Run away water in the slope in WDN

Question

Hi 
 I am working on the design of a WDN for a village which is located in a valley. The reservoir is located on a top place and water goes through the valley and then comes up on the other wall!. 
 The village has a main road with the slope of about 9% . I designed my main pipe from the reservoir to this road and then take approximately horizontal lines in the second paths and then for the connections. 
 Is it possible the water to runaway to the downstream of the main pipe line and from the access of upper places? How can I check this in the watergems? 
 The height difference between reservoir and the lowest point is 60 meters.

Jesse Dringoli · Accepted Answer

Hello Zeinab, 
 Regarding "I want to know if enough water reaches the connections" - are you wanting the model to tell you, based on the pressure at certain points, what the demand would be? (how much flow could leave?) Are you concerned that high pressure at the bottom of the hill will cause high outflow and reduce the pressure / outflow on the upstream side? If so, then as Tom said, your demands are likely not just from holes open to the atmosphere, so they will be controlled by faucets/showers/etc. Typically you would determine what the house demands would be, enter those as the demands on your nodes in the model, then the model will solve the pressure based on those assumed demands and the upstream boundary condition. 
 If you find that the pressure it too high on the downstream end, then perhaps smaller diameter pipes or a PRV would help. 
 If your outflow/demand points are very sensitive to pressure, you can use pressure dependent demands, and the demand will be higher as the pressure becomes higher. See: Using Pressure Dependent Demands 
 Regarding the concern about the part full flow, if you mean that the upstream-most pipe may not necessarily be submerged, you can adjust the reservoir element's elevation accordingly. If you are comfortable with the negative pressure that will be reported on the upstream-most end, then this should be OK. If a significant portion of the piping is partially full, you may consider this article: Modeling Fixed Inflow from a Marginal Source

Tom Walski · Answer

if you have a 6 inch (150 mm) pipe in the street and you open up a half inch (10 mm) faucet, how can that drain the system? 
 There are systems al over the world with 60 m pressure and none of them drain. 
 Unless the pies upstream are grossly undersized or the source runs dry, there should be no problem.

Jesse Dringoli · Answer

If the problem is with the source draining out, see the article linked to in my previous response: Modeling Fixed Inflow from a Marginal Source

Run away water in the slope in WDN

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