https://sci-hub.se/10.2307/25756872
(2010) "Reclaiming freshwater sustainability in the Cadillac Desert" Sabo et al.
Purely hydroelectic power dams are something of a special case of the overall dam programs, which were mostly geared towards providing water for large agribusiness concerns (especially high-value crops like fruits, nuts, alfalfa-dairy production, etc.) and for large desert cities (Las Vegas, Phoenix, etc.). The Colorado river is probably the main dam issue, as the ongoing fossil-fueled regional megadrought is pushing those dams towards 'dead pool' status, and there's a rising conflict between cities and agriculture over who will get the water. Recycling water is likely going to be necessary, aka 'toilet-to-tap'.
Here's the FERC decision on the Klamath. The history of the licensing of these dams goes back to the 1950s:
> "The original license order [1954] was for the construction and operation of the Big Bend No. 2 development, also known as the J.C. Boyle development. Later orders incorporated the other project developments into the license... The original license, issued to the California Oregon Power Company, was transferred to Pacific Power and Light Company on June 16, 1961 and then to PacifiCorp on November 23, 1988."
https://www.ferc.gov/media/h-1-p-2082-063
One takeaway is that investor-owned electric utilities have always been nothing but government-subsidized theft from electricity consumers; they're essentially natural monopolies and would be better as state-owned entities (see for example police and fire departments, which are not investor-owned nor subject to rent extractions by billionaires like Buffet and the B-H shareholders).