Low-Flow Frequency Curves 

for Selected Long-Term 

Stream-Gaging Stations 

in Eastern United States

' GEOLOGICAL SURVEY WATER-SUPPLY PAPER 1669-G
Low-Flow Frequency Curves 

for Selected Long-Term 

Stream-Gaging Stations 

in Eastern United States

By C. H. HARDISON and R. O. R. MARTIN

CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES 

GEOLOGICAL SURVEY WATER-SUPPLY PAPER 1669-G

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1963
UNITED STATES DEPARTMENT OF THE INTERIOR 

STEWART L. UDALL, Secretary

GEOLOGICAL SURVEY 

Thomas B. Nolan, Director

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

Washington 25, D.C.
CONTENTS

Page 

Abstract__ _____________________________________________________ Gl

Introduction._____________________________________________________ 1

Method of analysis._______________________________________________ 3

Description of tables and figures___--_--___---_-_-___-_---__---__---_ 4 

Discussion of results _______________________________________________ 6

ILLUSTRATIONS

Page 

FIGURE 1. Location of stream-gaging stations and identification of

reference periods._____________________________________ G2

2-13. Low-flow frequency curves of 7-, 30-, 120-, and 274-day data 

for 

2. First 10 stations listed in table !____________________ 19

3. Last nine stations listed in table !___________________ 20

4. Stations listed in table 2_.________________________ 21

5. First eight stations listed in table 3_________________. 22

6. Second group of stations listed in table 3_____________ 23

7. Third group of stations listed in table 3_-__-_---__-_- 24

8. Last three stations listed in table 3_-___---_---__--_. 25

9. First seven stations listed in table 4__________________ 26

10. Second group of stations listed in table 4_____________ 27

11. Third group of stations listed in table 4______________ 28

12. Fourth group of stations listed in table 4_____________ 29

13. Last six stations listed in table 4____________________ 30

in
IV CONTENTS

TABLES

Page

TABLES 1-4. Magnitude and frequency of annual low flow for selected 

long-term stream-gaging stations in:

1. Maryland, New York, Pennsylvania, and Virginia,

1913-57.___________________________ G7

2. North Carolina, 1897-1954_________________ 10

3. Alabama, Arkansas, Florida, Georgia, Louisiana, 

Mississippi, Oklahoma, South Carolina, and 

Texas, 1929-57_______________________ 11

4. Illinois, Indiana, Kentucky, Michigan, Missiuri,

Ohio, Tennessee, and West Virginia, 1924-55. _ _ 15
CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

LOW-FLOW FREQUENCY CURVES FOR SELECTED LONGTERM STREAM-GAGING STATIONS IN EASTERN UNITED 

STATES

By C. H. HARDISON and R. O. R. MARTIN

ABSTRACT

Curves showing the magnitude and frequency of annual low flow at 85 streamgaging stations located in 17 States east and 5 States west of the Mississippi River 

have been smoothed and adjusted to one of four long-term periods. TTiey are 

presented to show the similarity and dissimilarity of curves even in the same 

State and to provide background information for studies of the statistical properties of low-flow frequency curves and for studies of the relation betweer hydrologic environment and low flow. The results are presented as greatly reduced 

graphs to facilitate comparison and are summarized in tables from which expanded graphs can be plotted.

INTRODUCTION

Low-flow frequency curves, such as those presented in this report, 

are useful in planning the development of surface water resources. 

They show the magnitude and frequency of annual minimum f ow for 

periods of given length and can be used to estimate the amount of 

storage required to deliver the average flow shown by the curves.

Each curve in this report has been smoothed and adjusted to 

represent flow characteristics during one of four long-term periods. 

The curves were initially constructed to facilitate the extension of 

short-period records of low-flow frequency to a longer time period and 

have been so used in several States. They can also be used to show 

representative shapes that are useful in studying the statistical 

properties of low-flow frequency curves and in studying their relation 

to hydrologic parameters. This report was prepared to aid in the 

prosecution of these secondary objectives.

The gaging stations used in this report are distributed throughout 

most of the States east of the Mississippi River and south of the Great 

Lakes and in the States of Arkansas, Louisiana, Missouri, Oklahoma,

Gl
G2 CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

and Texas. Four different long-term periods were used as reference 

periods because of the variation in length of the streamflow records 

available in different parts of the area. The location of the stations 

and the identification of reference periods are shown in figure 1.

This report describes the method of analysis and th<>, tabular and 

graphical presentation of results. A brief discussion of the results 

is followed by the tables and graphs (figs. 2-13).

Station referred to one reference period

Station referred to one or more 

reference period

Station Primary reference

No. period

1-19 1913-57

20-24 1897-1954

25-53 1929-57

54-85 1924-55

FIGURE 1, Location of stream-gaging stations and identification of reference periods.
LOW-FLOW FREQUENCY CURVES, EASTERN UNITED STATF* G3 

METHOD OF ANALYSIS

Most of the gaging stations for which low-flow frequency curves 

are given in this report have records that cover the entire long-term 

period used as a reference period. For a few of these stations, records 

of periods other than the long-term reference period were used as a 

guide to the shape of the curves. For gaging stations Hiere the 

period of record does not cover the full reference period, the lowflow frequency data were extended to the full period by extrapolation 

from the low-flow data from nearby long-term stations.

The basic data used in the analysis are summaries of annual low 

flow obtained through use of an electric computer. Tl ese summaries show the lowest mean discharge each year (April to March) 

for selected numbers of consecutive days. Copies of the summaries 

for specific gaging stations can be obtained from the district office in 

charge of surface water investigations in the State in which the gaging 

station is located.

The recurrence interval used in plotting the annual low flows is 

computed from the formula

Recurrence interval= > 

m

in which n is the number of annual events and m is the number 

starting with the lowest as number 1.

Low-flow frequency curves for stations with records fcr the full 

length of a reference period were smoothed by comparing the observed 

annual minimums with those at two or more other long-teni stations 

used in the analysis. Each comparison was made by pitting on 

logarithmic paper the annual minimums arranged in order of magnitude at each of the two stations being compared and by drawing a 

smooth curve of relation. The relation curve was then usec1 to obtain 

estimates of the discharge for each order number at the station being 

analyzed based on the experience at the other station. Discharge 

estimated in this way was averaged with the observed discharge for 

the same order number at the station being analyzed to obtain adjusted values which were then plotted on extreme-value probability 

paper with a logarithmic ordinate. The results shown in this report 

are taken from smooth curves drawn to average these point?, By this 

procedure, a plotted value of an anomalously low discharge at one of 

the stations is raised by the experience at the other stations; at the 

same time this procedure tends to lower the plotted values of the 

lowest discharge experienced at the other stations. The relations 

between the low flows at pairs of gaging stations, which ar^, based on 

all the points in the array, are assumed to express the true difference 

in low-flow characteristics at the two stations so that the departures 

from the relations can be assumed to be due to chance.
G4 CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

The extension of low-flow frequency data at stations w'th records 

shorter than the reference period was made by relating the annual 

minimum flows to the annual minimum flows at long-term stations 

through use of an unregressed line of relation. That is, the relation 

curves were drawn so as to be equally applicable regardless of which 

station was used as the dependent variable. This procedure serves 

to maintain the variability of the observed data but can result in a 

decrease in accuracy unless a sufficient degree of correlation between 

stations is present. In general, the plotting of annual mirimum discharge for concurrent years of record showed a correlation coefficient 

of 0.7 or greater. For a few stations where the correlation coefficient 

was less than 0.7, adjustment was made only to the extent that 

the trend of all long-term stations on all sides of the short-term 

station was the same.

DESCRIPTION OF TABLES AND FIGURES

The low-flow frequency curves for each station are summarized in 

tables and graphs. The tabular data are sufficiently detailed to 

permit the low-flow frequency curves to be plotted on any type of 

scale; the graphical data are presented only for visual comparison. 

The tabular data are presented in four tables starting on page 7; 

each table is for a different reference period. Within each table the 

gaging stations are arranged alphabetically, first by States and then 

by station name within each State. The map number identifies the 

location of the gaging station in figure 1, and the station number is 

the number assigned to the gaging station in recent reports on "Surface Water Supply of the United States," issued annually by the 

U.S. Geological Survey. The numeral before the hyphen designates 

the number of the part in the annual series, and the letter following 

the numeral designates a subdivision of the part; the numerals following the hyphen are the station numbers within the part, assigned 

in downstream order. A complete description of the location of 

each gaging station together with information on the period of record 

and the amount of regulation can be found in one of the recent reports 

on surface-water supply for the indicated part.

The flow figures given in the table are mean discharge fo~ the indicated period of consecutive days of low flow. To obtain the volume 

of low flow in cfs-days, the figures should be multiplied by the number 

of days, and to obtain flow per square mile, they should be divided by 

the drainage area. At some stations the figures shown for 15 consecutive days of low flow are really the flow for 14 consecutive days, 

and at all stations, the 15-day figures can be used as the f ow for 14 

consecutive days. A change in the computer program from 15 to 14 

consecutive days was made after the project was started, but all
LOW-FLOW FREQUENCY CURVES, EASTERN UNITED STATEf G5

results are considered to be equivalent. The change was made to 

obtain a more natural figure of flow at stations where the flow was 

affected by a weekly pattern of regulation. At such stations the 

average flow for 14 consecutive days is more likely to represent 

natural flow than is the flow for 15 days. The difference in the 

average flow for 14 days and that for 15 days is probably not more 

than a few percent at most stations.

For some gaging stations located near the boundary separating the 

areas of different reference periods, low-flow frequency curves were 

prepared for both reference periods. Only the curves for the reference period applicable to the State in which the station is located 

are given in this report, but footnotes to the table indicate how the 

curves for such stations can be made applicable to the other reference 

period.

The content of each of the 4 tables is as follows:

Table Reference period State and number of stations

1 1913-57 Maryland 2 

New York 4 

Pennsylvania 5 

Virginia 8

2 1897-1957 North Carolina 5

3 1929-57 Alabama 5 

Arkansas 2 

Florida 2 

Georgia 5 

Louisiana 4 

Mississippi 4 

Oklahoma 1 

South Carolina 3 

Texas 3

4 1924-55 Illinois 6 

Indiana 3 

Kentucky 3 

Michigan I 

Missouri 4 

Ohio 5 

Tennessee 6 

West Virginia 4

For other reference periods, such as the period 1931-60 that is 

used as the climatological standard period by the World Meteorological Organization, the curves in this report can be adjusted to the 

new reference period by plotting the observed annual low flows for 

the new reference period on the same graphs used for the smoothed 

curves. The position of the adjusted curves would be based largely 

on the plotted points, and the shape and slope of the curves would 

be based largely on the smoothed curves taken from this report.

675121 63 2
G6 CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

Low-flow frequency curves for all 85 gaging stations included in this 

report are shown in figures 2-13 at the end of this renort. The 

curves are identified by station number, and the map number is 

shown in parentheses. The lowest of the four curves shorn for each 

station is that for 7 consecutive days, and the other three curves are 

for 30, 120, and 274 consecutive days. Curves for 15, 60, and 183 

consecutive days have been omitted for clarity.

The curves are plotted with an extreme-value probability scale as 

the abscissa and a logarithmic scale as the ordinate. The extremevalue probability scale is graduated to conform with Gumbo's theory 

of extreme values by use of a scale developed by Poy^ell. 1 The 

logarithmic scale is used because it tends to make the curves plot 

more nearly as straight lines than does an arithmetic scale. The lower 

ends of some curves were made straight lines when the basic data 

could be so interpreted, but for the most part no attempt was made 

to fit straight lines or any other predetermined type of distribution.

DISCUSSION OF RESULTS

The low-flow frequency curves for the 85 gaging statiors range in 

shape from the closely spaced mildly sloping curves of station 49 to 

the widely spaced steep curves of station 47. (See fig. 7.) Most of 

the curves tend to be concave upward, but some are concave downward; very few plot as straight lines on the type of graph paper used. 

There is no obvious relation between spacing and slope; some of the 

widely spaced curves are concave upward, and some ar<? concave 

downward. The variation in shape of these curves indicates the 

difficulty of finding a type of statistical distribution that would fit 

the data for all lengths of periods at every station.

The differences and similarities in the low-flow frequency curves 

for the 85 gaging stations presented in this report raise son:e interesting questions. To what extent, for example, does the slope of the 

curves depend on the rate of base-flow recession and to what extent 

on the frequency distribution of the length of dry pericrls. Also, 

to what extent does the spacing between curves depend on the two 

factors just mentioned and to what extent on how greatly the runoff 

of a drainage basin is affected by rainfall that occurs during periods 

of low flow. These questions would probably be studied in any investigation of the effect of hydrologic environment on low flows.

Although low flow for short periods is largely ground-water effluent, 

the flow for longer periods such as 60 and 120 days generally contains 

some contribution from rainfall during those periods. This coni Powell, R. W., 1943, A simple method of estimating flood frequency: Am. 8oc. Civil E;igineers Trans. 

v. 13, no. 2, pp. 105-106.
LOW-FLOW FREQUENCY CURVES, EASTERN UNITED STATES G7

tribution may vary from basin to basin not so much from differences 

in amount of rainfall as from differences in amount of infiltration.

It is not the intent of this report to discuss reasons for the variation 

in shape, slope, and spacing of low-flow frequency curves from station 

to station or to fit curves to a statistical distribution. The curves 

should serve, however, as a convenient starting point for such studies 

because they consolidate data from many stations located over a wide 

area.

A further use of the low-flow frequency curves presented in this 

report is in the computation of the amount of storage required to 

provide the average flow shown by the curves. The amount of 

storage required can be computed by drawing a mass curve for the 

discharges taken from the low-flow frequency curves for a given recurrence interval.2 The amount of storage thus computed makes 

no allowance for seepage and evaporation losses, both of which serve 

to increase the amount of storage required or to decrease the allowable draft. In addition, the method has a small bias that requires 

that the computed amount of storage be increased by about 10 percent.

TABLE 1. Magnitude and frequency of annual low flow for selected long-term 

stream-gaging stations in Maryland, New York, Pennsylvania, and Virginia, 

1913-57

[Observed or extended data for the reference period April 1,1913, to March 31,1958, smoothed by comparison 

with records at other long-term stations. See figures 2 and 3 for corresponding curver-1

Map

1

2

3

Station

No.

IB-6430

IB-6385

3A-0115

Station name

Monocacy

River at Jug

Bridge near

Frederick. Md.i

Potomac River

at Point of

Rocks, Md.

Allegheny

River at Red

House, N.Y.

Drainage

area

(sq

mi)

817

9,651

1,690

Period

(consecutive

days)

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

Annual low flow (cfs) for indicated recurrence interval

(years)

1.03

262

298

370

518

778

1,030

1,280

2,330

2,570

2,980

4,010

5,690

7,910

10,400

485

565

716

1,130

1,900

2,330

3,040

1.2

172

195

241

332

506

701

980

1,780

1,930

2,200

2,900

4,100

5,600

8,000

303

346

437

633

1,040

1,510

2,270

2

105

116

140

188

288

419

679

1,270

1,360

1,530

1,930

2,700

3,670

5,740

194

214

259

333

521

887

1,630

5

64

71

85

108

160

240

437

944

1,000

1,100

1,310

1,800

2,470

4,110

141

154

181

219

308

540

1,150

10

50

55

66

82

120

176

327

837

881

955

1,110

1,490

2,040

3,360

115

127

149

179

244

400

921

20

3£

44

52

64

91

133

24t

741

782

852

961

1.25C

1.68C

2.75C

95

104

12S

14f

196

300

74T

50

29

32

38

46

64

92

173

640

673

736

803

1,010

1,310

2,150

74

81

95

114

148

207

560

See footnote at end of table.

» Martin, R. O. R., and Hulme, A. E., 1957, Surface Water, in Rasmussen, W. O., and otherr. The water 

resources of northern Delaware: Delaware Qeol. Survey Bull.,no. 6, v.l, pp. 55-59.
G8 CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

TABLE 1. Magnitude and frequency of annual low flow for selected long-term 

stream-gaging stations in Maryland, New York, Pennsylvania, and Virginia, 

1918-57 Continued

[Observed or extended data for the reference period April 1,1913, to March 31,1958, smoothed by comparslon 

with records at other long-term stations. See figures 2 and 3 for corresponding curves]

Map

4

8

6

7

8

9

10

11

Station 

No.

IB-5310

IB-3700

IB-4265

IB-4810

3A-0215

IB-5480

IB-5620

IB-5365

Station name

Chemung

Biver at

Chemung,

N.Y.

Wallkill Eiver

at Pellets

Island Mountain, N.Y.i

West Branch

Delaware

River at

Hale Eddy,

N.Y.

Brandywine

Creek at

Chadds

Ford, Pa.i

French Creek

at Carters

Corners, Pa.s

North Bald

Eagle Creek

at Beech

Creek Station, Pa.

Kaystown

Branch Juniata Eiver at

Saxton, Pa.

Susquehanna

Eiver at

Wilkes-Barre,

Pa.

Drainage 

area 

(sq. 

mi.)

2,530

385

593

287

208

559

756

9,960

Period (consecutive 

days)

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

Annual low flow (cfs) for indicated recurrence interval 

(years)

1.03

394

451

598

995

1,630

2,210

2,290

160

192

251

388

666

753

842

212

268

363

541

821

1,030

1,270

216

238

275

312

371

427

521

50

58

84

143

251

328

463

228

249

281

386

530

702

L946

196

212

247

324

474

719

955

2,930

3,200

4,020

5,530

8,320

11,100

14,000

1.2

259

291

353

522

873

1,310

2,100

76

91

119

180

311

422

568

130

158

210

300

502

717

998

157

171

193

222

268

319

408

28

32

43

67

122

207

351

183

195

214

263

355

468

681

144

156

177

228

327

491

730

1,940

2,110

2,490

3,370

5,210

7,590

10,700

2

163

181

206

269

423

680

1,340

37

43

54

77

128

210

353

73

87

111

151

272

443

721

111

120

134

153

187

228

301

18

19

24

33

55

114

252

148

155

165

187

235

312

486

103

111

123

151

207

303

518

1.290

1,390

1,560

1,960

3,000

4,660

7,780

5

116

127

147

175

233

367

837

23

27

32

42

62

116

232

46

52

67

87

153

269

502

80

86

96

107

131

160

221

12

13

16

21

30

64

178

127

130

139

147

176

225

358

82

88

95

108

135

187

354

978

1,050

1,170

1,330

1,830

2,850

5,660

10

96

104

121

144

186

283

638

19

21

25

33

48

91

182

40

46

57

71

119

204

407

67

72

80

89

108

132

182

9.4

10

12

16

23

47

140

116

120

128

134

155

189

298

72

76

83

92

113

151

276

838

989

1,010

1,160

1,530

2,250

4,610

20

80

87

101

120

150

228

516

15

17

20

26

38

72

146

35

42

49

60

94

156

335

57

61

68

76

90

110

152

7.4

8.1

9.6

12

17

36

112

108

112

118

124

140

167

252

63

67

72

81

95

124

217

712

764

873

1,010

1,310

1,830

3,760

60

62

68

79

94

113

171

384

12

13

15

20

28

54

108

30

35

40

47

69

111

263

46

50

56

62

71

87

120

5.4

6.0

7.1

8.4

12

25

84

98

102

107

113

123

142

201

54

57

62

68

76

96

159

580

624

720

852

1,060

1,410

2,900

See footnotes at end of table.
LOW-FLOW FREQUENCY CURVES, EASTERN UNITED STATES G9

TABLE 1. Magnitude and frequency of annual low flow for selected long-term 

stream-gaging stations in Marylqnd, New York, Pennsylvania, and Virginia, 

WU-57 Continued

[Observed or extended data for the reference period April 1,1913, to March 31,1953, smoothed by comparison 

with records at other long-term stations. See figures 2 and 3 for corresponding curves]

Map

12

13

14

15

16

17

18

19

Station

No.

3B-5240

2A-0195

3A-1680

3B-4900

2A-0455

IB-6680

2A-0625

2A-0550

Station name

Clinch River at

Cleveland,

Va.i*

James River at

Buchanan.

Va.

New River at

Allisonia,

Va.»«

North Fork

Hols ton

River near

Gate City, Va.i*

Nottoway

River near

Stony Creek,

Va.J

Rappahannock

River near

Fredericksburg, Va.

Roanoke River

at Brookneal, Va.i

Roanoke River

at Roanoke,

Va.

Drainage

area

(sq

mi)

528

2,084

2,202

672

586

1,599

2,420

388

Period

(consecutive

days)

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

Annual low flow (cfs) for indicated recurrerce interval

(years)

1.03

154

170

223

321

513

674

918

655

722

835

1,290

1,790

2,540

3,170

1,690

2,100

2,520

3,110

3,590

4,200

226

333

475

810

1,060

1,340

213

244

311

396

574

652

760

609

721

868

1,120

1,520

1,810

2,410

1,280

1,390

1,590

1,920

2,410

2,900

3,240

141

154

184

252

337

419

505

1.2

115

125

153

203

316

431

681

511

555

618

801

1,130

1,640

2,320

1,270

1,530

1,800

2,180

2,540

3,050

135

183

243

397

540

796

126

146

185

236

350

433

600

381

450

552

724

1,040

1,340

1,870

978

1,050

1,190

1,420

1,760

2,120

2,590

98

106

126

166

222

284

373

2

82

88

101

121

177

250

462

383

405

437

500

660

958

1,640

945

1,120

1,280

1,510

1,800

2,270

91

114

140

213

292

504

61

72

90

117

181

252

416

198

233

289

393

612

877

1,310

670

722

813

948

1,190

1,440

1,970

64

70

80

99

132

173

248

5

64

68

74

82

107

153

304

314

330

345

382

440

587

1,070

737

846

940

1,090

1,300

1,690

67

80

94

127

178

317

26

32

40

54

88

142

246

79

97

125

180

320

527

848

440

474

536

617

782

1,000

1,440

47

50

56

63

80

104

159

10

56

60

65

70

89

121

238

296

309

321

350

389

488

808

634

720

792

927

1,090

1,420

58

67

76

100

139

243

14

18

24

33

58

98

172

40

50

67

101

200

370

611

343

373

421

488

640

827

1,170

41

44

48

53

65

84

125

20

5T

5<

5^

62

75

98

189

277

290

301

323

35?

421

620

551

629

693

806

94 "5

1,220

5?

&

658<?

112

192

8.2

11

15

21

38

7?

122

20

25

35e«

12?

2EO

4£1

250

3C4

345

410

MO 6f°

961

?6

f9

4-2

4-7

57

72

1C2

ea

44

47

50

52

61

74

142

256

268

278

292

308

351

439

480

538

593

686

804

1,040

46

50

54

67

90

145

4.0

5.6

7.7

11

23

44

79

7.5

10

15

25

57

140

261

215

233.

271

327

431

558

741

31

32

36

39

48-

61

76

1 Observed record extended to reference period 1913-57 by relation with records at other stations. 

1 Data are applicable to reference period 1924-55 if 7- and 120-day discharge is lowered 10 percent.

3 Data are applicable to reference period 1924-55 if all discharge is lowered 5 percent.

4 Data are applicable to reference period 1897 to 1954 if all discharge is raised 10 percent.
G10 CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

TABLE 2. Magnitude and frequency of annual low How for selected long-term 

stream-gaging stations in North Carolina, 1897-1954

[Observed or extended data for the reference period April 1,1897, to March 31,1955, smoothed by comparison 

with records at other long-term stations. See figure 4 for corresponding curves]

Map

20 

21 

22 

23 

24

Station 

No.

2A-1025 

3B-4515 

3B-5030 

3B-5500 

2A-1165

Station name

Cape Fear River at 

Lillington, N.C.ia

French Broad River 

at Asheville, N.CJ"

Little Tennessee 

River at Needmore, N.C.i i

Valley River at 

Tomotla, N.C.i 4

Yadkin River at 

Yadkin College, N.C.i 3

Drainage 

area 

(sq 

mi)

3,440 

945 

436 

104 

2,280

Period (consecutive 

days)

7 

15 

30 

60 

90 

120 

183 

274

7 

15 

30 

60 

90 

120 

183 

274

7 

15 

30 

60 

90 

120 

183 

274

7 

15 

30 

60 

90 

120 

183 

274

7 

15 

30 

60 

90 

120 

183 

274

Annual low flow (cfs) for indicated recurrence 

interval (years)

1.03

1,050

1,380 

1,910 

2,330 

2,990 

3,900 

5,020

1,260

1,570 

1,830 

2,060 

2,340 

2,780 

3,100

624

746 

880 

1,010 

1,140 

1,410 

1,640

111

143 

173

203 

260 

319 

358

2,180

2,650 

3,020 

3,380 

3,680 

4,230 

4,680

1.2

631

871 

1,210 

1,470 

1,930 

2,540 

3,490

942

1,150 

1,340 

1,490 

1,690 

1,980 

2,250

428

508 

594 

672 

757 

921 

1,140

72

88 

104 

120 

144 

184 

253

1,660

2,010 

2,270 

2,530 

2,720 

3,110 

3,550

2

311

462 

639 

779 

1,080 

1.460 

2,290

700

841 

980 

1,080 

1,210 

1,400 

1,700

318

370 

431 

473 

523 

637 

840

48

59 

69 

78 

90 

113 

168

1,230

1,470 

1,670 

1,860 

2,010 

2,300 

2,720

5

133

215 

298 

362 

539 

860 

1,450

507

606 

700 

778 

866 

1,040 

1,280

249

281 

317 

349 

390 

480 

641

34

41 

48 

54 

63 

78 

117

874

1,040 

1,180 

1,320 

1,430 

1,740 

2,120

10

82

131 

182 

222 

363 

612 

1,100

411

494 

567 

632 

712 

879 

1,080

214

243 

269 

298 

338 

415 

559

27

33

38 

43 

52 

67 

101

716

848 

970 

1,070 

1,190 

1,500 

1,830

20

54

88 

123 

149 

257 

441 

850

338

410 

437 

520 

600 

751 

939

186

210 

233 

257 

291 

371 

497

22

26 

30 

34 

43 

60 

92

618

739 

831 

922 

1,030 

1,300 

1,580

50

34

56 

78 

94 

163 

289 

604

262

314

362 

408 

486 

622 

786

154

174 

193 

213 

242 

329 

432

16

19 

23 

25 

34 

51 

82

' 507

609 

682 

760 

839 

1,070 

1,310

1 Observed record extended to reference period 1897-1954 by relation with records at other stations.

2 Data are applicable to reference period 1929-57 if 7- and 30-day discharge is lowered 30 percent and 60-day 

discharge 15 percent.

3 Data are applicable to reference period 1929-57 if all discharge is lowered 15 percent.

4 Data are applicable to reference periods 1929-57 and 1924-55 if all discharge is lowered 15 percent.
LCHV-FLOW FREQUENCY CURVES, EASTERN UNITED STATE'1 Gil

TABLE 3. Magnitude and frequency of annual low -flow for selected long-term 

stream-gaging stations in Alabama, Arkansas, Florida, Georgia, Louisiana, 

Mississippi, Oklahoma, South Carolina, and Texas, 1929-57

[Observed or extended data for the reference period April 1,1929, to March 31,1958, smoothed by comparison 

with records at other long-term stations. See figures 5-8 for corresponding curves]

Map

25

26

27

28

29

30

31

32

Station 

No.

2B-4040

2B-4795

2B-4285

2B-4555

2B-4500

7-0570

7-3635

2B-3655

Station name

Choccolocco

Creek near

Jenifer, Ala.*

Escatawpa

River near

Winner, Ala.«

Flat Creek at

Fountain,

Ala.i

Locust Fork at

Trafiord,

Ala.t

Mulberry Fork

near Garden

City, Ala.i

Buffalo River

near Rush,

Ark.

Saline River

near Rye,

Ark.t

Choctawhatchee

Eiver at

Caryville,

Fla.i

Drainage 

area 

(sq 

mi)

281

506

245

2625

368

1,091

2,062

*

3,499

Period (consecutive 

days)

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

1S3

274

7

15

30

60

120

183

274

7

15

30

60

120

1S3

274

Annual low flow (cfs) for indicated recurrence interval 

(years)

1.03

133

139

154

203

241

313

542

300

342

393

528

702

894

1,340

27

34

44

72

141

271

474

85

104

161

313

540

783

1,320

40

54

106

222

380

521

884

139

IBS

221

303

582

1,110

1,570

133

177

256

406

1.170

2,270

3,610

2,640

2,830

3,240

4,130

5, 220

6,580

8,610

1.2

105

110

118

146

173

218

356

171

193

218

302

435

616

933

12

14

18

28

51

92

205

43

52

74

127

237

402

808

17

22

36

72

156

265

525

79

93

119

157

302

581

1,030

56

70

101

161

428

960

2,090

1,820

1,940

2,220

2,740

3,500

4,410

5,780

2

85

88

93

107

127

153

243

102

113

124

166

245

376

642

5.5

6.4

7.6

12

20

36

96

22

27

35

52

96

187

457

8.0

9.6

13

22

56

115

301

46

53

64

78

141

262

597

26

30

39

56

133

329

1,010

1.230

1,300

1,480

1.740

2,230

2,810

3,630

5

69

72

75

82

96

113

181

66

84

82

106

148

224

497

2.8

3.3

4.0

5.7

10

17

52

15

17

22

29

50

86

287

5.3

5.9

6.6

9.7

24

52

200

30

34

40

48

78

128

349

13

15

18

25

50

115

447

980

1,030

1,130

1,290

1,640

2,060

2,620

10

58

60

63

67

80

93

150

50

56

63

82

120

170

416

1.7

2.1

2.5

3.7

7.0

12

37

11

14

18

24

39

64

223

4.3

4.8

5.4

7.4

17

36

155

22

25

30

36

59

95

263

9.0

10

12

17

34

71

275

8S6

930

1,020

1,120

1,430

1.790

2,290

20

47

49

52

54

67

77

126

38

43

49

63

98

138

352

1.0

1.3

1.6

2.5

5.2

8.9

28

10

12

15

20

32

51

176

3.6

4.0

4.4

6.0

14

29

123

17

19

22

27

46

74

203

6.6

7.7

9.0

12

24

49

183

811

848

903

982

1,250

1,560

2,000

50

36

38

40

42

54

61

100

27

30

35

45

75

107

283

.5

.7

.9

1.5

3.5

6.0

20

8.0

9.3

12

15

24

38

130

2.7

3.1

3.4

4.7

10

21

91

12

13

16

19

33

53

143

4.5

5.2

6.0

7.7

16

30

123

720

757

786

824

1,060

1,320

1,690

See footnotes at end of table.
G12 CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

TABLE 3. Magnitude and frequency of annual low How for selected long-term 

stream-gaging stations in Alabama, Arkansas, Florida, Georgia,, Louisiana, 

Mississippi, Oklahoma, South Carolina, and Texas, 1929-67 Continued

[Observed or extended data for the reference period April 1,1929, to March 31,1958, smooth?d by comparison 

with records at other long-term stations. See figures 5-8 for corresponding curves]

Map

33

34

35

36

37

38

39

40

Station 

No.

2B-3195

2B-2260

2B-3395

2B-3525

2B-2185

2B-3875

7-3646

2B-4920

Station name

Suwannee River

at EUaviUe,

Fla.i

Altamaha River

at Doctortown, Ga.i

Chattahoochee

River at West

Point, Qa.

Flint River at

Albany, Qa. 1

Oconee River

near Greensboro, Qa.1

Oostanaula

River at

Resaca, Qa.

Bayou Bartholomew near

Beekman, La.i

Bogue Chitto

near Bush, La.i

Drainage 

area 

(sq 

mi)

6,580

13, 600

3,550

5,310

1,090

1,610

1,645

1,210

Period (consecutive 

days)

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

Annual low flow (cfs) for indicated recurrence interval 

(years)

1.03

3,930

4,230

4,580

5,440

7,220

9,640

12,500

5,790

6,350

7,540

8,560

10, 700

12,300

16,800

2,430

2,700

3,120

3,710

4,240

5,030

6,410

2,850

3,280

3,590

4,360

5,180

6,040

8,100

667

717

793

954

1,160

1,400

1,700

886

980

1,140

1,530

2,010

2,520

3,850

247

278

339

490

943

1,660

2,530

837

882

949

1,110

1,330

1,680

2,610

1.2

2,550

2,730

2,930

3,410

4,420

5,790

7,230

4,090

4,430

5,120

6,070

7,200

8,400

11,100

1,720

1,910

2,240

2,690

3,170

3,720

4,730

2,210

2,410

2,670

3,160

3,780

4,470

5,800

467

500

559

670

818

958

1,190

631

684

777

994

1,320

1,650

2,620

160

174

200

260

450

770

1,530

691

721

764

867

1,020

1,230

1,730

2

1,480

1,530

1,590

1,790

2,230

2,840

3,390

3,200

3,460

3,760

4,190

4,970

5,820

7,510

1,100

1,240

1,470

1,810

2,240

2,620

3,380

1,630

1,760

1,920

2,200

2,670

3,180

4,000

296

321

373

459

568

674

850

461

492

541

632

832

1,060

1,740

103

140

121

144

211

330

792

578

597

621

684

795

928

1,250

5

1,120

1,150

1,180

1,220

1,380

1,680

2,010

2,560

2,720

2,980

3,210

3,910

4,630

5,800

700

788

944

1,180

1,550

1,940

2,550

1,290

1,370

1,500

1,680

2,060

2,470

3,070

169

189

230

290

377

491

654

363

382

410

471

620

805

1,370

70

75

80

90

123

179

420

500

519

538

575

667

762

1,050

10

961

985

1,010

1,050

1,160

1,370

1,590

2,200

2,340

2,540

2,750

3,370

4,000

4,870

526

597

712

883

1,230

1,610

2,150

1,130

1,200

1,300

1,430

1,750

2,110

2,620

117

133

168

215

289

398

551

322

340

362

413

550

719

1,210

57

62

66

71

96

143

313

468

486

499

532

612

703

960

20

839

858

878

910

981

1,130

1,280

1,900

2,030

2,200

2,390

2,910

3,470

4,120

403

454

542

678

979

1,350

1,830

980

1,050

1,130

1,240

1,520

1,830

2,270

82

96

123

162

223

325

470

288

303

322

370

491

640

1,080

49

52

55

60

80

116

247

441

455

470

496

567

652

889

50

698

710

722

757

796

874

961

1,570

1,690

1,820

1,970

2,420

2,890

3,330

283

320

383

477

733

1,070

1,480

823

881

948

1,020

1,250

1,510

1,880

52

62

83

112

161

251

378

249

262

279

319

426

554

940

40

42

44

48

62

88

183

407

423

432

456

516

591

803

See footnote at end of table.
LOW-FLOW FREQUENCY CURVES, EASTERN UNITED STATEf G13

TABLE 3. Magnitude and frequency of annual low How for selected long-term 

stream-gaging stations in Alabama, Arkansas, Florida, Georgia, Louisiana, 

Mississippi, Oklahoma, South Carolina, and Texas, 1929 57 Continued

[Observed or extended data for the reference period April 1,1929, to March 31,1958, smoothed ly comparison 

with records at other long-term stations. See figures 5-8 for corresponding cnrvef 1

Map

41

42

43

44

45

46

47

Station 

No.

8-0135

8-0225

2B-4790

2B-4860

2B-4875

2B-4415

7-3390

Station name

Calcasieu Elver

near Oberlin, La.i

Sabine River at

Logansport,

La.

Pascagoula

River at

Merrill, Miss.i

Pearl River at

Jackson, Miss.

Strong River at

Dlo, Miss.

Tombigbee

River at

Columbus,

Miss.

Mountain Fork

River near

Eagletown,

Okla.i

Drainage 

area 

(sq 

mi)

753

4,858

6,600

3,100

429

4,490

787

Period (consecutive 

days)

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

Annual low flow (cfs) for indicated recurrence interval 

(years)

1.03

135

146

167

279

641

1,310

2,370

372

433

619

1,030

2,190

4,060

5,740

2,560

2,740

3,090

4,090

5,630

7,900

13, 100

379

463

605

980

1,890

3,320

5,210

59

69

88

129

228

404

736

850

950

1,160

1,750

2,930

4, 720

8,390

76

106

153

269

699

1,120

1,450

1.2

80

84

94

136

225

423

1,050

183

209

278

424

798

1,650

3,270

1,730

1,840

2,030

2,580

3,500

4,800

8,110

241

279

337

484

878

1,540

3,130

37

41

49

66

113

202

429

537

595

700

938

1,420

2,260

5,100

23

36

56

118

354

714

1,070

2

52

54

58

74

100

176

503

74

84

103

140

233

551

1,640

1,230

1,290

1,400

1,690

2,240

3,030

5,220

146

159

179

228

396

661

1,720

25

27

29

35

53

90

227

333

367

418

518

728

1,070

2,830

2.0

3.5

6.2

21

98

324

703

5

42

43

45

50

61

94

270

32

35

39

49

75

207

841

962

1,020

1,070

1,220

1,590

2,080

3,700

105

111

118

138

228

354

1,060

21

22

23

25

32

48

133

244

268

299

360

484

643

1,710

0

.1

.1

1.1

19

112

423

10

37

38

40

43

51

72

197

22

24

26

31

46

136

553

861

904

948

1,050

1,360

1,730

3,160

92

97

104

117

174

270

859

19

19

20

22

28

39

107

204

225

250

300

400

524

1,390

0

0

0

.2

6.4

56

303

20

33

34

35

38

46

58

150

17

18

20

23

35

94

370

774

808

848

940

1,200

1,520

2,740

81

86

92

102

134

209

701

17

18

18

20

25

32

88

173

189

212

254

334

434

1,130

0

0

0

0

2.2

28

220

50

28

29

30

33

39

47

106

13

14

15

17

26

58

219

670

703

740

808

1,030

1,280

2,280

69

73

78

84

96

151

542

15

15

16

17

21

25

69

139

152

170

204

265

339

878

0

0

0

0

.6

12

145

See footnote at end of table.

075121 63-
G14 CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

TABLE 3. Magnitude and frequency of annual low How for selected long-term 

stream-gaging stations in Alabama, Arkansas, Florida, Georgia., Louisiana, 

Mississippi, Oklahoma, South Carolina, and Texas, 1929-57 Continued

[Observed or extended data for the reference period April 1,1929, to March 31,1958, smooth-"! by comparison 

with records at other long-term stations. See figures 5-8 for corresponding crrves]

Map

48

49

50

51

52

53

Station 

No.

2A-1320

2A-1730

2A-1590

8-1710

8-0335

8-0305

Station name

Lynches River

at Efflngham,

S,U.* n i 

South Fork

Edisto River

near Denmark, S.G. i

South Tyger

River near

Woodruff,

S.C.i

Blanco River at

Wimberley,

Tex.

Neches River

near Rockland, Tex.

Sabine River

near Rullff,

Tex.

Drainage 

area 

(sq 

mi)

1,030

720

174

364

3,623

9,440

Period (consecutive 

days)

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

Annual low flow (cfs) for indicated recurrence interval 

(years)

1.03

350

389

456

541

722

943

1,230

461

513

578

677

782

885

1,110

123

138

160

191

235

281

344

33

37

44

68

133

234

407

287

324

395

661

1,530

3,030

4,240

1,840

1,960

2,300

3,380

6,060

10,400

14,700

1.2

278

308

356

417

550

701

899

361

390

437

489

577

653

782

89

98

113

135

165

194

240

20

22

25

34

56

84

130

128

145

172

272

554

1,160

2,190

1,130

1,200

1,380

1,840

2,960

5,070

8,500

2

208

229

258

296

387

482

610

292

315

341

368

440

502

592

60

67

77

92

114

135

168

12

13

14

18

23

30

40

45

51

60

90

164

381

1,000

632

663

731

862

1,290

2,230

4,480

5

154

168

183

207

270

333

425

233

245

269

292

351

402

471

35

40

47

59

78

96

127

6.4

6.8

7.6

9.4

12

14

17

14

15

18

27

54

149

507

408

425

454

487

699

1,160

2,640

10

132

144

156

174

230

281

360

202

211

231

252

302

349

407

24

28

34

44

62

78

106

4.2

4.5

5.0

6.2

8.0

9.5

11

6.2

7.C

8.2

12

28

90

340

343

357

381

407

548

904

2,110

20

114

124

134

149

197

240

310

174

184

201

219

262

302

353

17

20

24

33

49

64

90

2.9

3.1

3.4

4.2

5.5

6.5

7.6

2.9

3.3

3.8

5.7

14

56

233

291

302

323

343

438

726

1,690

50

95

103

111

122

160

197

253

146

153

166

182

219

251

293

11

13

16

23

36

48

72

1.7

1.9

2.0

2.5

3.3

3.9

4.5

1.1

1.2

1.4

2.1

6.3

30

143

237

244

261

277

332

550

1,270

1 Observed record extended to reference period 1929-57 by relation with records at other stations. 

* Drainage area of 555 square miles should be used for low flow comparisons, as area upstream from dam 

on Blackburn Fork Is assumed not to contribute to the low flow at Trafford.
LOW-FLOW FREQUENCY CURVES, EASTERN UNITED STATES G15

TABLE 4. Magnitude and frequency of annual low flow for selected long-term streamgaging stations in Illinois, Indiana, Kentucky, Michigan, Missouri, Ohio, 

Tennessee, and West Virginia, 1924 55

[Observed or extended data for the reference period April 1,1924, to March 31,1966, smoothed by comparison 

with records at other long-term stations. See figures 9-13 for corresponding curves]

Map

64

66

56

67

68

59

60

61

62

Station 

No.

5-5970

3A-3455

5-5260

6-4355

5-5720

5-6700

3A-3735

3A-3266

3A-2765

Station name

Big Muddy

River at Plumfield, ni. i

Embarras River

at Ste. Marie,

111.

Iroquois River

near Chebanse,

HI.

Pecatonica River

at Freeport, 111.

Sangamon River

at Monticello,

111.

Spoon River at

at Seville, El.

East Fork White

River at

Shoals, Ind.

Mississinewa

River at

Marion, Ind.

Whitewater

River at

Brookville,

Ind.i

Drainage 

area 

(sq 

mi)

763

1,540

2,120

1,330

550

1,600

4,954

677

1,239

Period (consecutive 

days)

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

80

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

Annual low flow (cfs) for indicated 

recurrence interval (years)

1.03

15

20

38

139

443

638

1,080

116

142

198

414

938

1,460

2,070

179

234

304

536

1,130

1,780

2,910

522

561

613

718

972

1,270

1,580

37

46

65

134

293

620

740

161

196

283

510

972

1.640

2,060

983

1,030

1.220

1,850

3,090

4,650

7,800

82

96

123

184

357

526

879

280

326

388

536

818

1,070

1,830

1.2

5.4

7.2

13

42

136

261

605

59

74

101

190

402

667

1,250

87

111

142

252

546

894

1,660

393

421

456

527

658

808

1,010

18

22

30

56

116

231

417

89

106

145

239

431

705

1,170

610

640

744

1.080

1,710

2,580

4,900

51

60

74

104

190

292

555

190

215

251

331

500

687

1,250

2

1.4

1.8

3.3

9.2

32

74

242

28

35

46

73

137

237

612

43

51

62

93

200

338

761

280

305

326

367

427

490

612

6.5

8.2

12

20

37

69

186

42

49

65

100

168

264

578

380

399

444

581

837

1,230

2,600

30

36

42

55

90

139

298

123

136

154

191

273

381

739

6

0 3

.4

.8

2.0

7.2

17

72

15

19

24

31

48

81

249

24

29

36

45

72

120

313

213

236

252

281

319

351

432

2.4

3.1

4.8

7 4

12

21

71

21

25

32

48

78

117

304

284

298

320

366

446

603

1,270

20

24

28

34

48

69

146

92

99

110

123

156

209

390

10

0.1

.2

.3

.7

2.7

6.2

32

10

13

17

22

29

46

131

19

22

27

36

51

78

200

190

209

225

255

289

316

388

1.4

1.9

3.2

4 8

7.7

12

37

16

19

24

36

59

86

206

244

256

275

312

352

444

831

16

19

23

28

38

51

95

82

88

98

107

124

154

258

20

0.1

.1

.1

.3

1.1

2.4

14

7.5

9.4

12

15

21

31

66

15

18

23

30

42

59

133

170

187

203

231

261

287

351

1.0

1.3

2.1

3.2

5.2

8.3

20

12

15

19

29

48

70

141

213

224

239

270

306

362

579

12

16

19

24

32

42

66

73

78

88

96

110

126

184

50

0

0

0

.1

.3

.7

5.0

4.8

6.1

7.7

9.9

13

20

27

12

14

18

23

32

42

78

146

161

175

204

231

252

310

.6

.8

1.3

2.0

3.1

5.0

9.2

9.1

11

14

22

37

54

86

177

186

199

224

256

282

404

9.0

12

15

19

25

33

44

64

68

76

84

95

110

127

See footnote at end of table.
G16 CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

TABLE 4. Magnitude and frequency of annual low flow for selected lon^-term streamgaging stations in Illinois, Indiana, Kentucky, Michigan, Missouri, Ohio, 

Tennessee, and West Virginia, 1924-55 Continued

[Observed or extended data for the reference period April 1,1924, to March 31,1956, smootl <*d by comparison 

with records at other long-term stations. See figures 9-13 for corresponding curves]

Map

63

64

65

66

67

68

69

70

71

Station 

No.

3B-4045

3A-2125

3A-2535

4-1665

6B-9335

7-0375

5-5080

7-1860

3A-2475

Station name

Cumberland

River at Cumberland Falls,

Ky.

Levisa Fork at

Paintsville, Ky.i

Licking Eiver at

Catawba, Ky.'

Eiver Rouge at

Detroit, Mich.i

Gasconade River

at Jerome, Mo.

St. Francis River

near Patterson, Mo.s

Salt River near

New London,

Mo.

Spring River

near Waco, Mo.s

East Fork Little

Miami River

at Perintown,

Ohio.i

Drainage 

area 

(sq 

mi)

1,977

2,143

3,250

185

2,840

956

2,480

1,164

477

Period (consecutive 

days)

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

20

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

Annual low flow (cfs) for indicated 

recurrence interval (years)

1.03

328

402

550

1,020

1,690

2,370

3,650

310

378

578

966

1,980

2,610

3,280

350

461

788

1,270

2,150

3,260

4,280

23

26

32

46

70

99

154

936

1,040

1,180

1,410

2,190

3,370

5,410

96

114

146

233

476

959

1,790

121

ICC loo

317

875

1,760

2,270

2,630

219

249

304

469

852

1,420

1,900

34

45

100

186

338

519

709

1.2

116

147

208

385

786

1,300

2,590

122

149

238

405

890

1,380

2,250

121

156

258

421

910

1,770

3,390

16

17

21

28

41

60

102

662

717

783

894

1,250

1,780

2,680

56

67

84

123

249

487

1,060

44

65

107

247

615

1,080

1,610

126

140

160

211

341

600

960

10

14

23

54

132

244

500

2

41

51

71

122

297

590

1,610

42

50

70

124

292

561

1,340

41

50

78

121

312

784

2,060

9.6

10

12

15

22

32

59

481

506

540

598

765

1,010

1,410

30

36

43

58

112

207

546

13

19

31

70

181

383

820

62

69

79

95

134

223

436

2.9

3.7

5.7

13

40

87

289

5

19

24

31

47

113

251

902

20

24

30

40

87

192

715

19

22

32

44

113

335

1,050

6.6

7.0

8.4

9.5

13

18

32

372

389

407

448

545

667

880

18

20

24

29

54

92

283

3.1

4.6

7.4

16

44

111

360

26

29

33

40

57

93

185

1.2

1.4

2.2

4.1

12

27

125

10

13

16

223:

7:

157

620

14

16

20

25

49

103

471

14

If

22

20

6F

200

630

5.5

5.8

7.0

S.O

11

14

24

324

338

355

388

45S

545

697

13

15

18

22

40

64

190

1.2

1.7

2.9

7.1

20

54

201

15

17

19

23

33

53

106

.8

1.0

1.5

2.6

6.4

13

57

20

9.1

11

15

22

49

108

434

9.4

11

14

17

28

57

306

9.8

12

16

20

41

125

352

4.5

4.8

6.0

6.7

8.9

12

18

285

297

312

341

388

452

557

10

11

13

17

30

48

131

.2

.5

1.2

3.3

10

29

100

8.7

9.6

11

13

19

31

62

.6

.7

1.0

1.7

3.7

7.1

19

50

5.7

7.1

9.4

14

31

68

271

5.8

6.6

8.3

9.6

14

27

159

6.5

7.6

9.9

12

22

67

165

3.5

3.8

4.8

5.4

7.2

9.5

15

241

251

265

288

313

350

415

6.9

7.8

9.4

11

21

34

80

.4

1.3

4.2

13

34

4.3

4.8

5.5

6.6

9.4

15

31

.4

.4

.6

1.0

1.9

3.1

5.8

See footnotes at end of table.
LOW-FLOW FREQUENCY CURVES, EASTERN UNITED STATES G17

TABLE 4. Magnitude and frequency of annual low How for selected long-term streamgaging stations in Illinois, Indiana, Kentucky, Michigan, Missouri, Ohio, 

Tennessee, and West Virginia, 192^-55 Continued

[Observed or extended data for the reference period April 1,1924, to March 31,1956, smoothed by comparison 

with records at other long-term stations. See figures 9-13 for corresponding curves]

Map

72

73

74

75

76

77

78

79

80

Station 

No.

3A-1370

3A-1095

3A-2630

3A-2020

3B-6040

3B-4210

7-0295

3B-5320

3B-4355

Station name

Kokosing River

at Millwood.

Ohio.

Little Beaver

Creek near

East Liverpool,

Ohio.a

Miami River at

Taylorsville,

Ohio.

Raccoon Creek

at Adamsville,

Ohio.i

Buflalo River

near Flat

Woods, Term.*

Collins River

near McMinnville, Term.

Hatchie River at

Bolivar, Tenn.1 *

Powell River

near Arthur,

Tenn.

Red River near

Adams, Tenn.i «

Drainage 

area 

(sq 

mi)

454

505

1,155

587

447

624

1,430

685

678

Period (consecutive 

days)

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

Annual low flow (cfe) for indicatsd 

recurrence interval (years)

1.03

98

106

123

178

259

402

598

58

70

94

156

277

473

624

177

197

232

319

564

921

1,380

77

84

111

178

352

653

1,400

211

225

240

309

447

564

847

166

187

233

334

613

992

1,300

447

506

621

878

1,590

2,600

3,210

214

251

308

441

694

1,010

1,370

143

162

201

272

467

692

1,260

1.2

75

80

90

111

155

233

401

40

46

69

90

154

252

437

112

122

142

185

286

428

825

33

42

55

88

174

301

562

169

179

192

217

296

373

593

113

124

146

191

301

450

895

278

311

366

483

782

1,160

2,100

150

169

199

258

374

562

977

92

104

127

167

279

413

821

2

56

59

64

71

92

128

238

29

33

40

55

89

141

277

74

80

92

114

156

216

454

12

16

20

33

66

130

329

134

141

152

165

207

251

402

83

88

98

118

165

233

554

184

201

228

285

417

580

1,260

103

112

125

147

213

323

637

58

65

76

96

151

219

475

5

45

48

52

56

66

84

137

21

24

29

38

57

85

166

57

61

68

80

98

127

242

4.8

5.6

7.4

11

22

47

173

114

119

127

142

171

204

310

67

71

76

88

114

152

342

135

145

163

195

267

359

790

82

88

94

104

137

202

406

44

48

54

63

88

121

278

10

40

43

46

50

57

72

103

17

19

23

30

43

62

119

51

54

59

68

82

103

168

3.2

3.6

4.7

6.9

13

26

103

103

107

115

129

153

180

271

60

63

68

78

100

130

274

114

123

138

165

219

293

657

75

80

86

92

112

157

327

39

43

47

54

71

94

210

20

36

37

41

44

49

62

82

14

16

19

24

33

46

87

45

48

52

61

72

89

126

2.2

2.5

3.2

4.4

7.4

15

50

92

97

103

118

137

160

238

54

57

62

69

88

115

240

98

105

118

141

187

250

558

68

72

78

84

96

129

272

35

38

41

47

59

76

159

50

31

33

35

38

41

51

63

11

12

15

19

24

31

57

39

42

44

52

61

74

92

1.4

1.6

1.9

2.5

3.7

7.0

19

80

84

90

104

118

136

200

47

50

54

59

76

98

204

80

85

96

114

152

203

450

61

64

69

73

80

101

212

30

32

35

39

47

57

112

See footnotes at end of table.
G18 CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

TABLE 4. Magnitude and frequency of annual low flow for selected lov,g-term stream,' 

gaging stations in Illinois, Indiana, Kentucky, Michigan, Missouri, Ohio, 

Tennessee, and West Virginia, 1924-55 Continued

{Observed or extended data for the reference period April 1,1924, to March 31,1956, smoothed by comparison 

with records at other long-term stations. See figures 9-13 for corresponding curves]

Map

81

82

83

84

85

Station 

No.

7-0305

3A-0705

IB-6115

3A-1835

3A-0510

Station name

Wolf River near

Rossville,

Tenn.i *

Big Sandy Creek

at Rockville,

W. Va.s

Cacapon River

near Great

Cacapon,

W. Va.s

Greenbriar River

at Alderson,

W. Va.

Tygart River at

Belington,

W. Va.

Drainage 

area 

(sq 

mi)

503

200

677

1,357

408

Period 

(consecutive 

days)

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

7

15

30

60

120

183

274

Annual low flow (cfs) for indicated 

recurrence interval (y?ars)

1.03

220

238

253

292

381

520

820

42

58

92

157

245

368

473

92

104

128

181

297

479

679

328

422

578

1,100

1,600

1,940

2,410

102

138

197

361

555

748

1,020

1.2

182

194

206

231

296

385

583

23

32

52

89

155

248

371

70

78

91

123

189

307

477

188

227

300

508

853

1,210

1,860

52

70

100

191

340

507

780

2

149

156

165

179

219

270

389

10

14

23

40

82

144

266

53

56

63

79

113

175

300

96

110

137

203

354

591

1,240

20

27

39

78

173

295

532

5

128

134

140

151

177

207

276

3.9

5.4

8.6

16

38

74

177

44

47

50

58

73

103

185

54

58

72

94

155

271

685

6.3

8.5

12

25

67

150

332

10

116

122

128

137

If2

1?8

250

1.9

2.7

4.5

8.2

22

47

135

40

4?

4*51

6?

80

140

42

455<t

68

105

174

456

2.6

3.5

5.0

11

31

S4

231

20

107

112

118

126

149

173

229

.8

1.1

2.0

3.5

11

27

91

36

38

40

45

53

66

107

32

35

40

49

73

115

310

.9

1.2

1.9

4.2

11

40

136

50

95

100

105

113

133

154

204

.2

.3

.6

1.0

3.0

8.4

40

31

33

35

38

43

50

76

23

25

27

33

46

68

185

.2

.3

.4

.9

2.2

8.9

43

1 Observed record extended to reference period 1924-55 by relation with records at otter stations.

2 Data are applicable to reference period 1929-57 if all discharge is lowered 10 percent.

3 Data are applicable to reference period 1913-57 if all discharge is raised 10 percent.

4 Data are also applicable to reference period 1929-57.

5 Data are also applicable to reference period 1913-57.
LOW-FLOW FREQUENCY CURVES, EASTERN UNITED STATEf G19

1000 

500:

1.03 1.2

IB-4765 :

3A-C215 -

IB-5620 : 

(10)

10 20 50 1.03 1.2 2 

RECURRENCE INTERVAL, IN YEARS

1000

500

100

50

500

100

50

100

50

10

1000

500

100

1000

500

100

50

10 20 50

FIGURE 2. Low-flow frequency curves of 7-, 30-, 120-, and 274-day data for first 10 stations I'^ted in table 1.
G20 CONTRIBUTIONS TO THE HYDROLOGY OP THE UNIT-ED STATES

10,000

5000

1000

500

1000

500

100

50

1000

500

100

5000

1000

500

1000

500

100

50

-5365 '-

3B-5240 : 

(12)

2A-0195 - 

(13)

3A-1680 E 

(14)

3B-4900 E 

(15)

18-6680 - 

(17)

2A-0625 - 

(18)

2/»-0550 : 

(19)

1.03 1.2 5 10 20 50 ^-03 TO! 1.2 2 

RECURRENCE INTERVAL, IN YEARS

5 10 20 50

1000

500

100

50

1000

500

100

50

10

1000

500

100

500

100

50

10

FIGUEE 3. Low-flow frequency carves of 7-, 30-, 120-, and 274-day data for last nine stations listed In table 1.
LOW-FLOW FREQUENCY CURVES, EASTERN UNITED STATES G21

5000

1000

500

100

50

5000

1000

500

5000

1000

500

500

100

50

10

2A-1025 E 

(20)

3B-4515 E 

(21)

3B-5030 - 

(22)

3B-5500 - 

(23)

2A-1165 E

5000

1000

500

100

1.03 1.2 10 20 50 1.03 1.2 2 

RECURRENCE INTERVAL, IN Y£ARS

5 10 20 50

FIGURE 4. Low-flow frequency curves of 7- 30-, 120-, and 274-day data for the stations listed in table 2.
G22 CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

500

100

50

1000

500

100

50

aoo

50

10

5

1000

500

100

50

10

28-4040 E 

(25)

28-4795 : 

(26)

28-4555 - 

(28)

7-0570 E 

(30)

500

100

50

10

5

1000

500

100

50

10

500

100

50

10

5

10,000

5000

1000

500

1.03 1.2 5 10 20 50 1.03 1.2 2 5 

RECURRENCE INTERVAL, IN YEARS

10 20 50

FIGURE 5. Low-flow frequency curves of 7-, 30-, 120-, and 274-day data for first eight stations listed in table 3.
LOW-FLOW FREQUENCY CURVES, EASTERN UNITED STATES G23

10,000

5000

1000

10,000

5000

5000

1000

5.00

10,000

5000

1000

1000

500

100

50

2B-3195 

(33)

2B-2260 - 

(34)

2B-3395 : 

(35)

2B-3525 : 

(36)

2B-2185 - 

(37)

1.03 1.2

2B-387? :

\

7-364f E 

(39)

8-013!? ~ 

(41)

8-022? ; 

(42)

10 20 50 1.03 1.2 2 

*. RECURRENCE INTERVAL, IN YEARS

10 20 50

5000

1000° 

500

100

iooa

500

100

50

iooa

500

100O 

500

100

50

100O 

500

100

50

10

FIGUBE 6. Low-flow frequency curves of 7-, 30-, 120-, and 274 day data for second group of 10 stations listed

in table 3.
G24 CONTRIBUTIONS TO THE HYDROLOGY OF THE TOTTED STATES

10,000

5000

1000

5000

1000

500

500

100

50

5000

1000

500

2B-4790 : 

(43)

2B-4860 -j 

(44)

2B-4875 - 

(45)

2B-4415 : 

(46)

1.03 1.2 10 20 50 1.03 1.2 2 

RECURRENCE INTERVAL, IN YEARS

5 10 20 50

JFIGUBE 7. Low-flow frequency curves of 7-, 30-, 120-, and 274-day data for third grom of eight stations

listed in table 3.
LOW-FLOW FREQUENCY CURVES, EASTERN UNITED STATES G25

500

100

50

10

5

1

5000

1000

500

o 100

CD 50

-T I 1 I IP \ _

8-1710 3

'10,000 

5000

1000

500

100

V

(51)

8-0335 

(52)

8-0305 : 

(53)

1.03 1.2 2 5 10 20 50 

RECURRENCE INTERVAL, IN YEARS

FIGURE 8. Low-flow frequency curves of 7-, 30-, 120-, and 

274-day data for last three stations listed in table 3.
G26 CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

1000

500

100

50

10

1 

0.5

0.1

1000

500

100

50

10

1000

500

100

50

10 L

5-5970 -_ 

(54)

3A-3455 

(55)

5-5260 

(56)

1.03 1.2

5-4355 E 

(57)

5-5720 E 

(58)

5-5700 : 

(59)

3A-3735 

(60)

10 20 50 1.03 1.2 2 

RECURRENCE INTERVAL, IN YEARS

1000

500

100

500

100

50

10

5

1

0.5

1000

500

100

50

10

5000

1000

500

100

10 20 50

FIGUEE 9. Low-flow frequency curves of 7-, 30-, 120-, and 274-day data for first sevftn stations listed in

table 4.
LOW-FLOW FREQUENCY CURVES, EASTERN UNITED STATE * G27

1000 pr

500P

100

50

10

5000

1000

500

100

50

3B-4045 

(63)

\

3A-2125 : 

(f4)

3A-2535 - 

(65)

1.03 1.2 10 20 50 1.03 1.2 2 

RECURRENCE INTERVAL, IN YEARS

5000

1000

500

100

50

10

1000

500

100

50

100

50

5 10 20 50

FIGURE 10. Low-flow frequency curves of 7-, 30-, 120-, and 274-day data for second group of six stations

listed in table 4.
G28 CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

5000

1000 

'500

100

.1000

500

100

50

10

1000

500

100

50

10

5

1 

0,5

0.1

6B-9335 - 

(67)

7-0375 

(68)

1.03 1.2

7-1860 - 

(70)

3A-2475 

(71)

3A-1370 E 

(72)

3A-1095 ; 

(73)

10 20 50 1.03 1.2 2 

RECURRENCE INTERVAL, IN YEARS

5 10 20

1000

500

100

50

10

5

100

50

10

5

1 

0.5

500

100

50

500

100

50

10

FIQUEE'H. Low-flow frequency curves of 7-, 30-, 120-, and 274-day data for third group of seven stations

listed in table 4.
LOW-FLOW FREQUENCY CURVES, EASTERN UNITED STATE? G29

1000? 3B-4210 - 

(77)

7-0295 - 

(78)

1.03 1.2 10 20 50 1.03 1.2 2 

RECURRENCE INTERVAL, IN YEARS

1000

1500

100

50

1000

500

100

50

5 10 £0 50

FIGUEE 12. Low-flow frequency curves of 7-, 30-, 120-, and 274-day data for fourth group of six station

listed in table 4.
G30 CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

1000

1000

500

100

50 :

10

1000

500

100

500 =

100

50

10 r

1 r 

0.5 :

0.1

1.03 1.2

3B-4355 = 

(80)

7-0305 E 

(81)

3A-0705 E 

(82)

V

3A-1835 E 

(84)

3A-0510 E 

(P5)

5 10 20 50 1.03 1.2 2 

RECURRENCE INTERVAL, IN YEARS

10 20 50

500

100

50

5000

1000

500

100

50

10

1000

500

100

50

10

5

1

0.5

0.1

FIGURE 13. Low-flow frequency curves of 7-, 30-, 120-, and 274-day data for last six stations lifted in table 4.

o