The Columbia River Project

The Columbia River runs from Canada through Washington and Oregon, emptying itself into the Pacific ocean. Since it flows down the Rocky Mountains, the Columbia river produces an immense amount of energy.
When the government intervened and launched the Columbia River project under FDR using money from the Industrial Recovery Act in 1933, it opened thousands of jobs for the unemployed as construction workers and created a supply of cheap, affordable energy.
The Grand Coulee Dam became operable in 1942. Initially, it was planned to pump water for irrigation, but this was postponed in favor of establishing hydroelectric sources for the war effort.

When the irrigation aspect of the project came into play after the war, costs rose and the project as a whole suffered. One aspect of the project being to aid farmers to settle on small landholdings was abandoned. As a result of conflicts between the Bureau of Reclamation and the Department of Agriculture, corporate farms emerged as power players, rather than small-time farm owners who were originally set to benefit from the project.
The project's vision declined further in the 1960s, the cost of it had more than doubled over its course, and it was obvious the government wouldn't make back its investment in it. The enthusiasm that had fueled the project's beginnings dissipated, and it was left half finished when construction halted.
However, FDR's legacy remains with his project; the reservoir behind the dam was named in his honor, known as Franklin Delano Roosevelt Lake. According to a 2014 article, the Columbia River Basin provides over 40% of all of the United States' hydroelectric power generation.

Foner, Eric. “Give Me Liberty! Third AP Edition.” Norton Ebooks, 2014, digital.wwnorton.com/7754/r/goto/cfi/356!/4.

“Columbia Basin Project.” Wikipedia, Wikimedia Foundation, 23 Aug. 2018, en.wikipedia.org/wiki/Columbia_Basin_Project.