Drainage assets are arguably the most important enabling infrastructure on the transportation network, as water entering the pavement is a key contributor to premature pavement failure or large road failures such as slips and dropouts. Drainage assets exist to protect the integrity of the road pavement and adjacent properties by removing water from the carriageway surface and underlying pavement.

As part of the road network, Council maintain 1,842km of surface water channels, 119km of culverts and 1,243 other drainage assets including sumps, manholes and subsoil drains.

Investment in maintaining good drainage is critical to preserving the quality of the transportation asset and is one of our key investment areas.

Important activities include:

  • Network and asset inspections; identification, assessment and recording of defect information to enable robust maintenance programming.
  • Cyclic patrols; remedying minor drainage defects such as isolated blockages in conjunction with the road patrol.
  • Programmed maintenance; remedying drainage defects such as high shoulder (the lip that can form on the edge of the road preventing water to run off the road), blocked culverts, and isolated lined channel breaks to ensure the asset is maintained in a safe and serviceable condition, to minimise future maintenance costs and extend the life of the asset and/or the road.
  • Asset renewal; replacement of an asset when deemed to be at the end of its useful life, either when damaged beyond effective repair or deteriorated due to age and use.
  • Minor improvements; increasing the capacity (or size) of culverts or drains in conjunction with their renewal.