Since I brought it up, it's only fair I do a bit of legwork.

More here.

The gist of it seems to be that hydroelectric as a class already supplies a large chunk of California energy, and since the objective for environmentalists and politicians is forcing their favored alternatives, they don't want the big dams included as "renewable."

Dams are okay if they're tiny and useless.

I don't understand the difference between "geothermal" in category (i) and category (ii).

It's politics.

Also, large dams are "evil" in the eyes of this particular subset of environmentalists, just like wind farms are slowly becoming, and just like solar farms will become if they get large enough to do any good.