2006 - Pigging Project
Part of the old aqueduct near O'Shannassy Weir came into use for a brief
period during the 'pigging' (cleaning) of the pipes from O'Shannassy Reservoir in 2006.
Build up inside the pipes over time had reduced the water flow from O'Shannassy
considerably and it was determined that the most cost effective option was to clean the pipes (rather then duplicate or replace
However, this meant blocking
the pipes and shutting off water flows for a period of time. The abandoned O'Shannassy aqueduct was used as temporary
storage basin the receive water discharge during pigging. A series of permeable weirs were installed at 100m intervals
along the aqueduct to enable water to pass, but trap sediment. An impermeable weir was installed some 400m from the
stilling basin to prevent waters flowing into the continuing aqueduct length.
The pigging project was
a success and the pipeline flow capacity was markedly increased.