Understanding drain down and recharge

Step-by-step Guide

InfoWorks WS Pro allows you to simulate the drain down and recharge of the water network, which occurs when the network is no longer fully pressurized. Enabling drain down simulates the remaining water in the system and its gradual use by demand sources, identifying which customers will receive positive pressure, and for how long.

Imagine a water network supplied by a single pressure source, such as a pumping station. In a standard simulation, when the pressure source is disabled, then the entire network becomes isolated with no pressure.

Recharge occurs when a pressure source is reintroduced, and the network gradually returns to a fully pressurized state.

Note: Care should be taken when interpreting drain down and recharge results, particularly when dealing with complex control elements in the network. The results are also dependent on the simulation timestep and accuracy of the study.

To enable drain down and recharge by run:

1. From the Schedule Hydraulic Run dialog box, in the lower-left corner, expand the drop-down and select Simulation Options.
2. Click Options….
3. In the Simulation Options dialog box, Default column, deselect the box next to Allow Drain Down to change the Value to Yes.
4. Deselect Allow Recharge.
5. Click OK.

OR, to enable drain down and recharge by default:

6. In the Tools menu, select Options.
7. Select the Simulation Defaults tab.
8. Enable Allow Drain Down.
9. Enable Allow Recharge.
10. Click OK.