river modelling for tasmania volume 1: the arthur-inglis ... · 91.4 gl/year under the dry extreme...

Ling FLN, Gupta V, Willis M, Bennett JC, Robinson KA, Paudel K, Post DA and Marvanek S

A report to the Australian Government from the CSIRO Tasmania Sustainable Yields Project

December 2009

River modelling for Tasmania Volume 1: the Arthur-Inglis-Cam region

Contributors

Tasmania Sustainable Yields Project acknowledgments

Prepared by CSIRO for the Australian Government under the Water for the Future Plan of the Australian Government Department of the Environment, Water, Heritage and the Arts. Important aspects of the work were undertaken by the Tasmanian Department of Primary Industries, Parks, Water and Environment; Hydro Tasmania Consulting; Sinclair Knight Merz; and Aquaterra Consulting.

Project guidance was provided by the Steering Committee: Australian Government Department of the Environment, Water, Heritage and the Arts; Tasmanian Department of Primary Industries, Parks, Water and Environment; CSIRO Water for a Healthy Country Flagship; and the Bureau of Meteorology.

Scientific rigour for this report was ensured by external reviewers, Tony Jakeman, Murray Peel and Peter Davies.

Valuable input was provided by the Sustainable Yields Technical Reference Panel: CSIRO Land and Water; Australian Government Department of the Environment, Water, Heritage and the Arts; Tasmanian Department of Primary Industries, Parks, Water, and Environment; Western Australian Department of Water; and the National Water Commission.

We acknowledge the Tasmanian Department of Primary Industries, Parks, Water, and Environment for providing the original TasCatch models for use in the current project, and for assistance in providing cease-to-take rules, operating rules for storages, and environmental flows.

We acknowledge input from the following individuals: Richard McLoughlin, Alan Harradine, Louise Minty, Ian Prosser, Patricia Please, Martin Read, Rod Oliver, Dugald Black, Ian Loh, Albert Van Dijk, Geoff Podger, Scott Keyworth, Helen Beringen, Mary Mulcahy, Paul Jupp, Amanda Sutton, Josie Grayson, Melanie Jose, Ali Wood, Peter Fitch, Wenju Cai, Ken Currie, Eric Lam, Imogen Fullagar, Nathan Bindoff, Stuart Corney, Mike Pook and Richard Davis.

Tasmania Sustainable Yields Project disclaimers

Derived from or contains data and/or software provided by the Organisations. The Organisations give no warranty in relation to the data and/or software they provided (including accuracy, reliability, completeness, currency or suitability) and accept no liability (including without limitation, liability in negligence) for any loss, damage or costs (including consequential damage) relating to any use or reliance on the data or software including any material derived from that data or software. Data must not be used for direct marketing or be used in breach of the privacy laws. Organisations include: the Tasmanian Department of Primary Industries, Parks, Water, and Environment; Hydro Tasmania Consulting; Sinclair Knight Merz; Aquaterra Consulting; Antarctic Climate and Ecosystems CRC; Tasmanian Irrigation Development Board; Private Forests Tasmania; and the Queensland Department of Environment and Resource Management.

Data on proposed irrigation developments were supplied by the Tasmanian Irrigation Development Board in June 2009. Data on projected increases in commercial forest plantations were provided by Private Forests Tasmania in February 2009.

CSIRO advises that the information contained in this publication comprises general statements based on scientific research. The reader is advised and needs to be aware that such information may be incomplete or unable to be used in any specific situation. No reliance or actions must therefore be made on that information without seeking prior expert professional, scientific and technical advice. To the extent permitted by law, CSIRO (including its employees and consultants) excludes all liability to any person for any consequences, including but not limited to all losses, damages, costs, expenses and any other compensation, arising directly or indirectly from using this publication (in part or in whole) and any information or material contained in it. Data are assumed to be correct as received from the Organisations.

Citation

Ling FLN, Gupta V, Willis M, Bennett JC, Robinson KA, Paudel K, Post DA and Marvanek S (2009) River modelling for Tasmania. Volume 1: the Arthur-Inglis-Cam region. A report to the Australian Government from the CSIRO Tasmania Sustainable Yields Project, CSIRO Water for a Healthy Country Flagship, Australia.

Publication Details

Published by CSIRO © 2009 all rights reserved. This work is copyright. Apart from any use as permitted under the Copyright Act 1968, no part may be reproduced by any process without prior written permission from CSIRO.

ISSN 1835-095X

Photo on cover: Inglis River near Wynyard (CSIRO)

Project Management: David Post, Tom Hatton, Mac Kirby, Therese McGillion and Linda Merrin

Report Production: Frances Marston, Susan Cuddy, Maryam Ahmad, William Francis, Becky Schmidt, Siobhan Duffy, Heinz Buettikofer, Alex Dyce, Simon Gallant, Chris Maguire and Ben Wurcker

Project Team: CSIRO: Francis Chiew, Neil Viney, Glenn Harrington, Jin Teng, Ang Yang, Glen Walker, Jack Katzfey, John McGregor, Kim Nguyen, Russell Crosbie, Steve Marvanek, Dewi Kirono, Ian Smith, James McCallum, Mick Hartcher, Freddie Mpelasoka, Jai Vaze, Andrew Freebairn, Janice Bathols, Randal Donohue, Li Lingtao, Tim McVicar and David Kent

Tasmanian Department of Primary Industries, Parks, Water and Environment:

Bryce Graham, Ludovic Schmidt, John Gooderham, Shivaraj Gurung, Miladin Latinovic, Chris Bobbi, Scott Hardie, Tom Krasnicki, Danielle Hardie and Don Rockliff

Hydro Tasmania Consulting: Fiona Ling, Mark Willis, James Bennett, Vila Gupta, Kim Robinson, Kiran Paudel and Keiran Jacka

Sinclair Knight Merz: Stuart Richardson, Dougal Currie, Louise Anders and Vic Waclavik

Aquaterra Consulting: Hugh Middlemis, Joel Georgiou and Katharine Bond

Director’s foreword

Following the November 2006 Summit on the southern Murray-Darling Basin (MDB), the then Prime Minister and MDB

state Premiers commissioned CSIRO to undertake an assessment of sustainable yields of surface and groundwater

systems within the MDB. The project set an international benchmark for rigorous and detailed basin-scale assessment of

the anticipated impacts of climate change, catchment development and increasing groundwater extraction on the

availability and use of water resources.

On 26 March 2008, the Council of Australian Governments (COAG) agreed to expand the CSIRO assessments of

sustainable yield so that, for the first time, Australia would have a comprehensive scientific assessment of water yield in

all major water systems across the country. This would allow a consistent analytical framework for water policy decisions

across the nation. The Tasmania Sustainable Yields Project, together with allied projects for northern Australia and

south-west Western Australia, will provide a nation-wide expansion of the assessments.

The CSIRO Tasmania Sustainable Yields Project is providing critical information on current and likely future water

availability. This information will help governments, industry and communities consider the environmental, social and

economic aspects of the sustainable use and management of the precious water assets of Tasmania.

The projects are the first rigorous attempt for the regions to estimate the impacts of catchment development, changing

groundwater extraction, climate variability and anticipated climate change, on water resources at a whole-of-region-scale,

explicitly considering the connectivity of surface and groundwater systems. To do this, we are undertaking the most

comprehensive hydrological modelling ever attempted for the region, using rainfall-runoff models, groundwater recharge

models, river system models and groundwater models, and considering all upstream-downstream and surface-

subsurface connections.

To deliver on the projects CSIRO is drawing on the scientific leadership and technical expertise of national and state

government agencies in Queensland, Tasmania, the Northern Territory and Western Australia, as well as Australia’s

leading industry consultants. The projects are dependent on the cooperative participation of over 50 government and

private sector organisations. The projects have established a comprehensive but efficient process of internal and

external quality assurance on all the work performed and all the results delivered, including advice from senior academic,

industry and government experts.

The projects are led by the Water for a Healthy Country Flagship, a CSIRO-led research initiative established to deliver

the science required for sustainable management of water resources in Australia. By building the capacity and capability

required to deliver on this ambitious goal, the Flagship is ideally positioned to accept the challenge presented by this

complex integrative project.

CSIRO has given the Sustainable Yields Projects its highest priority. It is in that context that I am very pleased and proud

to commend this report to the Australian Government.

Dr Tom Hatton

Director, Water for a Healthy Country

National Research Flagships

CSIRO

© CSIRO 2009 River modelling for Tasmania. Volume 1: the Arthur-Inglis-Cam region ▪ i

Executive summary

This report describes the river system modelling undertaken for the Arthur-Inglis-Cam region as part of the CSIRO

Tasmania Sustainable Yields Project. The objective of the river system modelling is to estimate flows in river systems

across Tasmania using a consistent Tasmania-wide modelling approach for four scenarios involving a range of climate

conditions and catchment development levels. The four scenarios are:

Scenario A – historical climate (1 January 1924 to 31 December 2007) and current development

Scenario B – recent climate (data from 1 January 1997 to 31 December 2007 were concatenated to make an

84-year sequence) and current development

Scenario C – future climate (84-year sequence scaled for ~2030 conditions) and current development

Scenario D – future climate (84-year sequence scaled for ~2030 conditions) and future development.

In this project, current development is defined as the development at the end of 2007. Future development is defined to

include projected future levels of commercial forestry plantations, irrigation development and groundwater extraction.

This report only considers changes in future development associated with commercial forestry plantations as this is the

only factor which is likely to affect surface water availability in this region.

River system models were developed for each catchment to describe current infrastructure, water demands and water

management rules. These models were used to assess the implications of changed inflows for water availability and the

reliability of water supply to users. The models are node-link network models developed in Hydstra and they include

water allocations and extractions, streamflow routing and environmental flows. Gridded runoff, rainfall and areal potential

evapotranspiration were inputs to the models. The models were run on a daily time step and the runoff from each

subcatchment was routed through the river network to the next subcatchment downstream.

Over the historical period (1924 to 2007), the Arthur-Inglis-Cam region had a total mean annual flow of 4789 GL/year,

and a low level of extraction with a mean annual extraction of 92.6 GL/year (1.9 percent of total water in the region). The

Emu catchment has the greatest level of extraction (31.5 GL/year or 15 percent of total water in the Emu catchment) due

to requirements for water from industry and town water supplies.

The volume of water extracted in the region is not expected to reduce significantly under the future climate (Scenario C)

relative to the historical climate (Scenario A). Extractions reduce from 92.6 GL/year under the historical climate to

91.4 GL/year under the dry extreme future climate (Scenario Cdry), a reduction of 1.2 GL/year (1 percent). The largest

impact is in the driest years, with a projected decrease of up to 7 percent in extracted water in the Emu catchment for the

driest one-year period under the dry extreme future climate relative to the historical climate. This reflects the low level of

water use in the region. By comparison, future climate has a greater impact on total end-of-system flows for the region,

ranging from a decrease of 2 percent (under the wet extreme future climate (Scenario Cwet)) to a decrease of 11 percent

(under the dry extreme future climate) with a median reduction of 5 percent (under the median future climate (Scenario

Cmid)).

Under the recent climate (Scenario B), the monthly mean discharge is lower than the long-term mean in all catchments in

all months with the exception of September and October. The flow duration curves show that flows under the recent

climate are generally lower than the long-term mean over the full range of flows. The volume of extracted water

decreases by a mean of 2 GL/year (2 percent) under the recent climate relative to the historical climate. The

non-extracted water decreases by a mean of 656 GL/year (14 percent).

Future development in the Arthur-Inglis-Cam region includes a projected increase of 75 km2 in commercial forestry

plantations, which will increase total forest cover from 6 percent of the region to 7 percent of the region by 2030. The

majority of this projected increase is in the north-east of the region. Catchment runoff is projected to decrease by a

maximum of 3.7 percent in the Blythe catchment due to the expansion of forestry plantations under future development

(Scenario D). Reductions in inflows for the region as a whole are minimal, as are impacts on end-of-system flows.

ii ▪ River modelling for Tasmania. Volume 1: the Arthur-Inglis-Cam region © CSIRO 2009

© CSIRO 2009 River modelling for Tasmania. Volume 1: the Arthur-Inglis-Cam region ▪ iii

Table of contents

1 Introduction ............................................................................................................................ 1

2 Methods .................................................................................................................................. 5 2.1 Allocations and extractions ..............................................................................................................................................5

2.1.1 Water entitlements.............................................................................................................................................5 2.1.2 Unlicensed storages ..........................................................................................................................................6 2.1.3 Unlicensed extractions ......................................................................................................................................7 2.1.4 Environmental flows and releases.....................................................................................................................7 2.1.5 Diversions, storages, and model customisation ................................................................................................8

2.2 Future development .......................................................................................................................................................10

3 Under historical climate (Scenario A) and future climate (Scenario C)......................... 12 3.1 Water balance and water availability..............................................................................................................................12 3.2 Storage behaviour..........................................................................................................................................................22 3.3 Consumptive water use..................................................................................................................................................24 3.4 End-of-system river flow.................................................................................................................................................37 3.5 Share of available resource ...........................................................................................................................................44

4 Under historical climate (Scenario A) and recent climate (Scenario B) ........................ 51

5 Under future development (Scenario D)............................................................................ 57 5.1 Hydrological impacts of future development ..................................................................................................................57

6 Conclusions .......................................................................................................................... 64

7 References............................................................................................................................ 65

Tables

Table 1. Catchments in the Arthur-Inglis-Cam region..........................................................................................................................4 Table 2. Large storages in the Arthur-Inglis-Cam region.....................................................................................................................4 Table 3. Department of Primary Industries, Parks, Water and Environment surety descriptions (from DPIPWE, 2009) ....................6 Table 4. Extraction restriction rules......................................................................................................................................................8 Table 5. Mean annual water balance for each catchment under scenarios A and C ........................................................................13 Table 6. Storage behaviour under scenarios A and C.......................................................................................................................23 Table 7. Allocated and extracted mean annual flows for catchments under scenarios A and C .......................................................26 Table 8. Mean reliability of high and low priority annual allocations for catchments under scenarios A and C (annual)...................27 Table 9. Mean reliability of high and low priority allocations under scenarios A and C (summer – October to March inclusive) ......28 Table 10. Mean reliability of high and low priority allocations under scenarios A and C (winter – April to September inclusive)......29 Table 11. Indicators of use during dry periods for catchments under Scenarios A and change under Scenario C relative to Scenario A .........................................................................................................................................................................................36 Table 12. Peak flows for catchments under scenarios P and A, and under Scenario C relative to Scenario A ................................41 Table 13. Percentage of time end-of-system flow is greater than1 ML/day under scenarios P, A and C..........................................42 Table 14. End-of-system flow for catchments during dry periods under Scenario A, and under Scenario C relative to Scenario A.43 Table 15. Extracted and non-extracted shares of water for Arthur-Inglis-Cam region under scenarios A and C (annual)................44 Table 16. Extracted and non-extracted shares of water for catchments under scenarios A and C (annual).....................................47 Table 17. Extracted and non-extracted shares of water for Arthur-Inglis-Cam region under scenarios A and C (summer – October to March inclusive) .............................................................................................................................................................................48 Table 18. Extracted and non-extracted shares of water for catchments under scenarios A and C (summer – October to March inclusive) ............................................................................................................................................................................................49 Table 19. Percentage of water extracted as a proportion of total end-of-system flow for catchments under scenarios A and C (annual)..............................................................................................................................................................................................50 Table 20. Percentage of water extracted as a proportion of total end-of-system flow for catchments under scenarios A and C (summer – October to March inclusive) .............................................................................................................................................50 Table 21. Percentage of water extracted as a proportion of total end-of-system flow for catchments under scenarios A and C (winter – April to September inclusive) ..............................................................................................................................................50 Table 22. Mean annual extracted and non-extracted shares of water for Arthur-Inglis-Cam region under scenarios A and B.........54 Table 23. Extracted and non-extracted shares of water for Arthur-Inglis-Cam region under scenarios A and B (summer – October to March inclusive) .............................................................................................................................................................................54 Table 24. Mean annual extracted and non-extracted shares of water for catchments under scenarios A and B..............................55 Table 25. Extracted and non-extracted shares of water for catchments under scenarios A and B (summer – October to April inclusive) ............................................................................................................................................................................................56

iv ▪ River modelling for Tasmania. Volume 1: the Arthur-Inglis-Cam region © CSIRO 2009

Table 26. Comparison of inflows from catchment runoff under Scenario D relative to Scenario C ...................................................57 Table 27. Percent time end-of-system flow for catchments is greater than 1 ML/day under Scenario D relative to Scenario C.......57 Table 28. Comparison of extractions for catchments under Scenario D relative to Scenario C ........................................................58 Table 29. Comparison of change in peak flows for catchments under Scenario D relative to Scenario C........................................63

Figures

Figure 1. Project extent and reporting regions.....................................................................................................................................1 Figure 2. Land cover, major rivers and towns in the Arthur-Inglis-Cam region....................................................................................2 Figure 3. Modelled catchments, major storages and reporting locations in the Arthur-Inglis-Cam region ..........................................3 Figure 4. Subcatchment delineation and WIMS licence locations .......................................................................................................7 Figure 5. Increase in forest cover due to future commercial forest plantations in the Arthur-Inglis-Cam region ...............................11 Figure 6. River transects showing streamflow under scenarios P, A and C ......................................................................................19 Figure 7. End-of-system (EOS) streamflow in the Arthur-Inglis-Cam region under Scenario A, and difference from Scenario A under scenarios (a) Cwet, (b) Cmid and (c) Cdry ..............................................................................................................................22 Figure 8. Storage behaviour over representative ten-year period under scenarios A and C.............................................................24 Figure 9. Total annual extractions for Arthur-Inglis-Cam region under Scenario A, and difference from Scenario A under scenarios (a) Cwet, (b) Cmid and (c) Cdry.........................................................................................................................................................25 Figure 10. Allocation and extraction reliability for catchments under scenarios A and C (annual) ....................................................30 Figure 11. Allocation and extraction for catchments reliability under scenarios A and C (summer – October to March inclusive) ...33 Figure 12. Mean monthly end-of-system flow under and daily flow duration curves under scenarios P, A and C ............................37 Figure 13. Extracted and non-extracted shares of water for Arthur-Inglis-Cam region under scenarios A and C (annual)...............44 Figure 14. Extracted and non-extracted shares of water for catchments under scenarios A and C (annual) ...................................45 Figure 15. Mean end-of-system monthly flow and daily flow duration curves for catchments under scenarios A and B ..................51 Figure 16. Mean annual extracted and non-extracted shares of water for Arthur-Inglis-Cam region under scenarios A and B........54 Figure 17. Mean monthly end-of-system flow under scenarios P, A and C; and changes under Scenario D relative to Scenario C 61

© CSIRO 2009 River modelling for Tasmania. Volume 1: the Arthur-Inglis-Cam region ▪ 1

1 Introduction

This report is one in a series of technical reports from the CSIRO Tasmania Sustainable Yields Project. The terms of

reference for the project require an assessment of the current and likely future extent and variability of surface and

groundwater resources in Tasmania. This information will help governments, industry and communities consider the

environmental, social and economic aspects of the sustainable use and management of the precious water assets of

Tasmania.

The purpose of this report is to describe in detail the river system modelling undertaken for the project. The main

objective of the river system modelling is to estimate flows in river systems across Tasmania for four scenarios using a

consistent Tasmania-wide modelling approach, recognising that the natural and managed behaviour of rivers means that

variability in runoff is not uniformly translated to variability in river flows and water uses. The four scenarios are:

Scenario A – historical climate (1 January 1924 to 31 December 2007) and current development

Scenario B – recent climate (data from 1 January 1997 to 31 December 2007 were concatenated to make an

84-year sequence) and current development

Scenario C – future climate (~2030) and current development (84-year sequence scaled for ~2030 conditions)

Scenario D – future climate (~2030) and future development (84-year sequence scaled for ~2030 conditions).

These were compared with a fifth scenario, Scenario P, which represents water availability modelled with historical

climate, current infrastructure and no extractions. This allows the impact of extractions to be explicitly considered.

The results of the climate and runoff modelling are key inputs to the river system modelling. The climate and runoff

modelling are described in separate reports by Post et al. (2009) and Viney et al. (2009) respectively.

This report describes the river system modelling and results for the Arthur-Inglis-Cam region. The river system modelling

method is described in Section 2. The key modelling results for each scenario are presented in sections 3 to 5. This

report is part of a series of reports describing river system modelling for each of the five regions, namely the

Arthur-Inglis-Cam, Mersey-Forth, Pipers-Ringarooma, South Esk and Derwent-South East regions (Ling et al., 2009a–e).

The reporting regions are shown in Figure 1. The project provides only limited reporting on sustainable yields for parts of

the west coast and south-west and for the smaller offshore islands. Figure 2 illustrates the location of the major towns

and main land uses in the region. A map of the reporting locations in the Pipers-Ringarooma region is shown in Figure 3.

Figure 1. Project extent and reporting regions

2 ▪ River modelling for Tasmania. Volume 1: the Arthur-Inglis-Cam region © CSIRO 2009

Figure 2. Land cover, major rivers and towns in the Arthur-Inglis-Cam region


Figure 3. Modelled catchments, major storages and reporting locations in the Arthur-Inglis-Cam region


Table 1. Catchments in the Arthur-Inglis-Cam region

Number Catchment Area Mean Annual Rainfall

Mean annual Runoff

Mean annual extraction

km2 mm GL GL

01 Flinders Island 1316 766 169.0 1.9

23 Arthur 2493 1757 2547.0 4.9

24 Welcome 336 1139 76.7 0.4

25 King Island 1091 968 234.8 3.8

26 Montagu 360 1245 135.5 1.9

27 Duck 509 1232 239.4 12.8

28 Black-Detention 578 1322 319.2 11.2

29 Inglis-Flowerdale 571 1384 362.6 13.1

30 Cam 286 1425 160.0 4.2

31 Emu 246 1565 252.8 31.5

32 Blythe 365 1383 261.7 6.9

For modelling purposes, the Arthur-Inglis-Cam region was divided into 11 catchments (see Table 1). A large proportion of

the end-of-system (EOS) flow comes from the Arthur catchment, which is the largest catchment by area, with the highest

mean annual rainfall. Rainfall varies across the region from a mean of 766 mm/year over the Flinders Island catchment

to 1757 mm/year over the Arthur catchment.

The Arthur-Inglis-Cam region includes a number of large storages which were modelled as part of the river system. See

Table 2 for details of these storages. The release represents controlled releases only and not spill from the storages. The

degree of regulation is calculated by dividing the mean annual releases by the mean annual inflow.

Table 2. Large storages in the Arthur-Inglis-Cam region

Effective storage

Mean annual inflow

Mean annual

releases

Degree of regulation

GL GL/y

Major irrigation supply reservoirs

Companion Reservoir 1.35 29.20 10.36 0.35

Guide Reservoir 1.60 10.28 2.48 0.24

Lake Mikany 2.77 15.16 2.22 0.15

Pet Reservoir 2.50 11.62 4.31 0.37

Talbots Lagoon 2.75 20.48 4.74 0.23

Region total 10.97 86.74 24.11 0.28


2 Methods

This section is a summary of the generic approach used for river system modelling and a brief description of the

11 catchment models in the Arthur-Inglis-Cam region.

River system models describing current infrastructure, water demands and water management rules were used to

assess the implications of changed inflows for water availability and the reliability of water supply to users. Most of the

river system models are based on the TasCatch models developed for Department of Primary Industries, Parks, Water

and Environment (DPIPWE) (Willis, 2008). These models were funded by the Australian Government Water Fund, for the

Water Smart Australia Project, Better Information for Better Outcomes Enhancing Water Planning in Tasmania and the

Tasmanian Government SMART Farming budget initiative. New models were developed for the catchments which were

not covered by existing DPIPWE models.

TasCatch models are node-link network models developed in Hydstra (Kisters, 2009) which include a water balance

model, streamflow routing, water allocations and extractions, and environmental flows. For the purposes of this project,

the water balance and streamflow lag and attenuation were removed from the models. This is because gridded runoff,

rainfall and evaporation were provided as inputs to the models (Viney et al., 2009). The lag and attenuation of streamflow

was therefore removed as the calibration technique used to produce the input runoff grid implicitly included routing. The

models run on a daily time step and route the runoff through the river system. The runoff in each subcatchment was

calculated as the mean of the gridded runoff over the subcatchment. Runoff from each grid cell was weighted in the

averaging process depending on the proportion of the grid cell that fell within a subcatchment. Subcatchment runoff was

then routed through the river network to the next subcatchment downstream. In areas where a number of catchment

models flow into one another in series, the models were run in logical sequence so that the outflow from the upstream

model was an input to the downstream model. Running of the models was automated so that all catchment models were

run in logical order for each scenario.

Rainfall and evaporation grids were used to calculate the rainfall and evaporation occurring over the surface area of

storages within the models.

Model subcatchment delineation and definition of the river network was initially performed using CatchmentSIM GIS

software (Catchment Simulation Solutions, 2009). Within a given catchment, subcatchments were defined to be of similar

size and to ensure that the routing length between catchment centroids was representative of the river length.

Subcatchments were broken upstream of river junctions. The outputs were visually checked to ensure accurate

representation of the catchment, and modifications were made manually as required. The subcatchment delineation is

shown in Figure 4.

2.1 Allocations and extractions

2.1.1 Water entitlements

Information on the current water entitlements as of December 2008 was obtained from DPIPWE’s Water Information

Management System (WIMS) database. WIMS includes an annual allocation and period for each licence. For example a

particular licence may be for 200 ML from October to February. Each licence in the catchment is of a given surety (from 1

to 8), with surety 1 to 4 representing high priority extractions for modelling purposes and surety 5 to 8 representing low

priority. Details of surety levels are given in Table 3 and the location of WIMS licences are shown in Figure 4.


Table 3. Department of Primary Industries, Parks, Water and Environment surety descriptions (from DPIPWE, 2009)

Surety Description

High priority

1 Rights for the taking of water for domestic purposes, consumption by livestock or firefighting under Part 5 of the Water Management Act 1999 and rights of councils to take water under Part 6 of the Act. Surety 1 water is expected to be available at about 95 percent reliability.

2 The water provision allocated to supply the needs of ecosystems dependent on the water resource.

3 Rights of licensees granted a water licence as a replacement of the ‘prescriptive rights’ (‘pre-Hydro Tasmania rights’) granted under the previous Water Act 1957.

4 Rights of special licensees such as Hydro Tasmania.

Low priority

5 Rights issued for the taking of water otherwise than for the purposes described above under surety levels 1 to 4. This includes rights issued for the taking of water under Part 6 of the Act for direct extraction, and for winter storage in dams, for use for irrigation or other commercial purposes. Surety 5 water is expected to be available at about 80 percent reliability.

6 Rights at this surety level issued for the taking of water under Part 6 of the Act for direct extraction for use for irrigation and other commercial purposes and for winter storage in dams. Surety 6 water is expected to be available at less than 80 percent reliability.

7, 8 Water allocations available with a lower level of reliability than a surety 6 allocation.

There is no record of actual extraction amounts over the year because extractions are currently not metered. In the

absence of any information on the monthly profile of irrigation extractions, it was assumed that the allocation was

extracted evenly over the allocation period, resulting in a constant daily allocation over the allocation period. Allocations

were accumulated in each subcatchment, and daily extraction of the allocated amount was attempted, based on surety

priority. Where sufficient water is not available for the full allocation, the extracted amount equalled the amount available.

2.1.2 Unlicensed storages

In Tasmania, a water licence is not required for storages of less than 1 ML. Numbers of unlicensed storages were

estimated by visually identifying small dams not included in the WIMS database as extractions in selected catchments.

These results were then extrapolated to other similar catchments. Where unlicensed storages had been estimated for a

catchment in the TasCatch modelling process, these figures were used (Willis, 2008). For the remaining areas a

combination of dam counting and extrapolation of unlicensed storages in neighbouring catchments was used. Dams

were manually counted in all calibration catchment areas (details of calibration catchments can be found in Viney et al.

(2009)).


Figure 4. Subcatchment delineation and WIMS licence locations

2.1.3 Unlicensed extractions

It is assumed that there will be some unlicensed extractions. The volume of unlicensed extractions for each catchment

was estimated based on local advice provided by DPIPWE.

2.1.4 Environmental flows and releases

Environmental flows were included in the models where they had been set by DPIPWE and information was provided as

restriction rules (shown in Table 4). In the Arthur-Inglis-Cam region environmental releases have been set for sections of

the Pet River (Emu catchment), Guide River (Cam catchment) and Duck River (Duck catchment). These are detailed in

Section 2.1.5.


2.1.5 Diversions, storages, and model customisation

A number of catchments include water diversion infrastructure or specific rules which control extractions. This includes

rivers where a ‘cease-to-take’ flow rule is in place, meaning that extractions from the river must be ceased when flow in

the river at a specified location falls below a set minimum (or threshold) for a set number of days. Flow rules are set in

stages, with stage 1 as the first rule to be enforced, followed by stage 2, followed by the rules for other stages. In

catchments where a flow rule is in place, the models required custom coding to account for associated operating rules,

and these were treated as a reduction in allocation. Restriction rules for catchments in Arthur-Inglis-Cam region are

shown in Table 4.

Table 4. Extraction restriction rules

River Location Catchment Month Threshold Number of days below threshold before

restriction enforced

Restriction rule

ML/d

Duck Trowutta Road

Duck All year 25.0 1 All surety 6, 7 direct extractions are banned

Duck Trowutta Road

Duck All year 25.0 2 All surety 5, 6, 7 direct extractions are banned

Black South Forest Road

Black-Detention

All year 2.6 1 All direct extractions banned

Detention Newhaven Road

Black-Detention


Detention Coopers Road

Black-Detention


Welcome Weir Welcome All year 1.8 1 All direct extractions banned

Seabrook Creek

Nunns Road Inglis-Flowerdale


Blackfish Creek

Lowries Road

Inglis-Flowerdale


Generic model functions representing storage and restriction rules were coded for use in the models. The values specific

to the catchment conditions were passed to these functions during the running of the model. Customisations of

catchment models within the Arthur-Inglis-Cam region are briefly described below. A more detailed description of the

models can be found in Willis et al. (2009).

Duck River

Lake Mikany is a major storage in the Duck River catchment. Water is extracted from the pump station on Deep Creek,

downstream of the lake. The extracted water is considered water lost from the system. An industrial user and the

Smithton and Stanley townships are the major water users from this lake.

An environmental release of 1.7 ML/day downstream of pump station is mandated. The mean daily extraction rates from

Lake Mikany for winter and summer are 3.7 ML/day and 5.0 ML/day respectively. The lake has an effective storage of

2770 ML.

Emu River Model

Burnie Mill Water Supply System

A small but significant portion of the Arthur River catchment is diverted into the upper Emu catchment as part of the

Burnie Mill Water Supply System (BMWSS), which provides water for industrial users.

There are three major elements to the BMWSS:

1. Talbots Lagoon, on the upper reach of the Wey River (part of the Arthur River basin), which releases water into

the Wey River as required.


2. Wey River Weir and Diversion Canal, located downstream of Talbots Lagoon, which diverts up to 60 ML/day

from Wey River to the upper Emu River. When the canal’s capacity is exceeded, the additional water spills over

the Wey River Weir into the Wey River (and eventually onto the Arthur River).

3. Companion Reservoir, on the upper reaches of the Emu River downstream of the Wey River diversion canal,

which releases water into the Emu River as required.

The BMWSS effectively annexes 31 km2 of the Arthur River basin to the Emu River catchment. This is treated as part of

the Emu catchment in the Emu River model. To account for instances when the Wey River Diversion Canal’s capacity is

exceeded, the Emu River Model produces a time series of spill over the Wey River Weir. This time series is then input

into the Arthur River model.

The terms of the original agreement for operation of the BMWSS stipulated that the system will be operated to ensure

that up to 65 ML/day is released from the BMWSS (Companion Dam) into the Emu River such that:

90 ML/day could be extracted at the Emu River Weir at Fern Glade Reserve (Burnie)

6 ML/day could be extracted at Hampshire (Knoop, 2000)

In the absence of any other information, the rule coded into the Emu model assumes that the BMWSS is operated in

accordance with this original agreement.

Burnie Mill Water Use

An industrial user has licences to extract approximately 30,000 ML/year, which translates to an approximate daily

extraction of 81 ML/day at Emu River Weir at Fern Glade Reserve (Burnie). In the absence of more detailed information,

the Emu model assumes this demand to be a constant 81 ML/day. The use of a constant rate of extraction is appropriate

for such an industrial application. Unlike irrigation, industrial operation is not affected by seasonal (or other natural)

influences.

Burnie Town Water Supply System

A small but significant portion of the Cam River catchment is diverted into the Pet River in the Emu catchment as part of

the Burnie Town Water Supply System (BTWSS) which was designed to provide sufficient water to maintain the water

supply for the regional centre of Burnie. The system is operated by Burnie City Council.

There are two major elements to the BTWSS:

1. Guide Reservoir and Canal, located in the upper reaches of the Guide River in the Cam catchment. The Guide

Canal diverts water into upper Reaches of the Pet River.

2. Pet Reservoir (located below the Guide Canal outlet), and town water supply offtake pipe.

The Burnie Town Water Supply system effectively annexes 15 km2 of the Cam River catchment to the Emu River

catchment. This is treated as part of the Emu catchment in the Emu River model. To account for instances when the

water is released from the Guide Reservoir into the Guide River (for environmental releases or when the reservoir spills)

and then into the Cam River, the Emu Model produces a time series of downstream outflows from the Guide Reservoir.

This time series is then input to the Cam River model.

Burnie City Council provided detailed operating rules of the Burnie Town Water Supply system for use by this project

(P Triffett (Burnie City Council), 2009, pers. comm.). The Town Water Supply System is operated as follows:

Guide Reservoir and Canal:

5 ML/day is transferred through the Guide Canal to the Pet River from April to September (inclusive)

8 ML/day is transferred through the Guide Canal to the Pet River from October to March (inclusive)

An environmental release of 0.3 ML/day into the Guide River year-round.


Pet Reservoir:

18 ML/day is extracted by pipe from Pet Reservoir from April to September (inclusive) to supply Burnie with

town water

5 ML/day is extracted by pipe from Pet Reservoir from October to March (inclusive) to supply Burnie with town

water

An environmental release of 0.3 ML/day into the Pet River year-round.

Cam River Model

The Burnie Town Water Supply System effectively annexes 15 km2 of the Cam River catchment to the Emu River

catchment. This region is treated as part of the Emu River catchment, and is modelled by the Emu River model, as

described above. A proportion of water falling on this 15 km2 area does flow into the Cam River catchment. The Emu

Model produces a time series that accounts for this water, which is an input to the Cam River model.

Arthur River Model

The Burnie Mill Water Supply System effectively annexes 31 km2 of the Arthur River catchment to the Emu River

catchment. This region is treated as part of the Emu River catchment, and is modelled by the Emu River model, as

described above. A proportion of water falling on this 31 km2 area does flow into the Arthur River basin. The Emu Model

produces a time series that accounts for this water, which is an input to the Arthur River model.

2.2 Future development

No future irrigation developments are proposed in the Arthur-Inglis-Cam region. Future development in the

Arthur-Inglis-Cam region includes a projected increase of 75 km2 in commercial forestry plantations. This has the effect

of taking total forest cover from 6 percent of the region to 7 percent of the region by 2030. The majority of this projected

increase is in the north-east of the region (Viney et al, 2009). Future increases in forestry in the region are shown in

Figure 5.


Figure 5. Increase in forest cover due to future commercial forest plantations in the Arthur-Inglis-Cam region


3 Under historical climate (Scenario A) and future

climate (Scenario C)

This section reports on hydrology under Scenario A and on hydrology under Scenario C relative to Scenario A. Three

scenarios are presented for Scenario C: wet extreme (Scenario Cwet), median (Scenario Cmid) and dry extreme

(Scenario Cdry). The selection of these scenarios was based on projected changes in mean annual runoff from the

14 km resolution pattern-scaled projections of the 15 global climate models (GCMs). The selection of climate scenarios is

described in detail by Viney et al. (2009). In summary, the wettest of the three global warming projections from the

second wettest GCM (MIROC) was chosen as Scenario Cwet. The projection representing 1.0 degree global warming

from the eighth wettest GCM (MIUB) was chosen as Scenario Cmid. The driest of the three global warming projections

from the second driest GCM (NCAR-CCSM) was chosen as Scenario Cdry. This selection of scenarios Cwet, Cmid and

Cdry was performed separately for each region. As the selection of these scenarios was based on mean annual runoff

over the region, they can vary in order on the basis of season and catchment. In many catchments in the

Arthur-Inglis-Cam region, this results in a lower flow during summer under Scenario Cmid relative to Scenario Cdry. A

higher winter flow is also observed under Scenario Cmid relative to Scenario Cwet in some parts of the region.

Statistics reported for ‘summer’ or ‘winter’ refer to October to March and April to September respectively.

3.1 Water balance and water availability

The mass balance table (Table 5a–k) shows the net fluxes for each catchment in the Arthur-Inglis-Cam region. Fluxes

under Scenario A are presented as GL/year, while fluxes under all other scenarios are presented as a percentage

change relative to Scenario A.

The storage volumes refer to the major lakes within the region. The inflows are separated into flows from catchment

runoff, and flows from hydro-electric schemes. The catchment losses include any water transfers (diversions) into or out

of the catchment, and evaporation from major storages. Extractions are shown based on surety level. The catchment

losses are positive for a net loss for the catchment and negative for a net gain (for example, the loss will be negative if

rainfall over a storage surface exceeds evaporation, or water is transferred into a catchment).

The net catchment transfers/losses represent direct extractions from storages, and inter-catchment transfer of water. In

the Arthur-Inglis-Cam region these transfers include:

transfer of water into Arthur catchment when Wye River Weir spills in the Emu catchment,

direct extraction from Lake Mikany in the Duck catchment,

transfer of water into Cam catchment from Guide River in the Emu catchment,

transfer of water from the Emu catchment to the Cam catchment (Guide River) and Arthur catchment (Wye

River Weir spill) and direct extractions from Pet Reservoir.

Table 5 shows that the mean annual catchment runoff decreases under Scenario C relative to Scenario A for all

catchments in the region, other than Flinders Island where catchment runoff is higher under scenarios Cwet and Cmid,

relative to Scenario A. There are larger catchment losses under Scenario C relative to Scenario A, in all catchments

which include storages, reflecting an increase in evaporation under Scenario C. The extraction amounts decrease slightly

or remain the same under Scenario C relative to Scenario A. In the Emu and Cam catchments, extractions are 1 percent

greater under Scenario Cdry compared to Scenario Cmid. This reflects the fact that low flows under Scenario Cdry are

higher than they are under Scenario Cmid in these catchments. This can occur as the selection of scenarios Cdry, Cmid

and Cwet was based on annual runoff for each region. As a result, Scenario Cmid can be drier than Scenario Cdry on a

seasonal and catchment basis.


Table 5. Mean annual water balance for each catchment under scenarios A and C

(a) 01_Flinders Island

A Cwet Cmid Cdry

GL/y percent change relative to Scenario A

Storage volume

Mean annual change in volume na na na na

Inflows

From catchment runoff 169.0 5% 2% -8%

From flows downstream of hydro schemes na na na na

Total (inflows) 169.0 5% 2% -8%

Outflows

Net catchment transfers/losses (including storages if any)

na na na na

Net evaporation (evaporation – rainfall) from storages na na na na

Sub-total (net transfer and net evaporation) na na na na

Extractions

Surety 1 0.0 1% -1% -1%

Surety 2 0.0 na na na



Surety 5 0.5 0% -1% -2%

Surety 6 0.3 0% 0% -1%



Unlicensed 1.1 0% 0% -1%

Sub-total (extractions) 1.9 0% 0% -1%

End-of-system (EOS) streamflow 167.0 5% 2% -8%

Total (outflows) 169.0 5% 2% -8%na – not applicable

(b) 23_Arthur

A Cwet Cmid Cdry


Storage volume


Inflows

From catchment runoff 2574.0 -2% -4% -9%


Total (inflows) 2574.0 -2% -4% -9%

Outflows


-29.6 3% 7% 12%


Sub-total (net transfer and net evaporation) -29.6 3% 7% 12%

Extractions

Surety 1 0.1 0% 0% 0%




Surety 5 1.3 0% 0% 0%




Unlicensed 3.5 0% 0% 0%

Sub-total (extractions) 4.9 0% 0% 0%

End-of-system (EOS) streamflow 2598.7 -2% -5% -9%

Total (outflows) 2574.0 -2% -4% -9%na – not applicable


Table 5. Mean annual water balance for each catchment under scenarios A and C (continued)

(c) 24_Welcome

A Cwet Cmid Cdry


Storage volume


Inflows



Total (inflows) 76.7 -5% -12% -21%

Outflows


na na na na



Extractions





Surety 5 0.3 0% -1% -1%





Sub-total (extractions) 0.4 0% -1% -1%



(d) 25_King Island

A Cwet Cmid Cdry


Storage volume


Inflows



Total (inflows) 234.8 -7% -11% -20%

Outflows


na na na na



Extractions

Surety 1 0.2 0% -1% -1%




Surety 5 0.8 0% -1% -1%




Unlicensed 2.8 0% -1% -1%






(e) 26_Montagu

A Cwet Cmid Cdry


Storage volume


Inflows



Total (inflows) 135.5 -3% -7% -16%

Outflows


na na na na



Extractions

Surety 1 0.2 -1% -4% -3%




Surety 5 1.4 -1% -2% -2%




Unlicensed 0.3 -1% -3% -2%

Sub-total (extractions) 1.9 -1% -2% -2%



(f) 27_Duck

A Cwet Cmid Cdry


Storage volume

Mean annual change in volume 0.0 4% -14% -5%

Inflows



Total (inflows) 239.4 -2% -4% -13%

Outflows


1.6 0% 0% 0%

Net evaporation (evaporation – rainfall) from storages – Lake Mikany

-0.1 18% 54% 79%

Sub-total (net transfer and net evaporation) 1.5 1% 4% 5%

Extractions

Surety 1 0.8 0% 0% 0%




Surety 5 9.5 0% -2% -2%

Surety 6 0.2 0% -1% -2%



Unlicensed 2.3 -1% -5% -5%






(g) 28_Black-Detention

A Cwet Cmid Cdry


Storage volume


Inflows



Total (inflows) 319.2 -2% -5% -13%

Outflows


na na na na



Extractions

Surety 1 0.2 0% -1% 0%




Surety 5 8.0 -1% -2% -2%

Surety 6 0.3 -1% -1% -2%



Unlicensed 2.7 -1% -6% -4%




(h) 29_Inglis-Flowerdale

A Cwet Cmid Cdry


Storage volume


Inflows



Total (inflows) 362.6 -2% -5% -12%

Outflows


na na na na



Extractions

Surety 1 0.5 0% -1% -1%




Surety 5 6.3 0% -1% -1%

Surety 6 5.3 0% -2% -1%









(i) 30_Cam

A Cwet Cmid Cdry


Storage volume


Inflows



Total (inflows) 160.0 -4% -7% -14%

Outflows

Net catchment transfers/losses (including storages if any) -8.1 6% 10% 19%


Sub-total (net transfer and net evaporation) -8.1 6% 10% 19%

Extractions

Surety 1 1.4 0% 0% 0%




Surety 5 1.9 0% -2% -2%

Surety 6 0.0 0% -1% -1%







(j) 31_Emu

A Cwet Cmid Cdry


Storage volume

Mean annual change in volume 0.0 0% -5% -3%

Inflows



Total (inflows) 252.8 -4% -7% -12%

Outflows


41.9 -4% -7% -12%

Net evaporation (evaporation – rainfall) from storages – Companion Reservoir + Pet Reservoir + Guide Reservoir + Talbots Lagoon

-3.1 6% 12% 18%

Sub-total (net transfer and net evaporation) 38.8 -3% -6% -12%

Extractions

Surety 1 0.1 0% 0% 0%




Surety 5 30.4 0% -1% 0%

Surety 6 0.1 0% -1% -1%




Sub-total (extractions) 31.5 0% -1% 0%





(k) 32_Blythe

A Cwet Cmid Cdry


Storage volume


Inflows



Total (inflows) 261.7 -4% -7% -12%

Outflows


na na na na



Extractions

Surety 1 0.2 0% 0% 0%




Surety 5 6.1 0% 0% -1%

Surety 6 0.2 0% -1% -2%




Sub-total (extractions) 6.9 0% 0% -1%



Figure 6 shows the mean annual streamflow for the major river reaches in each catchment under scenarios P, A and C

where C range is defined by the upper and lower bounds of Scenario C streamflow. Generally this is defined by

streamflow under scenarios Cwet and Cdry, but due to the way that the C scenarios are derived, occasionally

Scenario Cmid may be used.

Other than in the Emu catchment, all the major rivers in the region are gaining reaches (where the flow in the river

increases moving downstream). The flow in the Emu catchment decreases under scenarios A and C relative to

Scenario P downstream of the point where Burnie Mill extractions from the river occur.

Up to a maximum of eight reporting locations were included for each major river reach. The number of reporting locations

on a river is related to the number of modelled subcatchments on the river. In some catchments, there are less than eight

reporting locations, as the largest river reach in the catchment is modelled by less than eight subcatchments.

End-of-system (EOS) represents the total flow at the end of the catchment. In catchments where there is a major river

and a number of smaller rivers, the EOS flow is the summation of the end-of-river flow for all rivers within the catchment.

The reporting locations are shown in Figure 3. The differences in the flows for Scenario P relative to Scenario A show the

impact of extractions from the river. In many cases the flows for Scenario P are indistinguishable from Scenario A as

there are relatively small extractions in the river.

On all the major rivers, river flows decrease or remain the same under Scenario C relative to Scenario A.


(a) 01_Flinders Island

0

50

100

150

200

EOS

Reporting location

Mea

n an

nual

flow

.(G

L)

C range

Cmid

A

P

(b) 23_Arthur (Arthur River)

0

500

1000

1500

2000

2500

3000

1 2 3 4 5 6 7 8 EOSReporting location

Mea

n an

nual

flow

.(G

L).

C range

Cmid

A

P

(c) 24_Welcome (Welcome River)

0102030405060708090

1 2 3 4 5 6 EOSReporting location

Mea

n an

nual

flow

.(G

L).

C range

Cmid

A

P

(d) 25_King Island (Sea Elephant River)

0

50

100

150

200

250

1 2 3 EOSReporting location

Mea

n an

nual

flow

.(G

L).

C range

Cmid

A

P

Figure 6. River transects showing streamflow under scenarios P, A and C


(e) 26_Montagu (Montagu River)

0

20

40

60

80

100

120

140

160


Mea

n an

nual

flow

.(G

L).

C range

Cmid

A

P

(f) 27_Duck (Duck River)

0

50

100

150

200

250

300


Mea

n an

nual

flow

.(G

L).

C range

Cmid

A

P

(g) 28_Black-Detention (Black River)

0

50

100

150

200

250

300

350


Mea

n an

nual

flow

.(G

L).

C range

Cmid

A

P

(h) 29_Inglis-Flowerdale (Flowerdale River)

0

50

100

150

200

250

300

350

400

1 2 3 4 5 6 7 EOSReporting location

Mea

n an

nual

flow

.(G

L).

C range

Cmid

A

P

Figure 6. River transects showing streamflow under scenarios P, A and C (continued)


(i) 30_Cam (Cam River)

020406080

100120140160180


Mea

n an

nual

flow

.(G

L).

C range

Cmid

A

P

(j) 31_Emu (Emu River)

0

50

100

150

200

250


Mea

n an

nual

flow

.(G

L).

C range

Cmid

A

P

(k) 32_Blythe (Blythe River)

0

50

100

150

200

250

300


Mea

n an

nual

flow

.(G

L).

C range

Cmid

A

P

Figure 6. River transects showing streamflow under scenarios P, A and C (continued)

A time series of annual total streamflow for the whole Arthur-Inglis-Cam region, represented as the total EOS flow, under

Scenario A is shown in Figure 7a. EOS flow is defined as the total flow at the end of the catchment. In catchments where

there is a major river and a number of smaller rivers, the EOS flow is the summation of the end of river flow for all rivers

within the catchment.

There is a high level of variability in total streamflow between years, ranging from 2559 to 7947 GL/year, with a mean of

4690 GL/year. High flows are not as large or as frequent over the last 25 years, compared with the previous 59 years.

Figure 7b–d shows the difference in annual total surface water under Scenario C relative to Scenario A. The annual total

streamflow decreases in all but one year under Scenario Cwet relative to Scenario A, by up to 189 GL/year with a mean

of 104 GL/year. The decrease in annual total streamflow under Scenario Cmid ranges from 120 to 391 GL/year with a

mean of 244 GL/year. Under Scenario Cdry, the decrease in annual total streamflow ranges from 274 to 917 GL/year

with a mean of 537 GL/year. The regional EOS flow is dominated by the Arthur catchment which accounts for over

50 percent of the regional EOS flow.


(a) Scenario A (b) Scenario Cwet

0100020003000400050006000700080009000

0 20 40 60 80

Year

Ann

ual E

OS

vol

ume

(GL)

.

-1000

-800

-600

-400

-200

0

200

0 20 40 60 80Year

Ann

ual d

iffer

ence

(G

L)

(c) Scenario Cmid (d) Scenario Cdry

-1000

-800

-600

-400

-200

0

200

0 20 40 60 80

Year

Ann

ual d

iffer

ence

(G

L) .

-1000

-800

-600

-400

-200

0

200

0 20 40 60 80

Year

Ann

ual d

iffer

ence

(G

L)

Figure 7. End-of-system (EOS) streamflow in the Arthur-Inglis-Cam region under (a) Scenario A, and difference from Scenario A under

scenarios (b) Cwet, (c) Cmid and (d) Cdry

3.2 Storage behaviour

The modelled behaviour of storages gives an indication of the level of regulation of a system, as well as how reliable the

storage is during extended periods of low inflows. Details of the behaviour of each storage under scenarios A and C for

the full 84-year model run can be seen in Table 6. The mean days between spills are unchanged under Scenario Cwet

relative to Scenario A, whilst the maximum days between spills is slightly larger under Scenario Cwet relative to

Scenario A. The mean and maximum days between spills are generally higher under Scenario Cwet relative to

Scenario Cdry. All storages show a lower number of mean days between spills for Scenario Cdry relative to

Scenario Cmid. This is partially due to storage operating rules, and partially a consequence of the method used for

selection of the wet, mid and dry scenarios, as discussed in Section 3. The selection of Cwet, Cmid and Cdry scenarios

was based on mean annual runoff and peak flows may actually be higher in some years under Scenario Cmid relative to

Scenario Cwet, or Scenario Cdry relative to Scenario Cmid because different GCMs were used to define these scenarios

and these GCMs may scale peak rainfalls by different amounts.

Time series of storage volume for a representative ten years are shown in Figure 8. These time series represent the

modelled storage behaviour which included 2007 operating rules. The storage behaviour, therefore, is not necessarily

representative of historical storage levels. All reservoirs are generally drawn down to lower volumes under Scenario C

relative to Scenario A, however, these differences are minor. All storages spill each year. This is consistent with

Scenario Cmid having a higher mean number of days between spills than either scenarios Cdry or Cwet.


Table 6. Storage behaviour under scenarios A and C

A Cwet Cmid Cdry

Companion Reservoir

Minimum storage volume (GL) 0 0 0 0

Mean days between spills 41 41 53 42

Maximum days between spills 192 195 203 201

Guide Reservoir




Lake Mikany




Pet Reservoir




Talbots Lagoon





(a) Companion Reservoir (b) Guide Reservoir

0.00.20.40.60.81.01.21.41.6

15 16 17 18 19 20 21 22 23 24Year

Vol

ume

(GL)

.

C range A Cmid

0.0

0.5

1.0

1.5

2.0

15 16 17 18 19 20 21 22 23 24Year

Vol

ume

(GL)

.

C rangeCmidA

(c) Lake Mikany (d) Pet Reservoir

0.0

0.5

1.0

1.5

2.0

2.5

3.0

15 16 17 18 19 20 21 22 23 24Year

Vol

ume

(GL)

.

C rangeCmidA

0.0

0.5

1.0

1.5

2.0

2.5

3.0

15 16 17 18 19 20 21 22 23 24Year

Vol

ume

(GL)

.C rangeCmidA

(e) Talbots Lagoon

0.0

0.5

1.0

1.5

2.0

2.5

3.0

15 16 17 18 19 20 21 22 23 24Year

Vol

ume

(GL)

.

C rangeCmidA

Figure 8. Storage behaviour over representative ten-year period under scenarios A and C

3.3 Consumptive water use

Consumptive water use includes both the licensed and unlicensed extractions from the river system. The modelling of

extractions is described in Section 2.1. Time series of annual extractions for Scenario A are shown in Figure 9. Total

annual extractions for the region vary from a minimum of 86 to a maximum of 97 GL/year over the 84 years. The

differences in annual extractions under Scenario C are also shown in Figure 9. Under Scenario Cwet, there are nine

years where extractions increase when compared to Scenario A. Extractions are lower in every year under

scenarios Cmid and Cdry relative to Scenario A. The mean annual reductions in extractions under scenarios Cwet, Cmid

and Cdry relative to Scenario A are 0.2, 1.2 and 1.2 GL/year respectively. These reductions are relatively small in

comparison to the mean annual extraction of 93 GL/year under Scenario A. The reductions in extraction volumes are

spread over a range of sureties, representing a reduction in both summer and winter extractions.

Vol

ume

(GL)

Vol

ume

(GL)

Vol

ume

(GL)

Vol

ume

(GL)

Vol

ume

(GL)


(a) Scenario A (b) Scenario Cwet

0

20

40

60

80

100

120

0 20 40 60 80Year

Ann

ual e

xtra

ctio

n vo

lum

e .

(GL)

.

-3.5

-3.0

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

0.5

0 20 40 60 80Year

Ann

ual d

iffer

ence

(G

L) .

(c) Scenario Cmid (d) Scenario Cdry

-3.5

-3.0

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

0.5

0 20 40 60 80

Year

Ann

ual d

iffer

ence

(G

L) .

-3.5

-3.0

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

0.5

0 20 40 60 80

Year

Ann

ual d

iffer

ence

(G

L) .

Figure 9. Total annual extractions for Arthur-Inglis-Cam region under (a) Scenario A, and difference from Scenario A under

scenarios (b) Cwet, (c) Cmid and (d) Cdry

Table 7 shows the mean annual volume of allocated and extracted water in each catchment in the region under

scenarios A and C. In the majority of catchments, the amount of water extracted is equal to or only slightly less than that

allocated. The exception is the Black-Detention catchment, where the mean extractions are 85 percent of the allocation

under Scenario A. There is very little change in the mean allocated or extracted volumes for all catchments under

Scenario C relative to Scenario A.


Table 7. Allocated and extracted mean annual flows for catchments under scenarios A and C

A Cwet Cmid Cdry

GL/y

01_Flinders Island

Allocated water 2.1 2.1 2.1 2.1

Extraction 1.9 1.9 1.9 1.9

Difference 0.2 0.2 0.2 0.2

23_Arthur


Extraction 4.9 4.9 4.9 4.9

Difference 0.0 0.0 0.0 0.0

24_Welcome


Extraction 0.4 0.4 0.4 0.4

Difference 0.0 0.0 0.0 0.0

25_King Island


Extraction 3.8 3.8 3.8 3.7

Difference 0.1 0.1 0.1 0.1

26_Montagu


Extraction 1.9 1.9 1.8 1.8

Difference 0.1 0.1 0.1 0.1

27_Duck


Extraction 12.8 12.8 12.6 12.5

Difference 0.1 0.1 0.1 0.1

28_Black-Detention


Extraction 11.2 11.1 10.9 10.9

Difference 1.9 1.9 2.1 2.1

29_Inglis-Flowerdale


Extraction 13.1 13.1 12.9 13.0

Difference 0.4 0.4 0.5 0.4

30_Cam


Extraction 4.2 4.2 4.1 4.1

Difference 0.5 0.5 0.6 0.5

31_Emu


Extraction 31.5 31.5 31.2 31.3

Difference 0.3 0.3 0.5 0.4

32_Blythe


Extraction 6.9 6.9 6.9 6.9

Difference 0.1 0.1 0.1 0.1

The mean annual reliability of high and low priority extractions is shown in Table 8 for each catchment as fraction

extracted per unit of water allocated. The reliabilities of extractions over summer and winter are shown in Table 9 and

Table 10 respectively. The annual reliability of high priority extractions is 98 percent or greater under all scenarios for all

catchments except Flinders Island, where the reliability of high priority extractions is 88 percent or greater. In summer,

the reliability of high priority extractions in Flinders Island and Black-Detention catchments is slightly lower than the

reliability of annual extractions. The reliability of low priority extractions is greater than 96 percent under all scenarios for

the majority of catchments, with the exception of Flinders Island, Cam and Black-Detention catchments. In these

catchments, the reliability of low priority extractions is lower in summer when compared to winter and annual reliability.


The reliability of extractions changes by less than 2 percent in all catchments for both high and low priority extractions

under Scenario C relative to Scenario A on an annual and seasonal basis.

The reliability of high priority extractions may be less than the reliability of low priority extractions, as these extractions

may be taken over different months of the year. For example, a licence for high priority extractions for town water supply

may apply year-round, whereas a licence for a low priority allocation may be for opportunistic extractions of peak flood

waters over winter.

Table 8. Mean reliability of high and low priority annual allocations for catchments under scenarios A and C (annual)

A Cwet Cmid Cdry

fraction extracted per unit allocated

01_Flinders Island

High priority (surety 1 to 4) 0.89 0.89 0.88 0.88

Low priority (surety 5 to 8 & unlicensed) 0.92 0.92 0.91 0.90

23_Arthur



24_Welcome

High priority (surety 1 to 4) - - - -


25_King Island



26_Montagu



27_Duck



28_Black-Detention






30_Cam



31_Emu



32_Blythe




Table 9. Mean reliability of high and low priority allocations under scenarios A and C (summer – October to March inclusive)

A Cwet Cmid Cdry


01_Flinders Island



23_Arthur



24_Welcome



25_King Island



26_Montagu



27_Duck



28_Black-Detention






30_Cam



31_Emu



32_Blythe




Table 10. Mean reliability of high and low priority allocations under scenarios A and C (winter – April to September inclusive)

A Cwet Cmid Cdry


01_Flinders Island



23_Arthur



24_Welcome



25_King Island



26_Montagu



27_Duck



28_Black-Detention






30_Cam



31_Emu



32_Blythe



Figure 10 shows the allocation and extraction reliability as percentage of years for exceedance of a given volume. The

allocation volume is not constant each year in some catchments due to regulations which restrict allocations under low

flow conditions (see Table 4). There is a slight reduction in extractions under Scenario C relative to Scenario A in some

catchments. The impact of future climate on extractions is small due to the low level of extractions in the region.

Figure 11 shows the same figures for summer only. Summer extractions are less reliable than annual extractions in all

catchments except Arthur and Welcome where they remain unchanged, and Cam catchment where the reliability of

summer extractions is greater than the reliability of annual extractions.

In the Flinders Island, Montagu, Black-Detention and Cam catchments, the extracted water volume does not meet the

allocated water volume in any year, reflecting the fact that water is not consistently available for extraction in these

catchments. In the absence of other information, the methodology used in the modelling assumes that irrigators are

attempting to extract water at a constant rate over the allocation period. In reality, irrigators will extract water

opportunistically as it is available, which is likely to result in a higher reliability of extraction than the modelled results. In

the Arthur and Welcome catchments, the extracted water volume is equal to the allocated water volume for all years

except one in the Welcome catchment.


(a-1) 01_Flinders Island – allocated water (a-2) 01_Flinders Island – extracted per allocated

0.0

0.5

1.0

1.5

2.0

2.5

0% 20% 40% 60% 80% 100%Percent of years exceeded

Ann

ual v

olum

e (G

L) .

C rangeCmidA

0.00.10.20.30.40.50.60.70.80.91.0


Ext

ract

ed v

olum

e pe

r

unit

allo

cate

d .

C range

Cmid

A

(b-1) 23_Arthur – allocated water (b-2) 23_Arthur – extracted per allocated

3.03.23.43.63.84.04.24.44.64.85.0


Ann

ual v

olum

e (G

L) .

C rangeCmidA

0.00.10.20.30.40.50.60.70.80.91.0


Ext

ract

ed v

olum

e pe

r

unit

allo

cate

d .

C range

Cmid

A

(c-1) 24_Welcome – allocated water (c-2) 24_Welcome – extracted per allocated

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40


Ann

ual v

olum

e (G

L) .

C rangeCmidA

0.00.10.20.30.40.50.60.70.80.91.0


Ext

ract

ed v

olum

e pe

r

unit

allo

cate

d .

C range

Cmid

A

(d-1) 25_King Island – allocated water (d-2) 25_King Island – extracted per allocated

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0


Ann

ual v

olum

e (G

L) .

C rangeCmidA

0.00.10.20.30.40.50.60.70.80.91.0


Ext

ract

ed v

olum

e pe

r

unit

allo

cate

d .

C range

Cmid

A

Figure 10. Allocation and extraction reliability for catchments under scenarios A and C (annual)


(e-1) 26_Montagu – allocated water (e-2) 26_Montagu – extracted per allocated

0.0

0.5

1.0

1.5

2.0

2.5


Ann

ual v

olum

e (G

L) .

C rangeCmidA

0.00.10.20.30.40.50.60.70.80.91.0


Ext

ract

ed v

olum

e pe

r

unit

allo

cate

d .

C range

Cmid

A

(f-1) 27_Duck – allocated water (f-2) 27_Duck – extracted per allocated

0

2

4

6

8

10

12

14

16


Ann

ual v

olum

e (G

L) .

C rangeCmidA

0.00.10.20.30.40.50.60.70.80.91.0


Ext

ract

ed v

olum

e pe

r

unit

allo

cate

d .

C range

Cmid

A

(g-1) 28_Black-Detention – allocated water (g-2) 28_Black-Detention – extracted per allocated

0

2

4

6

8

10

12

14

16


Ann

ual v

olum

e (G

L) .

C rangeCmidA

0.00.10.20.30.40.50.60.70.80.91.0


Ext

ract

ed v

olum

e pe

r

unit

allo

cate

d .

C range

Cmid

A

(h-1) 29_Inglis-Flowerdale – allocated water (h-2) 29_Inglis-Flowerdale – extracted per allocated

0

2

4

6

8

10

12

14

16


Ann

ual v

olum

e (G

L) .

C rangeCmidA

0.00.10.20.30.40.50.60.70.80.91.0


Ext

ract

ed v

olum

e pe

r

unit

allo

cate

d .

C range

Cmid

A

Figure 10. Allocation and extraction reliability for catchments under scenarios A and C (annual) (continued)


(i-1) 30_Cam – allocated water (i-2) 30_Cam – extracted per allocated

0

1

2

3

4

5

6


Ann

ual v

olum

e (G

L) .

C rangeCmidA

0.00.10.20.30.40.50.60.70.80.91.0


Ext

ract

ed v

olum

e pe

r

unit

allo

cate

d .

C range

Cmid

A

(j-1) 31_Emu – allocated water (j-2) 31_Emu – extracted per allocated

0

5

10

15

20

25

30

35


Ann

ual v

olum

e (G

L) .

C rangeCmidA

0.00.10.20.30.40.50.60.70.80.91.0


Ext

ract

ed v

olum

e pe

r

unit

allo

cate

d .

C range

Cmid

A

(k-1) 32_Blythe – allocated water (k-2) 32_Blythe – extracted per allocated

0

1

2

3

4

5

6

7

8


Ann

ual v

olum

e (G

L) .

C rangeCmidA

0.00.10.20.30.40.50.60.70.80.91.0


Ext

ract

ed v

olum

e pe

r

unit

allo

cate

d .

C range

Cmid

A

Figure 10. Allocation and extraction reliability for catchments under scenarios A and C (annual) (continued)


(a-1) 01_Flinders Island – allocated water (a-2) 01_Flinders Island – extracted per allocated

0.0

0.5

1.0

1.5

2.0

2.5

0% 20% 40% 60% 80% 100%

Percent of years exceeded

Sum

mer

vol

ume

(GL)

. C rangeCmidA

0.00.10.20.30.40.50.60.70.80.91.0


Ext

ract

ed v

olum

e pe

r

unit

allo

cate

d .

C range

Cmid

A

(b-1) 23_Arthur – allocated water (b-2) 23_Arthur – extracted per allocated

3.03.23.43.63.84.04.24.44.64.85.0

0% 20% 40% 60% 80% 100%


Sum

mer

vol

ume

(GL)

. C rangeCmidA

0.00.10.20.30.40.50.60.70.80.91.0


Ext

ract

ed v

olum

e pe

r

unit

allo

cate

d .

C range

Cmid

A

(c-1) 24_Welcome – allocated water (c-2) 24_Welcome – extracted per allocated

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0% 20% 40% 60% 80% 100%


Sum

mer

vol

ume

(GL)

. C rangeCmidA

0.00.10.20.30.40.50.60.70.80.91.0


Ext

ract

ed v

olum

e pe

r

unit

allo

cate

d .

C range

Cmid

A

(d-1) 25_King Island – allocated water (d-2) 25_King Island – extracted per allocated

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

0% 20% 40% 60% 80% 100%


Sum

mer

vol

ume

(GL)

. C rangeCmidA

0.00.10.20.30.40.50.60.70.80.91.0


Ext

ract

ed v

olum

e pe

r

unit

allo

cate

d .

C range

Cmid

A

Figure 11. Allocation and extraction for catchments reliability under scenarios A and C (summer – October to March inclusive)


(e-1) 26_Montagu – allocated water (e-2) 26_Montagu – extracted per allocated

0.0

0.5

1.0

1.5

2.0

2.5

0% 20% 40% 60% 80% 100%


Sum

mer

vol

ume

(GL)

. C rangeCmidA

0.00.10.20.30.40.50.60.70.80.91.0


Ext

ract

ed v

olum

e pe

r

unit

allo

cate

d .

C range

Cmid

A

(f-1) 27_Duck – allocated water (f-2) 27_Duck – extracted per allocated

0

2

4

6

8

10

12

14

16

0% 20% 40% 60% 80% 100%


Sum

mer

vol

ume

(GL)

. C rangeCmidA

0.00.10.20.30.40.50.60.70.80.91.0


Ext

ract

ed v

olum

e pe

r

unit

allo

cate

d .

C range

Cmid

A

(g-1) 28_Black-Detention – allocated water (g-2) 28_Black-Detention – extracted per allocated

0

2

4

6

8

10

12

14

16

0% 20% 40% 60% 80% 100%


Sum

mer

vol

ume

(GL)

. C rangeCmidA

0.00.10.20.30.40.50.60.70.80.91.0


Ext

ract

ed v

olum

e pe

r

unit

allo

cate

d .

C range

Cmid

A

(h-1) 29_Inglis-Flowerdale – allocated water (h-2) 29_Inglis-Flowerdale – extracted per allocated

0

2

4

6

8

10

12

14

16

0% 20% 40% 60% 80% 100%


Sum

mer

vol

ume

(GL)

. C rangeCmidA

0.00.10.20.30.40.50.60.70.80.91.0


Ext

ract

ed v

olum

e pe

r

unit

allo

cate

d .

C range

Cmid

A


(continued)


(i-1) 30_Cam – allocated water (i-2) 30_Cam – extracted per allocated

0

1

2

3

4

5

6

0% 20% 40% 60% 80% 100%


Sum

mer

vol

ume

(GL)

. C rangeCmidA

0.00.10.20.30.40.50.60.70.80.91.0


Ext

ract

ed v

olum

e pe

r

unit

allo

cate

d .

C range

Cmid

A

(j-1) 31_Emu – allocated water (j-2) 31_Emu – extracted per allocated

0

5

10

15

20

25

30

35

0% 20% 40% 60% 80% 100%


Sum

mer

vol

ume

(GL)

. C rangeCmidA

0.00.10.20.30.40.50.60.70.80.91.0


Ext

ract

ed v

olum

e pe

r

unit

allo

cate

d .

C range

Cmid

A

(k-1) 32_Blythe – allocated water (k-2) 32_Blythe – extracted per allocated

0

1

2

3

4

5

6

7

8

0% 20% 40% 60% 80% 100%


Sum

mer

vol

ume

(GL)

. C rangeCmidA

0.00.10.20.30.40.50.60.70.80.91.0


Ext

ract

ed v

olum

e pe

r

unit

allo

cate

d .

C range

Cmid

A


(continued)

The mean annual volume of extracted water for the lowest one-, three- and five-year periods under Scenario A, and the

percentage change under Scenario C relative to Scenario A are shown in Table 11. These figures indicate the impact on

water use during dry periods. In the majority of catchments, there is less than a 5 percent change in extracted water

during dry periods under Scenario C. The exceptions are in the Montagu, Duck, Cam and Black-Detention catchments

where there is greater than 5 percent change under Scenario Cdry for the lowest one-year period of extraction. The

greatest change is in the Black-Detention catchment which shows a reduction of 7.1 percent in the volume of water

extracted for the lowest one-year period of extraction under Scenario Cdry. Extraction volumes show a greater reduction

during dry periods under Scenario C relative to Scenario A when compared to changes in the long-term mean extractions,

indicating that the ability to extract water will be reduced in drier periods under future climate.


Table 11. Indicators of use during dry periods for catchments under Scenarios A and change under Scenario C relative to Scenario A

A Cwet Cmid Cdry


01_Flinders Island

Lowest 1-year period of extraction 1.6 0.6% 0.0% -3.8%

Lowest 3-year period of extraction 1.7 0.2% 0.0% -2.1%

Lowest 5-year period of extraction 1.8 0.1% -0.2% -1.7%

Mean annual extraction for 84 years 1.9 0.0% -0.3% -1.3%

23_Arthur

Lowest 1-year period of extraction 4.9 0.0% 0.0% 0.0%



Mean annual extraction for 84 years 4.9 0.0% 0.0% 0.0%

24_Welcome


Lowest 3-year period of extraction 0.4 -0.9% -1.9% -1.9%


Mean annual extraction for 84 years 0.4 -0.3% -0.8% -0.6%

25_King Island





26_Montagu





27_Duck





28_Black-Detention










30_Cam





31_Emu





32_Blythe






3.4 End-of-system river flow

The EOS monthly streamflow and daily duration curves for each catchment are shown in Figure 12 for scenarios P, A

and C. Scenario P represents current infrastructure with no extractions under historical climate. In the majority of

catchments, the shape of the flow duration curve is consistent under all scenarios. The exception to this is the Emu

catchment, where the impact of diversions from the catchment can be seen under low flows resulting in a drop in flow

volumes under scenarios A and C relative to Scenario P. A reduction in low flow volumes is observed in all catchments

under Scenario C relative to Scenario A.

The monthly flow curves show a strong seasonal distribution of flows, with highest flows occurring in winter months. The

mean monthly flow is generally reduced in all catchments under Scenario C relative to Scenario A in all months except

for July and August. In all catchments, July and August EOS flows under Scenario Cmid are greater than those under

scenarios Cwet and Cdry. This occurs as a result of the methodology used to select scenarios Cwet, Cdry and Cmid (as

discussed in Section 3) as selection of scenarios was based on mean annual runoff, and did not take into account the

seasonal distribution of flows.

(a-1) 01_Flinders Island – monthly flow (a-2) 01_Flinders Island – daily flow duration

0.0

0.2

0.4

0.6

0.8

1.0

1.2

J F M A M J J A S O N DMonth

EO

S m

onth

ly fl

ow (

GL)

. C rangeCmidAP

1

10

100

1000

10000

100000

0 20 40 60 80 100Percent time volume is exceeded

EO

S d

aily

flow

(M

L) .

C rangeCmidAP

(b-1) 23_Arthur – monthly flow (b-2) 23_Arthur – daily flow duration

0

2

4

6

8

10

12

14

16


EO

S m

onth

ly fl

ow (

GL)

. C rangeCmidAP

1

10

100

1000

10000

100000


EO

S d

aily

flow

(M

L) .

C rangeCmidAP

(c-1) 24_Welcome – monthly flow (c-2) 24_Welcome – daily flow duration

0.0

0.1

0.2

0.3

0.4

0.5

0.6


EO

S m

onth

ly fl

ow (

GL)

. C rangeCmidAP

1

10

100

1000

10000

100000


EO

S d

aily

flow

(M

L) .

C rangeCmidAP

Figure 12. Mean monthly end-of-system flow under and daily flow duration curves under scenarios P, A and C


(d-1) 25_King Island – monthly flow (d-2) 25_King Island – daily flow duration

0.00.20.40.60.81.01.21.41.61.8


EO

S m

onth

ly fl

ow (

GL)

. C rangeCmidAP

1

10

100

1000

10000

100000


EO

S d

aily

flow

(M

L) .

C rangeCmidAP

(e-1) 26_Montagu – monthly flow (e-2) 26_Montagu – daily flow duration

0.0

0.2

0.4

0.6

0.8

1.0


EO

S m

onth

ly fl

ow (

GL)

. C rangeCmidAP

1

10

100

1000

10000

100000


EO

S d

aily

flow

(M

L) .

C rangeCmidAP

(f-1) 27_Duck – monthly flow (f-2) 27_Duck – daily flow duration

0.00.20.40.60.81.01.21.41.61.8


EO

S m

onth

ly fl

ow (

GL)

. C rangeCmidAP

1

10

100

1000

10000

100000


EO

S d

aily

flow

(M

L) .

C rangeCmidAP

(g-1) 28_Black-Detention – monthly flow (g-2) 28_Black-Detention – daily flow duration

0.0

0.5

1.0

1.5

2.0

2.5


EO

S m

onth

ly fl

ow (

GL)

. C rangeCmidAP

1

10

100

1000

10000

100000


EO

S d

aily

flow

(M

L) .

C rangeCmidAP

Figure 12. Mean monthly end-of-system flow under and daily flow duration curves under scenarios P, A and C (continued)


(h-1) 29_Inglis-Flowerdale – monthly flow (h-2) 29_Inglis-Flowerdale – daily flow duration

0.0

0.5

1.0

1.5

2.0

2.5


EO

S m

onth

ly fl

ow (

GL)

. C rangeCmidAP

1

10

100

1000

10000

100000


EO

S d

aily

flow

(M

L) .

C rangeCmidAP

(i-1) 30_Cam – monthly flow (i-2) 30_Cam – daily flow duration

0.0

0.2

0.4

0.6

0.8

1.0

1.2


EO

S m

onth

ly fl

ow (

GL)

. C rangeCmidAP

1

10

100

1000

10000

100000


EO

S d

aily

flow

(M

L) .

C rangeCmidAP

(j-1) 31_Emu – monthly flow (j-2) 31_Emu – daily flow duration

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4


EO

S m

onth

ly fl

ow (

GL)

. C rangeCmidAP

1

10

100

1000

10000

100000


EO

S d

aily

flow

(M

L) .

C rangeCmidAP

(k-1) 32_Blythe – monthly flow (k-2) 32_Blythe – daily flow duration

0.00.20.40.60.81.01.21.41.61.8


EO

S m

onth

ly fl

ow (

GL)

. C rangeCmidAP

1

10

100

1000

10000

100000


EO

S d

aily

flow

(M

L) .

C rangeCmidAP

Figure 12. Mean monthly end-of-system flow under and daily flow duration curves under scenarios P, A and C (continued)


EOS daily peak flows for return periods of two, five and ten years are shown in Table 12 under scenarios A and P with

changes under Scenario C relative to Scenario A. Peak flows were determined based on the procedure used in the

Murray-Darling Basin Sustainable Yields Project (CSIRO, 2008) using a partial series analysis and a plotting position

assigned based on rank. Scenario P represents streamflow modelled with historical climate, current infrastructure and no

extractions taken from the river, allowing the impact of extractions to be explicitly considered by comparison to

Scenario A. Peak flows decrease for all return periods shown under Scenario Cdry in all catchments. The maximum

decrease in flows is 25 percent for the one-year return period in the Welcome catchment. In Flinders Island, Arthurs,

Duck and Inglis-Flowerdale catchments, peak flows increase under scenarios Cwet and Cmid. The maximum increase in

peak flows is 13 percent for the ten-year return period flow in the Flinders Island catchment. In some catchments, peak

flows under Scenario Cmid are greater than those under Scenario Cwet. The selection of Cwet, Cmid and Cdry

scenarios was based on mean annual runoff and peak flows may actually be higher in some years under Scenario Cmid

relative to Scenario Cwet, or Scenario Cdry relative to Scenario Cmid because different global climate models (GCMs)

were used to define these scenarios and these GCMs may scale peak rainfalls by different amounts.


Table 12. Peak flows for catchments under scenarios P and A, and under Scenario C relative to Scenario A

P A Cwet Cmid Cdry

ML/d percent change relative to Scenario A

01_Flinders Island

2-year 6,532 6,531 6% 9% -6%

5-year 10,020 10,016 10% 9% -2%

10-year 12,949 12,941 13% 9% -3%

23_Arthur

2-year 44,424 44,421 2% 4% -4%

5-year 53,347 52,786 6% 6% -2%

10-year 65,109 65,106 0% 7% -4%

24_Welcome

2-year 1,076 1,074 -4% -14% -25%

5-year 1,448 1,447 2% -3% -17%

10-year 2,037 2,036 -6% -9% -20%

25_King Island

2-year 6,781 6,759 -7% -6% -18%

5-year 9,784 9,761 -1% -6% -15%

10-year 12,646 12,631 -7% -12% -21%

26_Montagu

2-year 2,175 2,168 -3% -4% -15%

5-year 3,013 3,005 0% 0% -11%

10-year 3,736 3,728 -3% 1% -13%

27_Duck

2-year 4,397 4,353 4% 3% -8%

5-year 5,742 5,695 2% 3% -8%

10-year 6,797 6,752 0% 3% -6%

28_Black-Detention

2-year 8,371 8,332 3% 2% -9%

5-year 10,148 10,108 1% 2% -8%

10-year 11,413 11,374 1% 3% -6%


2-year 7,576 7,525 2% 1% -10%

5-year 10,006 9,975 2% 5% -7%

10-year 12,029 11,999 6% 5% -1%

30_Cam

2-year 3,549 3,568 -1% -2% -13%

5-year 4,694 4,677 -2% 0% -10%

10-year 5,770 5,750 -1% 0% -9%

31_Emu

2-year 4,229 4,093 -1% -2% -9%

5-year 5,338 5,283 -3% -1% -11%

10-year 6,349 6,180 1% -6% -11%

32_Blythe

2-year 4,728 4,699 -2% -4% -11%

5-year 6,800 6,771 -3% -2% -11%

10-year 7,638 7,609 -2% -1% -11%

The percentage of time EOS flow is greater than 1 ML/day under scenarios P, A, and C is shown in Table 13. Flows less

than 1 ML/day are defined as ‘cease-to-flow’ for the purposes of this report. The rivers in all catchments are essentially

perennial, ceasing to flow for only a small percentage of time. The percentage of time that the river is flowing decreases

by 2 percent or less under Scenario C relative to Scenario A in all catchments. A maximum reduction of 2 percent in the

time the river is flowing is seen in Scenario P relative to Scenario A reflecting the low level of extractions in this region.


Table 13. Percentage of time end-of-system flow is greater than1 ML/day under scenarios P, A and C

P A Cwet Cmid Cdry

01_Flinders Island 95% 93% 94% 93% 93%

23_Arthur 100% 100% 100% 100% 100%

24_Welcome 100% 100% 99% 99% 99%

25_King Island 100% 99% 99% 98% 98%

26_Montagu 100% 100% 100% 100% 100%

27_Duck 100% 100% 100% 100% 100%

28_Black-Detention 100% 100% 100% 100% 100%

29_Inglis-Flowerdale 100% 99% 99% 99% 99%

30_Cam 100% 99% 99% 98% 98%

31_Emu 100% 96% 96% 94% 94%

32_Blythe 100% 100% 100% 100% 100%

The EOS flow during dry periods under Scenario A with relative changes under Scenario C is shown in Table 14. The

EOS flow for the lowest one-, three- and five-year periods reduces significantly in all catchments under Scenario Cdry,

with a maximum reduction of 26.3 percent in King Island catchment for the lowest one-year period. This indicates that

under Scenario Cdry, the river system is more stressed in periods of low flow. The flow reduces for all reported periods

under scenarios Cwet and Cmid relative to Scenario A in all catchments except Flinders Island which shows an increase

in EOS flow for all reported periods under Scenario Cwet and the one- and five-year periods under Scenario Cmid.


Table 14. End-of-system flow for catchments during dry periods under Scenario A, and under Scenario C relative to Scenario A

A Cwet Cmid Cdry


01_Flinders Island

Lowest 1-year period of EOS flow 32.3 9.6% 2.4% -11.0%

Lowest 3-year period of EOS flow 59.9 4.2% -0.1% -12.5%

Lowest 5-year period of EOS flow 89.2 3.6% 0.8% -10.9%

Mean annual EOS flow for 84 years 167.0 5.2% 2.4% -8.3%

23_Arthur

Lowest 1-year period of EOS flow 1566.1 -3.1% -7.3% -11.6%



Mean annual EOS flow for 84 years 2598.7 -1.7% -4.5% -9.3%

24_Welcome





25_King Island





26_Montagu





27_Duck





28_Black-Detention










30_Cam





31_Emu





32_Blythe






3.5 Share of available resource

The mean annual volume of extracted and non-extracted shares of water for Arthur-Inglis-Cam region under scenarios A

and C are shown in Figure 13 and Table 15. The methods for modelling extractions and allocations are described in

Section 2.1. There is a low volume of extracted water relative to the total mean annual volume of water in the catchment.

The extracted water decreases by up to 1.2 GL/year under Scenario C relative to Scenario A. The non-extracted water

decreases by 537 GL/year under Scenario Cdry relative to Scenario A. Total flow in the region decreases under

Scenario C relative to Scenario A. The implication of these changes for environmental values is assessed in Graham

et al. (2009).

0

1000

2000

3000

4000

5000

A Cwet Cmid Cdry

Mea

n an

nual

vol

ume

(GL)

.

Non-extracted water Extracted water

Figure 13. Extracted and non-extracted shares of water for Arthur-Inglis-Cam region under scenarios A and C (annual)

Table 15. Extracted and non-extracted shares of water for Arthur-Inglis-Cam region under scenarios A and C (annual)

A Cwet Cmid Cdry

GL/y

Non-extracted water 4696 4592 4452 4159

Extracted water 93 92 91 91

Total 4789 4684 4543 4250

The mean annual extracted and non-extracted shares of water for each catchment are shown in Figure 14 and Table 16.

The volume of extracted water does not change significantly under Scenario C relative to Scenario A for any catchment.

The total streamflow decreases under Scenario C relative to Scenario A in all catchments except Flinders Island where

total streamflow increases under scenarios Cwet and Cmid relative to Scenario A. This implies that the reduction in the

runoff under Scenario C would be borne more in the non-extracted proportion of river flows due to the extraction rules,

which may have implications for the environmental values in the river systems.


(a) 01_Flinders Island (b) 23_Arthur

020406080

100120140160180200

A Cwet Cmid Cdry

Mea

n an

nual

vol

ume

(GL)

.


0

500

1000

1500

2000

2500

3000

A Cwet Cmid Cdry

Mea

n an

nual

vol

ume

(GL)

.


(c) 24_Welcome (d) 25_King Island

0

10

20

30

40

50

60

70

80

A Cwet Cmid Cdry

Mea

n an

nual

vol

ume

(GL)

.


0

50

100

150

200

250

A Cwet Cmid Cdry

Mea

n an

nual

vol

ume

(GL)

.


(e) 26_Montagu (f) 27_Duck

0

20

40

60

80

100

120

140

A Cwet Cmid Cdry

Mea

n an

nual

vol

ume

(GL)

.


0

50

100

150

200

250

A Cwet Cmid Cdry

Mea

n an

nual

vol

ume

(GL)

.


(g) 28_Black-Detention (h) 29_Inglis-Flowerdale

0

50

100

150

200

250

300

350

A Cwet Cmid Cdry

Mea

n an

nual

vol

ume

(GL)

.


0

50

100

150

200

250

300

350

400

A Cwet Cmid Cdry

Mea

n an

nual

vol

ume

(GL)

.


Figure 14. Extracted and non-extracted shares of water for catchments under scenarios A and C (annual)


(i) 30_Cam (j) 31_Emu

020406080

100120140160180

A Cwet Cmid Cdry

Mea

n an

nual

vol

ume

(GL)

.


0

50

100

150

200

250

A Cwet Cmid Cdry

Mea

n an

nual

vol

ume

(GL)

.


(k) 32_Blythe

0

50

100

150

200

250

300

A Cwet Cmid Cdry

Mea

n an

nual

vol

ume

(GL)

.


Figure 14. Extracted and non-extracted shares of water for catchments under scenarios A and C (annual) (continued)


Table 16. Extracted and non-extracted shares of water for catchments under scenarios A and C (annual)

A Cwet Cmid Cdry

GL/y

01_Flinders Island

Non-extracted water 167.0 175.7 171.0 153.1

Extracted water 1.9 1.9 1.9 1.9

Total 169.0 177.6 172.9 155.0

23_Arthur



Total 2612.2 2568.3 2494.2 2370.1

24_Welcome



Total 76.7 73.0 67.6 60.2

25_King Island



Total 234.8 218.0 210.0 186.8

26_Montagu



Total 135.5 131.7 126.1 113.6

27_Duck



Total 239.5 235.5 229.0 207.7

28_Black-Detention



Total 319.2 312.4 303.7 279.0




Total 362.6 353.7 343.8 319.1

30_Cam



Total 170.5 164.4 159.2 147.3

31_Emu



Total 207.2 199.1 193.3 182.3

32_Blythe



Total 261.7 250.6 243.5 229.3

The mean extracted and non-extracted shares of water for Arthur-Inglis-Cam region for summer only are shown in

Table 17. The total streamflow in summer is less under Scenario Cmid compared to Scenario Cdry. The mean summer

extraction does not change significantly under Scenario C compared to Scenario A. The extracted volume of water is

small in summer compared with the total streamflow available.


Table 17. Extracted and non-extracted shares of water for Arthur-Inglis-Cam region under scenarios A and C (summer – October to

March inclusive)

A Cwet Cmid Cdry

GL/season

Non-extracted water 1133 1108 991 1008

Extracted water 43 43 42 43

Total 1176 1151 1033 1050

The mean extracted and non-extracted shares of water for each catchment for summer only are shown in Table 18. The

total streamflow in summer is lower under Scenario Cmid relative to Cdry. The mean summer extraction does not change

significantly under Scenario C relative to Scenario A. The extracted proportion of water in summer is significant in the

Emu catchment. In all catchments, the extracted proportion of water over summer is larger than the annual extraction.


Table 18. Extracted and non-extracted shares of water for catchments under scenarios A and C (summer – October to March inclusive)

A Cwet Cmid Cdry

GL/season

01_Flinders Island



Total 45.4 51.1 45.8 45.7

23_Arthur



Total 633.9 620.1 555.6 576.1

24_Welcome



Total 21.4 20.6 17.7 17.1

25_King Island



Total 54.7 51.2 45.4 43.4

26_Montagu



Total 33.1 31.9 28.2 27.6

27_Duck



Total 59.0 56.9 52.1 49.9

28_Black-Detention



Total 70.6 68.4 61.4 61.3




Total 93.1 90.6 82.2 82.1

30_Cam



Total 42.4 41.2 36.9 37.0

31_Emu



Total 52.2 50.8 45.7 46.9

32_Blythe



Total 70.8 68.3 62.2 63.3

The mean percentage of water extracted as a proportion of total EOS flow under scenarios A and C annually and for

summer and winter are shown in Table 19, Table 20 and Table 21 respectively. On an annual basis, the percentage of

water extracted as a proportion of total flow is 6 percent or less in the majority of catchments. The exception to this is the

Emu catchment where an annual mean of 15 percent of water is extracted under Scenario A, reflecting water use in the

catchment for town water supply and industry. The proportion of the total flow extracted in summer is larger than the

annual proportion of flow extracted in the majority of catchments, with the largest proportional summer extractions in the

Duck, Black-Detention, Inglis-Flowerdale, Cam and Emu catchments. Mean summer extractions are 30 percent of total

flows under Scenario A in the Emu catchment, increasing to 33 percent under Scenario Cdry. The extraction as a


proportion of total flow is the same or less in winter relative to summer for all catchments other than under Scenario Cdry

in Flinders Island. All catchments show little or no change in the percentage of extractions as a proportion of total flow

under Scenario C compared to Scenario A.

Table 19. Percentage of water extracted as a proportion of total end-of-system flow for catchments under scenarios A and C (annual)

A Cwet Cmid Cdry

01_Flinders Island 1% 1% 1% 1%

23_Arthur 0% 0% 0% 0%

24_Welcome 0% 0% 1% 1%

25_King Island 2% 2% 2% 2%

26_Montagu 1% 1% 1% 2%

27_Duck 5% 5% 5% 6%

28_Black-Detention 4% 4% 4% 4%

29_Inglis-Flowerdale 4% 4% 4% 4%

30_Cam 2% 3% 3% 3%

31_Emu 15% 16% 16% 17%

32_Blythe 3% 3% 3% 3%

Region mean 2% 2% 2% 2%

Table 20. Percentage of water extracted as a proportion of total end-of-system flow for catchments under scenarios A and C (summer –

October to March inclusive)

A Cwet Cmid Cdry


23_Arthur 1% 1% 1% 1%

24_Welcome 1% 1% 1% 1%

25_King Island 1% 1% 1% 1%

26_Montagu 2% 2% 2% 2%

27_Duck 10% 10% 11% 12%



30_Cam 5% 5% 6% 6%

31_Emu 30% 31% 34% 33%

32_Blythe 3% 3% 4% 4%


Table 21. Percentage of water extracted as a proportion of total end-of-system flow for catchments under scenarios A and C (winter –

April to September inclusive)

A Cwet Cmid Cdry


23_Arthur 0% 0% 0% 0%

24_Welcome 0% 0% 0% 1%

25_King Island 2% 2% 2% 2%

26_Montagu 1% 1% 1% 1%

27_Duck 4% 4% 4% 4%



30_Cam 2% 2% 2% 2%

31_Emu 10% 11% 11% 12%

32_Blythe 2% 2% 2% 3%



4 Under historical climate (Scenario A) and recent

climate (Scenario B)

This section compares recent hydrology (under Scenario B) with historical hydrology (under Scenario A). The mean

end-of-system (EOS) flow volume in GL/year, and daily EOS flow duration plots for each catchment are shown in

Figure 15 for each catchment. The mean monthly flow for recent climate is generally less than the long-term mean in all

catchments in all months with the exception of September and October where flows are higher in some catchments

under Scenario B relative to Scenario A. Mean flows in September and October under recent climate are greater than the

long-term mean in the Black-Detention, Cam, Emu and Blythe catchments. Mean flows in January under recent climate

are higher than the long-term mean in Flinders Island catchment. The flow duration curves show that flows under recent

climate have generally been lower than the long-term mean over the full range of flows.

(a-1) 01_Flinders Island – monthly flow (a-2) 01_Flinders Island – daily flow duration

0.0

0.2

0.4

0.6

0.8

1.0


EO

S m

onth

ly fl

ow (

GL)

. B

A

1

10

100

1000

10000

100000


EO

S d

aily

flow

(M

L) . B

A

(b-1) 23_Arthur – monthly flow (b-2) 23_Arthur – daily flow duration

0

2

4

6

8

10

12

14

16


EO

S m

onth

ly fl

ow (

GL)

. B

A

1

10

100

1000

10000

100000


EO

S d

aily

flow

(M

L) .

B

A

(c-1) 24_Welcome – monthly flow (c-2) 24_Welcome – daily flow duration

0.0

0.1

0.2

0.3

0.4

0.5

0.6


EO

S m

onth

ly fl

ow (

GL)

. B

A

1

10

100

1000

10000

100000


EO

S d

aily

flow

(M

L) .

B

A

Figure 15. Mean end-of-system monthly flow and daily flow duration curves for catchments under scenarios A and B


(d-1) 25_King Island – monthly flow (d-2) 25_King Island – daily flow duration

0.00.20.40.60.81.01.21.41.61.8


EO

S m

onth

ly fl

ow (

GL)

. B

A

1

10

100

1000

10000

100000


EO

S d

aily

flow

(M

L) .

B

A

(e-1) 26_Montagu – monthly flow (e-2) 26_Montagu – daily flow duration

0.0

0.2

0.4

0.6

0.8

1.0


EO

S m

onth

ly fl

ow (

GL)

. B

A

1

10

100

1000

10000

100000


EO

S d

aily

flow

(M

L) .

B

A

(f-1) 27_Duck – monthly flow (f-2) 27_Duck – daily flow duration

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6


EO

S m

onth

ly fl

ow (

GL)

. B

A

1

10

100

1000

10000

100000


EO

S d

aily

flow

(M

L) .

B

A

(g-1) 28_Black-Detention – monthly flow (g-2) 28_Black-Detention – daily flow duration

0.0

0.5

1.0

1.5

2.0

2.5


EO

S m

onth

ly fl

ow (

GL)

. B

A

1

10

100

1000

10000

100000


EO

S d

aily

flow

(M

L) .

B

A

Figure 15. Mean end-of-system monthly flow and daily flow duration curves for catchments under scenarios A and B (continued)


(h-1) 29_Inglis-Flowerdale – monthly flow (h-2) 29_Inglis-Flowerdale – daily flow duration

0.0

0.5

1.0

1.5

2.0

2.5


EO

S m

onth

ly fl

ow (

GL)

. B

A

1

10

100

1000

10000

100000


EO

S d

aily

flow

(M

L) .

B

A

(i-1) 30_Cam – monthly flow (i-2) 30_Cam – daily flow duration

0.0

0.2

0.4

0.6

0.8

1.0

1.2


EO

S m

onth

ly fl

ow (

GL)

. B

A

1

10

100

1000

10000

100000


EO

S d

aily

flow

(M

L) .

B

A

(j-1) 31_Emu – monthly flow (j-2) 31_Emu – daily flow duration

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4


EO

S m

onth

ly fl

ow (

GL)

. B

A

1

10

100

1000

10000

100000


EO

S d

aily

flow

(M

L) .

B

A

(k-1) 32_Blythe – monthly flow (k-2) 32_Blythe – daily flow duration

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6


EO

S m

onth

ly fl

ow (

GL)

. B

A

1

10

100

1000

10000

100000


EO

S d

aily

flow

(M

L) .

B

A

Figure 15. Mean end-of-system monthly flow and daily flow duration curves for catchments under scenarios A and B (continued)


The extracted and non-extracted shares of water for Arthur-Inglis-Cam are shown in Figure 16 and Table 22 under

scenarios A and B. It can be seen that the total streamflow in the region is lower under Scenario B; however, the volume

of extracted water reduces by a mean of only 2 GL/year annually, reflecting the low level of extraction across the region.

The reduction in the total EOS flow under Scenario B relative to Scenario A is borne by the non-extracted water. The

implication of these changes for environmental values is assessed in Graham et al. (2009).

0500

100015002000250030003500400045005000

A B

Mea

n an

nual

vol

ume

(GL)

.


Figure 16. Mean annual extracted and non-extracted shares of water for Arthur-Inglis-Cam region under scenarios A and B

Table 22. Mean annual extracted and non-extracted shares of water for Arthur-Inglis-Cam region under scenarios A and B

A B

GL/y

Non-extracted water 4696 4040

Extracted water 93 91

Total 4789 4131

The extracted and non-extracted shares of water under scenarios A and B for summer only are shown in Table 23. There

is a decrease of 658 GL/season in mean summer flows under Scenario B relative to Scenario A. This has only a minimal

impact on the mean summer extraction volume, reflecting the low level of water usage in the region.

Table 23. Extracted and non-extracted shares of water for Arthur-Inglis-Cam region under scenarios A and B (summer – October to

March inclusive)

A B

GL/season

Non-extracted water 1133 962

Extracted water 43 42

Total 1176 1004

The mean annual extracted and non-extracted shares of water for each catchment are shown in Table 24 for each

catchment under scenarios A and B. The mean annual volume of total water is less under Scenario B relative to

Scenario A in all catchments. The volume of water extracted under Scenario B is the same or only slightly less than

Scenario A in all catchments. The total flow has greatly reduced under recent climate relative to the long-term mean, with

a reduction of 29 percent in the Welcome and King catchments. This may have implications for the environment such as

effects on connectivity of a river and its bordering ecosystem.


Table 24. Mean annual extracted and non-extracted shares of water for catchments under scenarios A and B.

A B

GL/y

01_Flinders Island

Non-extracted water 167.0 124.8

Extracted water 1.9 1.9

Total 169.0 126.7

23_Arthur



Total 2612.2 2343.7

24_Welcome



Total 76.7 55.2

25_King Island



Total 234.8 168.6

26_Montagu



Total 135.5 112.2

27_Duck



Total 239.5 197.1

28_Black-Detention



Total 319.2 263.9




Total 362.6 297.4

30_Cam



Total 170.5 150.3

31_Emu



Total 207.2 188.0

32_Blythe



Total 261.7 227.5

The mean annual extracted and non-extracted shares of water for each catchment for summer only under scenarios A

and B are shown in Table 25. The mean level of extraction is less than 12 percent in all catchments over summer, except

for in the Emu catchment where the level of extraction is high. The mean summer volume of water extracted does not

vary significantly under Scenario B relative to Scenario A.


Table 25. Extracted and non-extracted shares of water for catchments under scenarios A and B (summer – October to April inclusive)

A B

GL/season

01_Flinders Island



Total 45.4 37.4

23_Arthur



Total 633.9 543.6

24_Welcome



Total 21.4 16.2

25_King Island



Total 54.7 38.3

26_Montagu



Total 33.1 28.5

27_Duck



Total 59.0 48.1

28_Black-Detention



Total 70.6 60.9




Total 93.1 79.9

30_Cam



Total 42.4 38.4

31_Emu



Total 52.2 48.1

32_Blythe



Total 70.8 64.4


5 Under future development (Scenario D)

The impacts of future development under future climate are modelled in Scenario D. The impacts of future development

are shown relative to Scenario C, which models future climate with current infrastructure.

5.1 Hydrological impacts of future development

The projected changes in mean annual inflows to each catchment where there is an increase in future forestry

development are shown in Table 26 under Scenario D as a percent difference from Scenario C. Scenario C represents

future climate and Scenario D represents future development under future climate. There is a small change in inflows of

1 percent or less for the Black-Detention, Cam and Emu catchments under Scenario D relative to Scenario C. The

change in inflows under Scenario D relative to Scenario C is greater in the Inglis-Flowerdale catchment with a reduction

of 1.8 percent, and the Blythe catchment with a reduction of 3.6 to 3.7 percent. This reflects the fact that the largest

increases in future forestry were concentrated in these catchments (Viney et al., 2009), as shown in Figure 5.

Table 26. Comparison of inflows from catchment runoff under Scenario D relative to Scenario C

Dwet Dmid Ddry

percent change relative to Cwet

percent change relative to Cmid

percent change relative to Cdry

01_Flinders Island 0.0% 0.0% 0.0%

23_Arthur 0.0% 0.0% 0.0%

24_Welcome 0.0% 0.0% 0.0%

25_King Island 0.0% 0.0% 0.0%

26_Montagu 0.0% 0.0% 0.0%

27_Duck 0.0% 0.0% 0.0%

28_Black-Detention -0.3% -0.3% -0.3%

29_Inglis-Flowerdale -1.8% -1.8% -1.9%

30_Cam -0.7% -0.7% -0.7%

31_Emu -1.0% -1.0% -1.0%

32_Blythe -3.6% -3.7% -3.7%

Region mean -0.4% -0.4% -0.4%

The projected changes in end-of-system (EOS) flows are shown in Table 27 as change in percentage of time

end-of-system flows are greater than 1 ML. There are only very minor changes in the Inglis-Flowerdale, Cam and Emu

catchments. There is no change in percentage cease-to-flow time under Scenario D relative to Scenario C in the Blythe

catchment where the largest reduction in inflows was observed, as the river is essentially perennial.

Table 27. Percent time end-of-system flow for catchments is greater than 1 ML/day under Scenario D relative to Scenario C

Cwet Cmid Cdry Dwet Dmid Ddry

percentage of time EOS flow >1 ML/d

28_Black-Detention 100% 100% 100% 100% 100% 100%

29_Inglis-Flowerdale 99% 99% 99% 98% 97% 98%

30_Cam 99% 98% 98% 99% 98% 98%

31_Emu 96% 94% 95% 94% 92% 93%

32_Blythe 100% 100% 100% 100% 100% 100%


The small projected change in total flow and runoff under Scenario D relative to Scenario C is predicted to translate to a

reduction in extraction volumes. The mean total extractions in the Blythe and Inglis-Flowerdale catchments are reduced

by 3.5 and 6.9 percent respectively under Scenario Cdry relative to Scenario A. This indicates that the impact of future

development on the ability to extract water is greater than the impact of future development on catchment runoff or EOS

flows.

Table 28. Comparison of extractions for catchments under Scenario D relative to Scenario C


GL/y percent change relative Cwet



01_Flinders Island

Surety 1 0.0 0.0 0.0 0.0% 0.0% 0.0%

Surety 2 0.0 0.0 0.0 - - -

Surety 3 0.0 0.0 0.0 - - -

Surety 4 0.0 0.0 0.0 - - -

Surety 5 0.5 0.5 0.5 0.0% 0.0% 0.0%

Surety 6 0.3 0.3 0.3 0.0% 0.0% 0.0%

Surety 7 0.0 0.0 0.0 - - -

Surety 8 0.0 0.0 0.0 - - -

Unlicensed 1.1 1.1 1.1 0.0% 0.0% 0.0%

Total extractions 1.9 1.9 1.9 0.0% 0.0% 0.0%

23_Arthur

Surety 1 0.1 0.1 0.1 0.0% 0.0% 0.0%

Surety 2 0.0 0.0 0.0 - - -

Surety 3 0.0 0.0 0.0 - - -

Surety 4 0.0 0.0 0.0 - - -

Surety 5 1.3 1.3 1.3 0.0% 0.0% 0.0%

Surety 6 0.0 0.0 0.0 - - -

Surety 7 0.0 0.0 0.0 - - -

Surety 8 0.0 0.0 0.0 - - -

Unlicensed 3.5 3.5 3.5 0.0% 0.0% 0.0%


24_Welcome

Surety 1 0.0 0.0 0.0 - - -

Surety 2 0.0 0.0 0.0 - - -

Surety 3 0.0 0.0 0.0 - - -

Surety 4 0.0 0.0 0.0 - - -

Surety 5 0.3 0.3 0.3 0.0% 0.0% 0.0%

Surety 6 0.0 0.0 0.0 - - -

Surety 7 0.0 0.0 0.0 - - -

Surety 8 0.0 0.0 0.0 - - -

Unlicensed 0.0 0.0 0.0 0.0% 0.0% 0.0%


25_King Island

Surety 1 0.2 0.2 0.2 0.0% 0.0% 0.0%

Surety 2 0.0 0.0 0.0 - - -

Surety 3 0.0 0.0 0.0 - - -

Surety 4 0.0 0.0 0.0 - - -

Surety 5 0.8 0.8 0.8 0.0% 0.0% 0.0%

Surety 6 0.0 0.0 0.0 - - -

Surety 7 0.0 0.0 0.0 - - -

Surety 8 0.0 0.0 0.0 - - -

Unlicensed 2.8 2.7 2.7 0.0% 0.0% 0.0%



Table 28. Comparison of extractions for catchments under Scenario D relative to Scenario C (continued)





26_Montagu

Surety 1 0.2 0.2 0.2 0.0% 0.0% 0.0%

Surety 2 0.0 0.0 0.0 - - -

Surety 3 0.0 0.0 0.0 - - -

Surety 4 0.0 0.0 0.0 - - -

Surety 5 1.4 1.4 1.4 0.0% 0.0% 0.0%

Surety 6 0.0 0.0 0.0 - - -

Surety 7 0.0 0.0 0.0 - - -

Surety 8 0.0 0.0 0.0 - - -

Unlicensed 0.3 0.3 0.3 0.0% 0.0% 0.0%


27_Duck

Surety 1 0.8 0.8 0.8 0.0% 0.0% 0.0%

Surety 2 0.0 0.0 0.0 - - -

Surety 3 0.0 0.0 0.0 - - -

Surety 4 0.0 0.0 0.0 - - -

Surety 5 9.5 9.4 9.3 0.0% 0.0% 0.0%

Surety 6 0.2 0.2 0.2 0.0% 0.0% 0.0%

Surety 7 0.0 0.0 0.0 - - -

Surety 8 0.0 0.0 0.0 - - -

Unlicensed 2.3 2.2 2.2 0.0% 0.0% 0.0%


28_Black-Detention

Surety 1 0.2 0.2 0.2 -0.2% -0.7% -0.3%

Surety 2 0.0 0.0 0.0 - - -

Surety 3 0.0 0.0 0.0 - - -

Surety 4 0.0 0.0 0.0 - - -

Surety 5 7.9 7.8 7.8 -0.8% -0.8% -0.9%

Surety 6 0.3 0.3 0.3 -0.4% -0.3% -0.5%

Surety 7 0.0 0.0 0.0 - - -

Surety 8 0.0 0.0 0.0 - - -

Unlicensed 2.7 2.5 2.6 -2.3% -2.1% -2.2%

Total extractions 11.1 10.9 10.9 -1.1% -1.1% -1.1%


Surety 1 0.5 0.5 0.5 -4.4% -4.2% -4.5%

Surety 2 0.0 0.0 0.0 - - -

Surety 3 0.0 0.0 0.0 - - -

Surety 4 0.0 0.0 0.0 - - -

Surety 5 6.3 6.3 6.3 -3.6% -3.5% -3.7%

Surety 6 5.3 5.2 5.3 -2.7% -3.0% -2.8%

Surety 7 0.0 0.0 0.0 - - -

Surety 8 0.0 0.0 0.0 - - -

Unlicensed 1.0 1.0 1.0 -5.2% -4.8% -5.2%



Table 28. Comparison of extractions for catchments under Scenario D relative to Scenario C (continued)





30_Cam

Surety 1 1.4 1.4 1.4 -0.4% -0.4% -0.3%

Surety 2 0.0 0.0 0.0 - - -

Surety 3 0.0 0.0 0.0 - - -

Surety 4 0.0 0.0 0.0 - - -

Surety 5 1.9 1.9 1.9 -1.6% -1.7% -1.8%

Surety 6 0.0 0.0 0.0 -0.6% 0.0% 0.0%

Surety 7 0.0 0.0 0.0 - - -

Surety 8 0.0 0.0 0.0 - - -

Unlicensed 0.9 0.9 0.9 -1.9% -1.8% -2.0%


31_Emu

Surety 1 0.1 0.1 0.1 0.0% 0.0% 0.0%

Surety 2 0.0 0.0 0.0 - - -

Surety 3 0.0 0.0 0.0 - - -

Surety 4 0.0 0.0 0.0 - - -

Surety 5 30.4 30.1 30.3 -0.4% -0.5% -0.4%

Surety 6 0.1 0.1 0.1 -5.3% -5.4% -6.4%

Surety 7 0.0 0.0 0.0 - - -

Surety 8 0.0 0.0 0.0 - - -

Unlicensed 0.9 0.9 0.9 -1.0% -1.2% -1.1%


32_Blythe

Surety 1 0.2 0.2 0.2 -7.5% -7.6% -7.6%

Surety 2 0.0 0.0 0.0 - - -

Surety 3 0.0 0.0 0.0 - - -

Surety 4 0.0 0.0 0.0 - - -

Surety 5 6.1 6.1 6.1 -6.7% -6.6% -7.0%

Surety 6 0.2 0.2 0.2 -4.6% -4.1% -4.5%

Surety 7 0.0 0.0 0.0 - - -

Surety 8 0.0 0.0 0.0 - - -

Unlicensed 0.4 0.4 0.4 -4.2% -4.2% -4.9%


Total

Surety 1 3.6 3.6 3.6 -1.1% -1.1% -1.1%

Surety 2 0.0 0.0 0.0 - - -

Surety 3 0.0 0.0 0.0 - - -

Surety 4 0.0 0.0 0.0 - - -

Surety 5 66.4 65.9 65.9 -1.3% -1.3% -1.3%

Surety 6 6.4 6.3 6.3 -2.4% -2.6% -2.6%

Surety 7 0.0 0.0 0.0 - - -

Surety 8 0.0 0.0 0.0 - - -

Unlicensed 15.9 15.6 15.6 -1.0% -0.9% -1.0%


The mean monthly percent change in EOS flow under Scenario D relative to Scenario C is shown in Figure 17. The

largest percentage change is observed in the drier summer months. The maximum percentage change in mean monthly

EOS volume is 0.14 percent in the Blythe catchment.


(a-1) 28_Black-Detention – monthly flows (scenarios P, A and C)

(a-2) 28_Black-Detention – monthly flows (Scenario D)

0.0

0.5

1.0

1.5

2.0

2.5


EO

S m

onth

ly fl

ow (

GL)

. C rangeCmidAP

-16-14-12-10

-8-6-4-202


Per

cent

cha

nge

in E

OS

mon

thly

flow

rel

ativ

e .

to S

cena

rio

C .

D range

Dmid

(b-1) 29_Inglis-Flowerdale – monthly flows (scenarios P, A and C)

(b-2) 29_Inglis-Flowerdale – monthly flows (Scenario D)

0.0

0.5

1.0

1.5

2.0

2.5


EO

S m

onth

ly fl

ow (

GL)

. C rangeCmidAP

-16-14-12-10

-8-6-4-202


Per

cent

cha

nge

in E

OS

mon

thly

flow

rel

ativ

e .

to S

cena

rio

C .

D range

Dmid

(c-1) 30_Cam – monthly flows (scenarios P, A and C)

(c-2) 30_Cam – monthly flows (Scenario D)

0.0

0.2

0.4

0.6

0.8

1.0

1.2


EO

S m

onth

ly fl

ow (

GL)

. C rangeCmidAP

-16-14-12-10

-8-6-4-202


Per

cent

cha

nge

in E

OS

mon

thly

flow

rel

ativ

e .

to S

cena

rio

C .

D range

Dmid

(d-1) 31_Emu – monthly flows (scenarios P, A and C)

(d-2) 31_Emu – monthly flows (Scenario D)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4


EO

S m

onth

ly fl

ow (

GL)

. C rangeCmidAP

-16-14-12-10

-8-6-4-202


Per

cent

cha

nge

in E

OS

mon

thly

flow

rel

ativ

e .

to S

cena

rio

C .

D range

Dmid

Figure 17. Mean monthly end-of-system flow under scenarios P, A and C; and changes under Scenario D relative to Scenario C


(e-1) 32_Blythe – monthly flows (scenarios P, A and C)

(e-2) 32_Blythe – monthly flows (Scenario D)

0.00.20.40.60.81.01.21.41.61.8


EO

S m

onth

ly fl

ow (

GL)

. C rangeCmidAP

-16-14-12-10

-8-6-4-202


Per

cent

cha

nge

in E

OS

mon

thly

flow

rel

ativ

e .

to S

cena

rio

C .

D range

Dmid

Figure 17. Mean monthly end-of-system flow under scenarios P, A and C; and changes under Scenario D relative to Scenario C

(continued)

Peak flows under Scenario C and relative changes under Scenario D are shown in Table 29. Peak flows are reduced for

all return periods in all catchments under Scenario D relative to Scenario C, showing that high flows are impacted by

future development. These impacts are outcomes of the FCFC modelling used to determine the effects of forestry on

streamflow (Viney et al., 2009) and impoundments for the irrigation developments.


Table 29. Comparison of change in peak flows for catchments under Scenario D relative to Scenario C


ML/d percent change relative to Cwet



01_Flinders Island

2-year 6,953 7,123 6,168 0.00% 0.00% 0.00%

5-year 11,031 10,926 9,779 0.00% 0.00% 0.00%

10-year 14,602 14,129 12,531 0.00% 0.00% 0.00%

23_Arthur

2-year 45,219 46,266 42,583 0.00% 0.00% 0.00%

5-year 56,197 56,005 51,870 0.00% 0.00% 0.00%

10-year 64,914 69,496 62,603 0.00% 0.00% 0.00%

24_Welcome

2-year 1,031 924 808 0.00% 0.00% 0.00%

5-year 1,475 1,397 1,200 0.00% 0.00% 0.00%

10-year 1,918 1,846 1,624 0.00% 0.00% 0.00%

25_King Island

2-year 6,313 6,332 5,533 0.00% 0.00% 0.00%

5-year 9,656 9,165 8,288 0.00% 0.00% 0.00%

10-year 11,807 11,076 10,021 0.00% 0.00% 0.00%

26_Montagu

2-year 2,101 2,072 1,839 0.00% 0.00% 0.00%

5-year 2,996 3,001 2,684 0.00% 0.00% 0.00%

10-year 3,632 3,754 3,231 0.00% 0.00% 0.00%

27_Duck

2-year 4,548 4,493 4,014 0.00% 0.00% 0.00%

5-year 5,796 5,876 5,248 0.00% 0.00% 0.00%

10-year 6,780 6,954 6,332 0.00% 0.00% 0.00%

28_Black-Detention

2-year 8,557 8,460 7,574 -0.15% -0.24% -0.18%

5-year 10,242 10,308 9,279 -0.20% -0.20% -0.23%

10-year 11,451 11,744 10,713 -0.17% -0.20% -0.18%


2-year 7,650 7,596 6,738 -1.41% -1.40% -1.14%

5-year 10,179 10,440 9,279 -1.70% -1.38% -1.37%

10-year 12,714 12,650 11,876 -1.17% -1.45% -1.70%

30_Cam

2-year 3,536 3,488 3,109 -0.23% -0.37% -0.32%

5-year 4,595 4,683 4,193 -0.29% -0.42% -0.44%

10-year 5,710 5,728 5,239 -0.36% -0.36% -0.36%

31_Emu

2-year 4,035 4,008 3,742 -0.37% -0.35% -0.48%

5-year 5,131 5,208 4,723 -0.33% -0.33% -0.29%

10-year 6,252 5,814 5,522 -0.48% -0.46% -0.38%

32_Blythe

2-year 4,591 4,520 4,186 -1.79% -1.84% -2.72%

5-year 6,577 6,666 6,051 -1.96% -2.45% -1.93%

10-year 7,439 7,525 6,790 -2.19% -2.24% -2.11%


6 Conclusions

The Arthur-Inglis-Cam region has a mean annual flow of 4789 GL/year, and a low level of extraction with a mean annual

extraction of 92.6 GL/year (1.9 percent of total water in the region). The Emu catchment has the greatest level of

extraction (31.5 GL/year or 15 percent of total water in the Emu catchment) due to requirements for water from industry

and town water supplies.

The volume of extracted water in the region is not expected to reduce significantly under future climate (Scenario C)

relative to historical climate (Scenario A). The largest impact is seen in the driest years. In comparison to extractions, it is

projected that future climate has a greater impact on total end-of-system (EOS) flows.

Peak flows were evaluated for return periods of two, five and ten years. They are projected to decrease for all return

periods evaluated under Scenario Cdry relative to Scenario A in all catchments. Peak flows are projected to increase in

some catchments and decrease in others under scenarios Cwet and Cmid relative to Scenario A.

Under the recent climate (Scenario B), the monthly mean flow is lower than the long-term mean in all catchments in all

months with the exception of September and October. The flow duration curves show that flows under recent climate

have generally been lower than the long-term mean over the full range of flows. The mean volume of water extracted

decreases from 91 GL/year under Scenario A to 89 GL/year under Scenario B. The volume of non-extracted water

decreases in all catchments under Scenario B relative to Scenario A by a mean of 656 GL/year over the region as a

whole.

Future development in the Arthur-Inglis-Cam region includes a projected increase of 75 km2 in commercial forestry

plantations. This has the effect of taking total forest cover from 6 percent of the region to 7 percent of the region by 2030.

The majority of this projected increase is in the north-east of the region. The largest change in mean annual inflows

under Scenario D relative to Scenario C is in the Blythe catchment with a predicted reduction of 3.7 percent. Reductions

in inflows for the region as a whole are minimal, as are impacts on EOS flows.


7 References

Catchment Simulation Solutions (2009) Catchment-Sim. Viewed 10 September 2009, <http://www.csse.com.au/index.php?option=com_content&task=view&id=66&Itemid=127>.

CSIRO (2008) Water availability in the Murrumbidgee. A report to the Australian Government from the CSIRO Murray-Darling Basin Sustainable Yields Project. CSIRO, Australia.

Department of Primary Industries, Parks, Water and Environment (2009) Applying for a Water Licence. Department of Primary Industries, Parks, Water and Environment, Hobart. Viewed 6 August 2009, <http://www.dpiw.tas.gov.au/inter.nsf/WebPages/JMUY-4YA86N?open#SuretyLevels>.

Graham B, Hardie S, Gooderham J, Gurung S, Hardie D, Marvanek S, Bobbi C, Krasnicki T and Post DA (2009) Ecological impacts of water availability for Tasmania. A report to the Australian Government from the CSIRO Tasmania Sustainable Yields Project, CSIRO Water for a Healthy Country Flagship, Australia.

Kisters (2009) Hydstra/MO network modelling, Kisters Pioneering Technologies. Viewed 10 August 2009, <http://www.kisters.de/english/html/au/homepage.html>.

Knoop (2000) North Forests Burnie: Burnie Mill Water Supply System - Surveillance Inspection of Dams and Associated Infrastructure, Hydro Tasmania Report TAS-0200-SF-001, for North Forests Burnie. Hydro Tasmania, Hobart.

Ling FLN, Gupta V, Willis M, Bennett JC, Robinson KA, Paudel K, Post DA and Marvanek S (2009a) River modelling for Tasmania. Volume 1: the Arthur-Inglis-Cam region. A report to the Australian Government from the CSIRO Tasmania Sustainable Yields Project, CSIRO Water for a Healthy Country Flagship, Australia.

Ling FLN, Gupta V, Willis M, Bennett JC, Robinson KA, Paudel K, Post DA and Marvanek S (2009b) River modelling for Tasmania. Volume 2: the Mersey-Forth region. A report to the Australian Government from the CSIRO Tasmania Sustainable Yields Project, CSIRO Water for a Healthy Country Flagship, Australia.

Ling FLN, Gupta V, Willis M, Bennett JC, Robinson KA, Paudel K, Post DA and Marvanek S (2009c) River modelling for Tasmania. Volume 3: the Pipers-Ringarooma region. A report to the Australian Government from the CSIRO Tasmania Sustainable Yields Project, CSIRO Water for a Healthy Country Flagship, Australia.

Ling FLN, Gupta V, Willis M, Bennett JC, Robinson KA, Paudel K, Post DA and Marvanek S (2009d) River modelling for Tasmania. Volume 4: the South Esk region. A report to the Australian Government from the CSIRO Tasmania Sustainable Yields Project, CSIRO Water for a Healthy Country Flagship, Australia.

Ling FLN, Gupta V, Willis M, Bennett JC, Robinson KA, Paudel K, Post DA and Marvanek S (2009e) River modelling for Tasmania. Volume 5: the Derwent-South East region. A report to the Australian Government from the CSIRO Tasmania Sustainable Yields Project, CSIRO Water for a Healthy Country Flagship, Australia.

Post DA, Chiew FHS, Teng J, Vaze J, Yang A, Mpelasoka F, Smith I, Katzfey J, Marston F, Marvanek S, Kirono D, Nguyen K, Kent D, Donohue R, Li L and McVicar T (2009) Production of climate scenarios for Tasmania. A report to the Australian Government from the CSIRO Tasmania Sustainable Yields Project, CSIRO Water for a Healthy Country Flagship, Australia.

Viney NR, Post DA, Yang A, Willis M, Robinson KA, Bennett JC, Ling FLN and Marvanek S (2009) Rainfall-runoff modelling for Tasmania. A report to the Australian Government from the CSIRO Tasmania Sustainable Yields Project, CSIRO Water for a Healthy Country Flagship, Australia.

Willis M. (2008) TasCatch Finalisation Report – Stage 1 & Stage 2. HTC Report Consult-20294, for Department of Primary Industries and Water. Hydro Tasmania Consulting, Hobart.

Willis M, Bennett J, Robinson K, Ling F, Gupta V (2009) Tasmania Sustainable Yields River Modelling Methods Report. Hydro Tasmania Consulting, Hobart. in prep.

Tasmania Sustainable Yields Project reports

Region reports

CSIRO (2009) Water availability for Tasmania. Report one of seven to the Australian Government from the CSIRO Tasmania Sustainable Yields Project, CSIRO Water for a Healthy Country Flagship, Australia.

CSIRO (2009) Climate change projections and impacts on runoff for Tasmania. Report two of seven to the Australian Government from the CSIRO Tasmania Sustainable Yields Project, CSIRO Water for a Healthy Country Flagship, Australia.

CSIRO (2009) Water availability for the Arthur-Inglis-Cam region. Report three of seven to the Australian Government from the CSIRO Tasmania Sustainable Yields Project, CSIRO Water for a Healthy Country Flagship, Australia.

CSIRO (2009) Water availability for the Mersey-Forth region. Report four of seven to the Australian Government from the CSIRO Tasmania Sustainable Yields Project, CSIRO Water for a Healthy Country Flagship, Australia.

CSIRO (2009) Water availability for the Pipers-Ringarooma region. Report five of seven to the Australian Government from the CSIRO Tasmania Sustainable Yields Project, CSIRO Water for a Healthy Country Flagship, Australia.

CSIRO (2009) Water availability for the South Esk region. Report six of seven to the Australian Government from the CSIRO Tasmania Sustainable Yields Project, CSIRO Water for a Healthy Country Flagship, Australia.

CSIRO (2009) Water availability for the Derwent-South East region. Report seven of seven to the Australian Government from the CSIRO Tasmania Sustainable Yields Project, CSIRO Water for a Healthy Country Flagship, Australia.

Technical reports

Graham B, Hardie S, Gooderham J, Gurung S, Hardie D, Marvanek S, Bobbi C, Krasnicki T and Post DA (2009) Ecological impacts of water availability for Tasmania. A report to the Australian Government from the CSIRO Tasmania Sustainable Yields Project, CSIRO Water for a Healthy Country Flagship, Australia.

Harrington GA, Crosbie R, Marvanek S, McCallum J, Currie D, Richardson S, Waclawik V, Anders L, Georgiou J, Middlemis H and Bond K (2009) Groundwater assessment and modelling for Tasmania. A report to the Australian Government from the CSIRO Tasmania Sustainable Yields Project, CSIRO Water for a Healthy Country Flagship, Australia.

Ling FLN, Gupta V, Willis M, Bennett JC, Robinson KA, Paudel K, Post DA and Marvanek S (2009) River modelling for Tasmania. Volume 1: the Arthur-Inglis-Cam region. A report to the Australian Government from the CSIRO Tasmania Sustainable Yields Project, CSIRO Water for a Healthy Country Flagship, Australia.

Ling FLN, Gupta V, Willis M, Bennett JC, Robinson KA, Paudel K, Post DA and Marvanek S (2009) River modelling for Tasmania. Volume 2: the Mersey-Forth region. A report to the Australian Government from the CSIRO Tasmania Sustainable Yields Project, CSIRO Water for a Healthy Country Flagship, Australia.

Ling FLN, Gupta V, Willis M, Bennett JC, Robinson KA, Paudel K, Post DA and Marvanek S (2009) River modelling for Tasmania. Volume 3: the Pipers-Ringarooma region. A report to the Australian Government from the CSIRO Tasmania Sustainable Yields Project, CSIRO Water for a Healthy Country Flagship, Australia.

Ling FLN, Gupta V, Willis M, Bennett JC, Robinson KA, Paudel K, Post DA and Marvanek S (2009) River modelling for Tasmania. Volume 4: the South Esk region. A report to the Australian Government from the CSIRO Tasmania Sustainable Yields Project, CSIRO Water for a Healthy Country Flagship, Australia.

Ling FLN, Gupta V, Willis M, Bennett JC, Robinson KA, Paudel K, Post DA and Marvanek S (2009) River modelling for Tasmania. Volume 5: the Derwent-South East region. A report to the Australian Government from the CSIRO Tasmania Sustainable Yields Project, CSIRO Water for a Healthy Country Flagship, Australia.

Post DA, Chiew FHS, Teng J, Vaze J, Yang A, Mpelasoka F, Smith I, Katzfey J, Marston F, Marvanek S, Kirono D, Nguyen K, Kent D, Donohue R, Li L and McVicar T (2009) Production of climate scenarios for Tasmania. A report to the Australian Government from the CSIRO Tasmania Sustainable Yields Project, CSIRO Water for a Healthy Country Flagship, Australia.

Viney NR, Post DA, Yang A, Willis M, Robinson KA, Bennett JC, Ling FLN and Marvanek S (2009) Rainfall-runoff modelling for Tasmania. A report to the Australian Government from the CSIRO Tasmania Sustainable Yields Project, CSIRO Water for a Healthy Country Flagship, Australia.

Enquiries

More information about the CSIRO Tasmania Sustainable Yields Project can be found at <www.csiro.au/partnerships/TasSY.html>. This information includes the full terms of reference for the project and all associated reporting products.

More information about the Water for the Future Plan of the Australian Government can be found at <www.environment.gov.au/water>.

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