I don't think SF is an example of the place where the link between paying a lot of taxes and get the environment around improved is as obvious as you seem to imply.
Note though the reduction didn't come from anything getting in fact more efficient, but from "two companies donated materials and installation" - probably to quell the bad press. And it looks like $1.7m is still going to get spent, just maybe on two toilets instead of one.
The donated services and material was worth $425,000 [1]. The project costs came down on their own, meaning they never needed to be that high. It was an overestimate. If there wasn’t bad publicity then who knows if grift would have allowed it to stay too high or not, we’ll never know.
Where are you seeing the $1.7m is still getting spent?