The department is responsible for legislating delivery of water services across Western Australia.
- water supply service – supply of potable or non-potable water
- sewerage service – collection, treatment and disposal of sewage
- irrigation service – provision of water for irrigation for agriculture or pasture
- drainage service – management of stormwater, groundwater, surface water or soil salinity, which may include managing the quality of the water.
The delivery of water services is covered by a number of pieces of legislation and policy.