A large amount of data on water supplies was collected by the writer in the course of glacial investigations made under the direction of Prof. T. C. Chamberlin in the last five years in the Southern Peninsula of Michigan. These investigations resulted in a partial acquaintance with conditions in about 200 separate flowing-well districts and brought out matters of such exceptional importance that arrangements were made to extend them by examining each of the flowing-well districts in the State sufficiently to determine its essential characteristics, present state of development, and probable capacity for future development. It was arranged also that the quality of various classes of water, both surface and underground, as well as water supplies of, cities and villages, should be given attention. As the mineral waters of the State had already been discussed in some detail by the State geologist, Dr. A. C. Lane, in Water-Supply Paper No. 31 of the United States Geological Survey, it was deemed unnecessary to prepare another report on that subject, but arrangements were made with Doctor Lane for embodying in this report the large amount of material which had accumulated at his office relative to other classes of water supply, and also for furnishing reports on certain counties in which special investigations had been carried on by the State survey. The results of all these studies, so far as they apply to the middle- and northern counties (see fig. 1, on next page), are embodied in the present report; the remainder appears in a companion report on the southern counties of the Southern Peninsula of Michigan.
