A boil water notice has been issued in Glenorchy, near Queenstown, and water restrictions will be in place in Tauranga from tomorrow.
Routine testing detected the positive presence of E. Coli in the water supply, and the Queenstown Lakes District Council said about 180 households are affected.
Three days ago, the council announced it would temporary chlorinate the supply in Arthurs Point, Luggate and Glenorchy to ensure safe drinking water over the busy summer period.
At a council meeting yesterday, a number of Glenorchy residents opposed that.
The Council's chief executive, Mike Theelen, said the boil water notice reaffirms its decision to begin chlorination next week.
Meanwhile in Tauranga, the council said recent hot dry weather has put pressure on the capacity of the water treatment system.
It said from tomorrow, sprinklers and soak hoses can only be used between 5am and 8am, and between 7pm and 10pm.
The council said those are the coolest parts of the day so less water will be lost through evaporation.
Residents can still fill pools and wash cars as long as the hose is hand-held.
The council's city waters manager Steve Burton said the past 10 days has seen an increase in usage that isn't normally seen until January.
Mr Burton said the restrictions are in place until further notice but levels will be reviewed daily.