The troublesome problem of the levels of Lake Ontario is almost certain to come to the forefront of the news during the next few weeks. Because of the publicity put forward by the (U.S. and Canadian) Lake Ontario Beach Protective Associations and the Globe and Mail, the Governments of the United States and Canada will be the object of pressure and criticism as regards Lake Ontario levels.

2. The Great Lakes are, as you know, subject to cyclical fluctuations of water level. We know that, since 1860, the level of Lake Ontario has ranged from about 242.7 feet above mean sea level to about 249.2 feet. The highest levels reached were in 1870 and 1952. Though the range of elevations over the cyclical period of 95 years has been about 6 feet (excluding the effect of wind or barometric pressures which sometimes add two or more feet for brief periods), the annual fluctuation of range has never exceeded 4 feet though it has often varied between 2 and 3 feet.

3. The range of levels of the Great Lakes depends on flows into and out of the Basin. An inflow at the upper end may take several years before its full effect is felt at the lower end. Apart from some minimal control of inflow at Sault Ste. Marie (under I.J.C. supervision) the only way man can affect the levels of Lake Ontario is by increasing the potential outflow through the St. Lawrence River, i.e. at the International Rapids Section.

4. The proposed channel excavations in this Section will eliminate some underwater obstacles (such as parts of rock ledges which create rapids) which, naturally, impede the free flow of water. Coupled with the hydroelectric and control dams, it will become theoretically possible to lower the level of Lake Ontario by passing through these dams twice the otherwise natural output of the St. Lawrence at that point. While the output can be increased there, it should not take place, for example, during the spring freshets of the Ottawa River. Such a conjuncture of events would inevitably flood Montreal.

5. Under the Lake Ontario Reference of 1952, the I.J.C. is trying to see what, if anything, can be done to ameliorate the range of levels on Lake Ontario so as to benefit lakeshore owners.¹⁸⁷ With the construction of the St. Lawrence Project, the power and seaway entities must know soon to what low level the I.J.C. Board of Control will allow the River level to drop in the International Rapids Section. This level is dependent not only on the Lake Ontario range of levels to be selected by the I.J.C. but also on the Method of Regulation of the waters in the International Rapids Section. Such a Method of Regulation must be so cast as not to flood downstream communities, maintain a reasonable level and velocity of water for navigation purposes, assure a satisfactory regimen for the production of hydro power, be sufficiently high to allow domestic water pumpage and sewage and be sufficiently low to protect the landowners on the foreshore of Lake Ontario and the St. Lawrence River.

6. The wisdom of Solomon will be required to satisfy all interests. The I.J.C. will probably suggest a range of levels for Lake Ontario on March 15, 1955. Thereafter, it will be up to the United States and Canadian Governments to decide what that range shall be.

7. The experts of the I.J.C. are likely to suggest that the I.J.C. accept for Lake Ontario one of the three following ranges:

(a) 243 to 247 feet

(b) 244 to 248 feet

(c) 244 to 248.9 feet.

8. Technically, I understand that, because of the uncertainty of inflow into the Basin, it will be impossible to guarantee that a given range would not be exceeded. In the present state of development of hydrology applied to the Great Lakes Basin, it is said to be impossible to devise a Method of Regulation which will maintain a range within narrower limits than 4 feet. Accordingly, a range could theoretically be selected from between 242 feet and four feet or so above this scale for any number of combinations such as 242-246, 243-247, 244-248. Any Method of Regulation would be designed so that the maximum and minimum would NOT be reached more often per cyclical period than has hitherto been the experience in a "state of nature".

9. The Boundary Waters Treaty of 1909 fixes the following order of precedence in the use of boundary waters:

(a) domestic and sanitary purposes;

(b) navigation;

(c) power and irrigation. These provisions are not to disturb the existing uses of boundary waters. For domestic, sanitary, navigation and hydro purposes, a low limit of 242 (with its corresponding high of 246) is out of the question, though landowners would welcome a corresponding high of 246. A low limit of 243 is said to be too low for navigation purposes and not favoured by power interests though it might be acceptable from the landowners' viewpoint because of the reduced maximum of 247. From the viewpoint of navigation and power, a lower limit of 244 is probably close to ideal. But it does mean a maximum of at least 248 feet. The flood level for Lake Ontario is said to be 248.1 and was exceeded 18 times in the past 95 years. On the other hand, water went below the minimum of 244 feet only 8 times in that period - of which only 4 were during the navigation period.

10. The landowners have vociferously requested that Lake Ontario be kept within a range of 244 to 246 or 247 feet. They will be sorely disappointed if the I.J.C. recommends a range (as I believe it will) between 244 and 248 or possibly 248.3 feet (the maximum NOT to be exceeded more often than in a "state of nature"). If the I.J.C. makes such a recommendation, the Government will probably be bound to accept it.

11. If the Governments were to insist on a minimum of 243 feet, the cost of additional dredging in the International Rapids Section would be at least $15 million, not to speak of the cost of other works and the loss in hydro potential. (On reading the Department of Transport's brief to the I.J.C., I doubt that Mr. Marler would agree to anything but 244 feet. For that matter, Mr. Howe is likely to take the same view.)

12. In these circumstances, the Governments - directly and with the assistance of the technical experts and the I.J.C. - will have to put the case to the landowners. This will probably be attempted, in part, at public hearings to be held in Rochester, N.Y. and Hamilton probably towards March 31. Government representatives will have to say that the maximum levels will not be reached more often than in a state of nature; that there will be some improvement as the top levels above 248 feet and the bottom levels below 244 feet will be eliminated and that the Commission will keep a vigilant eye on future developments.

13. There is very likelihood that questions will be asked in Parliament either relating the problem to the I.J.C. or to the domestic situation. In the latter case, the responsibility for a reply may be Mr. Marler's or Mr. Lesage's rather than yours.¹⁸⁸

R.A. M[ACKAY]
for Under-Secretary of State
for External Affairs