Abstract
THE Mississippi and Missouri, together, form the longest river system in the world, extending to a length of 4,502 miles. Above its junction with the Missouri, the Mississippi has a length of 1,170 miles and drains an area of 171,500 square miles. In an article in Engineering of July 19, a description is given of that part of the Upper Mississippi lying between the Missouri and the town of Minneapolis in Minnesota, 659 miles long. In 1907, a project was adopted for the regulation and improvement of the river from Missouri to Minneapolis in order to provide a 6-ft. channel at times of minimum flow. The work carried out consisted mainly of dredging and the construction of wing dams to restrict the width of the low-water channel. Twenty years later, the U.S. Congress directed that a survey of the river should be taken with the view of providing a low-water channel with a depth of nine feet. The project involved the construction of a series of locks and dams, and fairly extensive dredging. The work was completed last March at a cost of 170 million dollars. Twenty-five dams were required, and special Tainter and Roller gates were used for regulating the flow. The gates of later construction are designed so that they can be lowered several feet below the normal level of the pool, allowing even heavy ice to pass over the top.
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Regulation of the Upper Mississippi. Nature 146, 227 (1940). https://doi.org/10.1038/146227b0
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DOI: https://doi.org/10.1038/146227b0