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East Gippsland Water

21 October 2010

Orbost Drought Response Plan

AECOMOrbost Drought Response Plan

21 October 2010

Orbost Drought Response Plan

60144336 Task 1.06

Prepared for

East Gippsland Water

Prepared by

AECOM Australia Pty Ltd

Level 9, 8 Exhibition Street, Melbourne VIC 3000, Australia

T +61 3 9653 1234 F +61 3 9654 7117 www.aecom.com

ABN 20 093 846 925

21 October 2010

60144336

© AECOM Australia Pty Ltd 2010

The information contained in this document produced by AECOM Australia Pty Ltd is solely for the use of the Client identified on the cover sheet

for the purpose for which it has been prepared and AECOM Australia Pty Ltd undertakes no duty to or accepts any responsibility to any third party

who may rely upon this document.

All rights reserved. No section or element of this document may be removed from this document, reproduced, electronically stored or transmitted

in any form without the written permission of AECOM Australia Pty Ltd.

AECOMOrbost Drought Response Plan

21 October 2010

Quality Information

Document Orbost Drought Response Plan

Ref 60144336

Date 21 October 2010

Prepared by Marisa Cesario

Reviewed by Steven Wallner

Revision History

Revision Revision Date Details

Authorised

Name/Position Signature

A 19-May-2010 Draft for Client Comment Andrew Grant

Associate Director -

Water

Original Signed

B 16-Sep-2010 Issue for Technical

Committee Review

Elisa Hunter

Elisa Hunter

C 21-Oct-2010 Final Elisa Hunter

Elisa Hunter

AECOMOrbost Drought Response Plan

21 October 2010

Table of Contents

1.0 Drought Response Preface 1 2.0 Introduction 2 3.0 System Description 3

3.1.1 Overview 3 3.1.2 Diversion 3 3.1.3 Storage 4 3.1.4 Water Treatment Plant 4 3.1.5 Supply 4

3.2 Changes to the Supply System 4 4.0 Objectives 5

4.1 General 5 4.2 Strategic 5 4.3 Planning 5 4.4 Operational 5

5.0 Action Plan for Responding to Drought 6 5.1 Introduction 6 5.2 Action Plan Summary and Flowchart 6

5.2.1 Water Restriction Trigger Levels 6 5.2.2 Introduction of Voluntary Restrictions 7 5.2.3 Introduction of Mandatory Stage 1 and 2 Restrictions 7 5.2.4 Mandatory Stage 3 and 4 Restrictions 8

6.0 Pre Drought Activities 9 6.1 Staff Training and Educations 9 6.2 Waste Minimisation 9 6.3 Promotion of Water Restrictions 9 6.4 Ongoing Monitoring and Reporting 10

6.4.1 Regular Pre Drought Activities 10 6.4.2 Water Supply System Monitoring and Reporting 10 6.4.3 Climate and Drought Outlook 11

6.5 Funding Strategy for Drought Response 12 7.0 Drought Response Options and Lifting of Restrictions 13

7.1 Introduction 13 7.2 Demand Reduction Options 13

7.2.1 Voluntary Demand Reduction 13 7.2.2 Water Watch Days 13 7.2.3 Demand Reduction due to Restrictions 14

7.3 Supply Enhancements during Drought 15 7.3.1 Water Carting 15 7.3.2 Groundwater Supply 15 7.3.3 Increased Share of River Flow 15 7.3.4 Transfer of Surface Water Entitlements 16

7.4 Lifting of Restrictions 16 8.0 Post Drought Activities 17

8.1 Evaluation of Objectives 17 8.2 Evaluation of Actions 17 8.3 Potential Impacts of Restrictions 17

8.3.1 Impact of Restrictions on the Community 17 8.3.2 Impact on East Gippsland Water 18

8.4 Revision of the DRP 18 9.0 Water Supply Context 19

9.1 Legal and Institutional Context 19 9.1.1 Bulk Water Entitlements 19 9.1.2 Applying for Qualifications to Bulk Entitlements 19 9.1.3 Groundwater Entitlements 19 9.1.4 Supply to Urban Users 19

AECOMOrbost Drought Response Plan

21 October 2010

9.1.5 Model Water Restriction By-law (No. 0001/08) 20 9.2 Levels of Service 20

10.0 Past Drought Experience 21 10.1 Previous Drought and Water Restrictions 21

11.0 Summary of Recommendations 22 12.0 References 23

Appendix A Drought Response Flowchart A

Appendix B Action Plan B

Appendix C EGW Water Restrictions By-Laws C

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1.0 Drought Response Preface

East Gippsland Water’s (EGW) Statement of Obligations (SoO) requires the Corporation to develop and

implement an effective Drought Response Plan (DRP) for each water supply system, with the intent of providing a

framework for ensuring timely and effective response to water shortages.

The SoO requires EGW to review, and if necessary amend its DRPs at intervals of no more than five years or

within twelve months of either:

• the lifting of any period of restriction imposed under the Corporation’s DRP

• any major change occurring to works or arrangements for conserving water for, or supplying water to, any

water supply system operated by the Corporation.

Given that the Water Supply Demand Strategy (WSDS) for Orbost was recently revised, the DRP must also be

updated to ensure that both documents are consistent.

This report is intended to form an update to the previous DRP titled ‘Drought Response Plan for Bemm River,

Buchan, Cann River, Marlo, Newmerella and Orbost’ that was prepared by SKM during 2006. This version of the

DRP will focus on the Orbost water supply system with separate DRPs to be prepared for the other towns.

This review and update of the Orbost DRP includes:

• revision of the current system configuration

• re-structuring of the DRP

• the update of statistics relating to drought history

• revision of restriction triggers based on the updated system configuration

• the update of available drought response options

• revision of the previous action plan;

• identification of information gaps

• recommendations.

Text in italics are direct excerpts from the previous DRP (2006).

This DRP should be read in conjunction with the Orbost WSDS (2010) and should be updated in the event of any

changes to the existing water supply system or its operation.

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2.0 Introduction

The aim of this DRP is to ensure a timely and effective response to water shortages, with the aim of minimising

the social, economic and environmental impacts of such shortages.

There are two components involved in securing an adequate water supply in times of drought. These are:

• the provision of an adequate supply system to satisfy current and future demands for design drought

conditions, ensuring that shortfalls in supply are within 'acceptable' levels

• the definition of the actions required when water supply shortfalls occur.

The first component represents the long term planning actions which result in a certain level of infrastructure

development. A high level of service (i.e. where shortages in supply are very infrequent) requires a high level of

investment in infrastructure. This means that consumers are paying a large premium every year to insure

themselves against potential shortfalls in supply during relatively infrequent drought events.

The second component relates to management actions which are required to minimise the impacts of shortfalls in

supply. These actions complement the long term planning process. While the Drought Response Plan relates

specifically to the second component, the short term response needs to be based on a good understanding of the

longer term security of supply for the supply system, as this defines the supply context for a DRP.

A full drought management plan for a water corporation involves an appropriate combination of long and short

term components, focussing on the actions to be taken and/or considered by East Gippsland Water in pre-

drought, drought and post-drought periods.

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3.0 System Description

3.1.1 Overview

Orbost, as well as Newmerella, Marlo and Jarrahmond (a small satellite settlement) are supplied with surface

water from the Brodribb and Rocky Rivers, via a water treatment plant at Orbost. Traditionally the Rocky River

has been the primary water supply source, however deterioration of the diversion main has resulted in an

increase in water losses and EGW are currently investigating whether it can continue to be a sustainable water

source.

A schematic of the Orbost supply system is shown in Figure 1. Further details on key components of the system

are included in the following sections of this DRP.

Figure 1: Orbost’s Water Supply System

3.1.2 Diversion

Water is pumped from the Brodribb River diversion site at a maximum rate of 5.74 ML/day via an 11 km long

rising main which transfers water to the Orbost raw water basin. The Rocky River weir gravity feeds a 21 km long

pipeline to the Orbost raw water basin with a maximum flow rate of 1.37 ML/d.

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3.1.3 Storage

The system has a