NZ WATER GUIDE
Is your water chlorinated? Check your city
Pick your city to see what your supplier uses to disinfect the water, its published hardness, and what that means for your shower.
Every figure comes from the supplier or regulator named beside it, read 3 October 2026. Where no figure is published, the field says so.
Or pick a city
NEW ZEALAND CITY COMPARISON
What each supplier uses, side by side
Every town supply below is chlorinated. Where a figure is not published, the cell says so rather than guessing.
| City | Hardness mg/L | Reads as | Disinfectant | Source |
|---|---|---|---|---|
| Christchurch | 45 | Soft | Free chlorine, since March 2018 | Christchurch City Council |
| Auckland | not published | Soft to moderately hard, by source | Free chlorine, about 0.6 to 0.8 mg/L at Forrest Hill | Watercare |
| Wellington, Hutt Valley and Porirua | 18 to 45 | Soft | Free chlorine, about 0.4 mg/L across the network | Tiaki Wai |
| Hamilton | about 40 | Soft | Chlorine, about 0.3 to 1.0 mg/L | Hamilton City Council |
| Tauranga | 10 | Soft | Chlorine | Tauranga City Council |
| Dunedin | not published | Not published | Chlorine | Dunedin City Council |
| Queenstown and Wānaka | not published | Not published | Chlorine, with UV | Queenstown Lakes District Council |
| Tank and bore | varies | Varies | Usually none | Water New Zealand |
Hardness is milligrams per litre of calcium carbonate, written mg/L as CaCO3. Tiaki Wai describes anything under 100 mg/L as soft.
HOW SHOWER FILTRATION WORKS
Chlorine, steam and vitamin C
Why New Zealand showers smell of chlorine
Free chlorine leaves water readily. That is why a glass left on the bench overnight tastes different by morning, and why the smell is so obvious in a hot shower.
New Zealand suppliers keep free chlorine in the pipes so the water stays safe all the way to your tap. Taumata Arowai has no record of any supplier using chloramine, so free chlorine is the whole story here.
That makes the smell a fair test in every city: if your shower smells like a pool, free chlorine is what you are smelling.
How vitamin C reacts with free chlorine
Ascorbic acid, which is vitamin C, reacts with free chlorine and reduces it to chloride as the water passes. It is a reaction, not a trap.
Activated carbon works the other way round: it holds chlorine on its surface and needs contact time to do it, which a fast-moving shower gives it little of.
That is why vitamin C suits a shower: the water never has to wait.
Using this guide
City figures and your own street
Suppliers blend sources and adjust treatment, so treat a city figure as a guide and check your supplier for the latest local information.
Smaller towns
Your council publishes its own drinking water information. Most council supplies keep a chlorine residual, and that page will say whether yours does.
Your street is not your city
Auckland draws on several sources, so hardness can vary between suburbs. Your supplier or a tap-water test gives you the local detail.
Tank and bore water
A rain tank or private bore is usually not chlorinated, so the chlorine story on this page is about town water.
CHOOSE A SUHAE SHOWER FILTER
Take the chlorine out at the shower head
SUHAE uses vitamin C to neutralise the free chlorine in New Zealand town water, in a handshower, a rainshower panel, or a filter that fits behind the head you already own.
Compare SUHAE shower filters