Assigning Water Demand Based on Population on a line

Question

Hi , I have a network of 314 Junctions and 384 Lines/Pipes , I want to assign Demands at each node based on the population on a given line. For example a 1000 m line has a population of 50. I have all the data in my excel file in the following format 
 Rate of Water Supply 240 Liters per capita per day

Start Node 
 Stop Node 
 Length 
 Population 
 Demand (LPD)

J-1 
 
 J-2 
 
 30 
 
 0

0

J-2 
 
 J-3 
 
 150 
 
 3

720

J-2 
 
 J-4 
 
 300 
 
 20

4800

I want to import demand from excel to each node in water gem. 
 Does water gems automatically calculate and assign demands based on population data? 
 
 please guide me thanks !

Yashodhan Joshi · Accepted Answer

Hello, 
 WaterGEMS will not assign loads directly to a pipe. Instead you would have to distribute the population among the nodes on your model. For example as per the table you have provided following can be the demand and populations at each of the junctions; 
 A pipe is running from J-1 to J-2 of length 30 m and serving 0 population with demand of 0 LPD. This means that J-2 has 0 population and 0 demand (assuming flow direction is from J-1 to J-2). 
 Similarly, J-2 to J-3 the population served is 3 and demand is 720 LPD, so J-3 must have population of 3 and demand of 720 LPD. (Note: I am assuming 720 LPD is the total demand here for a population of 3. If it is the "per capita demand" then your total demand would be 3 X 720 = 2160 LPD.) 
 From J-2 to J-4 the population served is 20 and hence demand at J-4 is 4800 LPD. 
 If you have the data in Excel format you can rearrange the data as per the calculation above and create a table for junctions and its demands. You can then import this into your model directly using the ModelBuilder tool. The following article explains import of data into WaterGEMS via ModelBuilder; 
 Using ModelBuilder to Import External Data 
 The loads (demands) can also be setup by means of customer meters along a pipeline if you have number of customers demanding from a pipe. For this you would have to know the individual populations at the household and the per capita demands (LPCD). 
 For example I have setup a similar scenario with customer meters demanding from a pipeline. 
 
 In this you can see that I have setup several customer meters demanding from the pipeline with each customer meter having its population and per capita demand. You can use the Load Builder tool to assign these to the nearest pipe. The following article explains this in detail; 
 Using LoadBuilder to assign Customer Meters to the nearest pipe using taps and laterals 
 Hope this helps.

Assigning Water Demand Based on Population on a line

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