What is in Canberra's tap water, and which filter fixes what

Canberra has some of the easiest water in the country to live with, and its utility says so plainly. Here is what Icon Water publishes, and what to buy if you want to filter it anyway.

Where the water comes from

Icon Water draws from the Bendora and Cotter reservoirs and the Murrumbidgee River for the Stromlo water treatment plant, and from Googong reservoir for the Googong plant. Both plants coagulate, filter, fluoridate and chlorinate; Stromlo adds ultraviolet disinfection. The 2024–25 Drinking Water Quality Report is the source for the figures below, with the appliances page for the hardness conversion.

The three things that matter

Chlorine, and a note on 2024. The report records that the Googong catchment, after drought and floods, needed higher chlorine dosing to hold a protective residual to the ends of the network, and that some customers temporarily received safe but higher-than-usual chlorine in 2024. If your water tasted more of chlorine last year than before, that is why, and a carbon filter is the fix. Because there is no chloramine, the cheap filters work: ordinary carbon in the kitchen, KDF in the shower.

Soft water. Average hardness of 37 mg/L puts Canberra among the softest capitals, beside Melbourne. Icon Water publishes the figure in several units for setting dishwashers, which is the only practical use of it here. No softener, no “hard water” shower filter.

Fluoride. Present at an average of 0.79 mg/L, added as sodium fluorosilicate at both plants. It is the one thing in Canberra water that a carbon filter cannot touch. The fluoride guide covers what does.

What Icon Water says about filters

Its water filters page states that it does not recommend using filters to further treat tap water, that it recognises some customers want them for aesthetic or medical reasons, and that it is not responsible for installation or maintenance costs. That is a fair statement of where Canberra sits: the water meets the guidelines, and filtering is a preference. Our view is the same: filter for taste or fluoride by choice, not for safety.

What to buy in Canberra

• Chlorine taste: a water filter jug or the Philips on-tap filter is all the water needs. Owners who want it plumbed can fit any under-sink carbon filter; a WaterMark-listed housing such as the Stefani twin ($159 at Bunnings) is enough.
• Shower: the Philips KDF filter, for the chlorine smell in a hot shower. The do shower filters work guide covers what to expect.
• Fluoride: a WaterMark-listed reverse osmosis system such as the Philips 75 GPD station. The cheapest online kits (Geekpure, iSpring) aren’t on the WaterMark register, so a licensed plumber can’t install them. The worth-it guide puts Canberra in the “only for fluoride” column, and the installation cost guide covers the plumber.
• Scale and hardness: nothing.
• Whole house: no case on Canberra mains water unless you want chlorine out of every shower, in which case the whole-house guide applies.
• Your own water: test your own tap water with hardness strips or a TDS meter before you buy. The test kit guide covers what a home kit can and can’t tell you, and when to use a NATA-accredited lab instead.

Queanbeyan and the surrounding region

Queanbeyan-Palerang Regional Council buys treated water from Icon Water for Queanbeyan, so the figures above broadly apply; towns further out have their own supplies and reports. Check your council’s water quality page before buying for scale or chloramine.

Reading Icon Water’s figures

Icon Water publishes more than most utilities and in more useful forms. Its appliances page gives Canberra’s hardness in every unit a dishwasher manual might ask for: 43 mg/L, 2.41 German degrees, 3.02 English degrees, 4.3 French degrees and 0.43 mmol/L, all from 2021–22 data. Set the dishwasher to its softest setting and skip the salt. The annual Drinking Water Quality Report, on the Key Publications page, has the network tables we quoted, with 5th and 95th percentiles for every parameter including chlorine, fluoride and hardness, and a treatment flow chart for each plant. All testing is done by a NATA-accredited laboratory. If you want to know exactly what is in your water before spending a dollar, the report answers it for free.

The one trap

Buying a chloramine-rated filter because south-eastern Australia has chloramine in places. Canberra does not, and Icon Water says so in its report. Catalytic carbon cartridges and vitamin C shower filters cost more and are consumed faster than the standard media that Canberra’s chlorinated water calls for. Buy the ordinary filter.

Sources: Icon Water, Drinking Water Quality Report 2024–25; Icon Water, Water quality and your appliances; Icon Water, Water filters; Australian Drinking Water Guidelines (NHMRC). The city comparison sets these figures beside the other capitals.