The Shawinigan Falls of the St. Maurice River in Canada occur at two points a short distance apart, the fall at one point being about 50 and at the other 100 feet high. A canal 1,000 feet long takes water from the river above the upper of these falls and delivers it near to the electric power-house on the river bank below the lower falls. In this way a head of 125 feet is obtained at the power-house. The canal in this case ends on high ground 130 feet from the power-house, and the water passes down to the wheels through steel penstocks 9 feet in diameter.
Fig. 16.—Power-house on White River, Oregon.
Another interesting example of conditions that require a power-house to be located some distance from the point where water is diverted from its natural course may be seen at the falls on the Apple River, whence energy is transmitted to St. Paul, Minn. By means of a natural fall of 30 feet, a dam 47 feet high some distance up-stream, and some rapids in the river, it was there possible to obtain a total fall of 82 feet. To utilize this entire fall a timber flume, 1,550 feet in length, was built from the dam to a point near the power-house on the river bank and below the falls and rapids. The flume was connected with the wheels, 82 feet below, by a steel penstock 313 feet long and 12 feet in diameter.
As the St. Mary’s River leaves Lake Superior it passes over a series of rapids about half a mile in length, falling twenty feet in that distance. To make the power of this great volume of water available, a canal 13,000 feet long was excavated from the lake to a point on the river bank below the rapids. Between the end of the canal and the river sits the power-station, acting as a dam, and the water passes down through it and the wheels under a head of twenty feet.
Fig. 17.—Power-house Across Canal at Sault Ste. Marie, Mich.
By means of a canal 16,200 feet long from the St. Lawrence River a head of water amounting to fifty feet has been made available at a point on the bank of Grass River near Massena, N. Y. There again the power-station acts as a dam, and the canal water passes down through it to reach the river.