.S. Army 

Corps of Engineers began a formal continuing 

program of sediment sampling. 

The lower Mississippi River system (fig. 3) is 

highly controlled and regulated, both for normal flow and flood flow. Prior to 1963, some of 

the Mississippi River flood flows went into the 

Red-Atchafalaya system through a connecting 

channel. In 1963, the Corps of Engineers completed a control structure on the by-pass channel to keep flow in the two river systems 

separated. 

Data for six stations within this complex system were used by the authors in computing the 

average annual suspended-sediment discharge 

for the Mississippi and Atchafalaya Rivers. 

These stations and their periods of record are 

listed below. Figure 3 shows the location of the 

six stations, 'and table 5 gives their latitude and 

longitude. 

Period of 

Station record 

1. Mississippi River at Baton Rouge, La ____ 1950-67 

2. Mississippi River at Red River Landing, 

La --------------------------------- 1958-63 

3. Mississippi River at Tarbot Landing, La _ 1963-69 

4. Atchafalaya River at Simmesport, La ___ 1952-69 

5. Wax Lake Outlet at Calumet, La -------- 1966-68 

6. Atchafalaya River at Morgan City, La ___ 1966-68 

Data for the three stations on the Mississippi 

River at Baton Rouge, La., Red River Landing, 

La. , and Tarbot Landing, La., were combined to 
EXPLANATION 

-1 

Station and number 

Jl 

Control structure 

Dikes 

----- 30°30' 

C ity 

FIGURE 3.-Sketch map of the lower Mississippi River drainage basin showing location of stations 

used to compute sediment discharge for the Mississippi River (area 17). Numbers correspond to list in text, "Mississippi River Drainage Basin." 

7 
compute the record for the Mississippi River at 

Red River Landing, La. (station 17a, table 4B). 

Data for the three stations on the Atchafalaya 

River at Simmesport, La., Calumet, La., and 

Morgan City, La., were used to compute the 

record for the Atchafalaya suspended-sediment 

discharge (station 17b, table 4B). 

A study of the suspended-sediment records 

for Simmesport, Calumet, and Morgan City indicated that about 31 percent of the sediment 

passing the Simmesport station was deposited 

in Grand Lake and Six Mile Lake; therefore, 69 

percent of the suspended-sediment discharge at 

Simmesport for 1950-65 was used and a summation of the Calumet and Morgan City stations 

for 1966-69 was used in deriving the average 

annual suspended-sediment discharge for the 

Atchafalaya River. 

Although they were not used in this report, 

historical sediment-discharge. data obtained 

during 1851-1931 are summarized in table 1. If 

TABLE 1.-Historical suspended-sediment discharge data 

for the lower Mississippi River 

[Data from U.S. Army, Corps of Engineers, New Orleans District] 

Location Period of record 

New Orleans ______ Feb. 17, 1851-

Feb. 15, 1852. 

New Orleans ------ Feb. 16, 1852- Feb. 20, 1853. Passes ------------ 1879-1893 ____ _ New Orleans ------ Dec. 19, 1879- 0ct. 8, 1880. Red River Landing __ Mar. 3, 1929-

June 22, 1929. Red River Landing __ Sept. 23, 193~ 

Feb. 26, 1931. 

Sus pended-tJedimen t discharge, in tons pe~ 

Day Year 

945,000 345,000,000 

1,364,000 498,000,000 

934,000 341,000,000 

995,000 363,000,000 

1,136,000 

296,000 

the annual sediment discharges shown are assumed to be relatively accurate, it would appear 

that the average annual suspended-sediment 

discharge contributed by the main stem Mississippi River to the Gulf of Mexico has been 

reduced by about 30 percent during the 100-year 

period (1851-1931, 1950-69). 

SEDIMENT DISCHARGE TO THE 

PACIFIC OCEAN 

PACIFIC OCEAN DRAINAGE AREA 

Sediment discharge to the Pacific Ocean was 

determined for eight major drainage areas 

(table 4C). Suspended-sediment discharges for 

this area range from 10,600 tons per year for 

area 20 to 67,816,000 tons per year for area 24. 

Sediment yields from the area draining into 

the Pacific Ocean in terms of tons per square 

mile are considerably greater than the yields 

from areas draining into the Atlantic Ocean or 

the Gulf of Mexico. The average annual suspended-sediment yields, exclusive of area 20 

(Colorado River) range from 60.5 tons per 

square mile for area 26 to 3,108 tons per square 

mile for area 24. Area 24, which contains the 

individual river that has the greatest sediment 

yield (Eel River, Calif., 9,426 tons ner square 

mile), has the greatest sediment yield for any 

area draining into the oceans from the conterminous United States. 

The average annual suspended-sediment concentrations range from 49 mg/1 for area 27 to 

1,634 mg/l for area 21. Area 24 has the highest 

discharge and yield and the second highest sediment concentration ( 1,630 mg/l). For the entire 

Pacific Ocean drainage area the dischargeweighted average annual suspended-sediment 

concentration of discharge is 201 mg/1. 

COLORADO RIVER DRAINAGE BASIN 

8 

The Colorado River drainage basin (area 20) 

has the lowest sediment discharge (10,600 tons 

per year) and sediment yield (0.04 ton per 

square mile per year) of any contributing area 

draining into the oceans from the conterminous 

United States. However, even with this extremely low sediment yield, the average annual 

suspended-sediment concentration (165 mg/l) 

is greater than that from any contributing area 

draining into the Atlantic Ocean. 

The apparent low sediment yield for this 

drainage basin is the result of better land-use 

practices and sediment entrapment in the highly developed reservoir system on the Colorado 

River. Data for the station Colorado River at 

Yuma, Ariz., are used to illustrate the dramatic 

effect these changes have had on the sediment 

discharge. During 1911-16, the average annual 

suspended-sediment dis-charge at Yuma was 

234,600,000 tons (966 tons per square mile). As 

a result of the development of the reservoir system and the increased use of water for irrigation the suspended-sediment discharge was reduced considerably and for 1965-67 the average annual suspended-sediment discharge was 
152,600 tons (0.63 ton per square mile). At the 

station used in this report, Colorado River at 

Miguel C. Rodriguez, Mexico, which is about 52 

miles downstream from Yuma, the average annual suspended-sediment discharge for the period 1965--69 was further reduced to 10,600 tons 

(0.04 ton per square mile), largely due to diversion of water for irrigation. Hydrographs of 

water discharge and suspended-sediment discharge for the Colorado River at Yuma, Ariz., 

for 1911-67 are shown in figure 4 and clearly 

indicate the major changes that have occurred 

during this period. 

25 

z tu 20 -w 

w·~ 

C!Jw 

~5 15 

:I:<( 

Uu. 

~0 

~~ 10 

we 

~~ 

~= ~ 5 

0+----~---.-----.---~---~~=-

1910 1920 1930 1940 1950 1960 1970 

350 

300 

250 

200 

150 

100 

50 

0+---~----~~----~=-~~~~--~ 

1910 1920 1930 1940 1950 1960 1970 

FIGURE 4.-Water discharge and suspended-sediment 

discharge for the Colorado River at Yuma, Ariz., 

1911-67. 

COMPARISON OF PRESENT ANI' PREVIOUS 

ESTIMATES OF SUSPENDED-~-.:<:DIMENT 

DISCHARGE 

One of the difficulties in comparing present 

and past estimates of sediment :rields is the 

difference in time periods used and the amount 

of data available at the time of the various 

studies. Also, different drainage ar~~ may have 

been used by the various writers. 

Trends of sediment yield for a given river or 

basin can never be determined ver;r accurately 

until long-term records of com par~ ble accuracy 

are available. As more and more records become 

available, more accurate and reasonable estimates of sediment yield and rate of denudation 

can be made. Some comparisons can be made, 

however, between the data presented in this 

report and past estimates for several of the 

major rivers and basins in the United States. 

9 

Regional erosion rates in the United States 

were estimated by Dole and Stable~ (1909) and 

rates of regional denudation of the United 

States were estimated by Judsor and Ritter 

(1964). A summary of data comparing estimates of these authors with pres~'lt estimates 

is given in table 2. Average annurl suspendedsediment discharges given in the table were 

computed by using the contribut!ng drainage 

area values given in this report r.nd the sediment yields estimated by the previous authors. 

Holeman (1968) presented estin1ates of sediment yields of the major rivers of the world. 

For selected river basins of Nortr America he 

estimated an average annual su~pended-sediment yield of 245 tons per square 1nile. The 

total drainage area contributing sediment discharge to the oceans from the United States is 

2,658,776 square miles. Using this drainage area 

and Holeman's estimate of 245 tons per square 

mile per year for North America. the average 

annual suspended-sediment discll arge to the 

oceans from the conterminous r"'lited States 

would be 651,400,000 tons as co~pared with 

491,449,600 tons determined- by this study. Most 

of the difference between Holeman's estimate 

and the authors' is due to the fact that he used 

the records for the station Color<:\<lo River at 

Grand Canyon Ariz., 1925-57, '"Thich is UPstream of most of the present reservoir system. 
TABLE 2.-Comparison between present and past estimates of sediment yields for 

selected rivers discharging to the oc.eans from the conterminous United States 

Average annual suspendedsediment yield, in tons per 

square mile Drainage 

Average annual suspend~­

sediment discharge, in 

thousands of tons Area or river basin 

Atlantic Ocean: 

Delaware River --------- Susquehanna River ------ Potomac River ---------- Pee Dee River ---------- Ogeechee River ----------

Gulf of Mexico: 

Apalachicola River ------- Tombigbee River --------- Alabama River ---------- Pearl River ------------- Mississippi River --------

Pacific Ocean: 

Colorado River ---------- San Francisco Bay ------- Sacramento River --------

Eel River --------------- Mad River ------------- Trinity River ----------- Columbia River ---------

Judson 

This and 

report Ritter 

49.5 

111 

81.0 

81.4 

15.2 

23.2 

217.4 

10.1 

128 

115 

133 

259 

157 .04 75.4 

116 

9,426 

5,549 

1,919 60.5 

(1964.) 

147 

120 

97 

244 

623 

1,190 

94 

5,846 

3,711 

1,141 

125 

Dole 

and 

Stabler 

(1909) 

97.2 

56 

35 

95 

154 

225 

220 

159 

104 

178 

58 

269 

387 

77 

86 

area, in ---------- square Judson Dole 

mDes This and and 

287,166 

6,780 

24,100 

9,651 

8,830 

2,650 

1,739,200 

17,200 

19,200 

22,000 

6,630 

1,262,000 

632,410 

245,000 

47,570 

23,530 

3,113 

485 

2,865 

258,200 

report Ritter Stab~ .. r 

14,204 

749 

1,953 

786 

442 

61.6 

378,179 173 

2,454 

2,528 

881 244,900 

99,067 10.6 3,585 

2,719 

29,345 

2,691 

5,497 

15,620 

(1964) (190'l) 

998 

2,300 

2,140 

308,000 

1 394,100 

292,000 

2,215 

18,200 

1,800 

3,270 

32,300 

2":',900 380 

845 

913 

1,360 

596 

38f,600 ~-.740 

~.ooo 

F,920 

385 34(,000 

94,800 

Z,660 

2,020 

1 Sum of Colorado, Pacific Slopes, California, and Columbia Regions. 

Based on the data given in this report, the 

average annual suspended-sediment yield from 

the conterminous United States to the oceans is 

184.8 tons per square mile. 

SUMMARY 

Suspended-sediment discharge data obtained 

from 27 drainage areas during the period 1950-

69 were used to estimate the sediment contributed to the oceans from the conterminous 

United States. The data are based on suspendedsediment samples obtained with standard 

United States depth-integrating samplers and, 

therefore, do not include that part of the total 

sediment discharge moving as bedload. The 

quantity of sediment transported as bedload 

may be estimated at about 10 percent of the 

sediment transported in suspension. 

The amount of sediment discharged each day 

into the Atlantic and Pacific Oceans is 38,915 

tons and 271,400 tons, respectively. The Gulf of 

Mexico receives about three times more sediment than both of these areas, a total of 

1,037,000 each day. A more pictorial way of 

expressing these figures is to transport this 

sediment discharge by train (a boxcar is equivalent to 100,000 pounds or 50 tons). Each day of 

the year it would take a train of 778 boxcars 

to transport the suspended-sediment discharged 

to the Atlantic Ocean and 5,4~,q boxcars to 

transport the Pacific Coast sedin1ent; to move 

the Gulf of Mexico sediment, it would take a 

daily train 20,7 40 boxcars long. 

10 

Average yearly sediment yields range from 

49.5 tons per square mile for the Atlantic Ocean 

drainage area to 217.4 tons per square mile for 

the Gulf of Mexico drainage area; the Pacific 

Ocean drainage area falls into th~ middle with 

156.6 tons per square mile. The mean for the 

entire conterminous United States (excluding 

the Great Lakes drainage area) is 184.8 tons 

per square mile. However, yields comnuted on 

the basis of total drainage area can be deceiving 

because good land-use practices and multiple 

reservoirs in the drainage area can dramatically 

reduce the amount of sediment delivered to the 

sea. The Colorado River drainage ]>~sin is a good 

example. The yield of the station Colorado River 

at Yuma, Ariz., was reduced from 966 tons per 

square mile during the period 1911-16 to 0.63 

ton per square mile during the period 1965-67. 

Concentrations of suspended sediment range 

from about 15 mg/1 along the sorthern part of 

the Atlantic Coast to over 1,600 n1g/l along the 

southern part of the Pacific Coast. The Gulf 

Coast region has the most drainar-~ basins with 

the lowest (15 mg/1) sediment corcentration. 

The amount of suspended-s<l<liment dis-
charged to the oceans from the conterminous 

United States is 491,449,600 tons per year. (See 

table 3.) If this amount was deposited in Washington, D.C., on the mall between tne Capitol 

and the Lincoln Memorial (an are(\. 11,000 feet 

long and 600 feet wide), it would r~ach a depth 

of about 1,400 feet or 2112 times a~ hip;h as the 

Washington Monument. 

TABLE 3.-Summary of suspended-sediment discharge to the oceans from the 

conterminous United States 

[Upper numbers are English units; lower numbers are metric 11nits] 

Suspended-sediment discharge 

Drain- Water discharge Tons per Minage area year Tons per grams 

(mi2 /km2 ) cfs/ems Percent (-'hort/ Percent mi2 /km2 per 

metric) litt>.r 

Atlantic Ocean (areas 1-10) - 287,166 359,350 20.6 14,204,000 2.9 49.5 40 743,760 10,180 20.6 12,885.,726 2.9 17.3 40 

Gulf of Mexico (areas 11-19) - 1,739,200 887,400 &0.8 378,179,000 77.0 217.4 433 4,504,528 25,120 50.8 343,080,207 77.0 76.1 433 

Pacific Ocean (areas 2(}--27 ) -- 632,410 499,065 28.6 99,066,600 20.1 156.6 201 1,637,942 14,132 28.6 89,872,229 20.1 5'4.9 201 

Total or mean --------- 2,658,776 1,745,815 100.0 491,449,600 100.0 184.8 286 6,886,230 49,432 100.0 445,838,162 100.0 64.7 286 

REFERENCES CITED 

Dole, R. B., and Stabler, Herman, 1909, Denudation, in 

Papers on the conservation of water resources: 

U.S. Geol. Survey Water-Supply Paper 234, p. 

78-93. 

Guy, H. P., and Norman, V. W., 1970, Field methods 

for measurement of fluvial sediment: U.S. Geol. 

Survey Techniques Water-Resources Inv., book 3, 

chap. C2, p. 3. 

Holeman, J. N., 1968, The sediment yield of major 

rivers of the world: Water Resources Research, v. 

4, no. 4, p. 737-747. 

Judson, Sheldon, and Ritter, D. F., 1964, Rates of 

denudation in the United States: Jour. Geophys. 

Research, v. 69, no. 16, p. 3395-3401. 

U.S. Geological Survey, Office of Water Data Coordination, 1971, Catalog of information on water data, 

edition 1970-Index to water quality data: Washington, D.C., U.S. Geol. Survey, 443 p. 

11 

[U.S.] Inter-Agency Committee on Water Resources, 

Subcommittee on Sedimentation, 1f13, Determination of fluvial sediment discharge, in A study of 

methods used in measurement and analysis of 

sediment loads in streams: Minneapolis, Minn., St. 

Anthony Falls Hydrol. Lab. Rept. 14, 151 p. 

Van Winkle, Walton, 1914a, Quality of the surface 

waters of Washington: U.S. Geol. Survey WaterSupply Paper 339. 

---1914b, Quality of the surface waters of Oregon: 

U.S. Geol. Survey Water-Supply Paper 363. 

Williams, K. F., and Reed, L. A., 197~. Appraisal of 

stream sedimentation in the Susq·uehanna River 

basin: U.S. Geol. Survey Water-Supply Paper 

1532-F. 

Wilson, Alfonso, and Iseri, K. T., 1967 (revised 1969), 

River discharge to the sea from th~ shores of the 

conterminous United States, Alasl·a, and Puerto 

Rico: U.S. Geol. Survey Hydrol. Inv. Atlas HA282. 

TABLES 4 AND 5 
~ 

~ 

TABLE 4.-Suspended-sediment discharge from the conterminous United States to the Atlantic Ocean, Gulf of Mea;ico, and th-e Pacific Ocean 

[Drainage area and water-discharge data from Wilson and Iseri (1967); asterisk (*) indicates revised data (Alfonso Wilson and K. 

T. Iseri, oral commun., 1971). E=estimated. N.d.=not determined] 

Drainage area (See figure 1 and table 6 for location.) 

No. Name 

1. Passamaquoddy Bay to Penobscott Bay_ 2. St. George River to Cape Cod Bay ___ _ 

3. Cape Cod Bay to New YorkConnecticut State line ------------ 4. New York-Connecticut State line to 

Cape May ---------------------- 5. Cape May to Cape Henry ----------- a. Delaware River at Trenton, N. J _ 

b. Susquehanna River at Harrisburg, 

Pa1 ----------------------- c. Potomac River at Point of Rocks, 

Md ------------------------ 6. Cape Henry to Neuse River --------- a. Tar River at Tarboro, N.C ___ _ 

7. Cove Sound to Black River ---------- a. Pee Dee River at Pee Dee, S. C __ 

8. Santee River to Sapela Island ------- a. Ogeechee River near Eden, Ga __ _ 

b. Edisto River near Givhans, S. C - _ 

9. Altamaha River to Cape Kennedy ---- 10. Cape Kennedy to Cape Sable --------

Total or annual average ----------

11. Cape Sable to Alligator Creek ------- 12. Peace River to New River ---------- 13. Apalachicola River ---------------- a. Apalachicola River at Chattahoochee, Fla ------------------- 14. Wetappo Creek to Perdido River ----

15. Mobile Bay ----------------------- a. Tombigbee River near Jackson, 

M~s ---------------------- h. Alabama River at Claiborne, Ala_ 

16. Pascagoula River to Pearl River ----- !l· . P~ar~ Ri.ver near Bogalusa, La __ _ 

17. MtsstssiPPl Rtver ------------------ a. Mississippi River at Red River 

Landing (see text) --------- b. Atchafalaya River (see text) __ 

Square 

kilometers 

30,047 

54,134 

46,537 

50,391 

205,283 

17,560 

62,419 

24,996 

73,199 

5,542 

75,247 

22,870 

102,525 

6,863 

7,071 

77,130 

E29,267 

743,760 

E15,540 

67,599 

51,800 

44,548 

36,778 

114,737 

Water 

discharge 

Cubic Cubic 

Square meters feet 

miles per per 

second second 

A. Atlantic Ocean 

11,601 665 

20,901 1,162 

17.~68 986 

19,456 928 

79,2,60 2,866 

6,780 

24,100 

9,651 

28,262 779 

2,140 ----- 29,053 805 

8,830 ----- 39,585 999 

2,650 

2,730 

29,780 732 

E11,300 255 

23,500 

41,020 

34,810 

32,770 

101,200 

27,500 

28,400 

35,290 

25,860 

9,000 

287,166 10,180 359,350 

B. Gulf of Mexico 

E6,000 71 

26,100 770 

20,000 756 

17,200 

14,200 711 44,~00 l,81R 

2,500 

27,200 

26,700 

25,100 

f\4,200 

49,72~ 19,200 

56,980 22,000 

51,023 19,700 883 

17,172 6,630 ----- *3,26~,580 *1,262,000 18,400 

2,923,851 1.128,900 

31,200 

650,000 

Period 

of 

record 

1950-69 

1964-68 

1961-69 

1959-67 

1967-69 

1963-64 

1967-69 

1967- 69 

1952-64 

1952-69 

1967--68 

195G--69 

1950--69 

Average annual suspended-sedimentYield, in 

Discharge, 

in thousands of 

tons per year 

Metric 

tons 

Short 

tons 

tons per Concensquare kilo- tration, 

meter or in millisquare mile grams 

per 

Metric Short liter 

tons tons 

471 460 13.9 39.6 

1,179 1,300 21.8 62.2 

780 860 16.8 47.9 

970 1,070 19.2 55.0 

5,262 5,800 25.6 73.2 

680 749 38.7 111 

1,771 1,953 28.4 81.0 

723 786 28.9 81.4 

1,361 1,500 18.6 53.1 

105 116 19.0 54.1 

1,270 1,400 16.9 48.2 

401 442 17.5 15.2 

943 1,040 9.2 26.3 

55.8 61.6 8.1 23.2 

19.1 21.1 2.7 7.7 

20 

32 

25 

33 

58 

54 

50 

30 

580 640 7.5 21.5 25 

122 134 4.2 11.9 15 

12,886 14,204 17.3 49.5 40 

33.6 

!i63 

:{54 

157 

907 

6,?.1)~ 

2,226 

2,293 

2,268 

799 

296,165 

222,168 

73,987 

37.0 

400 

390 

tn 

1,000 

f),I:U)() 

2,454 

2,528 

2,500 

881 

326,468 

244,900 

81,557 

2.2 

5.4 

6.8 

3.5 

24.6 

l54.~ 

44.8 

40.2 

44.5 

46.5 

90.6 

76.0 

6.2 

15.3 

19.5 

10.1 

70.4 

15~ 

128 

115 

127 

133 

259 

217 

15 

15 

15 

40 

l()q 

81 

510 
~ 

01 

18. Vermilion, Mermentau, and Calcasieu 

Rivers ------------------------- 19. Sabine River to Rio Grande --------- a. Brazos River at Richmond, Tex 

b. Colorado River at Columbus, Tex_ c. Nueces River near Three Rivers, 

Tex -----------------------

Rio Grande near Brownsville, 

Tex., North Floodway near 

22,533 

875,938 

114,012 

106,371 

40,404 

N.d. 

8,700 306 

338,200 1,407 

44,020 

41,070 

15,600 

N.d. N.d. 

10,800 

49,700 

1966-69 

1957-69 

1951-52 

N.d. 1966-69 

X16 ~6.400 

15,89~ 

1,901 

445 

1,229 

900 

40,124 

17,519 

2,096 

491 

1,355 

~6.3 103 

41.6 119 

139 398 

17.9 51 

11.0 31.5 

N.d. N.d. 

85 

820 

d. Arroyo Colorado at Mercedes, Tex.} 

Sebastian, Tex. ~------------------------ --------------------------------------------------------------- Total or annual average _____ 4,504,528 1,739,200 25,120 887,400 

20. Colorado River -------------------- a. Colorado River at Miguel C. 

Rodriquez, Mexico ----------- 21. Tia Juana River to Ventura River --- a. San Juan Creek near San Juan 

Capistrano, Calif ------------ b. Santa Clara River at Saticoy, 

Calif ---------------------- 22. San Jose Creek to Pesadero Creek ---- a. Salinas River near Spreckels, 

Calif ---------------------- 23. San Francisco Bay ---------------- a. San Joaquin River near Vernalis, 

24. 

25. 

26. 

27. 

Calif ---------------------- b. Consumnes River at Michigan Bar, 

Calif ---------------------- c. Sacramento River at Sacramento, 

Calif ----------------------

Lagunitas Creek to Smith River ---- a. Russian River near Guerneville, 

C~H ---------------------- b. Eel River at Scotia, Calif ----- c. Mad River at Arcata, Calif ____ _ d. Klamath River at Orleans, Calif _ e. Trinity River near Hoopa, Calif 2 _ 

Oregon coastal area --------------- a. Siuslaw River near Mapleton, Oreg 

b. Sixes River at Sixes, Oreg ------ c. Rouge River at Raygold, Oreg __ _ 

Columbia River ------------------- a. Columbia River at Vancouver, 

VVash --------------------- Naselle River to Nooksack River ___ _ a. Chehalis River at Porter, VVash _ b. Skykomish River at Monroe, VVash c. Snoqualmie River near Carnation, VVash ---------------- d. Skagit River near Mt. Vernon, 

;vash ---------------------

634,550 

634,550 

31,572 

275 

4,131 

28,801 

10,767 

*123,206 

35,069 

1,388 

60,943 

56,514 

3,471 

8,063 

1,256 

22,015 

7,420 

43,771 

1,523 

300 

5,317 

668,738 

624,190 

50,790 

3,351 

2,160 

1,562 

8,011 

C. Pacific Ocean 

245,000 

245,000 

12,190 

106 

1,595 

11,120 

4,157 

*45,570 

13,540 

536 

23,530 

21,820 

1,340 

3,113 

485 

8,500 

2,865 

16,900 

588 

116 

2,053 

258,200 

241,000 

19,610 

1,294 

834 

603 

3,093 

1.8 

1.8 

14 

68 

861 

1,192 

-----r 

1,509 

7,963 

2,523 

65 

65 1965-69 

500 

2,400 

30,400 

42,100 

53,300 

281,200 

89,100 

1967-68 

1968 

1966-68 

1956-69 

1963-69 

1957-69 

1958-69 

1958-69 

1957-69 

1967-69 

1968-69 

1968-69 

1968-69 

1912 

1964-69 

1962-68 

1967-69 

1968-69 

1910 

Total or annual average __ _ 1,637,942 632,410 14,131.8 499,065 

1 Three dams between station and mouth of river ( VVilliams and Reed, 1972). 2 Tributary to Klamath River. 

343,080 378,179 

9.6 

9.6 

730 

85.5 

68.7 ~.320 

531 

3,252 

350 

143 

2,464 

61,521 

4,135 

26,621 

2,441 

2,389 

4,987 

2,993 

104 

199 

59.2 

14,170 

9,704 

3,873 

115 

244 

263 

330 

10.6 

10.6 

805 

94.3 

75.7 

3,660 

586 

3,585 

386 

158 

2,719 

67,816 

4,559 

29,345 

2,691 

2,631 

5,497 

3,300 

114 

220 

65.3 

15,620 

10,697 

4,270 

127 

269 

290 

364 

89,872.2 99,066.6 

76.1 217.4 

0.015 0.04 

0.015 .04 

23.1 66 

311 890 

16.6 47.5 

115 329 

49.3 141 

26.4 75.4 

10 28.5 

103 295 

40.4 116 

1,089 3,108 

1,191 3,402 

3,302 9,426 

1,944 5,549 

108 310 

672 1,919 

68.3 195 

68.3 193.9 

663 1,897 

11.1 31.8 

21.2 60.5 

15.5 44.4 

76.3 218 

34.3 97.8 

113 323 

168 481 

41.2 118 

54.9 156.6 

433 

165 

1,634 

1,548 

120 

1,630 

63 

56 

49 

201 
...... 

0) 

TABLE 5.-Identification of river stations used to compute sediment data 

[OWDC, U.S. Geological Survey, Office of Water Data Coordination. Agency collecting data: GS, U.S. Geological Survey; CE, U.S. 

This 

report 

5a 

5b 

5c 

6a 

7a 

8a 

8b 

13a 

15a 

15b 

16a 

17a 

17a 

17a 

17b 

17b 

17b 

19a 

19b 

19c 

19d 

19d 

19d 

20a 

21a 

21b 

22a 

23a 

23b 

23c 

24a 

24b 

24c 

24d 

24e 

Station No. 

Agency 

collecting 

data 

01-463500 

01-570500 

01-638500 

02-083500 

02-131000 

02-202500 

02-175000 

02-358000 

02-470040 

02-429500 

02-489500 

01100 

03045 

03720 

03783 

08-114000 

08-161000 

08-210000 

08-470300 

08-475000 

08-468500 

11-046500 

11-113920 

11-152300 

11-303500 

11-335000 

11-447500 

11-467000 

11-477000 

11-481000 

11-523000 

11-530000 

Army Corps of Engineers; IBW, International Boundary and Water Commission] 

Station name 

OWDC 

51178 Delaware River at Trenton, N. J 

54044 Susquehanna River at Harrisburg, 

54253 Potomac River at Point of Rocks, 

52159 Tar River at Tarboro, N.C 

54435 Pee Dee River at Pee Dee, S.C 

67025 Ogeechee River near Eden, Ga 

53536 Edisto Rh er near Givhans, sp 

53276 Apalachicola River at Chattahoochee, Fla 

54582 Tombigbee River near Jackson, Ala 

54581 Alabama River at Claiborne, Ala 

53935 Pearl River near Bogalusa, La 

Mississippi River at Baton Rouge, La --------------------- Mississippi River at Red River Landing, La 

54880 Mississippi River at Tarbot Landing, La 

54776 Atchafalaya River at Simmesport, La 

68001 Wax Lake Outlet at Calumet, La -------- 54758 Atchafalaya River at Morgan City, La 

52812 Brazos River at Richmond, Tex ____ _ 

52824 Colorado River at Columbus, Tex 

63409 Nueces River at Three Rivers, Tex 

52761 Arroyo Colorado at Mercedes, Tex ------------------- 52834 Rio Grande near Brownsville, Tex __ 52833 North Floodway near Sebastian, Tex 

Colorado River at Miguel C. Rodriquez, Mexico 

61625 San Juan Creek near San Juan Capistrano, 

Santa Clara River at Saticoy, Calif ----------

66196 Salinas River near Spreckels, Calif 

69832 San Joaquin River near Vernalis, Calif 

51533 Consumnes River at Michigan Bar, Calif 

51605 Sacramento River at Sacramento, Calif 

51632 Russian River near Guerneville, Calif ---------------------- 51658 Eel River at Scotia, Calif -------------------------------- 51662 Mad River at Arcata, Calif __ _ 

51671 Klamath River at Orleans, Calif 

51678 Trinity River at Hoopa, Calif 

Latitude 

north 

40°13'18" 

40° 15'10" 

39°16'25" 

35°53'38" 

34°12'15" 

a2° 10' 

33°01'40" 

30°42'03" 

31°31' 

31°32'48" 

30°47'35" 

29°57' 

31 °00' 

31 °00'30" 

30°58'57" 

29°42'09" 

29°41'47" 

29°34'56" 

29°42'20" 

28"26'10" 

26°07'24" 

25°52'35" 

26°18'54" 

32° 16' 

33° 10'08" 

34"16'29" 

36° 33'14', 

37"40'34" 

38° 30'00" 

38°35'20" 

38°30'00" 

40°29'30" 

40°54'35" 

41 °18'13" 

41 °03'00" 

Agency 

Longitude collecting 

west data 

074°46'38" 

076°52'27" 

077°32'35" 

077°32'00" 

079°32'55" 

081°25' 

080"23'30'' 

084°51'33" 

087°56' 

087 ° 30' 45, 

089°49'15" 

090° 08' 

091°36' 

091° 37'25" 

091 °47'54" 

091 °22'07" 

091° 12'39" 

095°45'27" 

096°32'05" 

097°51'36" 

097°54'33" 

097°27'15" 

097°46'37" 

115°01, 

113°37'27" 

119 O 08 I 11 I I 

121 °32'50" 

121° 15'51, 

121 °02'45" 

121° 30'15" 

122° 56'05" 

124°05'55" 

124°03'35" 

123CI32'Q0' 1 

123"40'15" 

GS. 

GS. 

GS. 

GS. 

GS. 

GS. 

GS. 

GS. 

CE. 

CE. 

GS. 

CE . CE. 

CE. 

CE. 

CE. 

CE. 

GS. 

GS. 

GS. 

GS. 

GS. 

GS. 

IBW. 

GS. 

GS. 

GS. 

GS. 

GS. 

GS. 

GS. 

GS. 

GS. 

GS. 

GS. 
....... 

'1 

25a 

25b 

25c 

26a 

27a 

27b 

27c 

27d 

------ 14-307620 

------ 14-327150 

------ 14-359000 

------ 14-144700 

------ 12-031000 

------ 12-141100 

------ 12--149000 

------ 12-200500 

62966 Siuslaw River near Mapleton, Oreg ------------------------ 44°03' 45" 123°52'55" GS. 

62967 Sixes Rixer at Sixes, Oreg ------------------------------ 42°49'05" 124 °29'00" GS. 

----- Rouge River at Raygold, Oreg ---------------------------- 42°26'15" 122°59'10" GS. 

54203 Columbia River at Vancouver, Wash ----------------------- 45°37'15" 122 ° 40'20', GS. 

51906 Chehalis River at Porter, Wash --------------------------- 46°56'20" 123°18'45" GS. ----- Skykomish River at Monroe, Wash ------------------------ 47° 50' 48" 121 °58'10" GS. ----- Snoqualmie River near Carnation, Wash ------------------- 47°39'55" 121 °55'30" GS. 

51963 Skagit River near Mt. Vernon, Wash ----------------------- 48°26' 40" 122°20'25" GS.