Do you know the difference between "Household water use" and "Residential water use?" Figures vary regionally, however nationally are averaged by the American Water Works Assoc. (AWWA) and the EPA, among others. Residential water use is water that has been measured to supply residences.
Household water use is the sum total of water use fixtures WITHIN the house. The Residential figure includes outdoor water use and household water use combined (about 50/50) .
AWWA states that approx. 50% Residential water use is "Outdoor water use" AWWA and EPA along with Irrigation Assoc. of America figure approx. 30 % of spray irrigation water is lost to wind and misting!. Most irrigation systems when audited fall below 50% uniform distribution efficiency and that means 50% wasted!
Let me "recap" that for you. 50% is outdoor and 50% of that is lost to mist and other losses. If 50% of 50% is outdoor loss, then 25% of Residential use is wasted outdoors. This is what I call an "Elephant " in the landscape. Plumbing manufacturers use household figures to "weight " the fixture savings they have designed! Pie charts become "statistical monkeys" for social political and commercial gain. A figure of 27% toilet use with a 20% savings due to the manufacturer's design sounds more important than 20% of the actual 13% of "Residential" water use. Same goes for all household water use fixtures! Meanwhile, the Elephant is dancing in the yard without an audience!
One of the reasons for the excessive amount of misting in irrigation systems is that the systems are often exposed to the full street water main pressure of 120 psi or more, while they should only be getting 80 psi or less.
I have proposed a plumbing code change that would change the location of any required pressure regulator from at-the-building (which, obviously, only protects the building), to at-the-meter, which will provide the proper regulated pressure to the building and the outdoor systems. This will also reduce the stress and "hammer" effects on the water main from the meter to the house and irrigation valves. Keeping that line pressure at 80 psi or less reduces the possibility of damage and leaks - which get really annoying and expensive when it's located under your driveway, sidewalk, or favorite planter area.