Framework for Prioritising Waterways for Management in Western Australia

Framework for prioritising waterways for management in Western Australia

Centre of Excellence in Natural Resource Management University of Western Australia May 2011

Report no. CENRM120

Centre of Excellence in Natural Resource Management University of Western Australia Unit 1, Foreshore House, Proudlove Parade Albany Western Australia 6332 Telephone Facsimile
+61 8 9842 0837 +61 8 9842 8499 www.cenrm.uwa.edu.au

This work is copyright. You may download, display, print and reproduce this material in unaltered form only (retaining this notice) for your personal, non-commercial use or use within your organisation. Apart from any use as permitted under the Copyright Act 1968, all other rights are reserved. Requests and inquiries concerning reproduction and rights should be addressed to the University of Western Australia. Reference: Macgregor, C., Cook, B., Farrell, C. and Mazzella, L. 2011. Assessment framework for

prioritising waterways for management in Western Australia, Centre of Excellence in Natural

Resource Management, University of Western Australia, Albany.

ISBN: 978-1-74052-236-6

Front cover credit: Bremer River, Eastern South Coast bioregion in May 2006, looking downstream by Geraldine Janicke.

Disclaimer

This document has been prepared by the Centre of Excellence in Natural Resource Management, University of Western Australia for the Department of Water, Western Australian. Any representation, statement, opinion or advice expressed or implied in this publication is made in good faith and on the basis that the Centre of Excellence in Natural Resource Management and its employees are not liable for any damage or loss whatsoever which may occur as a result of action taken or not taken, as the case may be in respect of any representation, statement, opinion or advice referred to herein. Professional advice should be obtained before applying the information contained in this document to particular circumstances.

Acknowledgements

This project was funded by the Natural Heritage Trust and the National Action Plan for Salinity and Water Quality. The report was prepared by Colin Macgregor, Barbara Cook and Claire Farrell from the Centre of Excellence in Natural Resource Management at the University of Western Australia and Lisa Mazzella from the Department of Water. In-kind contributions were gratefully received from natural resource management (NRM) organisations Perth NRM Incorporated, Wheatbelt NRM Incorporated, Northern Agricultural Catchments Council, South West Catchments Council, South Coast NRM Incorporated and the Rangelands NRM Coordinating Group represented on the Technical Reference Group and the steering committee. The following people are acknowledged for their assistance and support during the project: Verity Klemm and Tim Storer (Department of Water).

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Contents

Summary..................................................................................................................... v

Backgroun d .................................................................................................................................. v The assessment proces s ............................................................................................................. v Case studies...............................................................................................................................viii

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

2 Elements of the framework .....................................................................................5

3 Values, indicators and measure s ..........................................................................2 0

3.1 Ecological values..............................................................................................................2 0 3.2 Social values ....................................................................................................................2 7 3.3 Economic values ..............................................................................................................3 2

4 Threats, indicators and measure s .........................................................................3 6

5 Case studies .........................................................................................................4 4

5.1 Subcatchment scale: Fortescue River (low quality data).................................................4 4 5.2 Reach scale: Marbellup Brook (high quality data )...........................................................6 5 5.3 Reach scale: Berkeley River (low quality data) ...............................................................7 3 5.4 Catchment scale: South Coast region (high quality data) ...............................................8 0

6 General comments and conclusion s .....................................................................9 6 Appendix A Appendix B
Contacts...........................................................................................9 7 Recommended GIS datasets and other sources of information.......9 9

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Shortened forms......................................................................................................1 11 Glossar y ..................................................................................................................1 13 References and further reading...............................................................................1 15

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Framework for prioritising waterways in Western Australia

Summary

Background

Based on an asset-threat management approach, and taking into account state and national developments in waterway prioritisation, the Centre of Excellence in Natural Resource Management at the University of Western Australia on behalf of the Department of Water has developed a framework for prioritising waterways for management in Western Australia.

The framework provides a consistent and transparent approach to setting priorities for management. It ranks waterways in terms of their ecological, social and economic values and also according to their level of threat, and based on these rankings, classifies these waterways into broad categories. Appropriate management responses for each of these categories are proposed.

The framework can be used at scales ranging from whole catchments down to individual reaches of a waterway. It can be used in situations where data is limited or plentiful, and of both a qualitative or quantitative nature. It also recognises that some natural resource management regions already have processes for prioritising waterways for management, and is thus designed to incorporate and complement all previous and present waterway prioritisation and assessment initiatives undertaken by government agencies and regional bodies in Western Australia.

The assessment process

The assessment approach is based on a framework of values, criteria, indicators and measures. Three broad categories of values are proposed – ecological, social (including cultural) and economic. For each of these values, a number of criteria are defined. For example, ecological value is determined using the criteria of naturalness, representativeness, diversity, rarity and special features. For each of these criteria, a number of indicators are proposed, and for each indicator, a number of possible measures are suggested. All waterway units in an assessment are scored for each indicator and measure on a scale of 1 to 3, where a higher rating represents a greater contribution to the value of that waterway unit. Indicators with more than one measure are scored by taking the mean value of these measures. For each criterion, the indicator scores are added together to derive a total score for that criterion, and scores are then standardised by scaling to 100 or 1.0. The assessment process would proceed as follows:

Identify the purpose of the assessment. Select an appropriate scale (choosing the size of the waterway units to be assessed, such as catchment, subcatchment or reach).

Identify the values of the waterway units, and the criteria, indicators and measures to be used to assess them.

Identify the threats to the waterway units and the indicators and measures to be used to assess them.

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Summary

Rank the waterway units according to their values and threats.

Place the waterway units on a ‘values–threats’ prioritisation matrix and use

their position on this to assign priorities. Identify the appropriate management responses.
The framework includes 10 threatening processes. These are: riparian zone degradation erosion and sedimentation eutrophication and deoxygenation inappropriate fire regimes pollution introduced animal and plant species salinisation and waterlogging acidification flow alteration In-stream habitat destruction and fragmentation.
A number of possible indicators and measures are proposed for each of these processes. The level of threat to waterway units is assessed by rating each threatening process on a scale of 1 to 3, where a rating of 3 represents a high level of threat, and a rating of 1 indicates a low level of threat.

Value scores are located against threat scores on the values–threats prioritisation matrix for each waterway unit (Figure 1). Values and threatening processes are

classified as being ‘high’, ‘medium’ or ‘low’, resulting in nine possible categories in the matrix. Three of these categories were classified as requiring ‘Priority 1’

responses, two categories were classified as requiring Priority 2 responses, and the remaining four categories were classified as requiring Priority 3 management responses.

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Summary

Values

High

Medium

Low

High value, high threat (HV/HT)
Medium value, high threat (MV/HT) Priority 2
Low value, high threat (LV/HT)

Priority 1

Priority 3

High value, medium threat
Medium value, medium threat
Low value, medium threat
(HV/MT) Priority 1
(MV/MT) Priority 2
(LV/MT) Priority 3

High value, low Medium value,

Low value, low

threat (LV/LT)

threat

low threat

(MV/LT) Priority 3
(HV/LT)

Priority 1

Priority 3

Figure 1 Values – threats prioritisation matrix

Once priorities have been assigned to each waterway unit, the appropriate management response can be chosen. The framework proposes a choice of seven general management responses. Table 1 lists the responses appropriate to each combination of value and threat, and Table 2 gives the goals of these responses and a brief description of them.

Table 1 Generalised management responses for value – threat combinations

Primary

Sub-priority level

Main management responses

priority level

111223333
1a HV/HT 1b HV/MT 1c HV/LT 2a MV/HT 2b MV/MT 3a MV/LT 3b LV/HT 3c LV/MT 3d LV/LT
Secure, stabilise, restore Secure, maintain, restore Monitor, secure, maintain Stabilise, contain, restore Contain Stabilise, restore Stabilise, contain, adapt Contain, adapt Adapt

HV = high value, MV = medium value, LV = low value HT = high threat, MT = medium threat, LT = low threat

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Summary

Table 2 Goals and descriptions of management responses

Goal

Management

response

To fully protect waterways values

Secure

of such importance that action is needed to

fully protect environmental, social and economic values

Maintain

Restore prevent deleterious alteration to existing waterway condition, practices and standards

To improve waterway health

To manage degradation reinstate specific values, conditions, standards or practices

Stabilise Contain Adapt halt degradation processes limit degradation processes

To manage function

accept that the waterway is highly degraded,

identify the functions still operational and manage those functions

To identify possible future threats
Monitor conduct regular assessments of water quality and riparian condition to identify emerging threats if and when they arise

Case studies

Four trials at different scales and with different quality data were carried out to assess the effectiveness of the framework over the range of situations it was intended to handle.

The four case studies were: a subcatchment scale trial of the Fortescue River in the Pilbara Region using secondary data from desktop sources available from the Internet and published documents (this considered ecological, social and economic values)

at a catchment scale, an ecological assessment of the major waterways in the South Coast region using high-quality primary data (this only considered ecological values)

at a catchment scale, an assessment of the Berkeley River in the north-east Kimberley exploring the potential for assessment where only minimal data was available (this considered ecological, social and economic values)

a reach scale assessment of the Marbellup Brook involving high-quality primary ecological and social data (this also considered ecological, social and economic values).

The trials showed that the framework was able to be used successfully in all the situations for which it was intended.

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Introduction

1 Introduction

1.1 Background

The Department of Water has determined that there is insufficient data on water quality and riparian vegetation condition to make comprehensive, objective assessments of waterway health in Western Australia. Waterways are defined in this report as rivers (including creeks, brooks and streams) and their floodplains, estuaries, inlets, coastal lagoons, reservoirs and broad, flat and undefined systems that flow intermittently. Waterways may also include wetland systems that overflow into rivers (Department of Water 2008a). In many parts of the state, a comprehensive assessment of the values and condition of, and threats to, waterway ecosystems has not been undertaken (Department of Water 2004), although for