who built the large dams in the colorado river basin
Colorado River Large engineering works began around the start of the 20thÂ century, with major guidelines established in a series of international and U.S. interstate treaties known as the "Law of the River". The U.S. federal government was the main driving force behind the construction of dams and aqueducts, although many state and local water agencies were also involved. Most of the major dams were built between 1910 and 1970; the system keystone, Hoover Dam, was completed in 1935. The Colorado is now considered among the most controlled and litigated rivers in the world, with every drop of its water fully allocated.
Hoover Dam On December 21, 1928 President Coolidge signed the bill authorizing the dam.[21] The Boulder Canyon Project Act appropriated $165Â million for the Hoover Dam along with the downstream Imperial Dam and All-American Canal, a replacement for Beatty's canal entirely on the U.S. side of the border.[22] It also permitted the compact to go into effect when at least six of the seven states approved it. This occurred on March 6, 1929 with Utah's ratification; Arizona did not approve it until 1944.[23]