I have a problem about creating an urban demand site. I know that "Annual Activity Level" is the number of people who live in that urban area; Also "Annual Water Use Rate" is the amount of water that is used by a person during a year. I have these two data, but my problem is "Consumption" tab. How can I calculate this section?
Thank you

Dear Mahsa,

Consumption means the amount of water that does not return into the system through a return flow. You'll notice that WEAP defaults to 100% consumption. This is not very realistic - it is as though your city does not produce any sewage.

To calculate consumption to enter into WEAP, I would try to see what data you can find about sewage quantities, and also destinations.

is there any formula to calculate the consumption? I'm little bit confused about this

Dear Aiman,
The consumption value will depend on what sort of Demand Site you have, as well as the local conditions. An agricultural or manufacturing demand site, for example, has much higher consumption (perhaps 50% or more) than a power plant cooling tower. WEAP does not provide a formula for this parameter.

I suggest searching the literature for consumption trends in your region. Consumption might also be adjusted as you seek to calibrate your model.

Remember that consumption is the fraction of water that is consumed--lost to evaporation, embodied in products, or otherwise unaccounted for. It essentially disappears from the system and therefore will not be included in return flows.

Anne