This is to supply numbers and conditions for two US communities.
1. Ordinary medium income county, moderate lawn watering, lots of heavy industry which draws its own water from wells or river and some industry which uses drinking water. Winter usage 30 mgd(million US gallons per day) for 200,000 people. Summer usage 60mgd for 200,000.
2. Affluent higher income county, no heavy industry, commercial and light industry only, heavy lawn watering, a "bedroom county". Winter usage 8 mgd for 80,000 people. Summer usage 32mgd for 80,000 people.
Both communities in Southeast USA, about 33 degrees latitude and both have been under state mandadeted water conservation rules in recent years. High consumption in community 2 is discouraged by a rate structure which escalates the higher consumption bracket rates.
Raw water is abundent for both systems.
Therefore we can see that per capita consumption is heavily influenced by industry, per capita income, rate structure, irrigation, etc.
Formerly (1940 to 1975)in the US the design guide for developing communities was 100 gal per day per capita. This number included commercial uses and a reasonable amount of light industry. Rates were made for commercial and industrial users which discouraged heavy use of the publically owned treatment works. Many systems are still operating this way.
This is a great forum. Let's hear some usage numbers from others.
Regards to all,
Gumlog