Overview
UtilityWatch.NZ is a free tool designed to help Auckland apartment residents understand their water consumption. It extracts data from uploaded bills and compares usage against regional benchmarks to identify whether costs are typical.
Note: This tool uses the Watercare apartment wastewater rate (95% of water usage), which is higher than the standard residential rate (78.5%).
Data Sources
Benchmarks and rates are derived from official Watercare pricing and the Water NZ National Performance Review.
- Watercare Services Limited How Residential Charges Work watercare.co.nz
- Water New Zealand 2022 National Performance Review waternz.org.nz
Calculations
Daily Usage
Total water consumption and billing period are extracted from the uploaded bill image, then daily usage is calculated:
Per-Person Comparison
When household size is provided, per-person daily usage is compared to Auckland's benchmark of 146 L/person/day. Otherwise, the Watercare household average of 479 L/day (assuming 3 people) is used.
Bill Breakdown
Bills are separated into components (water, wastewater, fixed charges) based on extracted line items. Only residential volumetric rates are included in comparisons.
Benchmarks
| Metric | Value | Source |
|---|---|---|
| Per-person daily usage (Auckland) | 146 L/day | Water NZ 2022 |
| Household daily usage (Auckland) | 479 L/day | Watercare1 |
| Water rate | $2.296/kL | Watercare 2025-26 |
| Wastewater rate | $3.994/kL | Watercare 2025-26 |
| Wastewater factor (houses) | 78.5% | Watercare 2025-26 |
| Wastewater factor (apartments) | 95% | Watercare 2025-26 |
| Fixed charge | $332/year | Watercare 2025-26 |
1 Based on the 2008 Water Use in Auckland Households Study, cited in Watercare's "Understand Your Bill" documentation.
Rates shown are standard residential. Actual rates may vary by provider or property type.
Limitations
- Calculations depend on successful data extraction from the image
- Results should be verified against the original bill
- This tool provides estimates only and is not professional advice
Contact
Found an error or have questions about the methodology? Please contact contact@utilitywatch.nz
Last reviewed: January 2026