Aucklanders are facing the fact their wastewater will be treated and turned into drinking water as authorities look at ways to deal with water shortages.
It comes after a deal between Auckland and Waikato to ensure enough water flows from the Waikato River to Auckland taps.
Watercare says purified, treated wastewater and desalination are two main long-term options.
Waikato Regional Council's Russ Rimmington says those options must be considered.
Watercare says public consultation and potentially a law change would be needed if wastewater was to be purified and treated.