Appraisal of

Stream Sedimentation in the

Susquehanna River Basin

GEOLOGICAL SURVEY WATER-SUPPLY PAPER 1532-F

Prepared in cooperation with the 

Pennsylvania Department of Forests and 

Waters, Pennsylvania Department of 

Agriculture, State Soil and Water 

Conservation Commission, and the 

U.S. Army Corps of Engineers, 

Baltimore District

Appraisal of

Stream Sedimentation in the

Susquehanna River Basin

By KENNETH F. WILLIAMS and LLOYD A. REED

HYDROLOGIC EFFECTS OF LAND USE

GEOLOGICAL SURVEY WATER-SUPPLY PAPER 1532-F

Prepared in cooperation with the 

Pennsylvania Department of Forests and 

Waters, Pennsylvania Department of 

Agriculture, State Soil and Water 

Conservation Commission, and the 

U.S. Army Corps of Engineers, 

Baltimore District

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON: 1972
UNITED STATES DEPARTMENT OF THE INTERIOR 

ROGERS C. B. MORTON, Secretary

GEOLOGICAL SURVEY 

W. A. Radlinski, Acting Director

Library of Congress catalog-card No. 77-184620

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

Washington, D.C. 20402 - Price 25 cents (paper cover)

Stock Number 2401-1228
CONTENTS

Page

Abstract _____________ ______-_ Fl

Introduction _______________________ 1

Previous sediment investigations _________ 2

Definition of terms ______________ _ 3

The basin _____________________________ 4

Climate and precipitation ____________ _ 4

Land use __________________________________ 5

Average-annual sediment yield _______________ 6

Appalachian Plateaus ________________ _ 6

Valley and Ridge ______________________________ 12

Blue Ridge __________________________________ 13

Piedmont ______________________________________ 13

Suspended-sediment concentration ______________________ 14

Particle size of suspended sediments _____________ __ _ 15

Reservoir sedimentation _______________________________ 16

Sediment discharge into the Chesapeake Bay ________________ 17

Trends in sediment discharge ___________________________ 20

Summary and conclusions ______________________________ 22

Selected references ________________________________ 23

ILLUSTRATIONS

Page 

FIGUBES 1-3. Maps:

1. Physiographic provinces of the Susquehanna River

basin ____________________________ F5

2. Average-annual sediment yields at stations in the

Susquehanna River basin _______________ 10

3. Generalized average-annual sediment yields in the 

drainage areas larger than 100 square miles in 

the Susquehanna River basin ____________ 11

4-8. Graphs:

4. Effect of forest cover on sediment yields in the

Appalachian Plateaus _________________ 12

5. Significance of forest cover and geology on sediment

yields in the Valley and Ridge province _____ 13

6. Range in size distribution of suspended sediment 

transported by streams in each physiographic 

province __________________________ 16

III
IV CONTENTS 

FIGUBES 4-8. Graphs Continued

Page

7. Design curves for predicting rates of sediment deposition in reservoirs ______ _ 17

8. Double-mass comparison of sediment discharge and

direct runoff for Juniata River at Newport, Pa. _ 21

TABLES

Page 

TABLE 1. Land use in the Susquehanna River basin, 1967 _________ F6

2. Summary of average-annual sediment yields in the Susquehanna River basin __________________________ 7

3. Frequency distribution of suspended-sediment concentrations

in Pennsylvania ____________________________ 14

4. Variation of suspended-sediment concentrations in the cross 

section of the Susquehanna River at Harrisburg, Pa., October l, 1963, to September 30, 1967 _________________ 15

5. Summary of selected reservoir-sedimentation surveys in and

adjacent to the Susquehanna River basin __________ 18
HYDROLOGIC EFFECTS OF LAND USE

APPRAISAL OF STREAM

SEDIMENTATION IN THE

SUSQUEHANNA RIVER BASIN

By KENNETH F. WILLIAMS and LLOYD A. REED

ABSTRACT

The Susquehanna River presently transports about 3.0 million tons of sediment annually (110 tons per square mile). Only about 1.8 million tons of sediment enters the head of Chesapeake Bay annually because some sediment is 

trapped behind the power dams on the lower Susquehanna. Measured annual 

sediment yields from subbasins in the Susquehanna range from 40 to 440 tons 

per square mile. The highest yields are from parts of the glaciated section of the 

basin, in the anthracite coal region, and the Piedmont province. The lowest 

yields are from parts of the glaciated section of the basin and the Appalachian 

high plateau.

Available data indicate that there has been a downward trend of sediment 

discharge in recent years. In the future, the high sediment yields associated 

with urbanization may offset this present downward trend.

INTRODUCTION

The Pennsylvania Department of Forests and Waters, the Baltimore District of the U.S. Army Corps of Engineers, and the Pennsylvania Department of Agriculture cooperated with the U.S. Geological 

Survey in a reconnaissance study of fluvial sedimentation in the 

Susquehanna River basin. The project is part of a study by State and 

Federal agencies to provide a comprehensive plan for the development 

and conservation of the water and related land resources of the 

Susquehanna River basin.

Adequate stream-sedimentation information is one of the many 

requirements for proper utilization of water and related land resources. Stream-sedimentation information is used to predict the 

usable life of on-stream reservoirs, to aid design of future domestic 

and industrial water supplies, to guide the selection of good waterFl
F2 HYDROLOGIC EFFECTS OF LAND USE

recreation sites, and to help define the suitability of the aquatic 

environment for fish.

This report describes the sediment yields throughout the basin, the 

variability and characteristics of sediment, the suspended-sediment 

concentrations, potential reservoir-sedimentation problems that may 

occur in the basin, and trends in sediment discharge. The report also 

points out potential problem areas where extensive sediment studies 

may be required.

Geologic, hydrologic, and other environmental controls over stream 

sedimentation are considered. Each physiographic province in the 

basin is considered as a separate entity which has unique erosion and 

resultant stream-sedimentation characteristics.

Much of the data used was collected between 1962 and 1967 at longterm U.S. Geological Survey stream-gaging stations having drainage 

areas of 100-800 square miles. In addition, data from independent 

studies in the basin were used to supplement data obtained during 

the reconnaissance study.

PREVIOUS SEDIMENT INVESTIGATIONS

The results of stream-sedimentation studies conducted in terrains 

similar to the Susquehanna River basin are included in reports on the 

Potomac and Delaware River basins by Wark, Keller, and Feltz 

(1961) and Wark and Hall (1959) respectively. The Potomac and 

Delaware River basin reports discussed average-annual sediment yield 

of streams, some of the variables causing excess stream sedimentation, 

and the particle-size distribution of suspended sediment.

Reservoir-sedimentation surveys for 16 reservoirs (U.S. Department 

of Agriculture, 1969) are included in this report to show storagecapacity losses in reservoirs in and near the Susquehanna basin.

Culbertson (1957) and Jones (1964 and 1966) reported on the 

sedimentation characteristics of several small agricultural basins in 

the central and north-central parts of the Susquehanna River basin. 

These studies evaluated the effects of conservation practices on 

hydrology and sedimentation in these basins.

McCarren, Wark, and George (1964) presented evidence of the 

effects of coal mining and processing on sediment yields from a small 

area in the upper Swatara Creek basin. That report describes the 

long-term changes in stream-sediment concentration that took place 

as coal mining and processing decreased in the early 1950's.

Schuleen and Higgins (1953) reported sedimentation rates in 

the Safe Harbor Reservoir and discussed the quantity and nature of 

sediment transported by the Susquehanna River into the reservoir 

during the period from 1948 to 1953.
STREAM SEDIMENTATION, SUSQUEHANNA RIVER BASIN F3

Williams and George (1968) presented a progress report on sedimentation in the Susquehanna River basin using data collected 

through September 1965.

Measurements of suspended-sediment discharge obtained during 

other studies were available for several sites in the Susquehanna 

River basin. The longest continuous record was for the Juniata 

River at Newport, Pa., where daily measurements of suspendedsediment discharge were begun in January 1951. These data were 

collected as a part of the U.S. Geological Survey program to define 

the long-term variation of stream sedimentation in selected river 

basins throughout the United States. All available suspendedsediment data for the Susquehanna River basin appear in the annual 

series of U.S. Geological Survey water-supply papers entitled 

"Quality of Surface Water of the United States" or in "Water 

Resources Data for Pennsylvania Part 2, Water Quality Records," 

(available from U.S. Geol. Survey, Harrisburg, Pa.) which replaced 

the water-supply papers in 1964.

DEFINITION OF TERMS

Bedload. Sediment that moves along in almost continuous contact 

with the streambed. Individual particles move by sliding, rolling, 

or skipping.

Bed material. The sediment mixture of which the streambed is 

composed.

Clay. Sediment particles with a mean diameter smaller than 0.004 

mm (millimeter).

Fluvial sediment. Fragmentary material that originates from the 

weathering of rocks and is transported by, suspended in, or deposited 

from water.

Sand. Sediment particles with a mean diameter between 0.062 and 

2.0 mm.

Sediment discharge. The quantity of sediment, expressed as dry 

weight, that is carried past a stream cross section in a unit of time. 

The unit of time may be a short measurement interval, a day, a month, 

a year, or some other period. Although some sediment is not sampled 

in the zone near the bed, the unmeasured component of the total 

sediment discharge is assumed to be small.

Sediment load. The sediment that is being moved by a stream. 

Load refers to the material itself and not to the quantity being moved.

Sediment yield. The sediment outflow from a drainage basin at a 

given location in a specified period of time. The sediment yield is 

the average-annual sediment discharge from the drainage basin, 

expressed in tons per square mile per year.
F4 HYDROLOGIC EFFECTS OF LAND USE

Silt. Sediment particles with a mean diameter between 0.004 and 

0.062 mm.

Specific weight. The ovendry weight of sediment per unit volume 

of deposit in place.

Suspended-sediment concentration. A ratio of the sediment to 

the water-sediment mixture, expressed as milligrams per liter.

Trap efficiency. The percentage of inflowing sediment that is 

retained in a reservoir.

THE BASIN

The Susquehanna River, which empties into the Chesapeake Bay, 

drains the largest basin along the east coast of the United States. 

The river drains an area of 27,500 sq mi (square miles) in the States 

of New York, Pennsylvania, and Maryland.

Four physiographic provinces lie within the Susquehanna River 

basin (fig. 1)': (1) the Appalachian Plateaus, (2) the Valley and 

Ridge, (3) the Blue Ridge, and (4) the Piedmont (Fenneman, 1938). 

The Appalachian Plateaus can be divided into a low section in the 

northeast and a high section in the southwest. Continental glaciation 

on the northeastern section (the low plateau) of the Appalachian 

Plateaus has produced well-rounded hills and broad flat valleys. 

Much of the southwestern section (the high plateau) was not glaciated 

and is characterized by flat-topped mountains having deeply incised 

narrow stream valleys. The plateau is underlain by horizontal strata, 

as only minor folding and faulting occurred in the area. The Valley 

and Ridge province, which encompasses most of the middle third of 

the basin, is characterized by steep mountains and ridges separated by 

broad valleys. The structure in the Valley and Ridge province is the 

result of extensive folding, faulting, and crushing of the formations, 

followed by erosion that cut valleys in the soft formations and left the 

hard strata as mountains.

Only a very small part of the mountainous Blue Ridge province 

lies within the Susquehanna River basin. The Piedmont province, 

which begins about 10 mi south of Harrisburg, Pa., contains terrain 

that is gently rolling to hilly. It consists of both upland and lowland. 

The lowland is underlain by limestone, sandstone, and shale, and the 

upland is underlain by crystalline rocks.

CLIMATE AND PRECIPITATION

The climate in the Susquehanna River basin is considered to be 

moderate. The length of the growing season ranges from about 120 

to 200 days, and the average is about 150 days. The growing season
STREAM SEDIMENTATION, SUSQUEHANNA RIVER BASIN F5

\

(-*£- HOLTWOOD 

r~ -CONOWINGO

" '~^^M

0 5 10 20 30 40 50 MILES

III I I I I

FIGURE 1. Physiographic provinces of the Susquehanna River basin. (From Fenneman, 1938.)

is shortest in parts of the Appalachian Plateaus and is longest near 

the mouth of the Susquehanna (Johnson, 1960; Kauffman, 1960).

Average annual precipitation ranges from 32 inches in the northwestern part of the basin to 44 inches in the southern and east-central 

parts. The basin as a whole receives approximately 40 inches of 

precipitation in an average year. About half of the annual precipitation eventually returns to the ocean as streamflow. The remaining 

water provides moisture for vegetal growth and is transpired or 

evaporates directly to the atmosphere. Relatively little water is consumed by industrial processes in the basin.

LAND USE

In the Eastern United States, climate, parent material, and topography have influenced the soil and the use of the land for many

443-561 O - 72 - 2
F6 HYDROLOGIC EFFECTS OF LAND USE

decades. Where the soils were productive, the flat to rolling countryside was cleared and cultivated. Forests occupy most of the areas 

where the soils are unproductive or the topography is too steep for 

cultivation.

Land use in the different physiographic provinces within the 

Susquehanna River basin in 1967 is summarized in table 1. The 

small part of the Blue Ridge province within the basin is included 

with the Valley and Ridge province.

The major bituminous coal fields within the Susquehanna basin 

are in the unglaciated section of the Appalachian high plateau. The 

major fields are in the southwestern part of this plateau, although 

some coal is mined in the headwaters of the Tioga River basin and 

along the southern section of the Juniata River basin.

The anthracite coal fields in the basin are in the Valley and Ridge 

province east of the Susquehanna River and north of Blue Mountain. 

Spoil banks, old mine-waste piles, and the wastes of old abandoned 

anthracite coal-processing plants provide a source of fine sediments.

AVERAGE-ANNUAL SEDIMENT YIELD

Sediment yields have been calculated for 42 stations in the Susquehanna River basin. Data at 33 of the stations were obtained for this 

study. The measuring stations and the corresponding average-annual 

sediment yields are shown in figure 2 and are summarized in table 2.

Figure 3 indicates the generalized average-annual sediment yields 

from subbasins larger than 100 sq mi in the Susquehanna basin. The 

ranges shown were developed from the measured sediment yields and 

from sediment-yield data for river basins adjacent to the Susquehanna. The generalized sediment yields shown in figure 3 are 

discussed in the following text by physiographic provinces, starting 

with the northernmost province, the Appalachian Plateaus.

APPALACHIAN PLATEAUS

The province having the widest range of sediment yields is the 

Appalachian low plateau province, where yields range from 40 tons

TABLE 1. Land use in the Susquehanna River basin, 1967

Physiographic 

province

Piedmont

Valley and Ridge

Appalachian high plateau

Appalachian low plateau

Percentage

of 

basin

7

37

 » -« j 56

Land i

Forest1

25

57

/ 76

I 46

ise (percentage of land area)

Grass2 Cultivated2 Urban2

33 34 8

19 18 6

12 9 3

29 21 4

1 U.S. Forest Service (written commun., 1966).

2 U.S. Soil Conservation Service (written commun., 1966).
TABLE 2. Summary of average-annual sediment yields in 

Drainage area 

(sq mi)

Map 

reference 

No. Station

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20

See

Susquehanna River at 

Unadilla, N.Y. _

Unadilla River at 

Rockdale N Y

Susquehanna River at 

Conklin, N.Y. ___ _

Chenango River at 

Greene N Y

Owego Creek near 

OWCETO N Y

Susquehanna River near

"WT*i v<-i"l v TO V

Corey Creek near

Elk Run near

Tioga River at

Crooked Creek at

Tioga River at 

Llndley, N.Y.

Canisteo River at 

West Cameron, N.Y. ___ 

Tioga River near

Cohocton River near

Pamnholl M V

Chemung River at

Susquehanna River at

Tunkhannock Creek near 

Tunkhannock, Pa. __ 

Fishing Creek near

Susquehanna River at

West Branch Susquehanna River at

footnotes at end of table.

Total

984 

518 

2,240 

598 

186 

4,780 

12.2 

10.2 

282 

122 

770 

342 

1,370 

472 

2,530 

7,797 

383 

274 

11,220

315

Contributing1

907 

518 

2,160 

598 

186 

4,500 

12.2 

10.2 

282 

122 

770 

320 

1,320 

440 

2,450 

7,440 

383 

274 

10,840

315

Physiographic 

province 

Appalachian low plateau __ 

_ __ __ do_ _ _ _ __

_ do __ ______

_ _ __ _ do

do_ __ __ __

_ _ _ do _

do

_____ do

Appalachian low and

Appalachian high plateau

Appalachian low and 

Appalachian low plateau ___ 

_do __

_ __ do

do

_ _ do

__ _ do

Valley and Ridge _ ___

Appalachian Plateaus and

Appalachian high plateau __
TABLE 2. Summary of average-annual sediment yields in the Sus

Drainage area 

(sq mi)

Map 

reference 

No. Station

21

22 

23 

24 

25 

26 

27

28 

29

30 

31 

32

33 

34 

35 

36 

37 

38

Driftwood Branch Sinnemahoning Creek at

Spring Creek near

Bald Eagle Creek at

Bald Eagle Creek at

Marsh Creek at

Pine Creek at

West Branch Susquehanna River at

Penns Creek at

East Mahantango 

Creek near

Juniata River at

Dunning Creek at

Raystown Branch 

Juniata River at

Kishacoquillas Creek at

Juniata River at 

NcwDort Pfl,

Bixler Run near

Sberman Creek at

Susquehanna River at

Yellow Breeches 

Creek near 

Camn Hill. Pa. _______

Total

272 

87.2 

265 

339 

44.1 

604

6,847 

301

162 

816 

172

756 

164 

3,354 

15.0 

200 

24,100

216

Contributing1

272 

87.2 

265 

339 

44.1 

604

6,510 

301

162 

816 

172

756 

164 

3,354 

15.0 

200 

23,400

216

Physiographic 

province 

Appalachiain high plateau _ 

Valley and Ridge _ ___ _

______ do ____________

do _

do _ __ ___

Appalachian high plateau

Appalachian high plateau 

and Valley and Ridge __

_______ do__ _ _ _

 _ _ _ _ do__ 

__ __do _

__ __ __ _ do _

do _ ______

do ___ ______

__ _ _ do _

_______ do ______

Appalachian Plateaus 

and Valley and Ridge ____

Valley and Ridge and 

Blue Ridee _ _____
STREAM SEDIMENTATION, SUSQUEHANNA RIVER BASIN F9

IN CO rH

O O O_

o w t-

§ "a §

I | 1

J P J

>> a d? H

JH ie

O b- T)H TH TH e»

K5 i-t CO

^ *J-a s *" e? '"w fcl .

«is -2*1*

sia«is«ls

S C

Sp'?*-^ rt a> r *o

gg|5g

^

lip!

lllll

443-561 O - 72 - 3
F10 HYDROLOGIC EFFECTS OF LAND USE

EXPLANATION

29 

Measuring station; map

reference number, table 2

280

Average-annual sediment 

yield, in tons per square mile

Power dam

0 5 10 20 30 40 50 MILES

III I I I I

FIGURE 2. Average-annual sediment yields at stations in the Susquehanna River basin.

per sq mi for the Unadilla River at Rockdale, N.Y., to 440 tons per 

sq mi for the Canisteo River at West Cameron, N.Y. In areas where 

the glacial advance and retreat left broad flat valleys, sediment yields 

are low; where the glacial activity was low and the stream valleys 

are narrow and steep, sediment yields are high.

Three different sediment-yielding areas are found in the Appalachian low plateau province (fig. 3): (1) a low-yielding area where 

sediment yields range from 40 to 100 tons per sq mi, (2) an area 

where sediment yields range from 100 to 200 tons per sq mi, and (3) 

a high-yielding area where sediment yields are greater than 200 tons 

per sq mi.

Sediment yields were measured at three stations in the Appalachian 

high plateau. Measured sediment yields range from 66 tons per sq mi
STREAM SEDIMENTATION, SUSQUEHANNA RIVER BASIN Fll

EXPLANATION

SEDIMENT YIELD,

IN TONS 

PER SQUARE MILE

40-100

100-200

>200

Power dam

0 5 10 20 30 40 50 MILES

III I I I I

FIGURE 3. Generalized average-annual sediment yields of drainage areas larger than 

100 sq ml In the Susquehanna River basin.

for the Driftwood Branch Sinnemahoning Creek at Sterling Run, 

Pa., to 120 tons per sq mi for the West Branch Susquehanna River at 

Bower, Pa. The extensive forest cover and soils derived from the 

sandstones in this province limit the amount of fine material available 

to streams.

Sediment yields do not seem to be high even in areas of the high 

plateau where strip mining has exposed large quantities of material 

in the bituminous coal fields. They probably do not exceed 200 tons 

per sq mi, as indicated by data for the West Branch Susquehanna 

River at Bower. Apparently much of the erodible exposed material 

is carried into strip pits and other internal drainage and never 

reaches the stream.
F12 HYDROLOGIC EFFECTS OF LAND USE

1 \J\J\J

z 500

O

z

. UJ

Q =!

y S 200

>- UJ

QC

Z ^

£0- l£ 10°

<«£

^

| 50

9n

\ \

 12

13.

6 .

EXPLANATION

17 Map reference number,

table 2

 Basins wholly within

Appalachian low plateau

x Basins include part of

Appalachian high plateau

® Basins wholly within 

Appalachian high plateau

8 *15 x

7 14 ^0 ^ 9 @2Q

26« 21@

*4

1 1 1 1

20 40 60 

PERCENTAGE OF FOREST COVER

80 100

FIGURE 4. Effect of forest cover on sediment yields in the Appalachian Plateaus.

No good correlation between sediment yield and land use, expressed 

as percentage of forest cover (fig. 4), exists for the Appalachian 

Plateaus section of the Susquehanna Eiver basin. Geology and topography appear to be the major factors controlling the sediment 

yield, but they are difficult to define quantitatively; thus, sedimentyield predictions beyond the generalized predictions shown in figure 3 

are difficult to make for subbasins in this part of the Susquehanna. 

If sediment could significantly affect a water-resources project in this 

area, a thorough sediment study should be undertaken.

VALLEY AND RIDGE

Sediment yields were measured at 15 stations in the Valley and 

Eidge province. Measured annual sediment yields range from 58 tons 

per sq mi for Dunning Creek near Belden, Pa., to 280 tons per sq mi 

for East Mahantango Creek near Dalmatia, Pa. The Valley and 

Eidge province can be divided into three sediment-yielding areas 

one having low sediment yields, one having moderate yields, and one 

having high yields (fig. 3). In the low-yielding area, which comprises most of the Valley and Eidge, sediment yields are generally less 

than 100 tons per sq mi. The high-yielding area is east of the Susquehanna Eiver and extends from the Scranton and Wilkes-Barre area 

south to the southern limit of the Valley and Eidge. Here sediment 

yields are influenced by the coal-processing activities and average 

greater than 200 tons per sq mi. In the moderate area, which includes
STREAM SEDIMENTATION, SUSQUEHANNA RIVER BASIN F13

Q d

EXPLANATION 

22 Map reference number, 

table 2

® Basins containing more 

than 25 percent limestone

 Other basins

24 ^*

20 40 » 60 

PERCENTAGE OF FOREST COVER

80 100

FIGDEB 5. Significance of forest cover and geology on sediment yields in the Valley

and Ridge province.

parts of the Conodoguinet and Yellow Breeches Creek basins, sediment yields range from 100 to 200 tons per sq mi (fig. 3).

Analysis of the Valley and Ridge data suggests that the sediment 

yields from basins having 25 percent or more limestone terrane are 

considerably lower than yields from other areas in this province that 

are similar with respect to land use (fig. 5). The lower slopes 

characteristic of limestone terrane may result in less erosion; however, 

the most significant factor contributing to the lower yields is internal 

drainage, which is characteristic of limestone terrane.

Figure 5 applies only to areas unaffected by anthracite coal mining 

and processing. Sediment yields from basins affected by mining depend on the amount of coal processed in the basin and on the methods 

used to dispose of the fine material. Thorough sediment studies 

should be undertaken in areas where sediment from anthracite mining 

could be a significant problem to a planned water-resources project.

BLUE RIDGE

No sediment-yield data are available for the very small part of the 

Blue Ridge province within the Susquehanna River basin. However, 

sediment yields from this heavily forested part of the basin are 

probably similar to those of the Appalachian high plateaus.

PIEDMONT

Measured sediment yields in the Piedmont Lowland range from 

180 to 220 tons per sq mi. Sediment yields in the Piedmont Upland 

probably average less than the yield of 350 tons per sq mi reported
F14 HYDROLOGIC EFFECTS OF LAND USE

for the South Branch Codorus Creek near York, which was the only 

sediment station established in the area. The estimated average 

sediment yield is about 300 tons per sq mi, as most of the upland is 

somewhat less subject to erosion than the Codorus Creek basin. The 

upland yields are significantly greater than lowland yields because 

the slopes generally are steeper, and the soils developed on the 

crystalline rocks are more erodible. Consideration should be given 

to sediment accumulation when designing water-resources projects 

in this area, especially in planning reservoirs having a small 

capacity-inflow ratio.

SUSPENDED-SEDIMENT CONCENTRATION

The presence of suspended sediment often creates problems for 

water users and water-resources planners. It increases watertreatment costs and may limit the recreational potential of a stream. 

Therefore, knowledge of the frequency distribution of suspendedsediment concentrations should be useful to water users and 

water-resources planners.

The frequency distribution of suspended-sediment concentrations 

at stations having sufficient data is summarized in table 3. Since 

most water users withdraw a fairly constant amount of water throughout the year, they are interested in prevalent sediment concentrations.

The data presented in table 3 indicate that two Piedmont streams, 

the South Branch Codorus Creek and the Conestoga Creek, characteristically have higher suspended-sediment concentrations during

TABLE 3. Frequency distribution of suspended-sediment concentrations in

Pennsylvania

Station

Period

of 

record

Mean daily concentration, in milligrams per liter,

that was equaled or exceeded for indicated

percentage of time

2 5 10 20 30 40 50 60 70 80 90 95 98

Fishing Creek Oct. 1, 1966- 50 27 14 7554332221

near Sept. 30, 1967

Bloomsburg 

Juniata River Oct. 1, 1951- 180 90 45 25 15 11 8 6 4 3 2 2 1

at Newport Sept. 30, 1967 

Bixler Run Oct. 1, 1954- 110 45 24 14 11 8 7 6 5 4 3 2 2

near Sept. 30, 1967

Loysville 

Susquehanna Oct. 1, 1963- 140 76 46 27 18 11 7 5 4 3 2 1 1

River at Sept. 30, 1967

Harrisburg 

South Branch Oct. 1, 1966- 400 180 55 34 27 22 18 16 13 11 8 6 5

Cordorus Sept. 30, 1967

Creek near

York 

Conestoga Jan. 1962- 250 160 120 85 60 45 40 30 20 15 10 9 6

Creek at Sept. 1964

Lancaster1

1 Synthesized from periodic data.
STREAM SEDIMENTATION, SUSQUEHANNA RIVER BASIN F15

periods of low flow than the streams in the Valley and Ridge. Observations suggest that higher concentrations during low flow also 

occur in the other Piedmont streams within the Susquehanna basin 

as well as in the main stems of the Conodoguinet and Yellow Breeches 

Creeks.

The main stem of the Susquehanna River is known to have lateral 

variations of chemical constituents (Anderson, 1963). There are 

also variations in the suspended-sediment concentrations in the cross 

section, as summarized in table 4. Sediment concentrations, according 

to the data, generally are highest on the east side of the river, a fact 

reflecting the high sediment discharge of the North Branch Susquehanna River and East Mahantango Creek. This knowledge may 

permit a water user to establish fixed intakes so that he can, on the 

average, withdraw water that has the least suspended-sediment concentration. Of course, variations of the other constituents within the 

cross section will also have to be evaluated so that the optimum 

withdrawal point can be established.

PARTICLE SIZE OF SUSPENDED SEDIMENTS

The particle size of suspended-sediment samples was determined 

for most streams sampled in the Susquehanna River basin. Figure 6 

summarizes the range in particle size of sediments transported by 

streams in each physiographic province. Because of the variation of 

the particle-size composition as sediment concentration and streamflow vary, only data collected during periods of peak discharge are 

used in the figure. Generally, from 50 to 75 percent of the annual 

sediment load is transported during the periods of peak stream discharge ; the results shown in the figure represent a reasonable approximation of the average sediment-weighted particle-size composition. 

The average composition of suspended sediment is fairly consistent, 

being approximately 10 percent sand, 50 percent silt, and 40 percent 

clay.

TABLE 4. Variation of suspended-sediment concentrations in the cross section 

of the Susquehanna River at Harrisburg, Pa., October 1, 1963, to September 

30, 1967

Mean daily concentration, in milligrams per liter,

that was equaled or exceeded for indicated

percentage of time

Station 2 5 10 20 30 40 50 60 70 80 90 95 98

East channel:

Station 300 (east bank) __ 210 110 60 38 25 15 10 6 4 4 3 1 1 

Station 1,000 _________ 160 80 50 27 17 11 7 5 4 3 2 1 1

West channel:

Station 400 __________ 110 60 38 22 14 9 54 32 1 1 1 

Station 1,000 (west bank) __ 100 56 35 20 14 10 7 4 3 3 2 1 1
F16 HYDROLOGIC EFFECTS OF LAND USE

100

80

60

40

g 20

Median

^

»

Im

^

V-T

^

»

I

I

EXPLANATION

PARTICLE SIZE, IN MILLIMETERS

7-3

| | Clay < 0.004

H| Silt 0.004-0.062

[^ Sand 0.062-2.0

ni"i

* MS/,

I -

0 '

Appalachian Appalachian

low high 

plateau plateau 

Number of streams Q . 

in province

Valley

and

Ridge

10

Piedmont

FIGURE 6. Range in size distribution of suspended sediment transported by streams 

in each physiographic province.

RESERVOIR SEDIMENTATION

Although reservoir sedimentation is not a serious problem in the 

Susquehanna River basin, sedimentation problems can occur, and 

construction agencies generally allow for sediment deposition during 

the design life of their structures. Design curves are presented here 

(fig. 7) so that sediment-deposition rates in reservoirs can be predicted. These curves were developed from the relation (Brune, 1953) 

between trap efficiency and capacity -inflow ratio (reservoir capacity 

divided by average annual inflow) . Sediment yields for basins larger 

than 100 sq mi can be estimated from figure 3.
STREAM SEDIMENTATION, SUSQUEHANNA RIVER BASIN FIT

A summary of storage-depletion rates for selected reservoirs in and 

adjacent to the Susquehanna River basin is given in table 5. Reservoirs were selected on the basis of the accuracy of the reservoir 

surveys and length of time between surveys. These data indicate 

that rapid depletion of the total storage capacity is not a serious 

problem for reservoirs having comparatively large capacity-inflow 

ratios; however, for reservoirs having fairly small capacity-inflow 

ratios, the rate of storage depletion could prove significant.

Reservoir-sedimentation problems can occur without a noticeable 

loss of storage capacity. As Bondurant and Livesey (1965) indicated, 

fairly small quantities of sediments can deplete the useful life of boat 

docks and other inlet facilities if inflowing sediment settles readily 

and fine sediments that stay suspended for long periods of time give 

the water a turbid appearance and make the reservoir esthetically 

undesirable.

SEDIMENT DISCHARGE INTO THE CHESAPEAKE BAY

Three major power dams span the Susquehanna River before it 

flows into the Chesapeake Bay (fig. 1). The Safe Harbor Dam,

i.o

o.i

E Q

LjJ

Q

IUJ .

i

Q

UJ 

V)

0.01 -

0.001

500

Average-annual sediment 

yield, in tons per 

square mile

Note: Specific weight of deposits assumed 

to be 60 pounds per cubic foot

0.01 0.10 1.0 10 

CAPACITY-INFLOW RATIO

FIGURE 7. Design curves for predicting rates of sediment deposition in reservoirs.
TABLE 5. Summary of selected reservoir- sedimentation surveys in an

StorSedi- age 

ment- capaccon- ity 

trib- at 

uting spilldrain- way 

age elevaarea Date of tion 

(sq reservoir (acreReservoir Location mi) surveys ft)

Aver- 

age 

annual 

Inflow 

(acre- 

ft) 

Susqnehanna River basin

Lake Williams __ _ __ York, Pa. _________

,9fi r 1912 2,686 1 

4J'6 lApr. 1939 2,232)

»30,400 

Chesapeake Bay area 

Atkisson Reservoir _ _ Belair, Md _________

77 -rOct. 1943 60,4101 

77-°\.Sept. 1961 59,864) 

91Q rOct. 1943 64,8131 

6 I June 1961 64,072; 

45 4 f May 1942 8961 

45-4 VMay 1954 705;

"66,500 

3188,000 

36,300 

Delaware River basin 

,-, /July 1937 3121 

171 I July 1957 244;

9f» n f 1900 137 1 

J0-"(.juiy 1951 106;

~ n f 1916 1,0191 

°'u I July 1951 970 /

 141,000 

310,600 

2,200 

Potomac River basin

TridelDbia Lake __ __Ashton. Md _

80>1 rJune 1942 20,2221

S63,600 
STREAM SEDIMENTATION, SUSQUEHANNA RIVER BASIN F19

basin iver 

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rt rt

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CO 0» O K3 O 

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CO CO CO iH

6

0000

o co co oo

os" oo* co* o&"

0 * O O

r-t CO CO CO

loco oo oeo oo

Or-t OO Ot- OO IN-* eoio o»co totcoco GdGS CdOi 0000 

PIP!

Pit- IN IN O-* t-0»

. 4J 4> . 

§ W 53 a a3 ^u 

I-SOQ 1-9 ^ < < OS VTT' w"~' % ' ^"""^

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d S vi a

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1 1 1

1 1 1

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"S t-M '

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Quemahoning Reser Loyalhanna Reservo

Crooked CreekReservoir Tygart River Reservoir

River basin

1

?

H

oo

6

o

PI

tT-l

co

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iH

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wo ootco"pf

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+J

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Schoharie Reservoir

River basin

$

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6

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t- co

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o

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f^

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t

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oj "S S 1

S 2

3 a

i i

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i i

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i i

Rushford Lake ____ Morris Mount

Reservoir _-

I

1&

co

"

g

co

o

1

o

6

IO

co

i

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IOcc"

co PI 

PIJ»

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1-8

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Carnegie Lake 

oi

co

T-t

2

5

1

ft^

"S 

 g

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S1

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OQ

P

.0

rg

% 1

Q, , H

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«§<!

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9 *" ^ 4}

Sns ^* ^

? 4) o3 fa

M !t1 § j\

Computed 1 ]from Density 2 of depos 3 Computed from iU.S. Geological £* 
F20 HYDEOLOGIC EFFECTS OF LAND USE

completed in 1931, is 33 miles upstream from the mouth of the Susquehanna; the Holtwood Dam, completed in 1910, is 25 miles upstream; 

and the Conowingo Dam, completed in 1928, is 10 miles upstream. 

Using the 45-year average-annual river flow of 26,500,000 acre-ft at 

Holtwood, the capacity-inflow ratios (Brune, 1953) were computed 

for each of the reservoirs created by the power dams.

Dam 

Safe Harbor

Holtwood

Conowineo

Head 

55

50.6

89

Approxi- Combined 

mate total Capacity- capacitystorage inflow inflow 

(acre-ft) ratio ratio

150,000 0.006 0.006 

60,000 .0023 .008 

300.000 .011 .019

Because the reservoirs operate ih series, the combined capacityinflow ratio for the three is 0.019 (based on a combined capacity of 

510,000 acre-ft), and the combined trap efficiency (Brune, 1953) is 55 

percent. In series, the individual trap efficiency for the three reservoirs is 30 percent for Safe Harbor, 8 percent for Holtwood, and 17 

percent for Conowingo.

As part of a coal-recovery operation, the Pennsylvania Power & 

Light Co. annually dredges 1 million tons of coal-laden deposits 

(Levin and Smith, 1954) from the reservoir formed by Safe Harbor 

Dam. Reservoir-sediment surveys by the Pennsylvania Power & 

Light Co. indicate that 1 million tons of incoming river sediments is 

deposited annually, replacing the dredged material. The surveys 

indicate that the reservoir is in a man-induced state of dynamic 

equilibrium (Schuleen and Higgins, 1953). Pennsylvania Power 

& Light Co. surveys indicate that the reservoir formed by the Holtwood Dam has been in a state of dynamic equilibrium since the late 

1940's.

The reservoir formed by the Conowingo Dam has not been surveyed ; however, the trap efficiency of 17 percent would indicate that 

0.2 million tons is being trapped annually. This makes the total 

sediment deposition in the three reservoirs 1.2 million tons per year. 

The remaining 1.8 million tons passes into the Chesapeake Bay.

TRENDS IN SEDIMENT DISCHARGE

There is evidence of changing sediment-discharge rates in and near 

the Susquehanna Eiver basin. O'Bryan and McAvoy (1966) described 

a pattern of decreasing sediment loads in the basin of the Gun 

Powder Falls Eiver, a tributary to the Potomac Eiver. The longterm sediment records for Juniata Eiver at Newport, Pa., a tributary 

to the Susquehanna, show a decline in the sediment-discharge rate 

(fig. 8). Figure 8 shows that, beginning about 1955 or 1956, a 31-
STREAM SEDIMENTATION, SUSQUEHANNA RIVER BASIN F21

1.2 i1967

1967

"012345 

CUMULATIVE DIRECT RUNOFF, IN MILLIONS OF CFS-DAYS

FIGURE 8. Double-mass comparison of sediment discharge and direct runoff for Juniata 

River at Newport, Fa., showing decrease in sediment discharge after 1955.

percent reduction in the sediment discharge occurred in the period 

from May through October, and a 24-percent reduction occurred in 

the period from November through April. These seasonal changes 

amount to a 25-percent reduction in the average-annual sediment discharge. Analyses of reservoir-survey data (Schuleen and Higgins, 

1953) for Lake Clarke, the lake formed by Safe Harbor Dam on the 

main stem of the Susquehanna south of Harrisburg, indicate that 

the amount of sediment discharged annually in the middle and late 

1930's was at least three to four times its present level.

Several investigators (McCarren, Wark, and George, 1964; 

Biesecker, Lescinsky, and Wood, 1968) have noted that, as a result 

of decreased mining activity and stricter waste-disposal laws, sediment 

discharges in tributaries of the Susquehanna River from areas producing anthracite coal have decreased. Other investigators (Wolman 

and Schick, 1967; Vice, Guy, and Ferguson, 1969) have shown that 

highway and urban construction increases the sediment discharge of
F22 HYDROLOGIC EFFECTS OF LAND USE

streams. Guy and Ferguson (1963) have shown, for example, that 

1 sq mi of urbanization can contribute a sediment discharge equivalent 

to that from 100 sq mi of rural land in the Piedmont terrain of the 

Potomac Eiver basin.

In the Susquehanna basin, problems of excessive sedimentation from 

urban and highway construction occur locally. However, the area 

affected is generally small when compared with the drainage area of 

the main tributaries. The decreasing sediment yields observed in the 

Susquehanna and some of its tributaries could be offset in the future 

by the high yields associated with urban and highway construction.

SUMMARY AND CONCLUSIONS

Under existing land-use and average-runoff conditions, the Susquehanna Eiver transports about 3.0 million tons of sediment annually 

(110 tons per sq mi). However, only about 1.8 million tons of sediment enters the head of the Chesapeake Bay, because some sediment 

is trapped behind the power dams of the lower Susquehanna. Measured sediment yields range from 40 tons per sq mi to 440 tons per 

sq mi. The lowest sediment yields in the basin are from the Susquehanna main stem in the glaciated part of the Appalachian low 

plateau, the Valley and Eidge, and parts of the heavily forested 

Appalachian high plateaus. The highest yields are from parts of the 

Chemung Eiver basin in the glaciated section of the Appalachian low 

plateau, the anthracite coal region, and the Piedmont. If sediment 

could significantly affect a water-resources project in the Appalachian 

low plateau, in the anthracite coal region, or in the Piedmont, 

thorough sediment studies should be undertaken.

Geology in the Valley and Eidge appears to be a variable that 

affects sediment yields, because basins containing more than 25 percent limestone have significantly lower sediment yields than basins 

having identical land use but containing less or no limestone. No 

relations were developed for the relatively small area of the Piedmont 

within the Susquehanna because sufficient sites were not available.

The Piedmont streams, as well as the main stems of Conodoquinet 

and Yellow Breeches Creeks, have significant suspended-sediment 

concentrations most of the time. Generally, other streams in the 

Susquehanna basin have such concentrations only during, and for a 

few days after, storm-runoff events.

The average particle-size composition of sediments transported by 

streams in each physiographic province is fairly consistent, being 

about 10 percent sand, 50 percent silt, and 40 percent clay.

Generally, reservoir sedimentation is a minor problem for all 

reservoirs. A few severe problems occur in reservoirs having low
STREAM SEDIMENTATION, SUSQUEHANNA BIVEB BASIN F23

capacity-inflow ratios, in reservoirs constructed in areas having high 

sediment yields, and in reservoirs subjected to temporarily excessive 

sedimentation from urban and highway construction.

Continuous sediment records for Juniata River at Newport, Pa., 

indicate that there has been a 25-percent reduction in the sediment 

discharge from the Juniata Eiver basin between 1951 and 1967. Considerable evidence exists to show that, owing to the decline of 

anthracite coal mining and processing, there has also been a downward trend of sediment discharge for the main stem of the Susquehanna Eiver. In the future, the high sediment yields associated 

with urbanization may offset this present downward trend in sediment 

discharge.

SELECTED REFERENCES

Anderson, P. W., 1963, Variations in the chemical character of the Susquehanna River at Harrisburg, Pennsylvania: U.S. Geol. Survey Water-Supply

Paper 1779-B, 17 p. 

Biesecker, J. E., Lescinsky, J. B., and Wood, C. B., 1968, Water resources of the

Schuylkill Biver basin: Harrisburg, Pa., Pennsylvania Dept. Forests and

Waters, Water Resources Bull. 3, 198 p. 

Bondurant, D. C., and Livesey, R. H., 1965, Sedimentation aspect in recreation

planning: Am. Soc. Civil Engineers Proc., v. 91, no. HY5, pt. 1, p. 51-64. 

Brune, G. M., 1953, Trap efficiency of reservoirs: Am. Geophys. Union Trans.,

v. 34, no. 3, p. 407-418. 

Culbertson, J. K., 1957, Progress report of hydrology and sedimentation in

Bixler Bun, Corey Creek, and Elk Bun watersheds, Pennsylvania: U.S.

Geol. Survey open-file report, 44 p. 

Fenneman, N. M., 1938, Physiography of Eastern United States: New York, McGraw-Hill Book Co., 714 p. 

George, J. B., 1963, Sedimentation in the Stony Brook basin, New Jersey,

1956-59 : U.S. Geol. Survey open-file report, 71 p.

Guy, H. P., and Ferguson, G. E., 1963, Sediment in small reservoirs due to urbanization: Am. Soc. Civil Engineers Trans., v. 128, no. 3457, p. 982-992. 

Hubbell, D. W, 1964, Apparatus and techniques for measuring bedload: U.S.

Geol. Survey Water-Supply Paper 1748, 74 p. 

Johnson, E. C., 1960, Climates of the States, New York, in Climatography of

the United States: U.S. Dept. Commerce, Weather Bur., no. 60-30, 20 p. 

Jones, B. L., 1964, Sedimentation and land use in Corey Creek and Elk Bun

basins, Pennsylvania, 1954-60: U.S. Geol. Survey open-file report, 112 p. 

 1966, Effects of agricultural conservation practices on the hydrology of

Corey Creek basin, Pennsylvania, 1954-60: U.S. Geol. Survey Water-Supply Paper 1532-C, 55 p. 

Kauffman, N. M., 1960, Climates of the States, Pennsylvania, in Climatography

of the United States: U.S. Dept. Commerce, Weather Bur., no. 60-36, 20 p. 

Keller, F. J., and Gilbert, B. K., 1966, The occurrence and characteristics of

fluvial sediment in the Genesee Biver basin a reconnaissance: U.S. Geol.

Survey open-file report, 34 p. 

Levin, Paul, and Smith, D. I., 1954, A modern river coal recovery operation

on the Susquehanna Biver: Baltimore, Md., Pennsylvania Water & Power

Co., 29 p.
F24 HYDROLOGIC EFFECTS OF LAND USE

McCarren, E. F., Wark, J. W., and George, J. R., 1964, Water quality of th* 

Swatara Creek basin, Pennsylvania: U.S. Geol. Survey open-file report, 

88 p.

O'Bryan, Deric, and McAvoy, R. L., 1966, Gunpowder Falls, Maryland: U.S' 

Geol. Survey Water-Supply Paper 1815, 90 p.

Pennsylvania Department of Mines and Mineral Industries, 1964, Anthracite 

Coal Division, 1963 annual report: Harrisburg, Pennsylvania Dept. Mines 

and Mineral Industries, p. 24-25.

Pennsylvania Power & Light Co., 1961, 1961 Holtwood River bed silt survey, 

Holtwood Dam to Shenk's Ferry: Holtwood, Pa., Pennsylvania Power & 

Light Co., 85 p.

Pennsylvania Topographic and Geologic Survey, 1964, Physiographic province^ 

of Pennsylvania: Pennsylvania Topog. and Geol. Survey map 13.

Schuleen, E. T., and Higgins, C. R., 1953, Analysis of suspended-sediment measurements for Lake Clarke, inflow and outflow, 1948-53: Holtwood, Pa., 

Pennsylvania Power & Light Co. rept. 970, 73 p.

Stuart, W. T., Schneider, W. J., and Crooks, J. W., 1967, Swatara Creek basin 

of southeastern Pennsylvania an evaluation of its hydrologic system: 

U.S. Geol. Survey Water-Supply Paper 1829, 80 p.

U.S. Department of Agriculture, 1969, Summary of reservoir sediment deposition surveys made in the United States through 1965: U.S. Dept. Agriculture Misc. Pub. 1143, 64 p.

Vice, R. B., Guy, H. P., and Ferguson, G. E., 1969, Sediment movement in an 

area of suburban highway construction, Scott Run basin, Fairfax County, 

Virginia, 1961-1964: U.S. Geol. Survey Water-Supply Paper 1591-E, 41 j.

Wark, J. W., and Hall, G. R., 1959, Appendix H, Fluvial sediment, in Report or 

the comprehensive survey of the water resources of the Delaware Rive:- 

basin : U.S. Army Corps of Engineers, Philadelphia Dist., 40 p.

Wark, J. W., and Keller, F. J., 1963, Preliminary study of sediment sources 

and transport in the Potomac River basin: Washington, D.C., Interstate 

Comm. on the Potomac River Basin Tech. Bull. 1963-11, 28 p.

Wark, J. W., Keller, F. J., and Feltz, H. F., 1961, Reconnaissance of sedimentation and chemical quality of surface water in the Potomac River basin, in 

Appendix H, Sediment Studies, Volume VII of Potomac River basin report: 

U.S. Army Corps of Engineers, Baltimore Dist., [1963].

Williams, K. F., and George, J. R., 1968, Preliminary appraisal of stream sedimentation in the Susquehanna River basin: U.S. Geol. Survey open-file 

report, 73 p.

Wolman, M. G., 1954, A method of sampling coarse river-bed material: Am 

Geophys. Union Trans., v. 35, no. 6, p. 951-956.

Wolman, M. G., and Schick, A. P., 1967, Effects of construction on fluvial sediment, urban and suburban areas of Maryland: Washington, D.C., Water 

Resources Research, v. 3, no. 2, p. 451-464.

U.S. GOVERNMENT PRINTING OFFICE: 1972 O 443-561