Introduction

Pursuant to legislation approved by President Eisenhower on May 13, 1954, and prior Canadian legislation effective December 21, 1951, the construction of the Seaway is being accomplished jointly by the St. Lawrence Seaway Development Corporation, a United States Government corporation, and a similar Canadian Government entity, the St. Lawrence Seaway Authority.

The Great Lakes-St. Lawrence waterway system presently provides 35foot depth from the Atlantic to Montreal (1,000 miles); 14-foot depth in the St. Lawrence reach from Montreal upstream to Ogdensburg, N. Y. (114) miles); and 21-foot controlling depth upbound and 25-foot downbound in the confined channel reaches from Ogdensburg to the head of the Great Lakes (about 1,200 miles).

The seaway-modernization program will increase the controlling channel depth in the upper St. Lawrence River from 14 to 27 feet, and in the Welland Canal from 25 to 27 feet. It will reduce the number of lift locks to be transited between Montreal and Lake Erie from 25 to 14.

In the upper St. Lawrence there are now 18 locks normally navigated by upbound shallow-draft vessels. Controlling lock dimensions of present facilities are 252 by 44 by 14 feet. These will be supplanted by the 7 new Seaway locks, having a controlling clear length of 768 feet, width of 80 feet, and sill depth of 30 feet. In the Welland Canal, connecting Lakes Erie and Ontario, the existing 7 lift locks (plus 1 guard lock) remain unchanged. They afford similar controlling dimensions.

With these new facilities, modern oceangoing freighters will be able to ply from the seven seas to the numerous ports along the Great Lakes Also, the eastern terminus of the Great Lakes shipping fleet will be extended from Ogdensburg, N. Y., 600 miles eastward to Seven Islands, Quebec, and to other points on the St. Lawrence Gulf. Through the present 14-foot restricted reach, vessel loadings are now generally limited to some 1,500 tons of general cargo and 2,500 tons of bulk commodities such as iron ore. With the larger ships that can be accommodated in the future, these cargo limits will be raised generally to about 8,500 and 25,000 tons, respectively.

In the 46-mile International Rapids section of the upper St. Lawrence River, major power development construction is underway jointly by the Power Authority of the State of New York and the Hydro-Electric Power Commission of Ontario. This development will result in the creation of a forebay pool for the new Seaway in this reach. The power entities are planning to create the new power pool in July 1958 and to place initial electrical output on the line shortly thereafter.

WORK DIVISION, LAKE ERIE TO MONTREAL SEAWAY

Lake Erie normally stands at 572 feet above sea level and Lake Ontario at 246. This 326-foot differential is overcome by the 27-mile Welland Canal, which connects the two lakes and transits navigation around Niagara Falls and Gorge. From Lake Ontario to Montreal the river descends 225 feet. This 182-mile reach is normally divided into the following units:

Thousand Islands section, 68 miles, Lake Ontario to Chimney Point below Ogdensburg, N. Y.

International Rapids section, 46 miles, Chimney Point to St. Regis, Quebec below Massena, N. Y.).

Canadian section, 68 miles from St. Regis to Montreal, Quebec. This reach includes the Lake St. Francis, Beauharnois, Lake St. Louis, and Laprairie Basin.

Following is a breakdown of the principal construction features underway by both countries.

Work by the United States:

Thousand Islands section. Channel enlargement between Clayton, N. Y., and Oak Point, N. Y.

International Rapids section.

(1) Construction of the 10-mile Long Sault Canal with its 2 locks, Dwight D. Eisenhower and Grasse River, and appurtenant works, including dikes near Massena, N. Y. This canal will bypass the power project's principal

structures.

(2) Construction of the superstructure of the new International HighLevel Highway Bridge across the South Channel at Cornwall Island.

(3) Channel enlargement in the South Cornwall Channel.

(4) Ancillary work, including installation of navigation aids in United States waters throughout the Thousand Islands and International Rapids sections.

Work by Canada:

Welland Canal. Channel enlargement in the canal approaches as well as in the canal proper between existing locks.

Thousands Islands section. Channel enlargement where necessary in the lower sector.

International Rapids section.

(1) Construction of the 11/2-mile Iroquois canal and lock, which bypasses the power project upper control dam.

(2) Construction of the substructure of the new International High-Level Highway Bridge across the South Channel at Cornwall Island.