GEOLOGICAL SURVEY CIRCULAR 367 . 

DEVELOPED AND· POTENTIAL WATER 

POWER OF THE UNITED STATES AND 

OTHER COUNTRIES OF THE WORLD 

DECEMBER 1954 

UNITED STATES DEPARTMENT OF THE INTERIOR 

Douglas McKay, Secretary 

GEOLOGICAL SURVEY 

W. E. Wrather, Director 

GEOLOGICAL SURVEY CIRCULAR 367 

DEVELOPED AND POTENTIAL WATERPOWER OF THE UNITED STATES 

AND OTHER COUNTRIES OF THE WORLD, DECEMBER 1954 

By Loyd L. Young 

Washington, D. C.,1955 

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

DEVELOPED AND POTENTIAL WATERPOWER OF THE UNITED STATES 

AND OTHER COUNTRIES OF THE WORLD, DECEMBER 1954 

By Loyd L. Young 

Abstract ••• 

Introduction • 

Page 

1 

2 

CONTENTS 

Definitions 

Discussion • 

Page 

• • • • • • 2 

• ••• 11 

ILLUSTRATION 

Page 

Figure 1. Increase in waterpower installations of the world, 1920-54 3 

TABLES 

Page 

Table 1. Installed capacity of waterpower plants of the world and of the United States 

compared, 1920-54 • • • • • • • • • • • • • • • • • • • • • • • • • • • • 3 

2. Summary, by countries, of capacity of waterpower plants of the world, plant 

factor, potential waterpower at ordinary minimum flow and mean flow at 

100 percent efficiency at end of 1954 • • • • • • • • • • • • • • • • • 4 

3· Potential waterpower, in horsepower, of the United States, existing flow, 

100 percent effie iency, and gross head • • • • • • • • • • • • • • • • • • 7 

4. Potential waterpower, in horsepower, of the United States, .existing storage 

and assumed development of known storage sites, 100 percent efficiency, 

and gross head • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 9 

ABSTRACT 

According to the estimates presented in 

this paper the installed capacity of the 

waterpower plants of the world was 130 

million horsepower on December 31, 1954. The 

United States had an installed capacity of 

about 35 million horsepower, or 27 percent 

of the world total. Since 1920 worldwide 

1 

waterpower installations have increased 564 

percent. Based on the ordinary minimum flow 

of streams in their present stage of development the world waterpower potential is estimated at 649 million l;lorsepower of which the 

United States possesses 36.5 million horsepower. The mean flow of the world's streams, 

it is estimated, would produce about 3 

billion horsepower of energy if all 
physically feasible sites were developed. 

In the United States the corresponding figure 

for mean flow is 116 million horsepower. 

Mean-flow waterpower potential amounts to 38 

horsepower per square mile in the United 

States. For the countries of the world as a 

whole the per-square-mile potential for mean 

flow ranges between lows of near nothing to 

a high estimated at 531 horsepower per square 

mile in Switzerland. 

By utilizing the gross head at known 

sites but without further regulation than 

now exists the low flow of streams in the 

United States could produce 36.5 million 

horsepower. However, by regulating streams 

at reservoir sites where construction is 

physically feasible it is estimated that this 

low flow potential could be almost doubled. 

The three Pacific Coast States possess about 

42 percent of the Nation's waterpower resources and these States with the 8 States 

of the Rocky Mountain area possess nearly 

65 percent of the potential waterpower of the 

United States. 

INTRODUCTION 

Classification of lands for waterpower 

purposes has been a function of the 

Geological Survey since the enactment on 

March 3, 1879, of the statute creating the 

office of the Director. The act of October 2, 

1888, specifically authorized investigations 

and reservations of sites for reservoirs and 

other hydraulic works. Insofar as they relate to the United States the tables that 

follow are a byproduct of the waterpower 

classification work. 

The potential waterpower of the United 

States was first estimated by the Geological 

Survey in 19o8. These estimates have been 

revised at intervals since that time and 

2 

were last released for 1952 as Circular 329. 

The compilation of potential and developed 

waterpower for the entire world was first 

made in 1918 when engineers of the U. S. 

Geological Survey prepared an estimate of 

the potential and developed waterpower of 

the world, by countries, for use at the 

Versailles Peace Conference. This estimate 

was published in 1921 by the Department of 

the Interior in World Atlas of Commercial 

Geology, Part II, Water Power of the World. 

Since that time the estimates, entitled 

Developed and Potential Water Power of the 

World, have been kept up to date and released at intervals of 2 to 3 years. Circular 329 was the first formal publication of 

the estimates since 1921. 

Tables 1 and 2 and figure 1 relate to 

developed and potential waterpower of the 

world as a whole and tables 3 and 4 to the 

waterpower of the United States. 

DEFINITIONS 

Installed waterpower--the total of the 

capacities shown by the name plate ratings, 

where known, or the estimated total capacities of the generating units. 

Mean flow--the average rate of discharge 

(estimated in all cases). 

Ordinary minimum flow--flow available 

95 percent of the time with existing stream 

regulation. 

Plant factor--the ratio of the average 

load to the aggregate installed capacity. 

Potential power--the aggregate horsepower estimated technically capable of being 

developed, economic infeasibility notwithstanding. 
Table 1.--Installed capacity of waterpower plants of the world and of the United States 

compared, 1920-54 

Year 1 Total capa~ i ty of waterpower United States Comparison with 1920 

plants (1,000 horsepower) as percent of (percent increase) (December) World united states total World united States 

1920 23,000 7,500 32.6 100 100 

1923 29,000 9,o87 31.3 126 121 

1926 33,000 11,177 33·9 143 149 

1930 46,000 14,885 32.4 200 198 

1934 55,000 16,(){5 29.2 239 214 

1936 60,000 17,120 28.5 261 228 

1938 63,900 17,949 28.1 278 239 

1940 69,400 19,000 27.4 302 253 

1941 71,600 19,816 27-7 311 264 

1945 77,800 24,223 31.1 338 323 

1947 86,900 24,500 28.2 378 327 

1950 101,000 27,500 27.2 439 367 

1952 115,8oo 31,000 26.8 502 413 

1954 129,718 34,700 26.8 564 463 

1 Years when estimtes were made by the U. S. Geological Survey. 

120 500 

a:: 

w 

~ 

0 

0.. 

w 90 400 (/) 1- a:: 

0 z :I: w 

(.) 

I.J.. a:: 0 1.1.1 

(/) 60 300 0.. 

z 

0 

::J 

...J 

~ 

30 200 

0 ~~--~--~--~--~--~~--~--~--~--~--L-~--~100 

1920 19 25 1930 1935 1940 1945 1950 1955 

Figure 1. Increase in waterpower installations of the world, 1920·54. 

3 
Table 2.--Summary, by countries, of capacity of waterpower plants of the world, plant factor, 

potential waterpower at ordinary minimum flow and mean flow at 100 percent 

efficiency at end of 1954 

Installed Plant Potential waterpower 

Continent and country waterpower factor Based on ordinary Based on mean flow minimum flow 

(1,000 hp) (percent) (1,000 hp) (1,000 hp) (hp/sq mi) 

Africa • . . . . . . . . . . 1,249.1 250,990 856,050 

Asia • . . . . . . . . . . . 14,948.8 155,700 865,200 

Europe • . . . . . . . . . . 54,793.0 63,780 220,300 

North America . . . . . . . 52,628.2 92,100 330,000 

Oceani • . . . . . . . . . . 1, 951.5 23,350 182,400 

South America . . . . . . . 4z147.5 62,700 625,000 

World • . . . . . . . 129,71S.1 648,620 3,078,950 

Africa: 

Algeria • . . . . . . . . 278.0 15 300 8,000 9 

Anglo-Egyptian Sudan . . - - 1,000 26,000 27 

Angola . . . . . . . . . 14.0 21 5,700 105,000 216 

Bechuanaland . . . . . . - - 30 5,000 18 

Belgian Congo and Mandate 355.0 63 130,000 240,000 260 

British Somaliland . . . - - - 100 3 

Dahomey • . . . . . . . . - - Boo 3,000 75 

Egypt • . . . . . . . . . 20.0 - 500 1,200 3 

Eritrea • . . . . . . . . 8.6 - - 300 1 

Ethiopia . . . . . . . . 9.0 50 5,700 47,000 115 

French Cameroons . . . . 40.0 - 7,000 10,000 294 

French Equatorial Africa - - 40,000 115,000 126 

French Guinea • . . . . . 12.0 - 3,000 15,000 169 

French Mandate in Togo . - - 400 2,000 140 

French Sudan and Senegal - - 1,400 2,500 6 

Gambia . . . . . . . . . - - - (a) (a) 

Gold Coast and British 

Mandate in Togo . . . 10.0 - 2,000 10,000 109 

Ivory Coast _. . . . . . . - - 3,000 15,000 83 

Kenya • . . . . . . . . . 20.0 46 2,000 22,500 100 

Liberia • . . . . . . . . 7-5 16 5,700 10,000 233 

Libya • . . . . . . . . . - - - 200 ·3 

Madagascar . . . . . . . 14.0 25 7,000 55,000 241 

Mauritius and Reunion 10.0 35 - 250 148 

Morocco • . . . . . . . . 193.0 25 350 2,000 12 

Mozambique . . . . . . . 14.0 - 5,000 20,000 66 

Nigeria and British 

Cameroons . . . . . . . 22.0 51 13,000 30,000 80 

Nyasaland • . . . . . . . - - 1,000 5,000 133 

Portuguese Guinea • . . . - - - 150 11 

Rhodesia . . . . . . . . 40.5 42 3,500 25,000 57 

Rio de Oro, Saguia Hamra, 

South Morocco and Ifni - - 350 1,000 9 

Sierra Leone . . . . . . - - 2,500 5,000 179 

Somali land . . . . . . . - - - 200 .s 

Southwest Africa • • • • - - 200 2,000 6 

Spanish Guinea (Rio Muni) - - 1,000 4,000 444 

Spanish Morocco • . . . . 15.0 28 10 150 14 

Tanganyika . . . . . . . 28.5 18 4,000 35,000 102 

Tangier • . . . . . . . . - - - (a) (a) Tunisia • . . . . . . . . 10.0 - 40 500 10 

Uganda . . . . . . . . . 126.0 - 4,000 20,000 212 

Union of South Africa • . 2.0 45 450 13,000 28 

Total • . . . . . . . . 1,249.1 250,990 856,050 

a Small 

4 
Table 2.--Summary, by countries, of capacity of waterpower plants of the world, plant factor, 

potential waterpower at ordinary minimum flow and mean flow at 100 percent 

efficiency at end of 1954--Continued 

Installed Plant 

Continent and country waterpower factor 

(1,000 hp) (percent) 

As~a: 

Afghanistan • • • • • • • 

B1.1rma • • • • • • • • • 

Ceylon • • • • • • • • 

Chinese Republic • • • • 

Formoso • • • • • • • • • 

French Indo China • • • 

India • • • • • • • • • 

Iran (Persia) • • • • • • 

Iraq and Saudi Arabia • • 

Israeli, Lebanon, Syria 

and Trans -Jordan • • • 

Japan • . . • • • • • • • 

Korea • • • • • • • • • • 

Manchukuo •••••••• 

Pakistan • • • • • • • • 

Siam and Malay States •• 

40.0 

10.0 

45.0 

3·5 

470.0 

.2 

1,000.0 

1.1 

50.0 

10,000.0 

1,800.0 

2o8.o 

84.0 

80.0 

Turkey • • • • • • • • • 32 • 0 

Union of Soviet Socialist 

Republics • • • • • • • 1--:=-l•r....:12:;::~~5· 0;.-.----1 

Total • • • • • • • 14,948.8 

Europe: 

Albania • • • • • • • • 

Austria • • • • • • • • • 

Belgium and Luxembourg • 

Bulgaria • • • • • • • • 

Czechoslovakia • • • • • 

Denmark • • • • • • • • • 

Eire ••• 

Estonia •• 

Finland •• 

France 

Germany • • • • • • • • 

Great Britain and North 

Ireland • • • • • • • • 

Greece • • • • • • • • • 

Hungary • • • • • • • • • 

Iceland • • • • • • • • • 

Italy • • • • • • • • • • 

Latvia and Lithuania • • 

Netherlands • • • • • • • 

Noi"WBy • • • • • • • • • 

Poland • • • • • • • • • 

Portugal 

Rumania •• 

Spain • • • 

Sweden •• 

Switzerland 

Union of Soviet Socialist 

8.0 

2,500.0 

38.0 

80.0 

300.0 

16.0 

250.0 

22.0 

1,150.0 

9,400.0 

4,ooo.o 

1,100.0 

15.0 

30.0 

83.0 

9,500.0 

100.0 

1.0 

5,250.0 

200.0 

875.0 

125.0 

3,000.0 

5,800.0 

4,550.0 

Republics • • • • • • • 6,000.0 

Yugoslavia • • • • • • • 400.0 

Total ••••••• 54.793.0 

a Small. 

b Available 50 percent of the time. 

27 

68 

44 

48 

65 

53 

35 

53 

30 

40 

40 

35 

59 

62 

30 

35 

6o 

38 

44 

30 

20 

59 

62 

42 

62 

42 

28 

27 

38 

6o 

45 

40 

40 

5 

Potential waterpower 

Based on ordinary 

minimum flow 

(1,000 hp) 

Based on mean flow 

100 

5,000 

500 

22,000 

1,000 

6,000 

27,000 

300 

(a) 

(a) 

12,000 

3,000 

1,000 

7,000 

5,700 

500 

64.000 

155,700 

200 

2,600 

75 

300 

700 

30 

500 

100 

1,000 

6,000 

2,000 

750 

350 

200 

700 

6,000 

150 

25 

10,000 

1,000 

600 

2,000 

3,500 

4,000 

3,000 

14,000 

4.000 

63.780 

(1,000 hp) 

10,000 

125,000 

1,500 

100,000 

3,000 

90,000 

115,000 

4,000 

1,500 

200 

25,000 

5,009 

8,000 

20,000 

25,000 

1,000 

b ~25.000 

865,200 

2,000 

9,000 

300 

1,000 

1,700 

100 

1,500 

200 

2,500 

20,000 

5,000 

2,500 

3,000 

1,000 

3,000 

20,000 

400 

100 

27,'000 

1,500 

2,000 

8,000 

16,000 

21,000 

8,500 

b 50,000 

1~.000 

220,300 

(hp/sq mi) 

41 

473 

59 

26 

216 

330 

94 

6 

3 

2 

173 

94 

20 

53 

100 

23 

45 

188 

278 

24 

23 

34 

6 

55 

11 

19 

94 

37 

27 

59 

28 

76 

172 

9 

8 

222 

12 

56 

81 

82 

121 

531 

43 

131 
Table 2.--Summary, by country, of capacity of waterpower plants of the world, plant factor, 

potential waterpower at ordinary mintmum flow and mean flow at 100 percent 

efficiency at end of 1954--Continued 

Installed Plant Potential Waterpower 

Based on ordinary Continent and country waterpower factor minimum flow Based on mean flow 

(1,000 hp) (percent) (1,000 hp) (1,.000 hp) (hp/sq mi) 

North America: 

Alaska • . . . . . . . . . 68.0 - 2,000 15,000 26 

British Honduras • . . . . - - 100 500 56 

Canada • . . . . . . . . . 16,684.0 60 36,600 95,000 25 

Costa Rica • . . . . . . . 31.0 55 1,400 8,000 407 

Greenland . . . . - - 1,000 15,000 18 

Guatemala . . . . . . . . 35.0 34 2,100 12,000 285 

Honduras • . . . . . . . . 7-5 45 1,400 8,000 135 

Mexico • . . . . . . . . . 900.0 40 8,500 45,000 59 Nicaragua . . . . . . . . ·1 48 1,100 6,000 105 

Panama (including Canal 

Zone • . . . . . . . . . 70.0 62 700 4,000 140 

Salvador • . . . . . . . 26.0 32 300 1,500 ll4 

United States . . . . . . 34,700.0 60 36,500 116,000 38 

West Indies . . . . . . . 1o6.o - 500 4,000 48 

Total . . . . . . . . 52,628.2 92,100 330,000 

Oceani: 

Australia and Tasmania • . 440.0 57 1,000 38,000 13 

Borneo, including New 

Guinea and Papua . . . . 5.0 - 10,500 70,000 ll7 

Celebes . . . . . . . . . ·5 - 1,400 9,000 124 

Hawaii • . . . . . . . . . 25.0 - 150 400 100 

Java. . . . . . . . . . 140.0 32 1,100 10,000 205 

New Zealand . . . . . . . 1,193.0 54 5,000 ll,OOO lo6 

Philippine Islands . . . . 110.0 - 2,000 17,000 147 

Sumatra . . . . . . . . . 20.0 32 2,000 26,000 152 

Other Islands . . . . . . 18.0 - 200 1,000 125 

Total . . . . . . . . 1,951.5 23,350 182,400 

South America: 

Argentina . . . . . . . . 140.0 24 5,400 40,000 37 

Bolivia . . . . . . . . 65.0 49 3,600 30,000 73 

Brazil • . . . . . . . . 2,585.0 32 20,000 240,000 73 

British Guiana • . . . . . - - 3,600 20,000 224 

Chile . . . . . . . . . 550.0 43 1,000 25,000 87 

Columbia • . . . . . . . 200.0 38 5,400 100,000 227 Dutch Guiana • . . . . . . - - 1,100 10,000 184 Ecuador . . . . . . . . . 22.0 38 2,000 35,000 348 French Guiana . . . . . . - - 700 7,000 201 Paraguay -5 - 2,800 10,000 64 

Peru • . . . . . . . . . . 325.0 26 6,400 55,000 114 Uruguay . . . . . . . . . 180.0 50 400 3,000 42 Venezuela . - . . . . . . 8o.o 53 4.300 '50.000. 141 Total . . . . . . . . 4,147.5 62,700 625,000 

6 
Table 3.--Potential waterpower, in horsepower, of the United States, existing flow, 100 percent 

efficiency, and gross head 

Available 95 Available 50 Based ·on 

State and division percent of percent of mean flow the time the time 

New England • . . . . . . . . . . 1,052,000 2,455,000 3,669,000 

Middle Atlantic . . . . . . . 4,465,000 7,864,000 9,862,000 

East North Central . . . . . 1,013,000 2,296,000 3,480,000 

West North Central . . . . . 1,667,000 j,238,ooo 4,947,000 

South Atlantic . . . . . . 2,067,000 5,176,000 7,663,000 

East South Central . . . . 2,660,000 5,035,000 7,473,000 

West South Central . . . . . 667,000 1,256,000 2,769,000 

Mountain . . . . . . . . . . 7,9o4,ooo 14,709,000 25,698,000 

Pacific . . . . . . . . . . . . 14ffi5,000 33,149,000 50,000,000 

United States . . . . . . . . 36,460,000 75,178,000 115,561,000 

New England: 

Maine . . . . . . . . 463,000 1,108,000 1,515,000 

New Hampshire . . . . . . . . 295,000 552,000 917,000 

Vermont . . . . . . . . . . 107,000 276,000 429,000 

Massachusetts . . . . . . 134,000 322,000 502,000 

Rhode Island . . . . . . . . 7,000 19,000 28,000. 

Connecticut • . . . . . . . 46,000 178,000 278,000 

Middle Atlantic: 

New York . . . . . . . . 4,183,000 6,452,000 7,677,000 

New Jersey . . . . . . . . . 12,000 86,000 125,000 

Pennsylvania . . . . . . . . . 270,000 1,326,000 2,o6o,ooo 

East North Central: 

Ohio . . . . . . . . 25,000 109,000 209,000 

Indiana • . . . . . . . . . . 54,000 186,000 327,000 

Illinois . . . . . . . . . . 284,000 711,000 1,136,000 

Michigan . . . . . . . . . 319,000 571,000 842,000 

Wisconsin • . . . . . . . 331,000 719,000 966,000 

West North Central: 

Minnesota • . . . . . . . . 215,000 528,000 857,000 

Iowa . . . . . . . . . . . 109,000 331,000 546,000 

Missouri . . . . . . . . . . 418,000 939,000 1,408,000 

North t8kota . . . . . . 232,000 323,000 443,000 

South Dakota . . . . . . . 519,000 763,000 1,139,000 

Nebraska . . . . . . . . . . . 123,000 217,000 343,000 

Kansas . . . . . . . . . 51,000 137,000 211,000 

South Atlantic: 

Delaware . . . . . . . . 2,000 7,000 11,000 

Maryland and the District of 

Columbia . . . . . . . . 80,000 334,000 550,000 

Virginia . . . . . . . . . 253,000 762,000 1,219,000 

West Virginia • . . . . . . 245,000 1,054,000 1,601,000 

North Carolina . . . . . . 461,000 1,133,000 1,455,000 

South Carolina . . . . . . . 579,000 1,027,000 1,226,000 

Georgia • . . . . . . . . 439,000 823,000 1,519,000 

Florida • . . . . . . 8,000 43,000 82,000 

7 
Table 3.--Potential waterpower, in horsepower, of the United States, existing flow, 100 percent 

efficiency, and gross head--Continued 

Available 95 Available 50 Based on State and division percent of percent of 

the time the time mean flow 

East South,Central: 

Kentucky • . . . . . . . 316,000 617,000 1,168,000 

Tennessee . . . . . . . . . . 1,328,000 2,380,000 3,243,000 

Alabama . . . . . . . . . . . 966,000 1,9o4,ooo 2,687;000 

Mississippi . . . . . . . 50,000 134,000 375,000 

West South Central: 

Arkansas . . . . . . . . . . . 135,000 333,000 888,000 

I.Duisiana . . . . . . . . 51,000 97,000 330,000 

Oklahoma . . . . . . . . 181,000 416,000 791,000 

Texas . . . . . . . . . . 300,000 410,000 760,000 

Mountain: 

Montana . . . . . 1,494,000 2,454,000 4,291,000 

Idaho . . . . . . . . 2,750,000 5,381,000 9,264,000 

Wyoming . . . . . . . 282,000 554,000 1,324,000 

Colorado . . . . . . . . . 385,000 1,184,000 2,323,000 

New Mexico • . . . . . . . . . 91,000 182,000 322,ooo· 

Arizona . . . . . . . . 1,548,000 2,642,000 4,184 ,ooo 

Utah • . . . . . . . . . 791,000 1,743,000 3,420,000 

Nevada • . . . . . . . . . . 563,000 569,000 570,000 

Pacific: 

Washington • . . . . . . . . 6,651,000 15,824,000 25,000,000 

Oregon • . . . . . . 4,492,000 9,172,000 12,500,000 

California • . . . . . . . . . 3,822,000 8,153,000 12,500,000 

8 
Table 4.--Potential waterpower, in horsepower, of the United States, existing storage and 

assumed development of known storage sites, 100 percent efficiency, 

and gross head 

Available 90 percent Available 50 percent 

State and division of the time of the time 

Horsepower Percent Horsepower Percent 

New England . . . . . . . 1,538,000 2-35 2,5.45,000 2.94 

Middle Atlantic . . . . . . 6,505,000 9-95 8,415,000 9.82 

East North Central . . . . . . 1,241,000 1.90 2,342,000 2-75 

West North Central . . . . 2,701,000 4.13 3,646,000 4.27 

South Atlantic . . . . . . . 4,200,000 6.43 5,801,000 6.79 

East South Central . . . . . . 3,976,000 6.o8 5,670,000 6.62 

West South Central . . . . 1,407,000 2.15 1,830,000 2.14 

Mountain . . . . . . . . 16,939,000 25-91 19,530,000 22.78 

Pacific . . . . . . . . . 26,867,000 41.10 35,876,000 41.89 

United States . . . . 65,374,000 100.00 85,655,000 100.00 

New England: 

Maine . . . . . 749,000 1.15 1,151,000 1.30 

New Hampshire . . . . . 397,000 .61 596,000 -70 

Vermont . . . . . 134,000 .20 277,000 -32 

Massachusetts . . . . . . 177,00 .27 323,000 .38 

Rhode Island . . . 7,000 .01 19,000 .02 

Connecticut . . . . . . . . . . 74,000 .11 179,000 .22 

Middle Atlantic: 

New York . . . . . . . . . 5,649,000 8.64 6,903,000 8.o6 

New Jersey . . . . . . . 46,000 .07. 86,000 .10 

Pennsylvania . . . . . . . 810,000 1.24 1,426,000 1.66 

East North Central: 

Ohio . . . . . . . . . . 44,000 .07 110,000 .13 

Indiana . . . . . . . 85,000 .13 227,000 .27 

Illinois . . . . . 3o6,ooo .47 710,000 .83 

Michigan . . . . . . . 386,000 -59 571,000 .67 

Wisconsin . . . . . . . . 420,000 .64 724,000 .85 

West North Central: 

Minnesota . . . . . . 300,000 .46 554,000 .65 

Iowa . . . . . . . . . 137,000 .21 331,000 -39 

Missouri . . . . . . 696,000 Lo6 1,o61,000 1.24 

North Dakota . . . . . . . . 374,000 -57 386,000 .45 

South Dakota . . . . . 827,000 1.27 854,000 1.00 

Nebraska . . . . . 263,000 .40 313,000 -37 

Kansas . . . . . . . lo4,ooo .16 147,000 .17 

South Atlantic: 

Delaware . . . 3,000 .00 7,000 .01 

Maryland and the District of 

Columbia . ... 286,000 .44 409,000 .48 

Virginia . . . . . . 667,000 1.02 930,000 1.09 

West Virginia . . . . . 8o4,ooo 1.23 1,121,000 1.31 

North Carolina . . . 831,000 1.27 1,170,000 1.37 

South Carolina . . . . 681,000 l.o4 1,074,000 1.25 

Georgia . . . . . . . 889,000 1.36 l,o4l,OOO 1.22 

Florida . . . . . . 39,000 .o6 49,000 .o6 

9 
Table 4.--Potential waterpower, in horsepower, of the United States, existing storage and' 

assumed development of known storage sites, 100 percent efficiency, 

and gross head--Continued 

Available 90 percent Available 50 percent 

State and division of the time of the time 

Horsepower Percent Horsepower Percent 

East South Central: 

Kentucky • . . . . . . . . . 557,000 0.85 780,000 0.91 

Tennessee . . . . . . 1,829,000 2.80 2,571,000 3.00 

Alabama . . . . . . . . . 1,400,000 2.14 2,100,000 2.45 

Mississippi . . . . . . . 190,000 .29 219,000 .26 

West South Central: 

Arkansas . . . . 554,000 .84 740,000 .86 

louisiana . . . . . . 77,000 .12 99,000 .12 

Oklahoma. . . . . . . . . . 326,000 -50 477,000 .56 

Texas . . . . . . . . 450,000 .69 514,000 .60 

Mountain: 

Montana . . . . . . . . . 2,770,000 4.24 3,359,000 3-92 

Idaho . . . . . . . . 4,530,000 6.93 5,870,000 6.85 

Wyoming . . . . . . . 573,000 .88 757,000 .88 

Colorado . . . . . 1,360,000 2.o8 1,636,000 1.90 

New Mexico . . . . . . 223,000 .34 291,000 .34 

Arizona . . . . . . . . 4,588,000 7.02 4,613,000 5.39 

Utah . . . . . . . . . 2,205,000 3-37 2,3o8,ooo 2.69 

Nevada . . . . . . . 690,000 1.05 696,000 .81 

Pacific: 

Washington . . . . . . 12,711,000 19.44 17,414,000 20.33 

Oregon . . . . . . . 6,753,000 10.33 8,999,000 10.51 

California • . . . . . . 7,403,000 11.33 9,463,000 11.05 

Outlying possessions: 

Alaska • . . . . . 7,143,000 - 9,286,000 - Puerto Rico . . . . . . . . 27,000 - 40,000 - Hawaii . . . . . 103,000 - 250,000 -

10 
DISCUSSION 

In preparing the original estimates of 

the developed and potential waterpower of 

the world the estimates published by the 

various countries were used wherever available. However, there were many areas where 

studies of potential power had not been 

made. For these areas the probable potential was determined from existing data on 

rainfall and topography. In cases where 

these data were later supplanted by estimates prepared in the countries themselves 

the two were in reasonable agreement. 

To keep the estimates of developed 

waterpower up to date all available sources 

have been used. In recent years this has 

been done almost entirely by following the 

waterpower developments of the various countries from reports and articles in yearbooks: from publications of the Department 

of Commerce, the Federal Power Commission, 

the World Power Conference, the United 

Nations, the International Union of Produc- ers and Distributors of' Electric Energy; and 

from various engineering and scientific 

journals appearing in the United States and 

abroad. Statistical information on waterpower development is never strictly up to 

date and recent development must be estimated for many countries. Nevertheless, 

the world total of 129.7 million horsepower 

of installed capacity is reasonably correct. 

Figure 1 shows the increase of waterpower installations since the first estimates were released. Table 1 shows the 

total installed capacity as determined for 

the various releases since 1920 and the percentage of increase over 1920. During the 

period studied installations estimated at 

23 million horsepower in 1920 were increased 564 percent to 129.7 million horsepower in 1954. T}le current situation is 

shown in table 2 where installed capacity, 

plant factor, and potential waterpower 

available with existing low and mean flow 

are given by country and continent. The 

mean-flow potential is also shown on a persquare-mile basis. 

Developed power by countries is based 

on the installed capacity of water wheels 

at constructed plants; it averages two to 

four times and may be as many as ten times 

the potential power at low flow at the same 

sites. This fact should be considered in 

comparing the potential power with the 

developed power and also in evaluating the 

percentage of the utilized waterpower re- sources of a nation. For any country a 

rough estimate of the ultimate installed 

11 

capacity of water wheels can be obtained by 

assuming it will equal the power available 

at mean flow and 100 percent efficiency. 

Mean flow is the constant flow required to 

equal the average annual volume. For the 

United States mean flow ·is roughly equal to 

the flow available 25 percent of the time. 

The sites already utilized are presumably 

the best sites in a country except where 

development is regulated for the purpose of 

preserving the scenic values, as at Niagara 

Falls, or in large countries where otherwise 

attractive sites are at long distances from 

populated areas. 

Table 1 shows an increase in installed 

capacity of water wheels of nearly 107 .million horsepower in the 34 years since 1920, 

yet the increase is continuing throughout 

the wor~d. The shortage of fuel, both oil 

and coal, and the increase in fuel prices 

makes waterpower seem more desirable than 

ever. The trend toward multiple-purpose 

projects and basin-wide conservation and 

development of resources has accelerated the 

rate of waterpower installation. New interest, with the resultant increased activity 

in the development of waterpower resources, 

is almost universal. 

At one time there was a question as to 

where to find a market for power from large 

projects such as Grand Coulee. Now, with 

wide interconnection, the market has outstripped the supply. Because of ease and 

speed of communication, travel, and transportation workmen are willing to live near 

remote waterpower sites. This accounts for 

a considerable proportion of present new 

waterpower developments and for development 

plans. 

The Union of Soviet Socialist Republics 

reportedly has many plants under construction 

but specific information on developments in 

that country is lacking. All the countries 

of Western Europe, Australia, New Zealand, 

and Japan, as well as many South American 

countries, are constructing waterpower plants 

and conducting water-resources studies at an 

unprecedented rate. In Africa waterpower 

sites are being studied with increasing interest, several large projects have been 

undertaken, and some plants of considerable 

size are actually producing electric current. 

Everywhere the power can be used as soon as 

it becomes available. 

The figures for installed capacity of 

water wheels, although fairly exact in themselves, do not present a complete picture of 

the utilized waterpower. In some countries 

with abundant resources of waterpower only 
the better sites are developed, and therefore the machinery installed can be operated 

to capacity a considerable part of the year. 

In other countries the installation is such 

that it can be used to full capacity for 

perhaps only 25 percent of the year. At 

other times it can be used to carry the peak 

load but not continuously. 

A stream can rarely, if ever, be made 

to flow constantly at an average rate and 

even if this were possible the demand for 

power rises and falls with the season and 

time of day. For these reasons installations invariably are larger than the average output of any powerplant would require 

if it operated continuously at full capacity. The plant factor indicates the amount 

by which the installation exceeds the capabilities of the plant, and, if fully developed, the power site itself. A plant factor 

of 50 percent indicates that an installation 

half the size would produce the same number 

of unit hours during a given period if it 

operated at full capacity the entire time. 

For Algeria the plant factor is extremely low, but it is based on reliable 

figures. This low plant factor is probably 

caused by the extreme variations in flow of 

streams in the area. The plant factor given 

for Canada seems high, yet it may be underestimated as it does not take into account 

the industrial plants, some of which have a 

very high plant factor. For Argentina the 

plant factor seems low, but it may be that 

the waterpower plants there carry mostly 

peak loads. For Peru it is possible that 

the reported output does not include some 

industrial plants and thus gives a corre- sponding low plant factor. 

In Europe the high plant factors for 

Bulgaria, Czechoslovakia, and Hungary may be 

due to the estimate of installed capacity 

being low because firsthand information on 

these countries is not available. Germany 

has large pumped storage plants for peaking 

purposes, and some of the power for pumping 

is supplied by steam plants. If the reported output includes power from pumped 

storage, which is not strictly comparable to 

the waterpower produced in other countries, 

the plant factor for Germany would be proportionately higher. For the Union of 

Soviet Socialist Republics the combined capacity of plants in Europe and Asia was used 

to obtain the plant factor. Information on 

the distribution of plants between eastern 

and western Russia is very limited, and the 

estimated values are only rough approximations. 

The plant factor for Korea is based on 

the output for 1943, which indicates that 

12 

the figure for the installed capacity is 

reasonably reliable for that time. Although 

some of the plants were damaged by war, it is 

assumed that they can be restored. The 

plants in Australia are located mainly in 

Tasmania where the nature of the streams 

makes a high plant factor possible. Australia 

is now building new plants with an ultimate 

capacity of over 1 million horsepower, but, 

owing to the regimen of the streams being 

developed, the new plants may not have the 

high plant factors of those now in operation. 

Japan and Italy illustrate the importance of the plant factor. Japan not only 

has a large total installed capacity but a 

very high plant factor. Italy, with approximately the same total installations, has a 

rather low plant factor. Using the average 

for the years 1950-54, Japan produced roughly 

50 percent more energy, operating at a plant 

factor of about 65 percent, than did Italy 

where the plant factor was 42 percent. Likewise, the installed capacity of Europe is 

greater than for North America, but the plant 

factors for the United States and Canada show 

that the output rate per installed horsepower 

is greater in North America. 

The estimates of potential waterpower 

by countries used in table 2 include developed and undeveloped sites and are computed 

at 100 percent efficiency. Estimates previous to 1937 were based on an assumed efficiency of 70 percent, and the change to 100 

percent efficiency was made to put the estimates on the same basis as those for the 

World Power Conference. For the same reason 

the effect of storage has been disregarded 

except for constructed reservoir sites, the 

potential power being based on the existing 

flow. In the United States the existing 

minimum flow is sufficient to produce 365 

million firm horsepower, but construction of 

reservoirs at known sites would increase the 

minimum flow sufficiently to double the present minimum-flow power. Such possibility for 

increase is doubtless true of most other 

countries. Estimates of the potential power 

based on the mean flow are considered quite 

reliable for the United States, Canada,and 

most countries of western Europe. They represent the amount of horsepower which is 

physically developable assuming mean flow of 

streams, gross head of sites, and 100 percent 

efficiency of plants. Except in instances 

where they may be too low because of lack of 

basic data, the estimates are considerably 

above the economically feasible power possibilities of a given country. The per-squaremile concentration of the mean-flow potential 

is an index to the relative position of an 

area insofar as waterpower resources are con- cerned. Comparison of the ratio of power at 

ordinary minimum flow to power at mean flow 
usually reveals the degree of variation in 

streamflow. 

It should be pointed out that the estimates of potential power for the United 

States, Canada, and many countries of Europe 

are based on known sites. For other countries, particularly in Asia (except Japan), 

Africa, and South America (except Brazil), 

the estimates are based principally on rainfall and topography and consequently are not 

as dependable. It is difficult to present 

in figures any exact estimate of the potential waterpower resources of a country. The 

flow of streams varies from year to year, 

and the storage required to equalize given 

flows varies with climate and other factors. 

However, in all countries the estimated potentials tend to approximate minimum and 

maximum power technically possible of development. The economic feasibility limit of 

power development will invariably be lower 

for a given flow rate than the estimate presented here. 

The largest unsurveyed areas as well as 

those with the greatest waterpower resources 

are central Africa and northern Asia. Central Africa, because of the heavy rainfall, 

undoubtedly has immense resources of waterpower and the need for cheap power in large 

amounts for metallurgical purposes will undoubtedly lead to the utilization of some of 

the sites, especially those within transmission distance of the Coast. In northern 

Asia there are large rivers, but, except at 

the headwaters, the precipitation is low and 

probably not well distributed throughout the 

year. The feasibility of util~zing these 

resources, therefore, is dependent upon the 

existence of good dam and reservoir sites. 

Another disadvantage to this area is the 

distance from ocean transportation. 

Lake Nyasa in Africa is an interesting 

example of a large waterpower resource with 

enormous obstacles to overcome before practical use can be made of it. The 2300-foot-deep 

lake lies on a plateau about lPOO feet above 

sea level. It has an area of 11,600 square 

miles and claims an additional 38,660-squaremile catchment area. Thirteen hundred feet 

of the total drop to the sea is concentrated 

in a 40-mile reach of the outlet stream, the 

Murcnison Cataract of the Shire River. However, the fall does not occur until the Shire 

River has meandered 75 miles across flat and 

swamplike terrain. The country around the 

lake and its outlet is so flat that debris 

brought down tributary streams will consolidate into obstructing bars upon which vegetation grows rapidly and floating weeds 

accumulate, thus seriously impeding the flow 

of the Shire. From 1914 to 1934 such a barrier damned the outlet to Lake Nyasa and 

prevented outflow even though the lake was 

13 

storing water a:t a rate of 6,000 cfs. If 

some economical method of controlling the 

level of the water in the lake and conducting 

the water through the 75-mile section to the 

head of the Murchison Cataract can be found 

at least 1 million horsepower of firm power 

could be produced. 

In China a project has been proposed 

that would involve a dam 750 feet high on the 

Yangtze River, creating a reservoir with a 

storage capacity of SO million acre-feet and 

having a powerplant of 14 million horsepower 

capacity. Such a dam and plant appear physically possible but smaller. sites are probably of greater value at present because they 

do not require such large outlays of capital. 

The potential waterpower of the United 

States, in horsepower, at 100 percent efficiency and gross head--for water available 

95 and 50 percent of the time and for the 

arithmetical mean flow under e~isting conditions--is shown in table 3· The effects of 

constructed reservoirs are reflected in this 

table, but no allowance is made for possible 

future storage. Where the center of a larger 

stream forms the boundary between States, the 

power has been divided between the States. 

Where a dam in one State backs water into a 

neighboring State the power has been divided 

on the basis of the length of the reservoir 

in each State. 

Though estimates on the basis of existing conditions for different areas are comparable, they usually fall short of completely reporting the waterpower ~esources of 

many streams. This is because of the omission of the effect of possible future storage. 

On the Colorado River, for example, primary 

power without storage will be multiplied sev- eral times by reservoirs which are reasonably 

sure to be constructed. Table 4 shows the 

potential waterpower of the United States 

with storage at known, large reservoir sites, 

both developed and undeveloped. However, it 

does not include many small sites which undoubtedly will be developed at some future 

time but would not individually add materially to the pbtential of the stream or the 

country as a whole. Development of sites 

now unused would double the waterpower obtainable from our streams. 

Estimates of potential waterpower in the 

United States made by the Federal Power Commission are in essential agreement with the 

estimates presented here. The potential 

power estimates in tables 3 and 4 are sums of the estimated power available at the various sites, whereas those of the Federal 

Power Commission are estimates of the power 

installations which are likely to be made at 

these sites. By adding the Federal Power 

Corumission estimates of average annual 
output in kilowatt hours for developed and 

potential power and converting that total to 

a continuous horsepower equivalent it will 

be seen that their estimate of the total 

waterpower resources of the Ynited States is 

near the 75 million horsepower shown in table 

3 as being available 50 percent of the time 

and that it is at the midpoint between the 

14 

potential power estimated to be available 

90 percent of the time and 50 percent of the 

time with development of known stora~ sites 

in table 4. 

Estimates of tidal power are not included in this report. 

INT.-DUP. SEC., WASH., D.C.80862