Time of Travel of Water

in the Potomac River 

Cumberland to Washington

GEOLOGICAL SURVEY
Time of Travel of Water

in the Potomac River 

Cumberland to Washington

By James K. Searcy and Luther C Davis, Jr.

GEOLOGICAL SURVEY CIRCULAR 438

Washington, D. C. 

7967
United States Department of the Interior

STEWART L. UDALL, SECRETARY

Geological Survey

THOMAS B. NOLAN, DIRECTOR

Free on application to the U.S. Geological Survey, Washington 25, D. C.
CONTENTS

Page Page

Abstract.____________________________ 1 Application with river stage

Introduction. _________________________ 1 known Continued

Computations ________________________ 2 Time of travel between other points __ 8

Control points__--_--_-----_------_- 2 Time of travel to Washington ________ 8

Discharge _____-___-______--_-_____ 3 Shortest time of travel-_-_-_--__---_ 8

Mean velocity ______________________ 4 Refinement by monitoring ___________ 8

Time of travel between control points. 4 Application based onflow characteristics. 10

Application with river stage known _____ 6 Summary---------------------------- 12

Time of travel from Cumber land _____ 6 References __________________________ 12

ILLUSTRATIONS

Page 

Figure 1. Location of stream-gaging stations on the Potomac River upstream from

Washington, D. C ________________________________________________________ 2

2. Correlation of monthly discharge, Potomac River, water years 1946 50 _________ 3

3. Relation of mean velocity and discharge, Potomac River at Point of Rocks, Md___ 5

4. Stage-discharge relation, Potomac River near Washington, D. C., 1957___________ 6

5. Time-of-travel chart, Potomac River, Cumberland, Md., to Washington, D. C.,

for selected stages and discharges near Washington _________________________ 7

6. Relation of stage and discharge near Washington, D. C., to time of travel from

selected upstream points _________________________________________________ 9

7. Duration curve of daily flow, Potomac River near Washington, D. C., 1931 58____ 10

8. Frequency of daily flow, by months, Potomac River near Washington, D. C.,

1931-58_______________________________________________________________ 11

TABLES

Page 

Table 1. Stream-gaging stations on Potomac River in downstream order-________________ 2

2. Computation of time of travel, Potomac River _____--___--_____--__-_--_-__-__ 4

III
Time of Travel of Water in the Potomac River 

Cumberland to Washington

By James K. Searcy and Luther C. Davis, Jr.

ABSTRACT

This report introduces a graphical procedure for-estimating the time required for water to travel down the Potomac 

River in the reach extending from Cumberland, Md., to 

Washington, D.C. The time of travel varies with the flow of 

the river; so the stage of the river at the lower end of the 

reach the gaging station on the Potomac River near Washington, D.C. is used as an index of flow. To develop the 

procedure, the reach between Cumberland and Washington 

was divided into five subreaches, delineated by six gaging 

stations. The average of the mean velocities of the river at 

adjacent gaging stations was used as the mean velocity in 

the intervening subreach, and a unit mass of water was assumed to travel at a rate equal to the mean velocity of the 

river.

A statistical analysis of possible variations in travel 

time between Cumberland and Washington indicated that the 

shortest travel time corresponding to a given stage near 

Washington would be about 80 percent of the most probable 

travel time.

The report includes a flow-duration curve and a flowfrequency chart for use in estimating discharge at the gaging 

station near Washington and subsequently the travel time of 

Potomac River water without knowledge of stage. The flowduration curve shows the percentage of time during which 

specified discharges were equaled or exceeded in the past, 

and it can be used to predict future flow in connection with 

long-range planning. The flow-frequency chart shows the 

time distribution of flow by months and can be used to 

make a more nearly accurate estimate of discharge in any 

given month than could be made from the flow-duration 

curve.

The method used to develop the time-of-travel charts is 

described in sufficient detail to make it usable as a guide 

for similar studies on other rivers, where the velocity of 

flow is relatively unaffected by dams and pools in the reach 

being studied.

INTRODUCTION

This report introduces graphical procedures by which the time of travel of water between any two points on the Potomac River in 

the reach between Cumberland, Md., and 

Washington, D.C., can be estimated, provided 

the river stage near Washington is known. If 

the stage near Washington is not known, a 

special flow-frequency chart can be used to 

estimate the probable discharge near Washington at any time of year. The corresponding

stage to use in the time-of-travel chart can 

be obtained from the stage-discharge relation 

curve. A flow-duration curve is presented 

for use in predicting the percent of time during which various flows will occur in the 

future. This curve would be useful for longrange planning.

The time-of-travel procedures in this report can be used to estimate the arrival time 

of possible contamination from an upstream 

source, because dissolved contamination can 

be assumed to travel at the same speed as a 

unit mass of water. An estimate of the time 

for contamination to travel down the river 

helps water users downstream plan any necessary action. Furthermore, the length of 

time organic pollution is in transit affects the 

oxygen requirements and thus is important in 

quality-of-water studies. Contamination that 

moves as suspended material is outside the 

scope of this report, because it travels more 

slowly than the water and dissolved contamination.

The JPotomac River (fig. 1) is formed by the 

confluence of its North and South Branches, 

21 miles downstream from Cumberland, Md. 

It flows east and southeast for 287 miles to 

Chesapeake Bay, passing Washington, D.C., 

186 miles downstream from Cumberland. The 

drainage area at the mouth is 14,500 square 

miles, of which about 11,600 is drained by the 

nontidal section of the river upstream from 

Washington. The reach of the river between 

Cumberland and Washington, which includes 

a 21-mile section of the North Branch from 

Cumberland to the confluence with the South 

Branch, is relatively free of dams. Thus the 

method used to develop the time-of-travel 

charts is applicable to other rivers where the 

velocity of flow is only slightly affected by 

dams and pools in the reach being studied.
TIME OF TRAVEL OF WATER IN THE POTOMAC RIVER, CUMBERLAND TO WASHINGTON

78°

39°

MARYLAND

Point of Rocks >*^

^L 

Washington, D. C\y

IS 30 MILES ""

Figure 1. Location of stream-gaging stations on the Potomac River upstream from Washington, D. C.

COMPUTATIONS

CONTROL POINTS

The reach of the river used in this study 

was divided into five subrcaches, delineated 

by six stream-gaging stations. Data gathered

at the gaging stations are available^ from 

which discharges and velocities at the station 

sites can be computed. The gaging-station 

sites, therefore, are ideal control points for 

computing the time of travel of water in intervening subreaches. Table 1 lists the six 

stream-gaging stations in the study reach.

Table 1. Stream-gaging stations on the Potomac River in downstream order

Number on 

figure 1

1.. .........

2...... .....

q

4...........

6...........

Location

Near Cumberland, MdJ__________

At Paw Paw W Va

At Hancock, Md ________________

At Shepherdstown, W. Va ________

At Point of Rocks, Md__ _________

Near Washington, D. C_ __________

Miles downstream from 

Cumberland

0

28.1

66.0

121.0

145.1

186.1

T"^T*a 1 KIQ Cff*

area 

(sq mi)

875

3,109

4 073

5,936

9,651

11,560

Average c

Period of 

record

1929-56

1938-56

1932-56

1928-53

1896-1956

1930-56

liseharge

Cubic feet 

oer second

1,219

3,152

4,083

5,804

9,378

11,260

1North Branch Potomac River.

Note. River mileages from Water-Supply Paper 800. Drainage areas and average discharges 

from Water-Supply Paper 1432, except for discontinued station at Shepherdstown, which is from 

Water-Supply Paper 1272.
COMPUTATIONS

The Geological Survey stream- gaging station near Washington is used as the index 

station in this study. It is located above tidewater on the Virginia side of the river, 2j 

miles upstream from Chain Bridge. In addition, the Weather Bureau operates a special 

recorder for use in predicting river stages. 

From this recorder, the river stage at any 

time can be determined automatically by coded 

message over a telephone.

corresponds to a given discharge at a given 

control point, correlations were made between 

streamflow records at successive control 

points for the 5 years, 1946 50, as follows:

(6) Washington and (5) Point of Rocks 

(5) Point of Rocks and (4) Shepherdstown 

(4) Shepherdstown and (3) Hancock 

(3) Hancock and (2) Paw Paw 

(2) Paw Paw and (1) Cumberland

DISCHARGE

To determine the discharge at the next upstream control point, which most probably

The correlation curve for Washington and 

Point of Rocks is shown in figure 2. It was 

used to find the most probable discharge at 

Point of Rocks corresponding to a given

100

Relation curve -

X

ge FE

yland, drai CUBIC OF 

!- 

O

n> V)

s. i 

II

o: o

 5 f

*^ 

.E Z

 £ i

? 8 

I $

? »

co O 

I

^

345 10

DISCHARGE, IN THOUSANDS OF CUBIC FEET PER SECOND 

Potomac River near Washington, D. C., drainage area 11,560 square miles

100

Figure 2. Correlation of monthly discharge, Potomac River, water years 1946 50.
TIME OF TRAVEL OF WATER IN THE POTOMAC, RIVER, CUMBERLAND TO WASHINGTON

discharge near Washington. For example, 

when the discharge near Washington is 3,100 

cfs (stage, 2.5 feet) the most probable discharge at Point of Rocks is 2,650 cfs.

The procedure for making correlations between gaging stations and for computing the 

standard error of estimate (shown as Se in 

figure 2) has been explained bySearcy (1960).

MEAN VELOCITY

To utilize the relation of mean velocity to 

discharge, curves of relation were developed 

for each control point by plotting the discharge 

against the mean velocity for each of the many 

discharge measurements that have been made 

at each gaging station. The relation curve 

for the control point at Point of Rocks is shown 

in figure 3.

It is assumed in this study that the average 

cross section in a subreach is the average of 

the measured cross sections at the two adjacent control points. Therefore, the mean velocity in a subreach is the average of the mean 

velocities at the two control points. Thus, 

with the discharge estimated as described in 

the preceding section, the mean velocity in 

each reach can be computed.

TIME OF TRAVEL BETWEEN CONTROL POINTS

The computations for time of travel in the 

subreaches Point of Rocks (5) to Washington 

(6) and Shepherdstown (4) to Point of Rocks (5) 

areshownin table 2. The figures in this table

were obtained as follows: Stages (column a) 

were selected for the critical point (Washington) to provide a suitable spacing of lines on 

the time-of-travel chart. (See fig. 5.) The corresponding discharges (column b) were taken 

from the stage-discharge relation curve 

(fig. 4).

The mean velocities (column c) that correspond to the discharges (column b) were taken 

from the mean velocity-discharge relation for 

Washington. This relation is similar to that 

shown for Point of Rocks. (See fig. 3.)

The most probable discharges at control 

point 5, Point of Rocks (column d), corresponding to the discharges at the critical point, 

Washington (column b), were taken from the 

correlation curve of figure 2. The corresponding mean velocities (column e) were 

taken from figure 3.

The mean velocities in subreach 5 to 6 

(column f) are the average of the corresponding mean velocities at the ends of the subreach 

(columns c and e). The length of the subreach 

(column g) is the difference in river miles below Cumberland of the control points at the 

ends of the subreach. (See table 1.)

The time of travel in hours (column h) was 

computed by dividing the distance by the mean 

velocity as follows:

Travel time in hours

_____Distance in miles x 5,280_______

Mean velocity (in feet per second) JK 3,600

Table 2. Computations of time of travel, Potomac River

Stage 

(feet) 

(a)

2.0____

2.3____

2.5____

3.0 __ .

3.5_...

4 _____

5 ____.

6 _____

9 _____

12 __ .

Washington (6)

Discharge 

(cfs) 

(b)

1,810

2,470

3,060

4,940

7,430

10,300

17,100

26,400

63,200

108,000

Mean

velocity 

(fps) 

(c)

0.77

1.05

1.32

2.16

3.10

4.15

6.35

8.70

12.40

14.50

Point of 

Rocks (5)

Discharge 

(cfs) 

(d)

1,510

2,060

2,550

4,120

6,200

8,600

14*300

22,000

52,800

90,200

Mean

velocity 

(fps)

(e)

1.13

1.24

1.32

1.55

1.79

2.10

2.59

3.06

4.13

4.77

Subreach (5) to (6)

Mean

velocity 

(fps)

to

0.95

1.14

1.32

1.86

2.44

3.12

4.47

5*88

8.26

9.64

Distance 

(miles) 

(g)

41.0

41.0

Time

of 

travel 

(hours) 

(h)

63.3

52.7

45.6

32.3

24.6

19.3

13.5

10.2

7.3

6.2

Shepherdstown (4)

Discharge 

(cfs) 

(i)

685

980

1,250

2,200

3,550

5,200

9,400

14,500

34,500

59,500

Mean

velocity 

(fps)

(JJ

0.34

.41

.48

.72

1.05

1.38

2.05

2.69

4.29

5.51

Subreach (4) to (5)

Mean

velocity

(fps) 

(k)

0,74

.82

.90

1.14

1.42

1.74

2.32

2.88

4.21

5.14

Distance 

(miles) 

(1)

24.1

24.1

Time

of 

travel 

(hours) 

(m)

47.8

43.1

39.3

31.0

24.9

20.3

15.2

12.3

8.4

6.9
COMPUTATIONS

100,000

0

1

LU 

CO

<r 10,000 

% 8000

ft 6000

UO

m 4000 

^ 3000

0 2000 

cr

<

1 

° 1000

800 

700 

600

400 

300

200 

inn

^

-/- /

i i rf 

 /- p±-/-

/

/

/

/

/ /

s*

/ /

/

y/

/

X

/

^

x

_S

s

/

1234

MEAN VELOCITY, IN FEET PER SECOND

Figure 3. Relation of mean velocity and discharge, Potomac River at Point of Rocks, Md.
TIME OF TRAVEL OF WATER IN THE POTOMAC RIVER, CUMBERLAND TO WASHINGTON

11

10

20 40 60

DISCHARGE, IN THOUSANDS OF CUBIC FEET PER SECOND

80 100

Figure 4. Stage-discharge relation, Potomac Rivet near Washington, D. C., 1957.

The time of travel in subreach 4 to 5 was 

determined by using a relation between discharges at Point of Rocks and Shepherdstown 

to obtain the most probable discharge at Shepherdstown corresponding to the discharge at 

Point of Rocks listed in column d. The mean 

velocity (column j) at Shepherdstown (control 

point 4) was then averaged with the mean velocity (column e) at Point of Rocks (control 

point 5) to obtain the mean velocity in the subreach. Then, by introducing the length of "the 

subreach (24.1 miles), the time of travel in 

the subreach was determined. The times of 

travel in succeeding subreaches were computed in similar manner.

APPLICATION WITH RIVER STAGE KNOWN

TIME OF TRAVEL FROM CUMBERLAND

A time-of-travel chart (fig. 5) for the Potomac River near Washington was plotted by 

cumulating the computed times of travel. The 

times of travel for each selected stage near 

Washington were cumulated for each subreach 

from Cumberland to Washington and the cumulations were plotted against the river miles 

downstream from Cumberland. The plotted 

points for each selected stage were connected 

by straight lines.
APPLICATION WITH RIVER STAGE KNOWN

360

340

320

300

418 hrs 

2.0ft 1810 cfs

CO

ca 

O

<

s

CL 

LU 

CO

O

1

2.3ft 

2470 cfs

2.5ft 

3060 cfs

Example

3.0ft 

4940 cfs

3.5ft 

7430 cfs

4.0ft 

10,300 cfs

5.0ft 

17,100 cfs

6.0ft 

26,400 cfs

9.0ft 

63,200 cfs

12.0ft 

108,000 cfs

o 

d

Q

8LU

LU 

Q.

LU 

U.

O 

00

z> 

o

1

'0 20 40 60 80 100 120 140 160 180 

DISTANCE DOWNSTREAM FROM CUMBERLAND, MARYLAND, IN MILES

Figure 5. Time-of-travel chart, Potomac River, Cumberland, Md., to Washington, D. C., for selected stages and discharges

near Washington.
8 TIME OF TRAVEL OF WATER IN THE POTOMAC RIVER, CUMBERLAND TO WASHINGTON

The resulting chart (fig. 5) shows the average time, in hours, for water to travel from 

Cumberland to points along the river at various river stages near Washington. For example, when the stage on the gage near Washington is 3.0 feet, the average time of travel 

of the water mass from Cumberland to Washington is 226 hours, and from Cumberland to 

Hancock, 76 hours.

TIME OF TRAVEL BETWEEN OTHER POINTS

The time of travel of water between other 

points on the Potomac River in the reach between Cumberland and Washington also can be 

obtained from the time-of-travel chart (fig. 5). 

For example, the average time of travel of 

water from Hancock to Point of Rocks when 

the stage is 3.0 feet near Washington is obtained from the time-of-travel chart as 

follows:

Time of travel 

Hours

Cumberland to Point of Rocks = 194 

Cumberland to Hancock = 76 

Hancock to Point of Rocks = 118

TIME OF TRAVEL TO WASHINGTON

The relation curves shown in figure 6, which 

are based on the same data as those in figure 5, 

are presented for convenience in estimating 

the time of travel from upstream points to 

Washington. They indicate the average travel 

time at any given stage at Washington.

The curves in figure 6 can also be used to 

interpolate between the curves shown in figure 5. For example, the curves in figure 6 

show that with a stage of 4.5 feet at Washington, the average travel time from Cumberland 

to Washington is 116 hours and from Hancock 

to Washington is 74 hours. The difference of 

42 hours, which is the travel time from Cumberland to Hancock, can be plotted on figure 5 

between the 4-foot and the 5-foot lines at the 

Hancock mileage to define the curve for 4.5 

feet.

SHORTEST TIME OF TRAVEL

Half the time the water mass will travel 

faster than it would under average conditions.

Statistical analysis using the methods described by Steacy (1961, p. 7 ) indicate that, 

except in exceedingly rare cases, the shortest 

time of travel that could result from unusual 

conditions within the reach would be about 80 

percent of the average time of travel. In this 

method, discharge corresponding to 3 times 

the standard error of estimate was added to 

the most probable discharge to obtain the 

maximum discharge that would be present 

in all but the extreme cases. The increased 

discharge gave faster mean velocities and 

shorter travel time for the given stage near 

Washington.

In this report, the maximum concentration 

of possible contamination is assumed to be at 

the center of the contaminated mass, as the 

effect of turbulence within the flowing mass 

and dilution of the mass with inflow from 

tributaries is not presently known. It is known, 

however, that dispersion caused by turbulence 

and by nonuniform flow tends to spread the 

contamination so that small amounts arrive 

in advance of the maximum contamination, 

and that the dilution effect of uncontaminated 

inflow tends torecJuce the concentration of the 

contaminant. The behavior of these variables 

and the behavior of contaminated sediment, 

which moves more slowly than dissolved pollution, is being studied by the Geological 

Survey and others.

REFINEMENT BY MONITORING

The most probable time of travel to Washington for a contaminant introduced accidentally into the Potomac River can be read from 

the time-of-travel chart (fig. 5), and the shortest probable time of travel can be estimated 

by using 80 percent of that figure. Nevertheless, the progress of the contaminated mass 

downstream would doubtless be traced by field 

examination. The observed time of arrival of 

the contamination front at various points could 

be used to refine the prediction of the arrival 

time of contamination at critical points.

For example, if a contaminant is introduced 

accidentally at Cumberland when the stage 

near Washington is 3.0 feet, the time of travel 

from Cumberland to Washington indicated by 

figure 5 is 226 hours and from Cumberland to 

Hancock, 76 hours. The actual time of travel 

to Hancock, however, is found to be 90 hours 

by field observation. The initial estimate of
APPUCATION WITH RIVER STAGE KNOWN

12

100 150 200 250 300 350 400 450 

AVERAGE TIME OF TRAVEL TO WASHINGTON, D. C., IN HOURS

Figure 6. Relation of stage and discharge near Washington, D. C., to time of travel from selected upstream points.
10 TIME OF TRAVEL OF WATER IN THE POTOMAC RIVER, CUMBERLAND TO WASHINGTON

travel time to Washington can now be improved in the following manner. The observed 

time to Hancock is plotted on the time-of - 

travel chart (fig. 5). A revised time-of-travel 

line is then drawn from Cumberland- to Hancock based on the observed time, which is 

fourteen twenty-fourths of the distance from 

the 3.0-foot line to the 2.5-foot line. By projecting the revised line downstream at the 

same ratio, a revised time-of-travel estimate 

from Cumberland to Washington is then found 

to be 273 hours.

APPLICATION BASZD ON FLOW CHARACTERISTICS

Use of the time-of-travel chart is not restricted to times when the river stage near 

Washington is known, because flow characteristics of the river at the gaging-station site 

near Washington provide a means of using the 

time-of-travel charts (figs. 5 and 6) without 

knowledge of stage.

The flow-duration curve (fig. 7), which 

shows the percentage of time specified

100,000

C 10,000

1000

\

\

\

\

\

\

\

0.01 0.1 0.5 1 2 5 10 20 30 40 50 60 70 80 90 95 98 99 99.5. 99.9 99.99 

PERCENT OF TIME INDICATED DISHARGE WAS EQUALED OR EXCEEDED

Figure 7. Duration curve of daily flow, Potomac River near Washington, D. C., 1931 58.
APPLICATION BASED ON FLOW CHARACTERISTICS 11

discharges were equaled or exceeded in the 

period 1931 58, canbe used topredict the percentage of time various discharges will exist 

in the future. This information is useful in 

long-range planning with regard to stream pollution and alternate water supplies. For example, the flow-duration curve (fig. 7) shows

that the discharge near Washington is less than 

6,500 cfs during 50 percent of the time,, and 

figure 4 shows that this discharge is equivalent 

to a stage of 3.3 feet. Then, by entering the 

time-of-travel chart (fig. 6) with a stage of 3.3 

feet, it is found that the time of travel'of water 

from Cumberland to Washington is 190 hours

100,000

a:

LJ

o.

o 

m

o

I

10,000

1000

7 i

7

L

V \\

V \

\

v> __ *,^

L\ z z

Maxim im day

10

25 

-Mean75

90

Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec.

Figure 8. Frequency of daily flow by months, Potomac River near Washington, D. C., 1931-58.
12 TIME OF TRAVEL OF WATER IN THE POTOMAC RIVER. CUMBERLAND TO WASHINGTON

or more during 50 percent of the time. The 

discharge at the 50-percent point on the flowduration curve is the median discharge and the 

corresponding stage of 3.3 feet is therefore 

the median stage at the gage near Washington.

The flow-frequency chart (fig. 8), also based 

on 28 years of record, was developed by 

cumulating, by months, the days when the discharge was within specified limits. When a 

reading from the river-stage gage near Washington is not available, the flow-frequency 

chart (fig. 8) can be used to make a more accurate estimate of discharge in any given 

month than could be made from the flowduration curve (fig. 7) and consequently to 

make a more accurate estimate of the time of 

travel of Potomac River water. For example, 

the flow-frequency chart (fig. 8) shows that 

the median discharge in March is 15,000 cfs 

and in October, 2,500 cfs, and figure 4 shows 

the corresponding stages to be 4.7 feet and 

2.3 feet. From the time-of-travel chart 

(fig. 6), the corresponding times of travel are 

110 hours and 345 hours, representing the 

median times of travel from Cumberland to 

Washington in March and October, respectively.

SUMMARY

For the purpose of this report the reach of 

the Potomac River from Cumberland to Washington was divided into five subreaches and 

cross sections at the ends of the subreaches 

were determined. The cross sections were 

developed from soundings copied from discharge measurements that are made regularly 

at gaging stations near the ends of the subreaches. These gaging stations were used as 

control points for estimating discharge and 

velocity. The discharges at each gaging station corresponding to various stages and discharges at the gage near Washington were determined from discharge correlation curves.

The velocity at each gaging station was obtained from a discharge-velocity relation 

based on discharge measurements, and the 

average velocity within each subreach was 

computed as the average of the velocities at 

the ends. Based on this information, the times 

of travel of specific quantities of water in the 

reach from Cumberland to Washington, corresponding to the various stages near Washington, were computed and used to prepare 

time-of-travel charts.

When information is available from field 

observations of change in water quality, a 

more accurate estimate of travel time can be 

made by revising the time-of-travel charts.

A duration curve and a frequency chart are 

provided for use in making estimates of travel 

time when information about the stage near 

Washington cannot be obtained or when estimates of future travel times are desired.

REFERENCES

Searcy, J. K., 1960, Graphical Correlation of 

gaging-station records, Manual of hydrology, pt. 1, General surface water techniques: 

U. S. Geol. Survey Water-Supply Paper 

1541-C, p. &7-100.

Steacy, R. E., 1961, Time of travel of water 

in the Ohio River, Pittsburgh to Cincinnati: 

U.S. Geol. Survey Circ. 439.

U. S. Geological Survey, 1937, The floods of 

March 1,936, pt. 3, Potomac, James and 

Upper Ohio Rivers: U. S. Geol. Survey 

Water-Supply Paper 800.

____1956, Surface water supply of the United 

States, 1953, pt. 1-B, North Atlantic slope 

basins, New York to York River: U.S. Geol. 

Survey Water-Supply Paper 1272.

____1959, Surface water supply of the United

States, 1956, pt. 1-B, North Atlantic slope 

basins, New York to York River: U.S. Geol. 

Survey Water-Supply Paper 1432.

INT.DUP,,D,C.61-«»«»3