Context

Learning from the Christchurch Earthquake sequence and other disasters has highlighted the need for New Zealand’s 3 Waters Services to be seismically resilient. In the context of these guidelines the key aspects of a resilient system are:

• Robust physical assets with key network routes having appropriate alternatives, and response arrangements in place
• Effective co-ordination arrangements (pre- and post-event)
• Realistic end-user expectations and appropriate measures of backup arrangements.

Purpose of the Levels of Service Performance Measures

The Levels of Service Performance Measures for the Seismic Resilience of 3 Waters Network Delivery provides a framework which may be used by engineers and asset managers to define the current or potential operating stage of any part, or parts, of a 3 waters network in the event of, or planning for, a significant earthquake. They are designed to be used in a number of ways:

• As a communication tool to explain the network status to communities and their leaders.
• As an aid to tracking recovery to normal Levels of Service after damage caused by a seismic event.
• A management tool to assist engineers and asset managers to explain the investment needs to improve the resilience of networks.

This document provides guidance on definitions of different stages of recovery and how to use the guidelines to develop target Levels of Service related to these stages.

This document is intended to be the first in a series of guidelines, with future documents providing guidance on assessing system vulnerability, estimating the duration to restore service and the design and implementation of works to improve resilience.