Upper Mississippi River 9-Foot Channel Project, Lock & Dam 26R, Alton, Madison County, IL

Significance: ...Lock and Dam NO. 26R constitute the first replacements of an original element of the Nine-Foot Channel Project. The new installation will replace Lock and Dam No. 26, located two miles upstream. The original installation is unable to adequately accommodate the present volume of river traffic and suffers from severe structural deficiencies. Lock and Dam No. 26R represent the present state of the art in river navigation control works. The basic components of the installation are comparable to those utilized in the 1930s. The most striking difference between the older installations and Lock and Dam No. 26R is the immense size of the new structures. The significance of the new installation is not limited to its size. Throughout the design and construction process, the Corps of Engineers and the various contractors have engaged in an extensive program of computer-assisted design, testing, and evaluation. These sophisticated studies represent perhaps the most significant difference between the older structures and Lock and Dam No. 26(R).
Survey number: HAER IL-32
Building/structure dates: 1979