711.4216 M 58/63
The Secretary of State to the British Chargé (Chilton)
Sir: Referring further to your note No. 467 of May 7, 1925, concerning the diversion of water from Lake Michigan by the Sanitary District of Chicago, I have the honor to furnish you with the following information in reply to the inquiries made by the Canadian Government:
- First: The actual average flow of the water passing Lockport during the year ending March 3, 1925, has been 9,700 cubic feet per second.
- Second: This average flow of water passing Lockport will not be immediately reduced by any amount under the terms of the permit issued by the Secretary of War on March 3, 1925.
- Third: This average flow may be reduced by December 31, 1929, by an amount varying from 1,750 to 3,000 cubic feet per second.
By way of explanation of the wide range over which the amount of reduction by December 31, 1929, varies, it should be stated that the amount of reduction depends upon the decrease in the sewage load on the water in the Drainage Canal. The permit prescribes that a minimum population of 1,200,000 be provided with the equivalent of 100% treatment. The program of sewage treatment plant construction contemplates the completion of plants which will give 100% treatment to a population of slightly over 1,400,000. If this program is carried to completion a larger reduction may be made [Page 565] in the flow than if only the requirements of the permit are carried out.
Furthermore, when the controlling works which are required to be placed in the Chicago River or Drainage Canal to prevent reversals into Lake Michigan in times of flood are completed and in operation it may be found practicable to make a much larger reduction in the flow of water with safety to the water supply of the City of Chicago during winter season, a time when the oxygen content of the diluting water is much higher than it is during the summer season.
It is also expected that there will be a substantial reduction in the amount of water consumed in the locality for domestic purposes as the result of a requirement of the permit of March 3, 1925, which makes it necessary for the City of Chicago to adopt and carry into execution a program of metering its water supply. By December 31, 1929, this reduction will vary between 400 and 600 cubic feet per second.
The net result of all these varying influences will be to make it possible to reduce the average flow by a minimum amount of 1,750 cubic feet per second and possibly by the maximum amount of 3,000 cubic feet per second.
To explain the apparent inconsistency between the amount of water specified in the permit (8,500 cubic feet per second measured at the intakes) and the flow at Lockport (9,700 cubic feet per second) it might be stated that the difference represents the amount of domestic water consumption by the City of Chicago which could not be authorized or included properly in a permit issued to the Sanitary District of Chicago, a separate municipality, other than to make the permit non-operative in case of failure on the part of the former agency to adopt certain measures of conservation which were specified. Condition 8 of the permit of March 3, 1925, looks to a substantial reduction of this portion of the flow in the Chicago Drainage Canal, at the same time condition 4 makes possible a reduction in the amount of water used for dilution of sewage.
Accept [etc.]