31. OTHER FLOOD-CONTROL PROJECTS FOR WHICH NO
ESTIMATES ARE SUBMITTED

1 Completed.

Reported previously by the St. Louis district as completed under provisions of sec. 6 of the

Flood Control Act approved May 15, 1928.

Awaiting local cooperation.

Status of all investigations for flood control called for by flood control acts and committee resolutions

1 Will be combined with comprehensive survey of Illinois River and tributaries, Illinois being made by the Upper Mississippi Valley Division under the provisions of the Flood Control Act approved Aug. 11, 1939.

IMPROVEMENT OF RIVERS AND HARBORS IN THE DETROIT, MICH., DISTRICT

This district comprises the eastern end of the upper, and the eastern half of the lower, or southern peninsulas of Michigan, northwestern Ohio, and a small portion of northeastern Indiana embracing the United States waters of Lakes Huron, St. Clair, and the western end of Lake Erie with their tributary watersheds from the head of St. Marys River and the Straits of Mackinac to Sandusky Bay, exclusive.

District engineer: Col. Allison Miller, Corps of Engineers. Division engineer: Col. H. A. Montgomery, Corps of Engineers.

1. ST. MARYS RIVER, MICH.

Location. This river is about 63 miles long, and flows in a southeasterly direction from the eastern end of Lake Superior into the northern end of Lake Huron. (See U. S. Lake Survey Charts Nos. 5 and 9.)

Previous projects.-Authorized by River and Harbor Acts of July 8, 1856, July 11, 1870, June 14, 1880, August 2, 1882, and August 5, 1886. For further details, see page 1955, Annual Report for 1915, and page 1529, Annual Report for 1938.

Existing project. This provides for channels through St. Marys River, which, at low-water datum, are suitable for vessels drawing 20 feet when up-bound and 24 feet when down-bound, with a least width of 500 feet in the up-bound and 300 feet in the down-bound routes. The specific improvements embrace channels through shoals between Lake Superior and the head of the falls, having minimum widths of 1,000 feet with depth at low-water datum of 27 feet through Round Island Shoals and Middle Ground and 26 feet through Vidal Shoals; widening Brush Point Turn to

bottom width of 1,200 feet and channel from Brush Point to Point Louise to bottom width of 1,000 feet; constructing and operating four locks, two canals, and an emergency dam for each of the canals at the falls; including a new lock on site of Weitzel lock, postwar removal of Bridge Island and structures therein to secure a depth of 27 feet at low water, deepening the approach channels and reconstruction of approach piers; deepening and widening the tailrace of the United States power plant and postwar construction of a new hydroelectric power plant of 14,000-kilowatt capacity; constructing remedial works at the inlet of the power canal of the Michigan Northern Power Co.; constructing compensating works at the falls; dredging through shoals between the lower end of the canals and the upper entrance to Lake Nicolet, including extension of anchorage and maneuver area below the locks and the widening of angle at black gas buoy No. 33; dredging to widen and deepen the upper entrance channel into Lake Nicolet, excavating channels from Lake Nicolet to Lake Munuscong on either side of Neebish Island, a distance via West Neebish of 14 miles and via Middle Neebish 15 miles, the Middle Neebish, or up-bound, route to have a least width of 500 feet, and the West Neebish, or down-bound, route 300 feet; and dredging shoals between Lake Munuscong and the mouth of the river. The following table shows the principal features of the locks and emergency dams. All structures are located at Sault Ste. Marie, Mich.

Includes canal excavations to provide necessary approaches to lock, canal walls, and piers, and emergency dam.

Excludes cost of deepening and enlarging South Canal, $1,653,378.

Excludes cost of North Canal, $2,572,611.

Excludes cost of canal excavations to provide necessary approaches to lock, canal walls ard piers, and emergency dam, $662,919.

* Construction about 981⁄2 percent complete.

* Including engineering, office, and inspection.

10 Not separable from cost of locks.

Actual costs to June 30, 1945, $12,365,212.82.

NOTE. The limiting draft to the locks is determined by the depth over the breast walls.

The Poe lock was operated and maintained under the permanent efinite appropriation from August 3, 1896, the Davis lock from tober 21, 1914, and the Sabin lock from September 18, 1919, to e end of the fiscal year 1935. The original State locks were erated and maintained under the same appropriation from June 1881, to November 2, 1886, after which they were destroyed by cavation for the present Poe lock.

The Weitzel lock, destroyed in 1942 by excavation for the Macthur lock, was operated and maintained under the same approation from Septmber 1, 1881, to the end of the fiscal year 1935. In the following table are stated other characteristic features the improvements belonging to the existing project.

12 channels past Bridge Island, each 108 feet wide; minimum width of connecting channel, 04 feet.

: Under construction.

3 Refers to datum plane of 579.4; project depth at datum plane in effect at time of contruction was 18 feet.

Refers to datum plane 579.4; project depth at datum in effect at time of construction was 4.5 feet.

The project depths are referred to low-water datum for Lakes Superior and Huron, which are 601.6 and 578.5 feet above mean cide at New York.

Each year the St. Marys River rises and falls about 1 foot as measured by the monthly mean levels. Since 1860 the difference between the highest and lowest monthly mean levels above the

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