water consumption per capita

[arj00]

I have to estimate the future water demands for a large city in the middle east where the water is scarce,the current demand is only 220 liters per capita per day,some views suggest to increase the demand to reach 350 liters per capita per day and some views want to keep the demand fixed in the future (220 liters ).

 

[EricC]

I have run into this problem myself. Likely the decision is ultimately out of your hands, but consider the reasoning behind the two approaches. I would bet proponents of 220 L per capita are more interested in lowering costs. Without knowing details like economic conditions, age of system, etc, the real number is likely to be somewhere in between these two numbers as in my experience use per capita increases with increasing service population, but Middle Eastern water consumption is generally slightly lower per capita than European or US communities that the 350 L per capita is based on.

 

[KRSServices]

That's a tough one, because the demand is going to be a function of use and the cost to the user. I've been in situations where waater is paid for as a bulk rate, and demands were in the order of 450 and 630 l/c/d...stupidly high, but that was the fact of life because it was essentially free and an endless supply. In areas where the cost of treatment is high, the end users tend to be more frugal and 220 l/c/d is actually quite liberal. My best advice is to look at what it will cost the end user and crystal ball a bit as to the implications of cheap (free or subsidized) versus expensive water bills. KRS Services

http://www.krs-services.com

 

[gumlog]

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

 

[hansid]

Dear Friend,

To estimate a figure is a tricky matter. I have experience of United Arab Emiraters and I hace noticed that the current demand in sone of the cities is well above 400 l/c/d.

What I suggest that you should study the goverment polocy regarding the water charges, pattern of water consuptiobn in villas and flats and commercial activities.

If you could pass me the city information, we can discuss further in detail.

 

[gumlog]

Is this a change in units? Hansid, are you talking about l/c/d where c is customer which can be several people like a family?
In u s we use 2.5 people per meter or customer in residential areas average unless disrtict has better census or statistics. All the numbers I used above are per person or per capita not per meter or customer.
The numbers do correlate well though. 400 or better l/household is about the same as 100 gal. and you say well over 100 gal/c/d then that is logical. Household use alone is about 50 gal. or 200 liters per person per day so 400 l/d would cover 4 people and there may be more that residing in a household using one meter.

 

[gumlog]

My post does not include irrigation, lawnwatering. Moderate use of clothes washing machine like one load per day is included.

 

[yolon]

I feel you need to see if this country is putting into place any water saving programme, in order to work out what the increase may be in the future. If a toilet flushes with a 9 Ltr flush, it will use an estimated 90.000 ltr/annum, if this were to be reduced to a 6 ltr flush, the usage will be 60,000 ltr/annum - some difference. Same for a tap, it can use anything from 6-20 ltr/minute that it is working.