It isn't only surface water that's concerning; it's groundwater, as well. Most H2O used by humans comes from aquifers below the surface, not from surface bodies of water; and they're being depleted fairly rapidly. Even with the mega drought in most of the West, I fear too many people in the USA do not grasp the seriousness of our ongoing water crisis. They see lots of water in various places, but may not understand that most of it is unavailable to humans.
Of all the H2O on Earth, only 1% of it is available for drinking, bathing, cooking, etc. The rest is either salt water or glacial ice or fresh water in remote places, or places where it relatively quickly runs to the ocean. By 2040, most human habitats in the world won't have enough water to meet year-round demand, & that includes most of the USA...unless we drastically alter our water use.
Step one: no lawn or golf course or sports field (& the like) anywhere should ever be watered...unless we figure out a really low-energy, cheap way to desalinate sea water. Presently, that's not in the cards. It's time to end the Great American Lawn Fetish. It wastes water, and artificial fertilizers & herbicides used on lawns run off, polluting streams & lakes. Lawn runoff contributes to eutrophication of bodies of water. Have you ever seen or smelled a eutrophic lake? There are plenty of alternatives to grass lawns.
