Subject: Return Flow from pipe leaking Posted: 11/16/2015 Viewed: 2457 times
Does anyone know how to simulate return flow from pipe leaking to or losses in the system to ground water???
Subject: Re: Return Flow from pipe leaking Posted: 11/17/2015 Viewed: 2419 times
There are 3 places you can plug in loss for a demand site.
1) On the way to the demand site: using a transmission link, under "Losses" you have the option of specifying percent of transmitted water loss to the system or lost to groundwater. Remember that this is "unused" water, and so when you specify losses here, it will increase the overall withdrawal of water to supply the demand site, because it has to account for those losses.
2) In the Demand Site itself, you can specify "Losses" however, these are lost from the system (WEAP considers no longer accounts for that water). To model water going to groundwater from the city, you can build a return flow link directly from the city to the groundwater node. This is after *after* demand site usage, so it will impacted by the consumption percentage you entered. And remember, the return flow will take all the unconsumed water if it is the only return flow from that demand site.
3) You can build a return flow from the city back to the river, and in that return flow, specify a percentage of water that is lost to groundwater (Inflows and Outflows/Loss to Groundwater). This is effectively the same math as option 2, but doesn't clutter your schematic as much, and may be more physically representative of your system. Again, this is "used" water, so subject to whatever consumption percentage you plugged into your demand site.