Dear Jim and Martin,
Jim's figure of 70 cubic metres per person per year looks a lot higher
than Martin's 6.3 and 11 cubic metres per year!
Currently, with level 3A water restrictions in Melbourne β 70
kilometres from Geelong β the people there are restricted to 1255
litres per person per day. This amounts to about 57 cubic metres per
person per year. By the way they're called kilolitres here when used
for measuring water.
In Geelong our local water authority, Barwon Water, says:
Did you know?...
On average, a person uses about 200 litres of water per day, of which
5-10 litres is for basic survival, ie drinking and food preparation.
The other 190 litres is discretionary and is used for washing
(showers, dishes, clothes, toilets) and the garden.
Some communities have been successful in reducing average personal tap
water usage to as low as 130 litres per day.
Approximately half the water supplied to urban areas in Australia ends
up as waste water, according to a report by the Institute for
Sustainable Futures prepared for the Water Services Association in 1998.
200 litres per day is about 73 000 litres per year (73 kL) , and
130 litres per day is about 47 000 litres (47 kL) per year.
Cheers,
Pat Naughtin
Geelong, Australia
On 2009/06/16, at 4:19 AM, James R. Frysinger wrote:
The old Navy rule of thumb was to ensure that shipboard desalination
plants could provide 50 gal of water per day per man in addition to
what was needed for propulsion plant needs. That 50 gal figure works
out to just about 192 L daily for each man or about 70 m3 per man
per year. Those human needs include drinking water (the rule was
prevalent in days of non-air-conditioned ships!), showers, laundry,
and cooking.
Once we get our new house built (soon, I hope!) we will look at the
expense of installing tanks and gutters to capture the rainfall from
its roof and that of our tractor shed. Recently we had a moderately
heavy rainfall of nearly 50 mm. That house runoff would have
amounted to about 6 m3 and the tractor shed's runoff would have
amounted to about 4 m3. I won't say that such runoff is wasted,
since we are sitting on a 100 ha farm and that water supplies some
of the needs of the pasture land and forest around us. But it might
be nice to redirect the runoff to the gardens and livestock.
Jim
Michael Payne wrote:
Interesting that most of this water requirement is for agriculture.
I looked at my water usage at home and it varies each year
depending on how much I water my lawn in summer. Last year we used
about 6,3 cubic meters for two, the previous year we used 11 cubic
meters. This is showers, laundry and watering the garden when
required, normally July August. Bear in mind I'm gone a lot and use
hotel water. Still it does not seem like a lot of water when I
compare it to the 1000 cubic meters needed per person in the
article below.
On another note, I read recently that it's illegal in a couple of
western states to collect rainwater off your roof. In Colorado they
are trying to change the law.
Mike Payne
----- Original Message ----- From: "James R. Frysinger" <[email protected]
>
To: "U.S. Metric Association" <[email protected]>
Cc: <[email protected]>
Sent: Saturday, 13 June 2009 13:36
Subject: [USMA:45230] Precipitation and water needs
I participate in CoCoRaHS (http://www.cocorahs.org/), an
organization that collects daily precipitation observations from a
rapidly growing network of nearly 10 000 volunteers in the U.S.
(Please consider joining!) After the daily report has been
submitted the acknowledgment page appears and it contains some
sort of anecdote, which changes periodically. Below my signature
is the one that appeared today.
It's nice to see that this anecdote is entirely metric (with but
one exception), as is our National Weather Service. Ironically,
CoCoRaHS requires non-metric values from its volunteers;
everything is measured in inches on their reports.
I have my Davis Vantage PRO 2 weather station set up to read out
in metric units and must then do a conversion to submit my
precipitation reports. Since NWS keeps its records in metric
units, it would be nice if CoCoRaHS migrated in that direction.
They could start by allowing metric data submission as a option
and then migrating their volunteers toward using metric rain
gauges, etc.
The anecdote reproduced here then would be immediately relevant to
the volunteers, since one liter is the same as a millimeter of
rain falling on one square meter of surface. And of course one
cubic meter is the same as 1000 liters.
My records show that my 100 hectare farm received 1208.3 mm of
rain last year, a droughty year since the normal for this area is
closer to 1500 mm. Still, that means that 1.2 million cubic meters
of rain fell on my farm in 2008, enough to "support" 1200 people.
That's the beauty of the metric system -- ease of calculation. So
one can calculate the area of some location in square kilometers
and then look at the annual rainfall there. Every millimeter of
rain that fells on each square kilometer of that location is the
amount needed by one person -- one to one!
My mode of getting that water to them was provision of timber,
eggs, and cattle as well as potable runoff (downstream and via
aquifers).
Jim
Water Footprint
The minimum water that each person requires, on average, for
drinking, hygiene and growing food is about 1,000 cubic meters per
year. That's about 2/5 of an olympic size swimming pool. Because
the distribution of global water resources varies widely, some
people get much more than this and some people get less.
Researchers have recently developed the concept of a "water
footprint". As indicated on the water footprint web page (http://www.waterfootprint.org
), βThe water footprint of an individual, business or nation is
defined as the total volume of freshwater that is used to produce
the goods and services consumed by the individual, business or
nation.β
You can figure out your own water footprint using the calculator
(quick and more extensive versions) on this site as well learn the
total water required to produce various products. Some interesting
facts about our water use from the water footprint web site:
* *The production of one kilogram of beef requires 16 thousand
litres of water.
* *To produce one cup of coffee we need 140 litres of water.
* *The water footprint of China is about 700 cubic meter per
year per capita. Only about 7% of the Chinese water footprint
falls outside China.
* *Japan with a footprint of 1150 cubic meter per year per
capita, has about 65% of its total water footprint outside the
borders of the country.
* *The USA water footprint is 2500 cubic meter per year per
capita.
In addition to the water footprint web site, check out the
August 2008 issue of Scientific American to learn more about the
global variability of fresh water.
--
James R. Frysinger
632 Stony Point Mountain Road
Doyle, TN 38559-3030
(C) 931.212.0267
(H) 931.657.3107
(F) 931.657.3108
--
James R. Frysinger
632 Stony Point Mountain Road
Doyle, TN 38559-3030
(C) 931.212.0267
(H) 931.657.3107
(F) 931.657.3108
Cheers,
Pat Naughtin
Author of the forthcoming book, Metrication Leaders Guide.
PO Box 305 Belmont 3216,
Geelong, Australia
Phone: 61 3 5241 2008
Metric system consultant, writer, and speaker, Pat Naughtin, has
helped thousands of people and hundreds of companies upgrade to the
modern metric system smoothly, quickly, and so economically that they
now save thousands each year when buying, processing, or selling for
their businesses. Pat provides services and resources for many
different trades, crafts, and professions for commercial, industrial
and government metrication leaders in Asia, Europe, and in the USA.
Pat's clients include the Australian Government, Google, NASA, NIST,
and the metric associations of Canada, the UK, and the USA. See http://www.metricationmatters.com
for more metrication information, contact Pat at [email protected]
or to get the free 'Metrication matters' newsletter go to: http://www.metricationmatters.com/newsletter
to subscribe.
