LoadBuilder: Allocate demands based on pipe length

Product(s): Bentley WaterGEMS
Version(s): 08.11.XX.XX, 10.00.XX.XX
Area: Layout and Data Input


Is it possible to automatically allocate demands based on pipe length?

For example, let's say the total demand in the Network (Steady State Analysis) is 500 L/s and total length of pipe in the network is 5000 m. So, the unit demand per meter of pipe length is 0.1 L/s/m. So, if pipe is 100 m, its demand contribution is 0.1 * 100 = 10 L/s and the two adjacent nodes will have 5 L/s each. In some calculations pipes with no habitations on either side are not considered in demand contribution.

Problem ID#: 82685


The Unit Line method in Loadbuilder (Tools > Loadbuilder) can be used to allocate demands based on total demand and pipe length. It will distribute the specified (Unaccounted + Known) demand in the Loadbuilder based on pipe length and assign that further to the adjoining junctions.

K factor will decide whether the demand must be distributed on both sides of pipe or on single side. If there are no users on either side of the pipe (the pipe is only used to transfer water to another part of the system), then K is 0. If there are users along only one side of the pipe (for example, pipes along a river), K is 0.5. If both sides of the pipe supply water to users, K is 1.

For more information, see the Help topic entitled "Allocating Demands using LoadBuilder", or the below article.

See Also

How does the Unit Line Loadbuilder method work?

Demand per Unit Length of Pipe Allocation in WaterGEMS/WaterCAD- Discussion 

Troubleshooting and Understanding LoadBuilder