WATER LEVELS OF

RNAL REPORT

THE INTERNATIONAL JOINT COMMiSSlON -

I ( Under the Reference of 25 June 1952 1-

3- BY THE INTERNATIONAL BOARD OF ENGINEERS WATER LEVELS OF LAKE ONTARIO

FINAL REPORT

THE INTERNATIONAL JOINT COMMISSION .(-Under the Reference of 25 June 1952 )

THE INTERNATIONAL LAKE ONTARIO BOARD OF ENGINEERS

December 1958 TABLE OF CONTENTS

Page

INTRODUCTION ...... 1 Authority ...... 1 Instructions to Board of ~ngineers...... 2 Membership of Board and Working Committee ...... 2 Acknowledgments ...... 3 Purpose and Scope ...... 4 Datums ...... 5

11 DESCRIPTION ...... 6 General ...... 6 Upper Great ...... 6 Lake Ontario ...... 9 St. Lawrence River ...... 12

I11 BASIC DATA ...... 19 Co-ordination Between Agencies of and the ...... -a 19 Flater Levels ...... 19 Discharges ...... 19 Hydrography and Topography ...... 20 Miscellaneous Data ...... 21

IV VARIATIONS IN LAKE ONTARIO >iATER LEVELS ...... 21 Natural Factors: ...... 21 Ranges in Lake Levels ...... 21 Inflows from the Upper Lakes ...... 22 Precipitation ...... 2Lc Evaporation ...... 25 Winds and Barometric Changes ...... 25 Ice Retardation ...... 26 ,.! Crustal Movement ...... , ..... 26 CONTENTS

Artificial Factors: ...... 28 Diversions ...... 28 Changes in the Outlet Control of Lake Ontario ...... 29 Changes in the Outlet Control of ...... 30 Changes in the Outlet Control of Lakes -Huron 33 Changes in the Outlet Control of ...... 33

INTERM REPORTS ...... General ...... 34 Report on Effect of Diversions on Lake Ontario hater Levels ...... 34 Report on Effect on Lake Ontario hater Levels of an Increase of 1. 000 Cubic Feet Per Second in the Diversion at Chicago for a Period of Three Years ...... 38 Report on Effects on Lake Ontario W~terLevels of the Gut Dam and Channel Changes in the Galop Rapids Reach of the St . Lawrence River ...... 40 Report on Regulation of Lake Ontario ...... 42

VI CONCLUSIONS ...... 49

(iii) LIST OF TABLES

1. S-ry of Results, Effects on Lake Ontario: Water Levels of Gut Dam and Channel Changes in the Galop Rapids Reach ... 43

LIST. OF PLATES %

1. and Pertinent Physical Data ...... 7 2. Lake Ontario Drainage Basin ...... 10 3. St. .lawrende River, Lake Ontario to Lake St. Peter ...... U- 4. and Galop Rapids Section Showing 1874 Conditions and Location of Improvements ...... 15 5. Hydrograph of Recorded Monthly Mean Water Levels of Lake Ontario at Oswego, N.Y. 186GJuly 1955 ...... 23 6. Daily and Hourly Hydrographs, Lake.Ontario at Cape Vincent, NeY. .e...e.....~n...... ~...... *.~ee*** 27' WATER LEVELS OF LAKE ONTARIO

FINAL REPORT TO THE INTERNATIONAL JOINT COMMISSION UNDER THE REF-CE OF 25 JUNE 1952

SECTION I - INTRODUCTION

Authoritg

1. In a Reference dated 25 June 1952, the Governments of Canada and the

United States of America requested the International Joint Commission to investigate and report on the following:

"In order to determine, having regard to all other interests, whether measures can be taken to regulate the level of Lake Ontario for the benefit of property owners on the shores of the lake in the United States and Canada so as to reduce the extremes of stage which have been experienced, the Governments of the United States and Canada have agreed to refer the matter to the International Joint Commission for investigation and report pursuant to Article IX of the Treaty relating to between the United States and Canada, signed January 11, 1909.

"It is desired that the Commission study the various factors which affect the fluctuations of water level on Lake Ontario, inclu- ding the construction in the St. Lawrence River known as 'kt Dm', and any diversion of water into or out of the , and shall determine whether in its judgment action can be taken by either or both Governments to bring about a more beneficial range of stage, having regard to the proposed plan for improvement for navigation and power of the International Rapids Section of the St. Lawrence River and the proposed method of regulation of the levels of Lake Ontario which is an essential feature of that plan.

"As a result of its studies under this Reference, it is desired that the Commission shall determine whether, in its judgment, changes in regard to edsting works or other measures would be practicable and in the public interest from t!le points of view of the two Governments, having in mind the order of precedence to be observed in the uses of boundary waters as provided in Article VIII of the Boundary Waters Treaty of 1909.

"In the event tha,t the Commission should find that changes in existing works or that other measures would be feasible and desirable, it should indicate how the interests on either side of the boundary would be benefited or adversely affected thereby. The Commission should estimate the cost of such changes in existing works or of such other measures, including indemnification for damage to public and private property arising therefrom and the cost of any remedial works that may be found to be necessary. With due regard to the final para- graph of this Reference and to the arrangements presently being pro- posed for development of power in the International Rapids Section of the St. Lawrence River, the Commission should indicate how the cost of , any measures and the amounts of any resulting damage should be apportioned between the interests involved.

"In the conduct of its investigation and otherwise in the per- formance of its duties under this Reference, the Commission may utilize the services of engineers and other specially qualified personnel of the technical agencies of Canada and the United States and will as far as possible make use of information and technical data heretofore acquired by such technical agencies or which may become available during the course of the investigation, thus avoiding duplication of effort and unnecessary expense.

"It is the desire of both Governments that consideration of this Reference shall not delay action by the Commission with respect to applications submitted to the Commission concerning the development of power in the Internatio~lalRapids Section of the St. Lawrence River."

Instructions to Board of En~ineers

2. Under the authority of this Reference, the lnternetional Joint Commission, in April 1953, established the International Lake Ontario Board of Engineers, the members of which were drawn from technical agencies of the two Govern- ments. In the letter of appointment-from the International Joint Cmmission, the International Lake Ontario Board of Engineers was instructed as follows:

"The duties of the Board will be to undertake through appropriate agencies in Canada and the United States, the necessary investigation and studies and to advise the Commission on all technical engineering matters which it must consider in making a report or reports to the two Governments under the Reference of 25 June 1952."

Membership nf Board and 1r;orkinp Committee 3. The International Lake Ontario Board of Engineers is composed of one representative from each Government. 14r. Gail A. Hathaway, formerly Special

Assistant to the Chief of Sngineers, Department of the Army, Washington, D.C., now Engineering Consultant to the International Bank for Reconstruction and Developent, is the United States member. Hr. T.M. Patterson, Director,

Water Resources Branch, Department of Northern Affairs and National Resources,

Ottawa, Ontario, is the Canadian member. 4. The Board arranged for technical assistance through the appointment of its International Lake Ontario Working Committee with two members each from the United States and Canada. Membership of the United States Section con- sists of Mr. F.F. Snyder, Hydraulic Engineer, Office of the Chief of

Engineers, Department of the Army, Nashington, D.C., Chairman, and IYir. Edwin

W. Nelson, Chief Engineering Consultant, Office of the Division Engineer,

North Central Division, Corps of Engineers, Chicago, Illinois. Mr. Snyder was appointed Chairman on 15 July 1957 to replace Brigadier General P.D.

Berrigan upon his resignation as member and Chairman of the United States

Section, and on the same date Ivir. Nelson was appointed a member. General

Berrigan became a member and Chairman of the United States Section vice

Colonel W.P. Trower when General Berrigan assumed responsibility as Division

Engineer, North Central Division, Corps of Engineers, on 6 June 1955. Member- of the Canadian Section consists of Mr. R.H. Clark, Chief Hydraulic

Engineer, Water Resources Branch, Department of Northern Affairs and National

Res?urces, , Ontario, Chairman, and Mr. R.H. Smith, Hydraulic Engineer,

St. Lawrence Seaway Authority, Montreal, Quebec. Mr. C .G. Cline, Hydraulic

Engineer, Department of Northern Affairs and National Resources, served as alternate to i%r. Smith pending the latter's appointment.

Acknowledgments 5. The Board recognize. ar?? ?cknowledges the major contribution that the Committee and its assistants made throughout the study and in the preparation of this report. 6. The Board also acknowledges the use of the services and of the engineer- ing facilities and equipnent of: the United States Army Corps of Bngineers, including the United States Lake Survey and the Waterways Experiment Stat4ion; the Federal Pawer Colnmission of the United States; the Power Authority of the

State of ; the Canadian Departments of Northern Affairs and National

Resources, of bfines and Technical Surveys, and of Transport; the St. Lawrence

Seaway Authority; the Hydro-Electric Power Conrmission of Ontario; the Quebec

Hydro-Electric Commission; and the Hydraulics Laboratory, National Research

Couhcil, Canada.

7. The Board also had available the reports and briefs submitted t.3 the

International Joint Commission by the various interests concerned with the regulation of the levels of Lake Ontario. Hearings under the Reference were held by the Commission at Watertown, New York, on 5 September 1952; at - on-the-Lake, Ontario, on 18 September 1952; at Detroit, Michigan, on 4 June

1953; at Rochester, New York, on 22 July 1952, 17 November 1953, and 12 April

1955; at Hamilton, Ontario, on 18 November 1953; and at , Ontario, on

23 July 1952, and 4 April 1955.

Purmse and Scope

8. This is the final report of the Board under the Reference of 25 June 1952 and summarizes the results of the investigations and studies made to advise the Commission on all technical engineering matters pursuant to instructions received from the Commission in its letter of appointment of members of the

Board and also in response to special instructions to the Board during the

course of the studies. 9. The following reports have been submitted by the Board:

1. Interim Report on Regulation of Lake ~ntario,dated 14 March 1955. (This report is included as Appendix D of the report, Regulation of Lake Ontario, dated March 1957. )

2. Effect on Lake Ontario Water Levels of an Increase of 1,000 Cubic Feet Per Second in the Diversion at Chicago for a Period of Three Years, dated l4 June 1955.

3. Effect of Diversions on Lake Ontario Water Levels, dated 15 March 1956. 4. Regulation of Lake Ontario (three volumes), dated March 1957. 5. Effects on Lake Ontario iater Levels of the Gut Dam and Channel Changes in the Gafop Rapids Reach of the St. Lawrence River (with three appendices) dated October 1958.

10. This report briefly summarizes the foregoing reports and incorporates the

results of studies of other factors affecting the levels of Lake Ontario.

Datums

ll, In the regulation studies all elevations on Lake Ontario and in the

. International Rapi.ds Section are referred to the United States Lake Survey

(U.S.L.S. ) 1935 datum. In Canada, the published water level records of the

Canadian Hydrographic Service at Surmnerstown, Ontario, on Lake St. Francis and

eastward to &iontreal Harbour are on the Ship Instrumental

datum (G.B.S.C.I. ), so that levels relating to Lake St, Francis, Lake St. Louis,

and luZontreal Harbour are on that datum. At Cornwall, Ontario, elevations on

U.S.L.S. 1935 datum are approxima.tely 0.8 foot greater than elevations on

G.E.S.C.I. datum.

12. In the studies to determine the effects on Lake Ontario water levels of

channel changes in the Galop Rapids reach, elevations on Lake Ontario and on

the St. Lawrence River are referred to the U.S.L.S. 1903 da.tum, with the

exception of the el.evations at the Ogdensburg gauge which, are referred to the

1935 datum. In the Galop Rapids reach elevations on the U.S.L.S. 1903 datw

are approdtely 0,3 foot less than elevations on the U.S.L.S. 1935 datum. -6-

SECTION I1 - DESCRIPTION

General 13. The Great Lakes basin, constituting the major part of the St. Lawrence

River system, has a drainage area, both land and water, of approximately

295,000 square above the head of the St. Lawrence River. Of this area about 41 per cent lies in Canada and the remainder in the United States. A map of the Great Lakes basin is shown on Plate 1 (page 7). The International

Boundary traverses all of the Great Lakes and their connecting channels, except which is wholly within the United States, and passes through the St. Lawrence River to a point near Cornwall, Ontario. Downstream of this point the St. Lawrence River is wholly within Canada. A map of the

St. Lawrence River from Lake Ontario to Lake St. Peter is shown on Plate 3

(page 11). The area, mean elevation, range of elevation and the mean outflow, for the period 1860 to 1954, for each of the Great Lakes are shown in the table on Plate 1 (page 7).

Upper Great Lakes l.4. Lake Superior is the uppermost and largest of the Great Lakes and dis- charges through the St. Marys River into . To compensate for power diversions around the rapids, where the greater part of the 22-foot drop to Lake Huron occurs, a gated dam was constructed across the St. Marys

River at the head of the rapids. Since the completion of this dam in 1921, the discharge from Lake Superior has been completely controlled under the supervision of the International Joint Commission through the International

Lake Superior Board of Control. The natural supply to Lake Superior has been increased by diversions from the basin through the Long Lake and - 7 - PLATE 1

PHYSICAL DATA PERTAINING TO THE GREAT LAKES (1860-1954)

Annual Drainage Area Storage Average Range Mean Outflow of Outlet Land Water ' Capacity Cubic Inches Elevation Mpnthly Lake on Surface per ~~~t Feet Mean River Area Area Total U.S.L.S. Per Drainage Square Square c.f.s. 1935 Stage Miles Miles Months Datum Feet Second Basin ----C----

Superior / 48,200 31,800 337,000 602.3 4.1 St. Marys 75.000 12.6

St. Clair 2294i10 Michigan 45'500 482,000 580.6 6.3 Lake St. Clair 189,000 11.6 ' Huron 1 49,600 23,000 Detroit Erie 30,008 9,900 105,000 572.4 5.4 Niagara 205,000 10.6 (Including Canal) I Outario 27,300 7,500 80,000 246.0 6.6 St. Lawrence 241.000 11.1

Totals 200,600 94,600

* Includes Lake St. Clnir and its local drainage area.

INTERNATIONAL JOINT COMMISSION WATER LEVELS OF LAKE ONTARIO GREAT LAKES DRAINAGE BASIN AND _ PERTINENT PHYSICAL DATA

INTERNATIONAL LAKE ON'iARIO BOARD OF ENGINEERS OCTOBER 1958 Ogoki projects in Canada commencing in 1939 and 1943 respectively. During the

period 1945 through 1957, the sum of these diversions has averaged about 5,000 cubic feet per second. Diversion into Lake Superior increases the water supply- to Lake Ontayio . 1. Lakes Michigan and Hyon stand at virtually the same level since they are

connected by the broad and deep and they are usually

treated as one lake in hydrologic considerations. The natural outlet for the

discharge from these lakes is through the St. Clair River, Lake St, Clair and

the intc Lake Erie, approximately eight feet lower than the

level of Lakes Nichigan and Huron. The slopes of water surface profiles along

'the St. Clair and Detroit Rivers are relatively uniform. Improvements to

increase depths in chmnels of these rivers have increased the discharge capa-

city. In later years, works have been built for the purpose of compensating

,these increases in discharge capacity. For given river channel conditions

the flow is a function of the elevations of both Lakes Huron and Erie. Since

1848 there have been diversions of water at Chicago from Lake ivIichigan into

the Mississippi River basin which averaged abcut 500 cubic feet per second

until 1900 and therea.fter increased progressively until a maximum annual

average of about 10,000 cubic feet per second was reached in 1928 and which

then decreased progressively from 1929 through 1938. Since 1938, with the

exceptions noted in paragraph 72, the diversion has been maintained at an

annual average of about 1,500 cubic feet per second exclusive of domestic

pumpage which has averaged about 1,600 cubic feet per second, resulting in a

total diversion of about 3,100 cubic feet per second. This diversion reduces 16. The natural outlet for the discharge from Lake Erie is through the

Niagara River into Lake Ontario, about 326 feet lower than the level of Lake

Erie. Approximately 310 feet of the difference in elevation between Lakes

Erie and Ontario occurs in the reach of the extending from the head of the Cascades upstream from to the lower end of the

-vVhirlpool Rapids six and one-half miles downstream of the Falls with about one-half of the difference in a sheer drop at the Falls. Water from Lake

Erie also reaches Lake Ontario by way of the and DeCew Falls power plant tail-race. This flow has averaged about 7,000 cubic feet per second since 1950.

Lake Ontario 17. Lake Ontario, the lowest in the Great Lakes chain, is also the smallest.

A map of the Lake Ontario drainage basin is shown on Plate 2 (pge 10). Dis- charge fromthe upper lakes of the Great Lakes system, augmented by water contributed from the Lake Ontario drainage basin, passes through the lake on its way to the sea. Variations in the water levels of Lake Ontario, which are of considerable importance to the owners of riparian property along the shores of the lake and to other interests, are determined by a relationship between the rates at which water is supplied to the lake and the rates at which water discharges from the lake through the St. Lawrence River. The natural and artificial factors that have affected.the water levels of Lake

Ontario in the pa.st are discussed in Section IV of this report.

18. The shore, of Lake Ontario varies from sparsely populated agricultural and undeveloped areas to the more developed sections in and adjacent to localities such as Rochester, Great and Oswego, New York, and

Toronto, Hamilton and , Ontario. In many communities extensive con- ,

PROVl NCE 0 F ONTARIO

YO,. o( Mllrl \. STATE OF NEW YORK I,Ow- I .- . '\ '.

PROVINCE

WATER LEVELS OF LAKE ONTARIO ST. LAWRENCE RIVER LAKE ONTARIO TO LAKE ST. PETER

*I. * YI*r INTERNATIONAL LAKE ONTARIO "., - BOARD OF ENGINEERS OCTOBER 195 I struction has taken place--- on low unstable barrier beaches as well as lakeward from the backshore at elevations below that considered reasonably safe from ------.------*-- -- __ _- ----_ flooding and wave n. The construction consists generally of summer - -- homes, permanent residences and various types of commercial establishments

' including docks and marine service facilities.

19. Uith the construction of the St. Lawrence Seaway and Power projects,

the outflows from Lake Ontario are being regulated and thus its levels are

subject to a measure of control. However, the natural and certain of the

artificial factors will continue to have a bearing on the water levels of the

lake.

20. The regulation of Lake Ontario, designed to bring about a more beneficial

range of stage on the lake and having regard for the plan of jmprovment of

the International Rapids Section of the St. Lawrence River for navigation and

power, will be conducted in accordance with criteria (a) through (k) set

forth in Section V under the heading "Regulation of Lake Ontario". The range

of Lake Ontario levels approved for regulation is from a minimum monthly mean

elevation cf 2l&.0 feet during the navigation seasoa to a maximum monthly

mean elevation of 248.0 feet, as nearly as may be.

-.-.-St. Lawrence------River 21. The St, Lawrence River is the natural o~tletfor the 295,000 square

Great Lakes drainage basin. Its discharge at the outlet of Lake Ontario is

remarkably steady because of the natural regulatory influence of the Great

Lakes. kt , Ontario, the monthly mean discharge for the 95 year period

(1860-1954) has averaged 21t1,000 cubic feet per second and has ranged from a

maximum of 3l.4,000 cubic feet per second in May 1870 to a minh of 154,000

cubic feet per second in February 1936, Immediately below Lake St. Lhuis, in which a portion of the discharge joins that of the St. Lawrence,

the monthly mean discharge has averaged 280,000 cubic feet per second and has

ranged from a maximum of 478,000 cubic feet per second in l%y 1876 to a mini-

mum of 170,000 cubic feet per second in February 1936.

22, From the outlet of Lake Ontario near Kingston, Ontario, to Father Point,

..,. Quebec, which marks its transition into the Gulf of St. Lawrence, the St.

Lawrence River falls 246 feet in a distance of 533 miles (Plate 3, page 11).

The major portion of this fall, some 226 feet, occurs between Lake Ontario

and Montreal, 183 miles downstream from the lake. Most of the remaining 20

feet of fall occurs in the 160 miles between Montreal and .

23. The Section extends from Lake Sntario to Chimney Point,

focr miles east of Ogdensburg, New York, a distance of about 68 miles, and

has a fall of about one foot at mean stage. Through this section the river

is from one to four miles wide and is generally deep with relatively slow

currents. Certain channel improvements were made by both countries in this

section prior to 1933 to provide a navigation channel about 25 feet deep.

This navigation channel is presently being widened and deepened, where neces-

sary, as a part of the 27-foot seaway project.. 24. The International Rapids Section extending from Chimney Point to the head

of Lake St. Francis, is 47 miles long with a total drop in water level of 92

feet at mean stage. Approximately 15 feet of the drop in this section occurred in the reach from the head of the Galop Rapids to Iroquois. The Galop- IRapids, ---. about 5 miles downstream from Ogdensburg, constituted the natural I hydraulic control of the levels of Lake Ontario. Since 18146 when the first I Galop Canal was built in order to by-pass the rapids, several navigation \ improvements have been made in the Galop Rapids reach which have affected r the levels of Lake Ontari~. A location plan (Plate 4, page 15) shows the

areas in which works were undertaken for the improvement of navigation with

controlling depths of 14 feet. These facilities included: the reconstruction

of the original Galop Canal; the dredging of a navigation channel in the

Canadian Galop Rapids; the construction of the North Channel improvement;

and the closure of the Gut Channel by the construction known as Gut Dam.

These projects were carried out during the perlod 1880-1909 by the Govern-

. ment of Canada. In January 1953 the Gut Dam was removed.

25. The development for navigation and power in the International Rapids

Section commenced in 1954. It includes a dam in the vicinity of Iroquois

Point to control the levels of Lake Ontario, a dam in the Long Sault Rapids

betwccn Barnhart Island and the United States shore and two powerhouses, one

on either side of the International Boundary at the foot of Barnhart Island,

with a total installation rated at 2.h million horsepower. The dam, dykes,

and relocations for the power pooi below the Iroquois control dam are

designed to provide for full Lake Ontario level but the Intcrnational Joint

Conrmission~sOrder of Approval for the project requires the pool t o be

operated initially at a maximum elevation of 238.0 feet at the powcrhouse.

Excavations in the river are designed to provide a controlling depth of 27

feet for navigation and satisfactory velocities for navigation and power. k

navigation lock and canal on the Canadian shore to by-pass the Iroquois

control dam and a canal with two locks on the United States shore to by-pass

Long Sault Dam are designed to provide 30-foot depths on the lock sills with

27-foot controlling depths in the .

26. A few miles belgw the Barnhart Tsland ~owerhouses,the river widens into

Lake St. Francis with a surface area of about 100 square miles. With the INTERNATIONAL JOINT COMMISSION I I - 16 -

exception of a small area at the upstream end bounded by about three miles

of shoreline, this lake lies in Canada. The level of the lake was under

partial control from 1932 to 1943, and since that time it has been under full

control by the Beauharnois power plant and a series of dams at its natural

outlet near Coteau Landing. The method of operation requires that Lake St.

Francis be maintained at levels which would have occurred under natural con-

ditions, althou.gh in practice the range of stage has been reduced during

periods of extreme high or low flows. The local inflow to the lake comes

from a drainage area of approximately 4,400 square miles:

27. Fromthe outlet of Lake St. Francis the river narrows and falls a dis-

tance of about 83 feet in 15.5 miles before discharging into Lake St. Louis.

The Cedars power plant, built in 1914, utilizes about 35 feet of this drop

and has an installed capacity of 197,000 horsepower. The Beauharnois power

plant, which is on the shore of Lake St, Louis, develops the full head

between Lakes St. Francis and St, Louis. The rating of the present install-

ation is 1,425,000 horsepower, but construction now under way will increase the rated capacity to 2,160,000 horsepower. The forebay of the plant is

connected to Lake St.. Francis by a combined power and navigation canal, about

16 miles long and 3,000 feet wide. Two locks, at the lower end of the canal, having depths of 30 feet over the sills, by-pass the power plant.

28. Lake St. Louis has a surface area of 56 square miles and, in addition to the inflow from the St. Lawrence River, receives a portion of the runoff of the Ottawa River through the Vaudreuil and Ste. Anne outlets of the Lake of the Two Mountains as well as the runoff from approximately 1,300 square miles

of local drainage. The percentage of the total Ottawa River flow discharged

into Lake St. Louis varies from about 50 per cent; under high flow conditions, to about 20 per cent under low flow conditions; 'the remainder flows through the Riviere des Mille Iles and Riviere des to join the St. Lawrence

River belaw Montreal Island. The drainage area of the Ottawa River is 57,000

square miles and the maximum and minimum daily inflows to Lake St. Louis from the Ottawa River have been 190,000 cubic feet per second and 3,000 cubic feet per second respectively, while the monthly means have ranged from 160,000 .

cubic feet per second to 4,000 cubic feet per second. A one-foot change in the level of Lake St. Louis at mean stage is equivalent to a change in dis-

charge of about 30,000 cubic feet per second.

29. From the outlet of Lake St. Louis to Montreal Harbour, a distance of about 13 miles, the fall in the' river is about' 47 feet, 33 feet of which

occurs through the Lachine Narrows and Rapids before the river widens to form

Laprairie Basin, a shallow lake of about 29 square miles. Various schemes

for developing the power in the Lachine Section have been proposed, with the

final plan still not formulated. The plan which is receiving present con-

sideration envisages one powerhouse to develop 35 feet of head available at

the Lachine Rapids, with the possibility of another powerhouse downstream

utilizing the remaining fall. The developnent of the Lachine Section of the

river for power will repire considerable excavation through the Lachine

Narrows at the outlet of Lake St. Louis to reduce velocities sufficiently to

allow an ice cnver to form. The plan contemplates control of Lake of the

Two Mountains on the Ottawa River,

30. The water levels in Montreal Harbour during the navigation season vary with the flows of the St. Lawrence and Ottawa Rivers and are influenced by the inflow from the tributaries entering the St. Lawrence River below

Montreal. The minimum recorded level. at Lock 1-Montreal Harbour, was ele- vation 16.6 feet on 20 October 1934, and the maximum recorded during the open- water season was elevation 34.4 feet on 15 May 1876, The maximum open-water levels occur during the spring runoff when Lake Ontario outflows are increasing and the Ottawa River discharge reaches a maximum. 31. An accurate determination of the relation between river discharge past Montreal and the open-water river stage is complicated by the fact that these stages are modified by the varying discharge of the tributaries entering the river belowMontrea1, including the discharge of the Ottawa River through the Riviere des Mille Iles and the Riviere des Prairies and are affected by long-term tidal fluctuations, as well as continual changes in outlet due to dredging in the St, Lawrence Ship Channel. A change in flow of 20,000 cubic feet per second changes the level in Montreal Harbour at low stages by about one foot. In winter the increased slope of the river, due to ice retard- ation, results in a rise of 11to 22 feet in the water surface in Montreal

Harbour, and ice jams, occurring during the break-up season, have raised the wter elevation 32 feet above low water level.

32, The St. Lawrence River from the lower end of Lake St. Louis to Montreal Harbour is by-passed by a 27-foot navigation canal on the south shore. The upper portion of this canal, from Caughnawaga to Cote Ste. Catherine, has been designed to permit a flow of 40,000 cubic feet per second to be by- passed from Lake St. Louis to Laprairie Basin during the non-navigation seasen. Two locks providing 30-foot depths over the sills, in conjunction with a dyked channel, overcome the difference in level between Lake St. Louis and Montreal Harbour. SECTION I11 - BASIC DATA

Co-ordination Between Agencies of Canada and the United States 33. It was necessaryto reach agreement on all pertinent basic hydraulic and hydrologic data for the studies required by the Reference and by the instructions from the International, Joint Commission to the Board. Con- currently the Federal agencies, having responsibilities in their respective countries for such basic data, established the Co-ordinating Committee on

Great Lakes Basic Hydraulic and Hydrologic Data. Certain data adopted by that Committee were utilized in the Board's studies. -bTater Levels 34. The water level records used in the several studies originated with the following agencies: the United States Lake Survey, Corps of Engineers,

United States Army; the Hydro-Electric Power Commission of Ontario; the

Hydrographic Service, Department of Mines and Technical Surveys, Canada; and the Department of Transport, Canada. Water level records at several points on Lake Ontario and at the 14-foot Canadian navigation structures in the St. Lawrence River were available for the period since 1860. ---Dis char= 35. In the conduct of its studies on the regulation of Lake Ontario, as well as for the effects of diversions on the water levels of Lake Ontario, the

Board utilized discharge data made available at that time by the Co-ordinating

Committee on Great Lakes Basic Hydraulic and Hydrologic Data. Subsequent to the completion of these studies, and during the course of its studies on the effects of channel changes in the Galop Rapids reach, the Co-ordinating

Committee made available L revised stage-discharge relctionship for the Lock 25 (lroquois) gauge based on measurements made in the St. Lawrence River by various agencies since 1911. The relationship adopted on I,!+ March 1956 by that Committee is expressed by the equation:

Q in c.f.s. = 23.79 (~ock25" - 188.51) 5/ 2

*Based on U.S.L.S. 1903 datum.

Based on this equation the Committee also macie available monthly mean dis- charges for Lake Ontario for the period 1860 to 1954 and daily discharges for the period 1917 to 1954. Use of these revissd data would not alter the con- clusions expressed in the report on regulation and on the effects of diversions.

The revised Lock 25 rating curve and the discharge data derived therefrom were utilized in the studies on the effects of channel changes in the Galop

Rapids reach.

36. Various agencies have made measurements of the flow in the separate channels of the Galop Rapids reach which were utilized in the studies. 37. The outflows from Lake St. Louis for the period 1860 to 1954 were deter- mined by the St. Lawrence Seaway Authority, Montreal, using rating curves derived from a study of all available discharge measurements and from compu- tations of the monthly mean outflows.

HyGrography and Topography 38. Hydrographic and topographic maps of the Galop Rapids reach showing river conditions at specific locations at various times commencing in 1874 were prepared from maps compiled by the following agencies: the United

States Lake Survey, Corps of Engineers, United States Army; the Canadian

Departments of Public Works, Transport and Northern Affairs and National

Resources; and the Hydro-Electric Power Commission of Ontario, Since no single may, was in sufficient detail and scope to represent the river conditions during particular periods of time it was necessary to prepare composite plans giving consideration to the available data.

Miscellaneous Data

39. Information on the aiounts of the diversions was obtained from the Water Resources Branch, Ottawa, Canada; the North Central Division, Corps of

Engineers, Chicago, Illinois, and the report of the lnternatioqal Joint -

Commission dated 1953 on the Preservation and Enhancement of Niagara Falls.

Surface float streamlines and velocities in the Galop Rapids reach were determined from field observations by the Hyd.ro-Electric Power Commission of

Ontario. Detailed water surface slopes in the Gut Channel were obtained during a joint survey in 1954 by the United States Lake Survey and the water

Resources Branch, Canada.

Natural Factors

40. Ranges in Leke Levels: The level of Lake Ontario, as of the other Great Lakes, varies naturally both annually and seasonally, as well as daily and hourly, at any given location on the lake.

41. The average level of Lake Ontario at Oswego, New York, for the period 1860 to 1954 is elevation 246.04 feet, United States Lake Survey 1935 datum.

The monthly mean level of the lake has varied from a low of elevation 242.68 for November 1934 to a high of 24.9.29 for Jwie 1952, making a total rsnge in monthly mean stage of 6.61 feet. (Refer to Plate 5, page 23).

42. In addition to these long-term variations, the levels of Lake Ontario show a seasonal pattern of high stages in spring and summer and low stages in fall and winter. The average monthly lake level is highest in June and lowest in January. The maximum and minimum seasonal changes from high to .- /' low lake levels for the period of record were 4.07 feet and 0.47 foot. The maximum and minimum seasonal changes from low to high lake levels were 3.54 feet and 0.32 foot.

43. Superimposed upon the long-range and seasonal fluctuations resulting fromthe change in quantity of water in the lake, there are daily and even hourly fluctuations resulting from tilting of the lake's surface induced by winds and differential barometric pressures. (Refer Plate 6, page 27).

These short-period fluctuations reach a.maximum &the east end of the lake, where the water surface may rise about three feet above the mean lake level.

44. Inflows fromthe Upper Lakes: The drainage area of the upper lakes to the outlet of Lake Erie, of which about one-third is lake area, is about

260,000 square miles, or 88 per cent of the total Great Lakes basin. The comparatively large water area in relation to the land provides an effective natural regulatory action on the supplies to the upper. lakes. The .o~tflow from ~akeErie, that is, the inflow to Lake Ontario from the upper lakes, is compar&ively kiform, the maximum monthly flow in the Niagara River being only about twice its minimum monthly flow,

45. During the 95-year period , 1860-1954, the net total supply to Lake Ontario, that is, all of the water reaching the lake minus the evaporation from its surface, has avei-aged 2L+l,000 cubic feet per second and the monthly supplies have ranged from a low of 135,000 cubic feet per second for October PLATE 5 1934 to a high of 414,000 cubic feet per second for April 1870. During the

95-year period, about 85 per cent of the net total supply to Lake Ontario has consisted of outflow from the other Great Lakes through the Niagara

River and about 15 per cent has consisted of supply from the Lake Ontario basin. On a monthly basis, the supply from the Lake Ontario basin has varied from a low in certain winter months of considerably less than the quantity of water evaporated from the surface of the lake to a high in certain early spring months of over 50 per cent of the net total supply for the month. It

- * is the variations in the local supply which cause the rapid fluctuations in - 4 rio . 46. Precipitation: Precipitation on the lake s surface is a direct contri- bution of water to the lake equal in amount to the precipitation. Precipi- tation on the surface of the lake's land drainage area results in an indirect

contribution to the lake, which is variable with respect to the precipitation

since the amounts ultimately reaching the lake as runoff are influenced by many factors. Much of the water that falls on the land never reaches the lake, a large percentage being evaporated or used by growing vegetation.

47. Excessive or deficient precipitation over the drainage basin of the

Great Lakes is not reflected necessarily in concurrent high or low supply,

respectively, to Lake Ontario. For example, although the precipitation over the Great Lakes basin during 1930 was about 20 per cent less than normal,.

the elevation of Lake Ontario averaged one foot higher than normal. The

previous few years had normal or higher precipitation and Lake Ontaria was

still receiving the effects of this due to the regulatory e.ction of the upper lakes. 48. The average monthly precipitation over the basin of the Great Lakes has a seasonal pattern: the minimum average monthly amount being of the order of 2 inches, occurring in February; the riaximum being of the order of 3 inches,

occurring in September, with about the same amount occurring in June. This pattern does not bear a direct relation with the seasonal cycle of the lake levels in all respects. Precipitation on the land drainage areas of the

Great Lakes is modified by other seasonal factors before it becomes a part of the water supply to the lakes. In the spring, thawing weather releases water stored on the ground as during the winter and the spring rains fall on ground that is more saturated than later in the year so that the /" amount of water flowing into the lakes is increased and the levels rise. /' During the summer, rwoff from the land into the lakes diminishes from. the

spring high to the point where net total supply to the lakes becomes less than outflow and the levels start to fall.

49. Evaporation: Direct measurements of the evaporation from Lake Ontario

are not available. The depth of water removed by evaporation from Lake

Ontario has been computed to average about two feet per year.

50. Winds and' Barometric Changes : Winds produce short-period fluctuations

of the lake level raising the le&s on the leeward shore and lowering them

on the windward shore, Each locality is affected a different extent because the magnitude of the fluctuations is dependent upon the configura~ tion of the shores and bottom of the lake and the direction, force, duration and fetch of the wind,

51. Because of the large area of Lake Ontario, variations in the air pressure over the surface of the lake cause temporary tilting of the lake

surface. Usually such a disturbance of the water surface is slight and the effects of pressure changes are not near1y.a~great as those from winds.

52. Phximum rises above mean lake level occur at the east end of the lake

as a result of strong westerly winds along the long asof the lake. A

temporary rise in stage at one end of the lake from this cause is accompanied

by a lowering at the opposite end. Temporary rises in stage caused by wind

or barometric effects can induce or inertial oscillations of lake

\~. level.

53. An example cf daily and hour-Ly variations in lake levels at Cape

Vincent, New York, is shob-n on Plate 6, page 27.

54.. Ice Retardation: During the winter period, an ice cover is formed in

the. St. Lawrence River above the International Rapids Section. The direct

effect of this ice cover is a diminution of flow from Lake Ontario which

results in a rise in the lake levels above what they would be under open-

water river conditions. The cumulative effect of ice retardation during a

severe winter may result in increased levels of the lake by as much as one-

half foot at the end of winter. The effect of retardation is rapidly itissi-

pated during the following surmner. 55. Crustal Movement: Geologists, in their study of the Great Lakes basin, have discovered that uplift of several hundred feet has occurred in some

places in the area since glacial times, Frcm current information availeble

in Canada and the United States it is evident that this uplift is continuing and that it- is measurable. Studies have been made of the rate of differen- tial crustal movement of the earth's surface along the shores of Lake Ontario

and in the International Section of the St. Lawrence River by agenci,es of

\Canada and the United States. These studies have shown that the earth's

crust in the Galop Rapid:: reach. the naA-lralcontrol of the levels of Lake 27 PLATE 6

25 FEE. TIME IN HOURS,

VARIATIONS IN WATER LEVEL DURING 25-26 FEBRUARY 1956

12 18 TlME IN DAYS

DAILY VARIATIONS IN WATER LEVEL DURING FEBRUARY 1956

I

INTERNATIONAL JOINT COMMISSION

WATER LEVELS OF LAKE ONTARIO

DAILY AND HOURLY HYDROGRAPHS LAKE ONTARIO AT CAPE VINCENT, N.Y.

INTERNATIONAL LAKE ONTARIO BOARD OF ENGINEERS OCTOBER 1958 Ontario, has been rising with respect to that at Oswego at a rate of 0.55 foot per hundred years, and with respect to that at the western end of the lake at the rate of about one foot per hundred years.

56. The effect of this natural phenomenon has been to raise the level of the lake. For example, with 1954 outlet conditions, a discharge of 272,000 cubic feet per second wmld have occurred in 1870 with Lake Ontario at elevation 246.98 feet measured at Oswego, whereas in 1954, 84 years later, this discharge occurred with Lake Ontario at elevation 247.44 feet, measured at Oswego. Thus, for the same conditions, there has been a rise in the -water level-land relationship at Oswego of 0.46 foot in 84 years. Also, it may be noted that the effects of crustal movement are not transitory, but C -are cumulative. Artificial Factors

57. Superimposed upon the natural variations in the water levels of Lake Ontario, there have been changes in water level resulting from diversions into and out of the Great Lakes basin, from alterations in the outlet control of Lake Ontario, and from alterations in the control of the outlet channels in the upper lakes.

58. Diversions: Diversion out of Lake Michigan, which reduces the water supply to Lake Ontario, commenced prior to the period of lake level record in 1860. Diversions into Lake Superior, which increase the water supply to

Lake Ontario, commenced in 1939 and 1943. Since these diversions into and out of the Great Lakes basin have not been constant during the periods of their existence, they have had a variable effect on the supplies to Lake

Ontario and.thus on the lake's levels and outflows. The full effect of a diversion is not attained immediately but builds up progressively over a period of time related to the storage and outlet capcities of the lake or lakes involved. The full effect on Lake Ontario of a continuous diversion from Lakes Michigan-Huron is realized in about 15 years.

59. The maximum lowering of Lake Ontario levels due to diversions was about 0.43 foot and occurred during the period 1930 to 1935. The effects on Lake

Ontario of the diversions into and out of the basin were in balance about

1947. By 1954, the 'average annual rates of the diversions were stabilized so that the ultimate net effect on Lake Ontario supplies would be to increase - them by about 1,900 cubie feet per second corresponding to an increase in the level of Lake Ontario of about 0.09 foot. The Board has.submitted a - 94 detailed report on the effect of the diversions on Lake Ontario water levels which is summarized in Section V.

60. Changes in the Outlet Control of Lake Ontario: Prior to the construc- tion of the St. Lalrirence Seaway and Power projects, the outflow from Lake

Ontario was controlled by the natural barrier forming the Galop Rapids in the St. Lawrence River. - Changes made for the improvement of navigation in this reach of the river affected the lake level-outflow relationship, and thus the lake levels, and consisted of: dredging- in the Canadian Galop Rapids channel; the realignment of the Galop Canal; construction of the North - IB I Channel improvement; and construction of Gut Dam. These changes were accom- -LP- plished during the period 1881to 1908. The net effect of thesew--from cs=------cs=------1909 until 1952, when operations to remove Gut Dam were commenced, amounted to an increase of 34 inches at mean lake level. The effect of Gut- Dam alone was to raise- water levels 5 inches at mean lake level. iiith the removal of Gut Dam in 1953, the water levels were lowered by about 4h inches at mean lake level. The effects of these changes on Lake Ontario water levels have been the subject of a separate report by the Board which is summarized in

Section V.

61. The Board took recognition of several miscellaneous artificial changes which had taken place in the Thousand Islands Section. Included among these changes are: construction of the Thousand Islands (Ivy Lea) Bridge which was completed in 1938; dredging in the Thousand Islands Section; and dredging, and deep water disposal in the river, in the vicinity of Ogdensburg. The

Board is of the opinion that these works had negligible effect on the water levels of Lake Ontario.

62. Changes in the Outlet Control of Lake Superior: The St, hrys River is the natural outlet of Lake Superior and discharges the runoff from the

80,000 square miles of the Lake Superior drainage basin. The rapids.in the river at Sault Ste. Marie which provided the natural control of the outflows and levels of Lake Superior presented an obstacle to navigation and as early as 1798 steps were initiated to by-pass the rapids, The navigation facili- ties constructed prior to 1887 are considered to have had negligible effect upon the natural flow conditions in the river. In 1887 and 1888 an interna- tional bridge was constructed across the river at the head of the rapids.

The piers and approaches of the bridge had the effect of reducing the natural discharge capacity. Subsequently, there were several changes to the natural control resulting from power developments and navigation improvements some of which reduced the discharge capacity and some of which increased the discharge capacity. The net effect of these works was to provide a greater capacity for outflow from Lake Superior than existed prior to 1887. These changes were completed by August 1921, when the outflow from Lake Superior became completely controlled. 63. In May 1914, the International Joint Commission issued two Orders of Approval for the obstruction, diversion and use of the waters of the St. i4arys River in connection with power developments on both sides of the

International Boundary. The works approved included a gated dam, known as

the compensating works, across the river at the head of the rapids, as well

as the power diversion facilities. The Orders of Approval specified that the control and operation of the compensating works would be under super-

vision of the Intarnational Lake Superior Board of Control created for that

purpose. The duties of this Board of Control are to formulate rules under which the compensating works and power canals and their head gates and by-

passes shall be operated so that the level of Lake Superior shall be regulated between .e,&evation602..1 and elevation 603.6 above mean at New York as

.nearly as may be, and in such a manner as not to interfere with navigation.

Since completion of the compensating works in August 1921, the outflow from

Lake Superior has been completely controlled under the direction of that

Board.

64. For the period 1888-1921, a comprison of recorded outflows from Lake

Superior with outflows computed for natural conditions of the outlet indi-

cates that, on the average, the actual outflow was slightly less than the natural. The comparison indicates that the actual outflow was. less than natural during 20 years of the 34-year period and greater than natural during

4 years. The maximum differences from natural, plus and minus, were some- what smaller than have occurred since the outflows were completely regulated,

and had smaller effects on the levels of Lake Ontario than those due to the

regulation of Lake Superior. 65. As previously noted, Lake Superior has been completely regulated since

August 1921. Under regulation, the outflow from Lake Superior has frequently been increased above and decreased below what the natural flow would have been.

The equalizing effect of the large areas and storage capacities of Lakes

Michigan-Huron and Erie has reduced the effect on Lake Ontario of rapid 2nd abrupt fluctuations of outflows from Lake Superior and has distributed the effect of each of these changes over longer periods of time with the result that the inflow to Lake Ontario has been either above or below its natural rate for several years in succession but with the maximum variations materi- ally reduced fromthose which occurred in Lake Superior outflows. As a result of the large storage effect of Lakes Michigan-Huron and Erie, and of the further storage effect of Lake Ontario, the maximum increase in discharge from Lake Ontario due to the regulation of Lake Superior was about 4,500

. ."Gk'ci cubic f

The approdmate effects of Lake Superior regulation on Lake Ontario levels during certain critical periods of low and high water on Lake Ontario are shown in the following tabulation:

Recorded Lake Ontario Stage Approximate Effect of at Oswego, in Lake Silperior Regula- -Date - Feet tion, in Inches June 1929 248 46 November 1934 242.68 November 1935 2-43 13 February 1936 242.82 June 1943 248 73 July 1947 248.97 June 1952 2-49 • 29 66. As is shown by the table the effects of the regulation of Lake Superior on the levels of Lake Ontario have not been related to Lake Ontario stage.

The storage effect of the large intervening lakes on releases of water from

Lake Superior, before such water becomes a part of the supply to Lake Ontario, results in a time lag of several months between the date that the releases are made and the time that they have appreciable effect as a part of Lake Ontario supply. -It is not considered feasible to regulate outflows- from Lake Superior for the pur Ing the extremes of Lake Ontario stages. - _C h - * 67. Changes in the Outlet Control of Lakes Michigan-Huron: Changes in the channels of the St. Clair and Detroit Rivers may have caused slight temporary variations in the supply to Lake Ontario. However, once a change is made, conditions would gradually stabilize and the ultimate effect on Lake Ontario levels would be -insignificant. 68. Changes in the Outlet Control of Lake Erie: The Niagara River is the natural outlet for discharges from Lake Erie into Lake Ontario. Diversions for navigation and for power, and structures such as the remedial works above . . .-- the Falls, have caused slight transitory variations in the sup~l~toLake

Ontario. These variations resulted from the temporarily increased or decreased outflow from Lake Erie that existed following each change during periods of adjustment between Lake Erie storage and the modified outflow regimen. However, the modifications to the outflow regimen have had only C temporary effects on Lake Ontario levels because the discharge from Lake

Erie into Lake Ontario became essentially the sane after the adjustment period as it would have been wlthout -6hb nodificetion. - 34 -

SECTIOIf V - INTERIM REPORTS

General

69. The studies conducted by the Board under the Reference of 25 June 1952 have been submitted to the Commission in five separate reports as follows:

1. Interim Report on Regulation of Lake Ontario, dated

l4 March 1955. This report is included as Appendix D

to Report on Regulation of Lake Ontario dated March 1957.

2. Effect on Lake Ontario Levels of an Increase of 1,000 Cubic

Feet Per Second in the Diversion at Chicago for a Period

of 3 Years, dated 14 June 1955. f

3. Effect of Diversions on Lake Ontario Water Levels, dated

15 March 1956. 4. Regulation of Lake Ontario (three volumes) dated March 1957.

5. Effects on Lake Ontario Water Levels of the Gut Dam and

Channei Changes in the Galop Rapids Reach of the St. Lawrence

River (with three appendices) dated October 1958.

A summary of the results of the studies contained in these repoGs is pre- sent ed hereunder.

Report on Effect of Diversions on Lake Ontario Water Levels

70. There have been four diversions of water into or out of the Great Lakes

basin which have affected the water levels of Lake Ontario; namely, the

Illinois and Michigan Canal, the Chicago Sanitary and , the Long

Lake project and the Ogoki project. The first two named have been diversions

out of the basin and the last two, diversions into the basin. The locations

of these diversions are shown on Plate 1, page 7, 71. The Illinois and Michigan Canal extended 97 miles from the south branch of the Chicago River at Chicago, southwesterly to La Salle, Illinois, where it entered the Illinois River. Construction of the canal began in 1836 and was completed in 1848. The canal was fed in part by water pumped from the

Chicago River and in part by water diverted from the Calumet River through a feeder canal in addition to water supplied from the Mississippi River drainage basin. The water pumped from the Chicago River was intended initi- ally to help obtain navigable depths in the canal but later, after it had been noted that the polluted Chicago River was perceptibly cleaner due to the diversion, additional quantities beyond the navigation needs were diverted in the latter interest. After construction of the Chicago Sanitary and Ship

Canal in 1900, the Illinois and Michigan Cmal fell into disuse and was abandoned in 1910. The average annual diversion into the canal increased until between the years 1871 to 1883 it .was about 300 cubic feet per second.

From 1883 until it was abandoned in 1910 the average annual diversion varied between 500 and 1,000 cubic feet per- second.

72. The Chicago Sanitary and Ship Canal between the Chicago River.and the

Des Plaines River forms a portion of the connecting Lake

Michigan and the Mississippi River. Construction of the Chicago Sanitary and Ship Canal began in 1892 and the canal was first opened.for the diversion of water in January 1900. The flow of water in the canal is controlled by a dam and gates at Lockport, Illinois. From the tine of its completion, the diversion of water from Lake Michigan was increased progressively until a maximum annual average of about 10,000 cubic feet per second was reached in

1928 and was then decreased progressively from 1929 through 1938. The annual cveraZn diversion from Lake Michigan through the Chicago Sanitary and Ship Canal is now limited, by,the decree of the United States Supreme Court

issued on 21 April 1930, to 1,500 cubic feet per second in addition to

domestic pumpage. The annual average diversion rate of 1,500 cubic feet per

second, specified for the period since 31 December 1938, has not been exceeded

except during five years, 1940, 1942, 1944, 1956 and 1957, when the average

rates were, respectively, 1,681, 1,528, 1,531, 1,699 and 2,387 cubic feet

per second, In 1940, the United States Supreme Court authorized an additional

diversion for ten days in the interest of pollution abatement. In 1942 and

194.4, additional amounts were diverted as war emergency measures in the

interest of navigation. From 17 December 1956 to 28 February 1957, additio-

nal amounts were permitted by the United States Supreme Court to alleviate

an emergency in navigation caused by low water in the Mississippi River. %en the above increased diver,sions are considered, total diversions,- inclu-- -

73. Diversions into Lake Superior from the watershed via the Long Lake project and the Ogoki project began in 1939 and 1943 respectively.

Water diverted from the Ogoki River is retained in Lake until

required for generation of power at hydro-electric plants on the Nipigon

River. The water diverted from Long Lake is used at a power development on

the . The sum of these diversions has averaged about 5,000

cubic feet per second during the period 1945 through 1957. For the purposes of this study, it was assumed that the Ogoki and Lang Lake diversions were

made directly into Lakes Michigan-Huron. I 74. The report on diversions presents the effects of the recorded diversions into and'out of the Great Lakes basin on the water levels and outflows of

Lake Ontario,.. The maximum lowerin of lake levels due to the diversions was reached during the period from 1930 to 1935 when Lake Ontario levels on the average were about 0.43- foot lower than they would have been without the diver- sions. In November 1934, when the minimum monthly mean level of record was

reached on Lake Ontario, the effect of diversions out of Lake Michigan was to

lower the level of Lake Ontario by about 0.42 foot. The maximum raising of levels was reached during- 1950 when the average rise was about 0.07 foot which is only about 0.02 foot lower' than the ultimate rise which will be caused at

medium lake levels if the diversions remain at the present averages. There

was no rise in Lake Ontario levels prior to 1947 due to the net diversion

quantity. In that year the raising effect on Lake Ontario levels of the Ogoki

and Long Lake project diversions into Lake Superior about equalled the lowering

effect of the Chicago Sanitary and Ship Canal diversion out of Lake Michigan. -In June 1952 when the maximum monthly mean level of record was reached on Lake Ontario, the level was 0.06 foot higher than it would have been without the -- --. -. diversions.- The ultimate effect on Lake Ontario water levels, at an average elevation of about 246.0 feet, of the three existing diversions is a rise of

about 0.09 foot under outlet conditions existing prior to construction of the

St. Lawrence Seaway and Power projects.

75. The maximum effect of the Illinois and Michigan Canal diversion was reached durin~the period 1888 to 1892 and resulted in about 0.04 fooO lowering of Lake

Ontario levels. The Chicago Sanitary and Ship Canal maximum diversion effect

produced a maximum lowering on Lake Ontario levels of about 0.43 foot in the

period 1930 to 1935. During-that period the effect of the Illinois and

Michigan Canal diversion had become zero and the Ogoki and Long Lake project

diversions had not commenced, The maximum effect of the Ogoki and Long Lake

project diversions to the end of 1954 was reached in 1951 and caused a rise

in Lake Ontario water levels at medium stages of about 0.22 foot, Report on Effect on Lake Ontariowater Levels of an Increase of 1,000 Cubic Feet Per Second in thzDiversion at Chicago for a Period of Three Years

76. As a result of proposals before the United States Congress to increase the diversion at Chicago by 1,000 cubic feet per second for a period of three years, each section of the International Joint Commission in letters, dated

31 January 1955, directed the respective Chairman of the ~nternatisgalLake Ontzrio Board of Engineers -

'I... to study and report upon the effect which an increase of 1,000 c,f.s. in the diversion from Lake Michigan at Chicago for a period of three years would have upon the levels of Lake Ontario, under- conditions now prevailing. he Board's report should indicate also the consequent effect of the resultant levels of Lake Ontario upon navigation in Lake Ontario and the St. Lawrence River and upon the generation of hydro-electric power at.Niagara and in the St. Lawrence River in accordance with conditions anticipated as of 1 July 1955-

"In addition, the Board's report should include any relevant infomation regarding the effect of such an increase in the diversion on the levels and flows and on navigation and power generation else- where in the Great Lakes Basin, which the Board has acquired during the course of its study of the effects on the levels of Lake Ontario. It will be sufficient for the Commission's purposes if the effsct on navigation is expressed in terms of inches at critical points and the effect on power is expressed in terms of kilowatts.''

77. For the purposes of this report all effects were determined on the basis of mean monthly lake stages of record for the %-year period, 1860 to 1954.

78. An increase of 1,000 cubic feet per second in the diversion at Chicago for a period of three years would result in temporary reductions in lake levels and river flows downstream from the point of diversion, The maximum temporary effect on lake levels and river flows was found to be as follows:

Maximum Reduction in Maximum Reduction in Stage in inches Outflow in c..f .s.

Lakes Michigan-Huron 5/8 Lake Erie 3/8 Lake Ontario 318 Lake St. Louis 1/4 Montreal Harbour 3/g The Board considered that these temporary reductions in levels would have no

significant effect on navigation.

79. As a result of the temporary diversion, which was assumed to commence

on 1 July 1955, it was estimated that there would be reductions in the depen-

dable capacity of 2,600 and 2,750 kilowatts at the Niagara River plants in

Canada and the United States respectively, and of 2,145 kilowatts at the

Beauharnois plant on the St. Lawrence River. However, the Board considered

that these computed reductions would be of such small magnitude and of such

temporary character that the provision of any replacement capacity would not

be justified although there would be the possibility that as a result of

this loss in capacity a small amount of energy would require replacement at

somewhat higher than normal rates through purchase from interconnected systems.

80. Losses in the production of electrical energy in the Niagara and St.

Lawrence Rivers were estimated for the computed reductions in flows at exis-

ting plants, at plants under construction, and for additional plants contem-

plated in the United States 2nd Canada to develop approximately the total

power potential between Lake Erie and Montreal. The total computed loss in

energy at the above plants was 420,000,000 kilowatt hours. Of this amount

only 276,000,000 kilowatt hours would be lost at existing plants and plants

either under construction or actually scheduled for construction. In this

latter category were the Sir Adam Beck No.2 and the Barnhart Island plants.

Additional developments in the United States at Niagara Falls and at

I Beauharnois and Lachine Rapids in Canada had not actually been scheduled as ! of July 1955. Consequently the computed loss in energy of about 14l+,000,000 kilowatt hours at these proposed additional developnents was only conjectural. ' However, subsequent to the date of this report on a temporary diversion, construction was begun on the third powerhouse at the Beauharnois site and

on a power project near Lewiston, N.Y. on the Niagara River.

Report on Effects on-Lake Ontario Water Levels of the Gut Dam and Channel Changes in the Galop Rapids Reach-,of the St. Lawrence River

81. The report on "Effects on Lake Ontario Water Levels of the Gut Dam and

Channel Changes in the Galop Rapids Reach of the St. Lawrence River" relates to that portion of the 25 June 1952 Reference which requested that 'I. .. the Commission study the various factors which affect the fluctuations of water levels on Lake Ontario, including the construction in the St. Lawrence River known as 'Gut Dam1.. .I1 The report sets out the determinations of the net

and separate effects, where possible, of the man-made changes which have

occurred in the Galop Rapids reach between the periods 1860 to 1880 (state

of nature) and 1953 to 1955 (prior to construction operations for the St. Lawrence Seaway and Power projects) . 82. The man-made changes, the effects of which were studied by the Board

were as follows:

Feature Period of Construction

Canadian Galop Rapids Dredging 1881-1888, 1897-1901, 1904-1908. Galop Canal Realignment 1889-1896. North Channel Improvement 1897-1908. Gut Dam Construction 11 September 1903 - 11 November 1903 ( ~utChannel closure ) . Gut Dam Removal 30 October 1952 - 6 January 1953.

The loczitions of these works are shown on Plate 4, page 15.

83. In order to deterinine the effects of these features, three engineering

procedures were utilized, namely: gauge relationships, backwater computa-

tions; and a hydraulic model. The details of these three procedures are set

out in separate Appendices A, B and C to the report. The gauge relationship

study utilized all.avaiiable water level records from the various gauges between Lake Ontario and the Long Sault Rapids. The backwater and model studies employed all known hydraulic and topographic data in the Galop Rapids reach. The effects by backwater were.ccmputed for a discharge of 240,000 cubic feet per second only. The hydraulic model of the Galop Rapids reach was constructed and tests conducted at the National Research Council, Ottawa, in accordance with the Board's specifications. The scale of the model was

1:240 horizontal and 1:48 vertical. The model provided values of the effects at 180,000, 240,000, 267,000 and 310,000 cubic feet per second.

84. Generally the three procedures - gauge relationships, backwater compu- tations and the hydraulic model - gave results which supplemented each other.

Some of the channel changes coincided in time and others followed each other with little or no time interval, so that in most instances gauge relation- could not be used to isolate the effects of each feature of the work.

Also, adequate hydrographic data were not available to establish river conditions existing at any specific time during the period 1881-1908 so that the separate effects of the changes, at the time they were made, could not be determined by backwater computations or the hydraulic model.

85. Since water level records were available during periods of stable regimen prior and subsequent to the work carried out during 1881-1908 as well as during 1881-1953, gauge relationships provided the best determination of the net effects of the work carried out during these periods. Gauge relation- ships also provided values for the effects of the works constructed during the period 1881-1901, The backwater computations and the hydraulic model on the other 'hand, provided a measure of the separate effects of regimen changes since these two procedures were not necessarily limited to a study of river conditionz that existed at any given time. 86. The Board's determinations, from a consideration of the results obtained from gauge relationships, backwater computations and the hydraulic model, of the effects on Lake Ontario water levels of Gut Dam and channel changes in the

Galop Rapids reach of the St. Lawrence Ever are summarized in Table 1, page 43. 87. Operations for the construction of the St. Lawrence Seaway and Power projects comenced in 1954. In July 1955, these operations began to affect the regimen of the St. Lawrence River at the natural control for Lake Ontario outflows in the Galop Rapids reach. Lalte Ontario levels and outflows since that time have been, and will continue to be, artificially controlled.

Therefore, the channel changes outlined in this report have not been physical factors affecting the levels of Lake Ontario subsequent to July 1955.

Report on Regulation of Lake Ontario

88. In the Reference the Commission was requested to determine whether, in its judgment, action could be taken by either or both Governments to bring about a more beneficial range of stage having regard to the proposed plan for improvement of navigation and power in the International Rapids Section, and the proposed method of regulation which was an essential feature of that plan.

The proposed plan for improvement of the river and the method of regulation for Lake Ontario were set forth in the applications of the Governments of

Canada and the United States to the International Joint Commission for the developnent of power in the International Rapids Section. The Order approving these applications was issued on 29 October 1952, and referred specifically to Method No.5 as a regulation plan for Lake Ontario. The planning of the power and navigation projects, including the channel excavations and back- water computations, had been based on the levels and flows produced by this TABLE 1

SUMMARY OF RESULTS

EFFECTS ON LAKE ONTARIO WATER LEVEZS OF GUT DAM AND CHANNEL CHANGES IN THE GALOP RAPIDS REACH r -- - EFFECTS IN FEET AND IN INCHES AT INDICATED FLOWS

ITEM 180,000 240,000 267,000 310,000 REMARKS c.f.s. c.f.s. c.f.s. c.f. s.

Feet Inches Feet Inches Feet Inches Feet Inches

Includes all known works prior to Gut Dam construc- tion - Canadian Galop dredging during periods 188 1- Work during Period 1888 and 1897-1901; North Channel improvement and 1881-1901 -0.07 -1 -0.07 -1 Galop Canal realignment practically completed. Effect at 180,000 c.f.s. estimated as minus 1 1/2 inches.

Construction of Gut Channel closed between 11 September 1903 and Gut Dam t0.40 t4 3/4 t0.41 +5 t0.40 t4 3/4 t0.33 t4 11 November 1903.

Effects as of 1909-1952 compared to 1860-1880, i.e. Work durlng Period t0.30 t3 1/2 t0.34 t4 t0.33 t4 all known works prior to Gut Dam removal. Effect at 1881-1908 180.000 c.f.s. estimated as plus 3 inches.

Gut Dam removed between 30 October 1952 and 6 -0.36 -4 1/4 -0.37 -4 1/2 -0.40 -4 3/4 -0.34 -4 Removal of Gut Dam January 1953.

Effects as of 1953-1955 (subsequent to the removal of Gut Dam) compared to 1860-1880, i.e. all known works Work during Period -0.05 - 1/2 prior to initiation of Seaway and Power projects. 1881-1953 J Lowering would be greater at low flows and smaller at high flows.

periods of activity:. 1881-1888, 1897-1901, 1904-1908. Canadian Galop -0.36 -4 1/4 -0.32 -3 3/4 Effect at 180i000 c.f.s. estimated to be minus 5 inches Rapids Dredging and at 310,000 c.f.s., minus 3 inches.

Galop Canal Negligible Effect Period of activity 1889 - 1896. Effect would probably Realignment be a very small rise.

North Channel to. 17 t2 tO.18 t2 1/4 t0.19 t2 1/4 t0.24 t3 1 Period of activity 1897-1908. .Improvemetlt method. Because revisions had been made to certain of the basic flow data used in Method No.5, and since that method was not designed to meet the terms of the Reference, further regulation studies were undertaken by the Board.

These studies are documented in the Board's report on ttRegulation of Lake

Ontariott dated March 1957.

89. Early in 1955 the navigation interests and the power entities urgently needed advice as to what the critical water profiles under regulation would be in the international reach or' t,he St. Lawrence River. On the premise that computations based on 48 years of record, that is, from 1905 to 1952, which included the extreme low water of the 1930's and the high water of 1952, would provide sufficient data to define a suitable range of stage on the lake, interim studies were prepared on that basis for the consideration of the Commission in March 1955.

90. These interim regulation studies showed that damage to shore property would be reduced materially by reducing the upper level of regulation to elevation 248.0 and that the maximum range of levels should be at least four feet in order to provide the necessary flexibility of operation and to main- tain the basic requirements of downstream interests. It was also indicated that a limiting level on Lake Ontario below elevation 244.0 in the navigation season would result in increased costs and reduced benefits to navigation and power interests in the international reach of the St. Lawrence River, and to navigation on Lake Ontario.

91. As a result of the review of these studies, which are contained in the

Board1s interim report on tlRegulation of Lake Ontario", dated 14 March 1955,

(included as Appendix D of the Marsh 1957 report on ttRegulation of Lake

Ontario") the Cornmission concluded that measures could be taken, having regard to the interests of all concerned, to regulate the level of Lake

Ontario for the benefit of property owners on the shores of the lake in both countries, so as to reduce the extremes of stage which have been experienced in the past. By identical letters, dated 17 March 1955, the Governments were informed of the Commissionls tentative conclusi~onsand that the project works should be operated in accordance with the following criteria:

(a) The regulated outflow from Lake Ontario from 1 April to 15 December shall be such as not to reduce the minimum level of Montreal Harbour below that which would have occurred in the past with the supplies to Lake Ontario since 1860 adjusted to a condition assuming a conti- nuous diversion out of the Great Lakes Basin of 3,100 c.f.s. at Chicago and a continuous diversion into the Great Lakes Basin of 5,000 c .f ,s, from the Albany River Basin (hereinafter called the "supplies of the past as adjustedt').

(b) The regulated winter outflows from Lake Ontario from 15 December to 31 March shall be as large as feasible and shall be maintained so that the difficulties of winter power operation are minimized.

(c) The regulated outflow from Lake Ontario during the annual spring breakup in Montreal Harbour and in the river downstream shall not be greater than would have occurred assuming supplies of the past as adjusted.

(d) The regulated outflow from Lake Ontario during the annual flood discharge fromthe Ottawa River shall not be greater than would have occurred assuming supplies of the past as adjusted.

(e) Consistent with other requirements, the minimum regulated monthly outflow from Lake Ontario shall be such as to secure the maximum dependable flow for power.

(f) Consistent with other requirements, the maximum regulated outflow from Lake Ontario shall be maintained as low as possible to reduce channel excavations to a minimum.

(g) Consistent with other requirements, the levels of Lake Ontario shall be regulated for the benefit of property owners on the shores of Lake Ontario in the United States and Canada so as to reduce the extremes of stage which have been experienced.

(h) The regulated monthly mean ievel of Lake Ontario shall not exceed elevation 2,!+8,0 with the supplies of the past as adjusted. (i) Under regulation, the frequency of occurrences of monthly mean ele- vations of approxima,tely 247.0 and higher on Lake Ontario shall be less than would have occurred in the past with the supplies of the past as adjusted and with present channel conditions in the Galop Rapids Section of the St. Lawrence River.

(j) The regulated level of Lake Ontario on 1 April shall not be lower than elevation 244.0. The regulated monthly mean level of the lake from 1 April to 30 November shall be maintained at or above eleva- tion 244.0.

(k) In the event of supplies in excess of the supplies of the past as adjusted, the works in the International Xapids Section shall be operated to provide all possible relief to the riparian owners upstream and downstream. In the event of supplies less than the supplies of the past as adjusted, the works in the International Rapids Section shall be operated to provide all possible relief to navigation and power interests.

92. Subsequent to this action, the Commission held hearings in

Rochester, New York, and in Toronto, Ontario. At these hearings the criteria and range ofstage, set out in the 17 March 1955 letters, were explained and discussed. Briefs and oral statements were presented by various interests.

In the meantime, studies had been initiated to develop a plan of regulation to meet the requirements of the criteria and range of stage for the entire period of record, 1860 to 1954. A plan of regulation designated 12-8-9 was developed and presented to the Commission at its executive session on 5 May 1955, in Buffalo, New York.

93, As a result of its deliberations on 5 May 1955 the Commission recommended to the Governments by identical letters, dated 9 May 1955, that the criteria set out in its letters of 17 March 1955, and the range of mean monthly ele- vations of 244.0 (navigation season) to 248.0 as nearly as may be, be adopted.

It was further recommended that final design of channel excavations be based on this range and plan of regulation 12-A-9 with the assurance that any adjustment required would be of a minor nature. 94. The Commission instructed the Board to undertake a further review of the plan and its effect on the various downstream interests and develop such minor adjustments to Plan 12-4-9 as might be necesszry to best meet their requirements. As a result of this further review, a plan of regulation, involving minor revisions to Plan 12-A-9 was developed. This plan, designated as Plan 12-A-9(M) eliminated many of the objectionable features of Plan 12-8-9 insofar as downstream interests are concerned.

95. Although Plan 12-A-9(M) hed not been presented formally to the Commission, or Goverm.ents, the Governments took into consideration the results of this plan particularly in regard to its critical profiles for channel excavations, and the adjustments it contained to satisfy downstream interests. Accordingly, in the Governments' reply of 3 December 1955 to the Commission's letters of

9 Nay 1955, Plan 12-A-9 was approved for the purpose of calculating critical profiles and the design of channel excavations only, The Commission's recommended range of stage of 2.44.0 (navigation season) to 248.0 as nearly as may be, and the recommended criteria for the operation of the regulatory works were approved. Further, with respect to the adjustments to Plan 12-A-9, the Government of Canada, in a letter dated 3 December 1955 to the Chairman,

Canadian Section, International Joint Commissiori, expressed its concern about the effeots which the regulation of Lake Ontario levels might have in the exclusively Canadian section of the river, particularly in relation to the flow during the ice-forming period each yeer, and the flooding hazard in

February and March each year in the Montreal erea. Also, the Government of

Canada informed the Commission that arrangements had been made for the re- < design of the new 27-foot canal in the vicinity of Montreal which would allow a flow of 40,000 cubic feet per second to be by-passed from Lake St. Louis to Laprairie Basin through the canal during the non-navigation season. 96. Following the Governments1 replies, dated 3 December 1955, to the

Co~ssion~srecommendations made in the 9 May 1955 letters, the Commission met with its advisers, including the Board, on several occasions, and on 2

July 1956, issued a Supplementary Order to its 29 October 1952 Order of

Approval. This Supplementary Order gave effect to the actions of the Govern- ments with respect to the adoption of criteria, the range of stage and acceptance of Plan 12-A-9 as the basis for calculating critical water profiles and designing the channel excavations in the river. 97. In its report on regulation the .Board concluded that further studies were necessary to incorporate additional minor adjustments in the plan of regulation so that the requirements of all interests, both upstream and

downstream, would be more nearly met. By direction of the Commission, the

International St. Lawrence River Board of Control continued the reg&tion studies. -SECTION VI - CONCLUSIONS

98. The average level of Lake Ontario at Oswego, New York, for the period 1860 to 1954 is elevation 246.04 feet, United States Lake Survey 1935 datum.

The monthly mean level of the lake has varied from a low of elevation 242.68 for November 1934 to a high of elevation 249.29 for June 1952, making a total range in recorded monthly mean stage of 6.61 feet.

99. In addition to these long-term variations, the levels of Lake Ontario show a seasonal pattern of high stages in spring and suer and low stages in fall and winter. The average monthly lake level is highest in June and lowest in January. The maximum and minimum seasonal changes from high to low lake levels for the period of record were 4.07 feet and 0.k7 foot. The maximum and minimum seasonal chznges from low to high lake levels were

3.54 feet and 0.32 foot,

100. Superimposed upon the long-range and seasonal fluctuations resulting from the change in quantity of water in the lake, there are daily and even hourly fluctuations resulting from tilting of the lake's surface induced by winds and differential barometric pressures. These short-period fluctua- tions reach a maximum at the east end of the lake where the water surface may rise about three feet above mean lake level.

101. Differential crustal movement of the earth's surface affects the levels of Lake Ontario. The earth's crust in the Galop Rapids reach is rising at a rate of 0.55 foot per hundred years with respect to the land at

Oswego and at a rate of about one foot peq hundred years with respect to the land at the west end of the lake. Since the natural control of the outle% was in the Galop Rapids reach, crustal movement at the above rates has had the effect of decreasing the discharge capacity of the lake outlet for the same lake level or of increasing the water levels of the lake at any point on the shore for the same water supply conditions. Thus, at Oswego the water level has raised 0.52 foot wit11 respect to the land due to differential movement of the earth's crust between Oswego and the Galop Rapids during the period of record from 1860 to 1954. The effects of the other natural factors and the artificial factors would be superimposed on, and be inde- pendent of, this crustal movement effect.

102. The predominant factor affecting the levels of Lake Ontario duringthe period from 1860 to 1954 has been the variation in supplies of water to the lake. The change in the amount of water in the lake during any given period I equals the inflow frcm the upper lakes. plus the runoff from the lake's drainage basin and plus the direct precipitation upon the lake's surface minus the evaporation from the lake's surface and minus the outflow through the St. Lawrence River. The net total supplies which would have occurred under natural conditions have been affected by artificial works of man.

Other works of man have changed the discharge capacity of the natural outlet of Lake Ontario. The effects of these works resulted in a variation in the fluctuations of the level of Lake Ontario from those which would have obtained in a state of nature. If such a state of nature had existed, recorded fluctuations in the monthly mean levels of Lake Ontario would have had a total range of about 6.1 feet which is about 0.5 foot less than actually occurred.

103. The major artificial factors which have affected the levels of Lake

Ontario are: diversions out of and into the Great Lakes basin; Gut Dam and channel changes in the Galop Rapids reach of the St. Lawrence River; and the regulation ~f outflows from Lake Superior. Other factors have been regimen changes in the connecting rivers between the Great Lakes and diversions

from Lake Erie and the Niagara River for power and navigation.

104. Diversions have been made and are continuing out of Lake Michigan at

Chicago to the Mississippi River drainage basin and into Lake Superior from the Hudson Bay drainage basin. Diversions from Lake $iichigan commenced in

1848 and'into Lake Superior in 1939. The effects on Lake Ontario levels of

these diversions have varied with the magnitudes and timing of the actual

diversions. Diversions out of the Great Lakes basin have the effect of

lowering Lake Ontario levels while those into the Great Lakes basin raise

the lake's levels. The maximum lowering of Lake Ontario levels due to diver-

sions was during the period 1930 to 1935 when lake levels were on the average

about 0.43 foot lower than they would have been without the diversion out of

Lake Ivlichigan. In November 1934 when the minimum monthly mean level of record

was reached on Lake Ontario, the effect of diversions out of Lake Michigan was to lower the level of Lake Ontario by about 0.42 foot. Prior to 1947

the net effect of diversions was a lowering of Lake Ontario levels. During

1947 the raising effect on Lake Ontario levels of diversions into Lake

Superior was about the same as the lowering effect due to diversions out of

Lake Michigan and consequently, at that time, Lake Ontario levels were not affected by dive-osions. In June 1952, when the maximum monthly mean level of record was reached on Lake Ontario, the raising effect on Lake Ontario

levels of the diversions into Lake Superior exceeded the lowering effect of

the diversions out of Lake Michigan t? the extent that the lake level was about 0.06 foot higher than it would have been without the diversions, dith

the average net rate of diversion of about 1,900 cubic feet per second into

the Great Lakes basin, the ultimate effect on Lake Ontario water levels, at an average elevation of about 246.0 feet, is to raise Lake Ontario water

levels by about 0.09 foot under outlet conditions existing prior to

construction of the St. Lawrence Seaway and Power projects.

105. The net effect on Lake Ontario levels of Gut Dam and channel changes

in the Galop Rapids reach of the St. Lawrence River was to raise the lake

levels 0.33 foot or 4 inches at high lake stages, The effect of Gut Dam at

such high stages was of the same magnitude. At mean lake stage the net

effect of Gut Dam and channel changes in the Galop Rapids reach was to raise

the lake levels 0.30 foot or 3 1/2 inches. At such lake stage the effect of

Gut Dam was to raise the lake level 0,41 foot or 5 inches. At low lake

levels the net effect of Gut Dam and channel changes was to raise such levels

by about 3 inches with the effect of Gut Dam being a raising of O,40 foot or

about 4 3/4 inches,

106. The effects on Lake Ontario levels of regulation of Lake Superior ~ levels and outflows since 1922 have varied from a raising of about 2 3/4 inches to a lowering of about 2 1/4 inches. The effects are not related to

Lake Ontario stages and can be either a raising or lowering at either high

or low stages of Lake Ontario. In June 1952 when the maximum monthly mean

level of record was reached on Lake Ontario, the effect on Lake Ontario

levels of Lake Superior regulation was a raising of about 1 1/2 inches, and

in November 1934, when the minimum monthly mean level was recorded, the

effect was a lowering of about 1 1/4 inches,

107. Other factors such as regimen changes in the connecting rivers between

the Great Lakes and in the St. Lawrence River above the Galop dapids reach

and diversions from Lake Erie and the Niagara River for power and navigation

ha.ve had only minor and transitory effects 3n the levels of Lake Ontario, 108. In June 1952, at the highest recorded monthly mean level of elevation

249.29 for Lake Ontario, the net effect on Lake Ontario of the Gut Dam and

channel changes in the Galop Rapids reach was to raise levels 0.33 footy the net effect of diversions out of and into the Great Lakes basin was to raise

levels 0.06 foot and the effect of Lake Superior regulation was to raise

levels about 0.13 foot. Thus without these artificial changes the water levels of Lake Ontario in June 1952 would have been at elevation 248.77

United States Lake Survey 1935 datum or about 0.52 foot lower than the

recorded level. In November 1934 at the time of the lowest monthly mean

level of record of elevation 242.68, the effect on Lake Ontario of diversions

out of Lake Michigan was to lower levels 0.42 foot, the net effect of the Gut

Dam and channel changes was to raise levels about O.Q5 foot and the effect of

Lake Superior regulation was to lower levels about 0.11 foot. Thusy without these artificial changes the water levels of Lake Ontario in November 1934

would have been at about elevation 242.96 or 0.28 foot higher than the

recorded level

109. Operations for the construction of the St. Lawrence Seaway and Power pro-

jects commenced in 1954. In July 1955, these operations began to affect the

regiment of the St. Lawrence River at the natural control for Lake Ontario

outflows in the Galop Rapids reach. Lake Ontario levels and outflows since that time have been, and will continue to be, artificially controlled.

110. The Board concludes that, having regard to all other interests, measures

can be taken to regulate the level of Lake Ontario for the benefit of property

owners on the shores of the lake in the United States and Canada so as to

reduce the, extremes of stage which have been experienced. As a result of

regulation studies conducted by the Board a range of regulated lake eleva- tions, 244.0 (navigation season) to 248.0, as nearly as may be, was approved

by the two Governments. This range provides benefit to the property owners

on the shores of Lake Ontario, and permits the application of a plan of

regulation which would protect the interests of navigation, permit feasible

developnent of power in the international sect.ion and in the Canadian

section of the St. Lawrence River, and meet the known requirements of other

interests,

111. The regulat,ion .li~:iC:j :~r Lake Ontario adopted by the Governments were

defined in terns of the fixed lard-tc-=%ST level relationship at the gauge

at Oswego, New Pork, wnich is on the U.S.L.S. 1935 datum. With the land-to-

water level relat,ionship fixed at Oswego, and if crustal movement continues

as in the past, the stmctures and channel bottoms in the International

Rapids Section would rise with respect to lake levels as determined at the

Oswego gauge, while the land at the western end of Lake Ontario would subside

with respect to the same lake levels. It is concluded that crustal movement

will need to be considered in the future in connection with the regulation

of Lake Ontario.

112. This report completes the assignment of this Board from the International

Joint Commission under the Reference dated 25 June 1952.

------Menber for United Stat.es-. "--- Member for Canada I1 #'' #''

Gail A, Hathaway, I/ T .M. Patterson, Engineering Consultant. Director, International Bank for Recon- Water Resources Branch, struction aCd Develcpnent , Department of Northern Affairs Washington 25, D.C, and National Resources, Ottawa 4, Ontario, Canada.

.10 December 1958.