Richard P. Joy, of Detroit, has for some time taken a deep interest in the subject of the probable effect of the drainage canal now being constructed at Chicago on the depth of water in the lakes and connecting waters. He has all along held that the outflow of water through the canal to the Mississippi river, would materially lower the level of the lakes system, and be the cause of great damage to the interests of navigation thereon. Has written several able articles on the subject, setting forth the futility of spending millions to make a deep channel through the rivers and then spending millions more to drain off the water and neutralize the good effect of the deep channel expenditure. He says, with a great deal of truth and reason, that any proceeding by which the level of theses lakes would be lowered should be stopped and at once. One of his letters has brought out a confirmatory reply from Gordon H. Nott, an engineering expert of Chicago, from which are gathered some conclusions, based on careful computation, that may be of interest to those who are to consider the subject.
He says that the canal will carry off not less than 600,000 cubic feet per minute, south to the Illinois river, and thence to the Mississippi. This amount of water will decrease by about 7 per cent the flow of water now flowing out of Lakes Huron and Michigan through the St. Clair river. He believes that the level of the water in the St. Clair and Detroit rivers and Lake St. Clair will be lowered by 15 or 16 inches and Lake Erie a little more. He says, with a good show of reason, that the proposed construction of solid jetties, to impede the flow of water, and thus raise the level of Lake Huron, would create so swift a current there as to materially impede navigation, and if a solid jetty will not do to decrease the flow, the St. Clair and Detroit rivers would have to be narrowed, perhaps their entire length, at immense cost. He says in conclusion that the loss of water by the drainage canal will be practically one-fourteenth of the quantity passing through the St. Clair river, and such a loss cannot be laughed down.