In CA and the US many dams have been built and all the good locations for dams already have dams.
If you build a dam in a lesser location it will have a higher ratio of surface to volume and have a high evaporation loss, require much more land, have higher construction costs, have higher risk of failure, and go dry very quickly because they have low inflow rates.
Having said that, there is room for 2 more dams on the Colorado river which would benefit CA, but both dams would be in the Grand Canyon. In the 50s and 60s the Bureau of Reclamation tried to build one of these dams in the Canyon which was called Bridge Canyon Dam, but public opinion killed it.
“In CA and the US many dams have been built and all the good locations for dams already have dams.”
All the good locations in the US are gone?
Every single one...there are no places left?
Hard to believe. That’s a very broad statement.
And any google search with the words California and Dam comes up with at least a half dozen serious proposals for large scale dams in California, which have been stalled for reasons other than suitability/location.
Dumb question. Throughout the northwest, dams have been removed over the years for environmental or safety reasons. Are these former dam sites now deemed no longer a ‘good’ site for a dam?