Nunawading Water Hardness & Quality Report (2026)

Nunawading's drinking water is supplied by Yarra Valley Water as water retailer, with bulk supply from Melbourne Water drawing predominantly from the Thomson Reservoir and Upper Yarra Reservoir direct catchment supply for the City of Whitehorse LGA inner eastern Melbourne distribution in Victoria. Water hardness in Nunawading is measured at 40 mg/L — classified as soft — well below the Australian Drinking Water Guidelines (ADWG) aesthetic guideline of 200 mg/L published by NHMRC. Nunawading, in the Whitehorse City LGA — an established eastern Melbourne suburb adjacent to Mitcham and Blackburn, known for the Whitehorse Road retail corridor, the Nunawading train station and bus interchange, the Whitehorse Enterprise Centre, and the established residential community of the Box Hill–Nunawading corridor — receives dramatically soft supply despite being in the same Whitehorse LGA as Box Hill (110 mg/L), confirming significant supply routing variation even within the same LGA.

Nunawading's soft supply reflects predominantly direct Thomson Reservoir and Upper Yarra catchment supply with a minimal Winneke Water Treatment Plant fraction at this inner eastern Whitehorse Yarra Valley Water distribution sub-zone. The Thomson and Upper Yarra storages drain exclusively across Devonian granite and rhyodacite — the most chemically resistant igneous rock types — in protected wilderness catchments, contributing essentially negligible dissolved minerals. The Nunawading inner eastern Whitehorse distribution at 40 mg/L and TDS 73.7 mg/L is dramatically softer than the Box Hill sub-zone (110 mg/L), confirming very different supply routing with minimal Winneke blending in the Nunawading distribution corridor.

Nunawading residents enjoy very low limescale accumulation on taps and in kettles — descaling every two to three months is typically adequate and scale build-up is negligible. Hot water systems accumulate minimal scale with excellent element life. The low lead reading (0.002 mg/L) is excellent. Yarra Valley Water provides water quality information at yvw.com.au, with all ADWG health standards consistently met. Nunawading's Whitehorse corridor residential community and the Whitehorse Road retail precinct benefit from this very soft, clean supply.