Waterloss guidelines

Water New Zealand provides are suite of resources to provide water suppliers with the tools necessary to analyse and reduce the level of water losses in a water distribution network. Available guidelines include:

Water loss Guidelines Detailed Technical Guide - Provides detailed guidance, tools, and supporting information for measuring, monitoring, and managing real water losses from public water supply networks. Guidance was updated in 2023, building on the previous water loss guideline, available at the link below. Non-members of Water New Zealand are required to pay a fee to access this guide.

Waterloss Guidelines Overview – A quick insight into the key factors to help water supply managers and others understand core water loss principles and how their ‘status quo’ measures up. This includes what an achievable target level of water loss should be for the networks they manage.

Water Loss Guidelines Edition One, 2010 – This is a superseded version of the Water loss Guideline, Detailed Technical Guide

Benchmarking of Water Losses NZ Manual - This document is the User Manual for Benchloss NZ, available below.

The following excel based calculators can also be downloaded from the attachments shown at the bottom of this page:

Minimum night flow calculator: An excel workbook to calculate current levels of water loss in a water supply network based on current minimum night flow rates.

Winter water use analysis template: an excel workbook to calculate a water balance over a winter period when customer water use is less effectively by outdoor water use and irrigation.

BenchlossNZ: An Excel Workbook developed in 2008 that allows users to calculate Unavoidable Annual Real Losses and other components of the IWA standard Water Balance.


8 MB
15 Sep 2023

Winter Water Use Analysis Template.xlsx

154 KB
15 Sep 2023

Benchloss Software Feb 2015.xls

463 KB
15 Sep 2023

MNF Calculation Template.xlsx

249 KB
15 Sep 2023