View Full Version : Modeling Reuse System

Darrell D
May 2, 2013, 08:25 AM
I am using InfoWater to model our reuse system (I don't really have a need for gravity mains and other aspects of InfoSWMM). The treated effluent from our Wastewater Treatment Plant (WWTP) is sent to a pumping station where, depending on the water level in the tank, it is pumped to one of four different storage locations. I think I've got that situation pretty well figured out (I had to model it as two tanks to account for the weir). There is a lead and lag pump for each of the four locations. Two are inactive because that fourth facility is currently being built.

Anyway, here is my problem: I'd like to be able to vary the flow from the WWTP to represent our actual outflow pattern. I have the WWTP modeled as a reservoir connected to a pump running to the effluent station. I don't think that it's possible to have the pump send flow according a pattern and I can't assign a demand pattern to the effluent tank. I thought about putting a patterned demand node on the far side of the second tank and setting the pipe condition to that node to flow only after an unattainable head is reached in the second tank. Does that seem reasonable? Would that cause an error? Any other thoughts?


Darrell D
May 2, 2013, 08:50 AM
Sometimes it helps to read the Help documents. "Replace the reservoir with junctions that have negative demands equal to the schedule of source flows." I think I'll give that a shot.

Shawn Huang
May 16, 2013, 02:36 PM
Yes, negative demand is often used to represent a water source with varying flow.
You can also control pump flow through the option of implicit VSP. Set the VSP with "Controlled by Pump Flow", and a specified flow, and a specified pattern.