Saving vs. Saving Up?

Steven writes about water conservation in Portland. This paragraph makes me wonder about word usage:

"Conserving" something usually means "saving it for later" -- but there isn't anything here to save. We here in western Oregon are not short of fresh water, and we won't be for the forseeable future. And excess water here runs off into the ocean; there's no way to "save it for later".

Has the word save changed its meaning since I was little so that now consuming less counts as saving even if nothing is set aside for later? In other words, is there now a vocabulary difference between saving and saving up?

Similarly, is Steven correct that conserving means saving up? I would disagree. As I normally hear the word used, someone could "conserve money" if they spend less to minimize debt even if they do not accumulate any savings, and someone could "conserve energy" if they lower their home's electric bill even if the power plant does not notice because their neighbor has increased electric use.