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Future Water Options

TABLE OF CONTENTS
1

Introduction

1

2

Future Water Options Project

1

3

What is a Reliable Water Supply?

2

4

Key Planning Variables

2

5

Likely Future Water Demand

3

6

Hydrological Model

4

7

Need for New Supply

5

8

Community Views

6

9

Improving the Efficiency of Existing Infrastructure

6

10

Evaluation of the Cotter Option

7

11

Evaluation of the Tennent Option

8

12

Evaluation of the Tantangara Option

9

13

Further Supply Measures
13.1

14

Angle Crossing Option (formally known as the Virtual Tennent Option)

Recommendations

10
11
12

14.1

Immediate Action

12

14.2

Future Actions

13

14.3

Future Analysis

14

Document No: 4688 - Summary of the Future Water Options Implementation Plan

i

Future Water Options

1

Introduction
In April 2004, the ACT Government released: Think water, act water – a strategy for sustainable water resources management. The strategy defined actions to achieve sustainability objectives for water use in the ACT out to 2050, including to: increase the efficiency of water use; and provide a long-term reliable source of water for the ACT and region.
As part of the development of this strategy, ACTEW produced an evaluation report in April
2004: Options for the next ACT water source, which identified nearly 30 possible options for a long-term reliable water source for the ACT. It concluded that three options were suitable for more detailed assessment: building a new dam on the Cotter River, just downstream of, and thus effectively enlarging, the existing Cotter Dam; building a new dam on the Gudgenby River near Mount Tennent, south of Tharwa; and transferring water from Tantangara Dam in New South Wales to the ACT.

2

Future Water Options Project
ACTEW initiated the Future Water Options Project to examine the three options in detail and to recommend a preferred approach to the ACT Government.
ACTEW established a project team of specialists in water resources management, hydrological modelling, environmental studies, planning analysis, engineering, economics and related areas to conduct this analysis. The project team comprised more than 20 engineers, scientists and other professionals drawn from ACTEW, ActewAGL, other ACT agencies and specialist contractors and consultants. A thorough technical, environmental and planning analysis has been undertaken for each option.
For each option, alternatives have been assessed to determine the optimum proposal. The alternatives have involved different sizes of storages, and different ways of treating and transferring water. They included the Angle Crossing Option (formerly known as the Virtual
Tennent Option), whereby water allocated from the Gudgenby River is pumped from the
Murrumbidgee River to the existing Googong Reservoir instead of building a new storage, and allowing Tantangara water to flow to the ACT along the Murrumbidgee River.
This document summarises the technical, social, environmental and economic implications of the various options, restates the need for additional supply and describes the preferred path to provide a reliable water source for the ACT, for consideration by the ACT Government.
Companion reports are available on the many technical studies that informed the analysis, individual reports on each of the three broad options and their alternatives, and a final report to the ACT Government of which this is a summary. For further information and references, refer to the report: Future Water