They wanted to build more dams and didn't want the first one to get in the way of more due to malfunction.
It is interesting what you can build and the quality of the product if you use Americans, American materials and American pride to build it.
Today you couldn’t get the idea of building the Hoover Dam from thought to drawing because of the EPA, BLM, California Coastal Commission, INS etc. However we can build a high speed rail in the desert. No problem. Talk about a give away program.