Businesses, schools, commercial premises and community facilities are urged to check their water if they are reopening at Alert Level 3.
Waipā District Council water services manager Martin Mould said quality issues for drinking water could occur after taps are switched on for the first time in several weeks.
"With many facilities closing throughout Alert Level 4, water has been sitting in pipes for more than one month," he said.
"If the water is stagnant, it could be poor tasting, odorous or dirty. But these issues alone don't mean the water is unsafe to drink, it just might be unpleasant."
These issues can be fixed by running taps for a few minutes until the water is clear or appears normal. Flushing may take longer for larger premises.
It is recommended to use an outdoor tap at the furthest point from the road and drinking fountains to ensure all water in the system is flushed.
Those who use roof water or a private bore are also urged to flush water until it appears normal, using a tap at the furthest point from the source.
Waipa residents are also advised to:
•Check for blockages, leaks or breaks in pipes and taps.
•Look for physical matter in your water tank - leaves, and ensure the tank has enough water to operate.
•Check pumps, filters and UV systems and ensure there are sufficient chemical stocks.
Residents can contact Council on 0800 WAIPADC (0800 924 723) if issues with drinking water quality remains after running taps, or contact water services provider for further advice and support.