Tasman District Council has adopted an amendment to the Public Water Supply Bylaw which is aimed to "protect and manage the community’s access to safe, secure water."
TDC notes: "The bylaw includes a water restrictions protocol for how we will manage water use during a drought or an emergency."
A copy of the bylaw can be downloaded here. From page 24 onward you will find breakdowns of the phases in the Water Restriction Protocol.
It makes for a good read in case we get another drought.