To add any value, the draw-down test needs to be completed in conjunction with a pressure logging study.

The pressure logger will be installed on the appropriate stand pipe.  At the end of the pressure logging, our draw-down rig will be installed on a fire hydrant on the same network as the stand pipe.  Our rig includes the hydrant connection, valve, water-meter with reed switch, pressure transducer + pressure logger.

High-level procedure:

  1. connect to the hydrant, rig valve closed
  2. open the hydrant full
  3. slowly open the valve
  4. slowly close the valve

If the pressure on the stand pipe drops significantly during the draw-down, it is indicative of network pressure supply issues, ie no further load can be handled by the network without upgrades.  If the opposite is true, the network is healthy and can possibly accommodate additional development.