Chicago Main Drainage.
N. W. Weston, superintendent of construction for the sanitary district, reports that the twenty miles of main canal now under contract between Summit and Lockport can be completed by April, 1897, although seven sections are being badly handled. One section, No. 6, at the present rate of progress, will take sixteen years to complete, and one section, No. 14, which is in the hands of a receiver, is to be relet by the court.
The diversion of the Des Plaines river, which requires the excavation of about 1 600,000 cubic yards of glacial drift and 2,400,000 cubic yards of rock, is virtually completed. The new channel, which is about twenty miles long, extends from near Riverside to the Romeo road. It is 200 feet wide on the bottom and the main drainage canal is protected against any overflow from it by a continuous level averaging about eleven feet high.
The drainage trustees have lately awarded contracts for five miles of excavation, extending from Summit to Central Park avenue, parallel to and about 1100 feet north of the old Illinois and Michigan canal. The prices varied from 19.7 cents 1028 cents per cubic yard. The total excavation is 6,534,000 cubic yards, and the aggregate cost foots up to $1,635,817. In their report on the letting, the finance committee, after claiming to have made a careful investigation of the bidders in regard to cash capital, their proposed methods of work, experience and all other matters required to form a proper judgment in making awards for the best interest of the district, say that the experience of the board in regard to several of the contract sections lying between Summit and Lockport has clearly demonstrated that it is not always wise to let to the lowest bidder, even when said lowest bidder may be able to give the required bond. The board must exercise a wise discretion and select such bidders as in its opinion will prosecute the work diligently to completion within the limit of time set forth in the contract.
As a matter of fact, the committee refused to let a section to either of two bidders, one at 28 cents and the other at 28.4 cents’, as the two firms bidding were not able to convince the committee that they were capable of handling such large contracts, and the award was made to another firm that has the next section to it at 29 cents, they taking the section in dispute at the lowest bid, viz., 28 cents. The total length of canal now under contract is twenty-five miles.