How much water is 1 gallon/day/person?

 How much water is 1 gallon/day/person?

I saw an ad on television that stated that if everyone used
1 gallon of water less per day, in one year enough water would
be saved to fill (US) Lake Superior more than 30 times over.

While saving 1 gallon per day per person is a significant amount
(New York City uses about 1 billion gallons a day, so with 7 billion
people the water savings is enough for about 7 NYCs), I think
that a year's worth of such savings is small compared with the
volume of Lake Superior.

Lake Superior covers about 31000 square miles and has a volume of
about 2900 cubic miles.  A cubic foot is more than 7 gallons.
(Volume from "World Almanac and Book of Facts 2006", and Wikipedia.)

There are about 7 billion people and less than 400 days a year,
so there would be a savings of less than 2800 billion gallons/year.

However the lake contains more than
  (2900 cubic miles)* (7 gallons/cubic foot) *
  (5280*5280*5280 cubic feet per cubic mile)

This is more than
 2900 billion *5*5*5*7 gallons

I.e., the volume of Lake Superior is more than
 2900 billion * 125*7 gallons
 
Comparing to 2800 billion gallons saved per year,
we see that the volume of the lake is more than
875 (125*7) times the volume of water saved in a year,
so the "fill Lake Superior over 30 times" wrong by a factor
more than 25000 (875*30).

In fact, I think that the ad referred to the US population
of 300 million, not the world population of 7000 million,
so the comparison is off by a factor more than 1/2 million.

By the way, does anyone know the source of the ad?
I want to tell them their numbers are more than a little wrong.

  The way we got the Tenderfeet to conserve water was to give them the 5
gallon water bottle when it was empty and have them hike down the
trail a ways to the pump. The consumption per person plummeted after
that lesson.

 
Don't buy shorefront property on the lakes downstream.

It's about how much one person drinks in a day, or one flush. It's a
lot when you have to disinfect and carry it but only a few seconds of
rainwater on your roof. It's so expensive to transport that what is
the point of saving a little water in a rainy part of the world?

 I lost you at "Lake Superior covers about 31000 square miles".

All I know is that's a lot of water savings, now matter how you do the
calculations.

I'm on a well, so shag it!!!!!!!

Steve

 


   Yes, so?  Do you think that water that is drawn from an aquifer rather than a
surface source somehow doesn't count in the grand scheme of things?

Vaughn