Comparative Evaluation of Environmental Flow Assessment ... · geomorphological significance through their effects on vegetation growth. Vegetation affects channel morphology by altering

Comparative Evaluation of

Environmental Flow

Assessment Techniques:

R&D RequirementsOccasional Paper No 24/98

Comparative Evaluation

of Environmental Flow

Assessment Techniques:

R&D Requirements

A. H. Arthington

B.J. Pusey

S.O. Brizga

R.O. McCosker

S.E. Bunn

I.O. Growns

CCISR

Published by: Land and Water Resources Research and Development CorporationGPO Box 2182Canberra ACT 2601Telephone: (02) 6257 3379Facsimile: (02) 6257 3420Email: [email protected]: www.lwrrdc.gov.au

© LWRRDC

Disclaimer: The information contained in this publication has been published by LWRRDC to assistpublic knowledge and discussion and to help improve the sustainable management of land,water and vegetation. Where technical information has been prepared by or contributed byauthors external to the Corporation, readers should contact the author(s), and conduct theirown enquiries, before making use of that information.

Publication data: ‘Comparative Evaluation of Environmental Flow Assessment Techniques: R&D Requirements’,Angela H. Arthington, Bradley J. Pusey, Sandra O. Brizga, Robert O. McCosker,Stuart E. Bunn and Ivor O. Growns, LWRRDC Occasional Paper 24/98.

ISSN 132-0992

ISBN 0 642 26743 X

Authors (see page 22 for contact details):Australian Water Technologies Dr Ivor O. Growns

Brizga and Associates Pty Ltd Dr Sandra O. Brizga

Centre for Catchment and In-Stream Professor Angela H. ArthingtonResearch, Griffith University Associate Professor Stuart E. Bunn

Dr Bradley J. Pusey

LANDMAX Robert O. McCosker

The research project ‘Comparative Evaluation of Environmental Flow Assessment Techniques’ has produced the following

four reports.

Arthington, A.H., Pusey, B.J., Brizga, S.O., McCosker, R.O., Bunn, S.E. and Growns, I.O. (1998) Comparative Evaluation ofEnvironmental Flow Assessment Techniques: R&D Requirements. LWRRDC Occasional Paper 24/98. ISBN 0 642 26743 X.

Arthington, A.H., Brizga, S.O. and Kennard, M.J. (1998) Comparative Evaluation of Environmental Flow Assessment Techniques:Best Practice Framework. LWRRDC Occasional Paper 25/98. ISBN 0 642 26744 8.

Arthington, A.H. (1998) Comparative Evaluation of Environmental Flow Assessment Techniques: Review of Holistic Methodologies.LWRRDC Occasional Paper 26/98. ISBN 0 642 26745 6.

Arthington, A.H. and J.M. Zalucki (Eds) (1998) Comparative Evaluation of Environmental Flow Assessment Techniques: Review ofMethods. (Authors – Arthington, A.H., Brizga, S.O., Pusey, B.J., McCosker, R.O., Bunn, S.E., Loneragan, N.,

Growns, I.O. & Yeates, M.) LWRRDC Occasional Paper 27/98. ISBN 0 642 26746 4.

Designed by: Green Words & Images, Canberra

Printed by: Panther Publishing & Printing

December 1998

iii

Contents

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

2. R&D on methods addressing geomorphological issues .................................................................. 2

2.1 Limitations of existing methods ................................................................................................................................... 2

2.2 R&D priorities: Geomorphological issues .................................................................................................................... 4

3. R&D on methods for wetland and riparian vegetation .................................................................. 5

3.1 Wetland vegetation ...................................................................................................................................................... 5

3.1.1 Limitations of existing methods ......................................................................................................................... 5

3.1.2 R&D priorities for flow requirements of wetland vegetation ............................................................................. 5

3.2 Riparian vegetation ...................................................................................................................................................... 6

3.2.1 Limitations of existing methods ........................................................................................................................ 6

3.2.2 R&D priorities for flow requirements of riparian vegetation ............................................................................. 7

4. R&D on methods for freshwater fish ............................................................................................... 8

4.1 Limitations of existing methods ................................................................................................................................... 8

4.2 R&D priorities for flow requirements of fish ................................................................................................................ 9

4.2.1 R&D on ecological issues .................................................................................................................................. 9

4.2.2 Habitat requirements of fish .............................................................................................................................. 9

4.2.3 Fish life history and relationship to hydrology ................................................................................................. 10

4.2.4 Patterns of fish movement and relationship to hydrology ................................................................................ 11

4.2.5 Inter-specific interactions between freshwater fishes and understanding of links between landscape,hydrology and community metabolism ........................................................................................................... 11

5. Influence of river flows on coastal fisheries ................................................................................... 13

5.1 Limitations of existing methods ................................................................................................................................. 13

5.2 R&D priorities: River flows and coastal fisheries ........................................................................................................ 13

5.2.1 Development of predictive models .................................................................................................................. 13

5.2.2 Research on causal mechanisms ....................................................................................................................... 14

6. R&D on methods for invertebrates ................................................................................................ 15

7. R&D priorities to improve holistic methodologies ....................................................................... 17

7.1 Limitations of existing methodologies ........................................................................................................................ 17

7.2 R&D priorities to improve ‘bottom-up’ holistic methodologies ................................................................................. 17

7.3 R&D priorities to improve a ‘top-down’ process of benchmarking against modified flow regimes .............................. 19

7.4 R&D strategy to support the best practice framework ................................................................................................ 21

iv

Appendix: Author contact details....................................................................................................... 22

References ..............................................................................................................................................23

Table and figure

Table 1: Summary of research needs identified for the development of environmental flow allocation methodsfor invertebrates .................................................................................................................................................16

Figure 1: Pressure-State-Response (PSR) curve ...................................................................................................................20

v

List of abbreviations

CRCFE Cooperative Research Centre for Freshwater Ecology

DPI Department of Primary Industries

IFIM In-stream Flow Incremental Methodology

LWRRDC Land and Water Resources Research and Development Corporation

1

1. Introduction

Angela H. Arthington

This report is the final of four arising from the project‘Comparative Evaluation of Environmental FlowAssessment Techniques’ funded by EnvironmentAustralia, the Land and Water Resources Research andDevelopment Corporation (LWRRDC) and theNational Landcare Program. An introduction to theproject is provided in LWRRDC Occasional PaperNumber 27/98 Comparative Evaluation of EnvironmentalFlow Assessment Techniques: Review of Methods(Arthington & Zalucki 1998a).

The objectives of the project are as follows.

1. Review currently used and available techniques forassessing flow requirements, so that water managershave the key information and recommendations onwhich techniques are suitable for which suite ofenvironmental values, their limitations, advantagesand cost-effectiveness.

2. Propose a ‘best practice’ framework for theapplication of techniques to environmental flowassessment.

3. Provide research and development priorities for therefinement, development and integration of thetechniques to facilitate their use in water allocationand water reform.

Reports arising from the project are:

• Comparative Evaluation of Environmental FlowAssessment Techniques: R&D Requirements(Arthington, Pusey, Brizga, McCosker, Bunn &Growns, this report).

• Comparative Evaluation of Environmental FlowAssessment Techniques: Best Practice Framework(Arthington, Brizga & Kennard 1998).

• Comparative Evaluation of Environmental FlowAssessment Techniques: Review of HolisticMethodologies (Arthington 1998).

• Comparative Evaluation of Environmental FlowAssessment Techniques: Review of Methods(Arthington & Zalucki 1998a).

This report is concerned with R&D requirementsand priorities to ensure the refinement, developmentand integration of methods and frameworks to facilitatetheir use in water allocation and water reform. Itpresents two main strands of R&D.

1. R&D required to improve individual methods ofenvironmental flow assessment, based on therecommendations of the reviews contained inLWRRDC Occasional Paper Number 27/98,Comparative Evaluation of Environmental FlowAssessment Techniques: Review of Methods (Arthington& Zalucki 1998a).

2. R&D required to improve existing holisticmethodologies and the proposed best practiceframework for environmental flow assessment.

2

Sandra O. Brizga

2.1 Limitations of existingmethodsThe following summary of methods addressing thedevelopment of flow requirements for geomorphologicalpurposes is taken from Brizga (1998).

In Australia, geomorphological contributions inrelation to the identification of flow requirements forchannel morphology have largely been reported in the‘grey’ literature rather than in peer-reviewed publicationssuch as international scientific journals. This may reflectan implicit attitude to this type of work as an‘application’ of knowledge and methods derived fromother research (eg. impacts of regulation) rather than aresearch field in its own right. This may at least be partlydue to geomorphology’s origins as a science ofdescription and explanation, and discomfort and a lackof protocols within the discipline regarding involvementin management intervention (Brizga 1998).

Much of the geomorphological literature concernedwith relationships between flow and channelmorphology focuses on the identification of a singlerepresentative ‘dominant’ or ‘channel forming’ flowwhich can be used as an input to equations derived fromregime-based engineering approaches. This contrastswith the requirement of environmental flow studies foran understanding of the geomorphological significanceof the full range of flows.

Geomorphological explanations of links betweenflows and channel morphology have been focusedprimarily on the medium to high flow end of thespectrum, on the assumption that flows only affectchannel morphology through erosion and sedimenttransport, and that it is the high flows which have thegreatest potential to erode and transport most of thesediment. However, low flows can be argued to havegeomorphological significance through their effects onvegetation growth. Vegetation affects channelmorphology by altering flow hydraulics and surfaceresistance to erosion, and thus can influence processes oferosion and deposition by altering the effectiveness oflarger flows.

It is widely agreed in the geomorphologicalliterature that river flows have significance for estuarineand coastal systems, and that upstream regulation canlead to considerable impacts in these areas. However,there are no established methodologies for determiningenvironmental flow requirements for geomorphologicalpurposes in estuarine and coastal systems.

A weakness in many environmental flow studies isin the area of hydraulics. Hydraulics provides a criticallink between hydrology and geomorphological processessuch as sediment transport. However, the majority ofenvironmental flow teams have not included anhydraulics expert. Hydraulic information made availablein environmental flow studies is generally limited tosingle points along the river, and the data provided maybe unreliable, resulting in uncertainty in the flowsspecified for geomorphological purposes (eg. flushingflows and entrainment flows).

Considerable benefits could be gained throughcloser integration of hydraulic expertise intoenvironmental flow studies. The use of suitablehydraulic models would provide hydraulic informationthat is reach-based rather than applying only atindividual points along the river. Better hydraulicinputs would allow more detailed and definiteconclusions to be drawn about geomorphologicalprocesses.

No environmental flow regime which makesprovisions for geomorphological purposes has yet beenimplemented in Australia (Brizga 1998). Haworth(1996) pointed out that the flow regime proposed bythe Snowy River Expert Panel is “quite unlike anythingthat has existed before, and therefore the geomorphicresponse may not resemble the pre-impoundmentconditions”. Thus the current status of environmentalflow recommendations in this field is the generation ofhypotheses which are yet to be tested. There is a need toactually implement and monitor an environmental flowregime designed to address geomorphologicalconsiderations, to ensure that it actually fulfils thedesired purpose. Wherever possible (eg. where there isexisting infrastructure), trial releases should be used totest proposed environmental flow regimes.

Carrying out a trial of an environmental flowregime before making a binding commitment is notfeasible in all circumstances (eg. where high flow

2. R&D on methods addressing geomorphologicalissues

3

R&D ON METHODS ADDRESSING GEOMORPHOLOGICAL ISSUES

recommendations are used to constrain the extent ofdevelopment in a catchment, or the nature of newinfrastructure such as the size of gates in a new dam orweir). Therefore it would be desirable to carry outrigorously monitored trials on a range of representativerivers throughout Australia as a scientific study, and touse the results of the trials to evaluate and refinemethodologies.

An important consideration in the design ofmonitoring and evaluation programs is the long lagtimes involved in geomorphological adjustments, whichmay take decades to centuries or even longer. This alsohas implications for the specification of time frames formonitoring and for management adaptation in responseto monitoring outcomes.

Dams and weirs do not only affect the flow regimesof rivers, they also affect sediment delivery processes,because they at least partially obstruct the downstreamflow of sediment. There would appear to be little pointin providing an environmental flow capable of deliveringsediment to an estuary or coastline if the requiredsediment is being trapped in a dam or weirfurther upstream.

Sediment delivery has often been ignored orinadequately addressed in Australian environmental flowstudies, as it generally falls outside the brief for suchstudies. There are at least two reasons why it needs to beaddressed: (1) the long-term implications of reducedsediment delivery to estuaries and coasts; and (2)clearwater erosion is rare downstream of Australian damsbecause floodflows generally only occur as infrequentspills. If flows capable of scouring the bed are releasedon a regular basis (eg. to satisfy environmental flowrequirements for flushing or maintenance flows), there ispotential for clearwater erosion problems to develop ifthere is no ongoing supply of sediment for the riverto scour.

Overseas, some attempts are now being made tobypass sediments around dams and weirs (eg. byinjection of bedload immediately below weirs). Thesuitability of such approaches to Australian river systemsneeds to be assessed.

The role of factors other than flow regulation needsto be taken into account in environmental flow studies.There are few catchments in Australia where the solehuman impact is flow regulation. Generally, flowregulation is one of many factors which may haveaffected a river system. Other factors include clearing,agricultural development, forestry, roads, present andhistorical mining, river and floodplain management, and

urban development. Thus assessments of the impacts ofregulation carried out as part of environmental flowstudies need to determine the significance of flowregulation relative to other factors in terms of producingobserved disturbances, as not all observed changes anddisturbances are flow-related, and the effects of somechanges may cancel out or compensate for flow-relatedimpacts. For example, Brizga and Craigie (1997) foundthat on the Yarra River, although there had been adownward shift in the flood frequency distribution as aresult of water resource development for Melbourne’swater supply, implying reduction in stream power, insituations where the river is confined by levee banks, thereduction in stream power has been compensated byincreases in stream power resulting from theconfinement of flow by levee banks.

Assessments which have been narrowly focused onflow-related issues have been the subject of criticism. Forexample, Haworth (1996) argued that Erskine (1996)paid insufficient attention to the effects of sediment andnutrient inputs from agricultural parts of the catchment,particularly the Monaro Tablelands, in his assessment ofthe impact of the Snowy Mountains Scheme on theSnowy River. In some instances, a narrow focus on flowhas been encouraged in the briefs written forenvironmental flow studies; for example, the TechnicalAdvisory Panels involved in the Queensland WaterAllocation and Management Planning projects haveuntil recently been strongly urged to restrict theirdeliberations to flow-related issues.

Environmental flows are one of a broad suite ofmanagement tools that can be used to maintain andenhance riverine ecosystems. The extent of benefitprovided by an environmental flow may depend onother measures. For example, in the case of theBarron River, it was argued that there was little point inspecifically providing sufficient flow to deliver sedimentto the coast at a rate equal to or greater than the rate atwhich sediment was being removed by coastal processes,unless measures were also taken to make that sedimentavailable downstream of Barron Gorge Weir(Brizga 1997).

4

COMPARATIVE EVALUATION OF ENVIRONMENTAL FLOW ASSESSMENT TECHNIQUES: R&D REQUIREMENTS

2.2 R&D priorities:Geomorphological issuesThe following R&D priorities addressing thedevelopment of flow requirements for geomorphologicalpurposes are taken from Brizga (1998).

1. Development of a checklist of geomorphologicalissues and potential impacts to be considered inenvironmental flow studies would help ensure asystematic approach to environmentalflow assessments.

2. R&D is required to clarify the relationship of thefull range of flows to channel morphology andgeomorphological processes, including low andmedium flows which have hitherto been largelyignored in the geomorphological literature.

3. There is a need to determine whetherenvironmental flows recommended forgeomorphological purposes actually achievetheir objectives.

4. The potential for monitoring to contribute toadaptive management varies. In situations where anew dam or weir is constructed on the basis of anenvironmental flow provision, it is too late to makemajor changes which would require infrastructurealterations. Therefore it is necessary forenvironmental flow trials to be carried out in arange of streams as a research exercise, and theresults documented in detail and disseminated.

5. There is a need to develop a framework andmethods for environmental flow assessment forestuarine and coastal requirements; at present littlehas been done in this area.

6. Studies are required to determine the feasibility ofsediment bypassing dams and weirs, and to developguidelines in relation to this matter. Fieldexperiments would probably be required.

7. The integration of hydraulics, including hydraulicmodelling techniques, into environmental flowstudies needs to be developed.

5

Robert O. McCosker

3.1 Wetland vegetation

3.1.1 Limitations of existing methodsThe following summary of methods addressing thedevelopment of flow requirements for wetland andriparian vegetation is taken from McCosker (1998).

Methods used for assessing flooding requirements ofterminal wetland vegetation are primarily concernedwith determining quantities of water required toinundate a given area. Both the water budget andsatellite imagery approaches have been found to providereasonably accurate estimates in this regard. However,other factors, including timing, duration and frequencyof flooding, are important parameters that should beconsidered for the maintenance of wetland plantcommunities. The normal procedure for estimatingwetland flooding requirements has been to initiallydetermine the volume of water required by applicationof either of the above methods. Timing, duration andfrequency have then been estimated by a combination ofanalysis of historical streamflow records and assessmentof the flooding requirements of certain elements of thewetland biota, most commonly waterbirds.

There is general agreement amongst wetland plantecologists that the suite of plant species present in awetland exist in response to the particular water regimethat has historically prevailed in that wetland. Becausethere is limited published information about the waterregime requirements of specific plant species, thecommon approach has been to recommend restorationof a flooding regime that mimics the natural regime.Unfortunately, no methodology has been formulated forassessing environmental flow requirements of wetlandvegetation that considers all aspects of a water regime.

The techniques described in this review that havebeen used to assess water requirements of terminalwetlands have not been developed to the extent thatthey could be considered formally as methodologies.They are techniques that researchers have trialled in aquest to more confidently predict the quantity of waterrequired to inundate specific wetlands. Because ofunsatisfied demand for water by the irrigation industry

in valleys that contain significant wetlands, the focus hasbeen to determine bulk water requirements of wetlands.Water managers have been required to allocate water forwetlands without eroding the security of entitlement ofextractive water users. Consequently, the primary focushas been on water quantity, with less emphasis ontiming, duration and frequency. Further research isrequired to develop these techniques into methodologiesthat include consideration of other critical aspects ofwater regimes.

Methods for assessing the water regime of floodplainwetlands rely heavily on the availability of reliable long-term hydrological data (including rainfall, evaporationand streamflow) from locations in reasonably closeproximity to the wetlands under examination. Riverheight levels at which wetlands fill can be determined bylocal knowledge, ground survey, or analysis of remotelysensed images. The advantage of utilising localknowledge is the low cost, however, the reliability ofsuch information may be questionable. Conductingground surveys and acquiring a set of satellite imagescan both be quite expensive. However, there is a greaterdegree of confidence in the accuracy of informationgained through these avenues. The advantage of thisessentially desktop methodology for studying the waterregime of floodplain wetlands is that it is cost-effectiveand utilises existing data that are available for mostAustralian rivers.

3.1.2 R&D priorities for flow requirements ofwetland vegetation

1. Techniques for assessing terminal wetland waterrequirements need to be further refined to includeconsideration of water quantity and the timing,duration and frequency of flooding.

2. Existing information on the water regimerequirements (eg. depth, duration, timing andfrequency) of common riverine and wetland plantspecies should be collated. Further research will berequired to fill important information gaps.

3. Building on 2 above, develop a list of indicatorplant species of healthy and degraded rivers andwetlands for different climatic zones in Australia,and document the water regime tolerances ofthese species.

3. R&D on methods for wetland and riparianvegetation

6


4. Techniques for assessing the interaction betweensurface water and groundwater in wetlands need tobe developed.

5. A prescriptive manual that outlines a step-by-stepprocedure for assessing the water regimerequirements of riverine and wetland plantcommunities would be a valuable addition to allenvironmental flow methodologies.

3.2 Riparian vegetation

3.2.1 Limitations of existing methodsThe methods described in McCosker (1998) that havebeen used to determine flow requirements of riparianvegetation along Australian rivers have received limitedapplication and few of the applications have beenreported in the literature. Consideration of riparianvegetation has been a recent addition to environmentalflow assessment methodologies. As yet, there is noprescriptive procedure for assessing the water regimerequirements of riparian vegetation.

Because of the limited understanding of the waterregime requirements of riparian vegetation, theapplication of all available methodologies draws heavilyon the assessment of past and present flow regimes andthe extent to which a modified regime may haveaffected the vegetation (McCosker 1998).Recommendations for environmental flows for riparianvegetation are normally made under the assumptionthat a modified flow regime that mimics the naturalregime will be best for the vegetation.

The Expert Panel (Swales & Harris 1995) andHabitat Analysis (Walter et al. 1994) methods relyprincipally on prior knowledge by the riparianvegetation expert about the riparian vegetationcommunities and the dynamic relationship between thevegetation and hydrology of the river being studied.There is no formal process in either of these techniquesfor the expert to follow and no quantitative studies areundertaken. Predictions about how the riparianvegetation communities may respond to changes in flowregime are based on opinion. The lack of formalprocedure raises questions about the capacity of themethods to be accurately replicated by differentpractitioners in the same river, and/or the samepractitioner in different rivers.

The Expert Panel and Habitat Analysis methods arerelatively cost-effective and can be conducted over a

short time frame. The multidisciplinary nature of thepanel allows a broad ecosystem perspective of the riverto be presented. These methods are useful rapidassessment techniques for providing a ‘snapshot’ of thecondition of the riparian vegetation of a river at aparticular point in time. However, as they do not rely onquantitative analysis, there may be risks in using them asthe basis for making long-term decisions about the flowrequirements of riparian vegetation.

The Building Block Methodology (King & Louw1998) and Flow Restoration Methodology (Arthington& Zalucki 1998b) require much more detailedknowledge of the riparian vegetation community at eachrepresentative site as a basis for makingrecommendations. By conducting a detailed botanicalsurvey at representative sites and recording the locationof species within the channel, the practitioner is forcedto consider the relationship between plant species andstreamflow. Analysis of hydrological data for the siteassists the practitioner to develop an understanding ofkey elements of the flow regime that should be restoredor preserved. Important elements of the flow regimeinclude quantity, timing, rate of rise and fall, duration,peak flows, and return periods (McCosker 1998).

An ability to make accurate predictions about thepotential impact of a modified flow regime on riparianvegetation may require a more detailed understanding ofvegetation and hydrological links than the relationshipbetween vegetation and streamflow. It has been foundthat alluvial groundwater can play a significant role insupplying water to riparian vegetation, particularly insemi-arid environments (Mitsch & Gosselink 1986;Kondolf et al. 1987; Harris 1988) . Research in Australiahas found that river red gums (Eucalyptus camaldulensis)can draw a substantial proportion of their waterrequirements from shallow alluvial aquifers (Bacon et al.1993; Thorburn et al. 1994). Australian applications ofmethods to determine flow requirements of riparianvegetation have largely ignored the role thatgroundwater may play in supplying water to plants inthe riparian zone.

The riparian vegetation along many Australian rivershas been severely altered by clearing, grazing and exoticplant invasion. In many instances the present vegetationbears little resemblance to that which existed beforewhite settlement. This raises questions about the desiredfuture state of vegetation on rivers where riparianvegetation has been substantially altered byanthropogenic factors. Should management aim topreserve the status quo, or attempt to restore the original

7

R&D ON METHODS FOR WETLAND AND RIPARIAN VEGETATION

vegetation structure and floristics? The restoration of anapparently favourable flow regime for riparian vegetationmay be ineffective if factors such as intensive grazingand weed invasion are at play (see McCosker 1998). Theapplication of techniques currently available for assessingenvironmental flow requirements of riparian vegetationmay be placing a disproportionate expectation on riverflows to restore and maintain the vegetation. A greaterunderstanding is required of the interaction betweenfluvial and terrestrial factors in the shaping of riparianplant communities.

A knowledge of the flooding requirements andtolerances and the role that floods play in the life cyclesof individual plant species is required to enableconfident predictions about the long-term response ofvegetation to modified flow regimes. For example,identification of plant species as flood-dependent or flood-tolerant may enable more accurate predictions to bemade about the potential effect of altering a flow regime.Flood-dependent species are likely to be more sensitiveto changes in flow regime than flood-tolerant species,which may thrive in a regulated stream. This is evidentin the Brisbane River below Wivenhoe Dam, where theflood-tolerant weeping bottlebrush (Callistemonviminalis) has extensively colonised shorelines at theregulated flow level. The apparently more flood-dependent river oak (Casuarina cunninghamiana)appears to have received less opportunities forrecruitment following river regulation. The result ofriver regulation in this instance is a trend towards amonoculture of weeping bottlebrush (McCosker 1998).

There is little published information about the waterregime requirements of plant species that commonlyoccur in the riparian zones of Australian rivers. Theexception is river red gums. A body of research has beendirected toward defining the flooding requirements andtolerances of this species (eg. Gomes & Kozlowski 1980;Bren & Gibbs 1986; Chesterfield 1986; Dexter et al.1986; Bren 1987; 1988; 1992; Brewsher et al. 1991;Bacon et al. 1993; Mensforth et al. 1994; Thorburnet al. 1994; Bacon 1996).

Published research on water uptake by black box(Eucalyptus largiflorens) includes papers by Jolley andWalker (1996) and Slavich et al. (in press). Craig et al.(1991) made recommendations about the floodingrequirements of lignum (Muehlenbeckia florulenta) froman examination of the effects of edaphic and flood-related factors on its distribution and abundance on theMurray River floodplain in South Australia.

Raine and Gardiner (1995) provide a valuableaddition to the scant pool of literature on the life historyand habitat preferences of Australian riparian plantspecies. Their report draws on the results of a researchproject designed to promote the use of native vegetationin rehabilitating and managing riparian land. Althoughthe project was based on the coastal rivers of northernNew South Wales, much of the information is applicableto other regions. The report discusses at length the roleof native plants in river and riparian management. Itdescribes the growth habit, any special requirements forgrowth, preferred location within the riparian zone,and requirements for recruitment of many riparianplant species.

Further knowledge about the hydrologicalrequirements of Australian riparian plant species isneeded to enable more accurate predictions regardingin-stream flow requirements of riparian vegetation. Inparticular, we need to place more attention on theinteraction between surface streamflow and groundwaterand the extent to which vegetation draws water fromeach. This aspect of riparian plant ecology has receivedlittle attention in the application of environmental flowassessment methods in Australia.

3.2.2 R&D priorities for flow requirements ofriparian vegetation

1. All existing information about the water regimerequirements and flooding tolerances of plants thatoccur in riparian zones in different regions ofAustralia needs to be collated into asingle publication.

2. Greater knowledge is required of the most suitabletiming, frequency, duration and recession ratesof floods for recruitment and maintenance ofriparian vegetation.

3. A research effort needs to be directed towardassessing the role of groundwater in maintainingriparian plant communities.

4. Improved knowledge is required of the potentialeffectiveness of implementing environmental flowsto rivers where the original riparian vegetation hasbeen substantially altered by clearing, grazing andexotic plant invasion.

5. A prescriptive manual that outlines a step-by-stepprocedure for assessing the water regimerequirements of riparian plant communities wouldbe a valuable addition to all methodologies.

8

Bradley J. Pusey

4.1 Limitations of existingmethodsPusey (1998) has highlighted some of the deficienciesassociated with the methods used in Australia to definethe environmental flow requirements of freshwater fish.Recommendations for future research are made in lightof these deficiencies, and personal research experience inthe fields of environmental flow management and fishecology.

Environmental flow management is, in a real sense,a predictive exercise. The critical question beingaddressed is one of ‘how much water can be harvestedfrom a river without ecological damage?’ Thus waterresource managers are using a knowledge base which hasbeen forced to move from the purely descriptive into apremature predictive phase. The various methodsavailable for assessing environmental flow needs mustthemselves be assessed in light of this problem, inaddition to considerations related to time and cost-effectiveness (Pusey 1998).

The Montana Method (Tennant 1976) and flowduration curve analysis (Stalnaker & Arnette 1976) areobviously rapid mechanisms by which environmentalflows may be defined, and have the added advantage ofnot requiring extensive field observations. However, ashas been previously stated (Richardson 1986;Arthington & Pusey 1993), their application isconstrained by profound uncertainty as to theapplicability of North American criteria to Australiancircumstances. No studies have ever been undertaken tocompare habitat ‘quality’ at different percentile flows,nor to determine how long ecosystems can bemaintained at set levels of flow (eg. 20th percentile flow)without detriment. Thus the use of these rapidhydrological methods cannot be strongly defended. Thatis not to say, however, that flow duration curve analysishas no role in the assessment process; it is necessarily acritical inclusion needed to establish the nature of theflow regime and boundary conditions.

Transect analysis and habitat modelling(ie. PHABSIM or RHYHABSIM) provide moresophisticated mechanisms to establish flow guidelines

and are focused much more strongly on the relationshipbetween flow and habitat. Consequently, they are morelikely to be more relevant to the protection of fishspecies. However, both methods are labour-intensive andtime consuming. Notwithstanding the criticismsdetailed in Pusey (1998) concerning the hydraulic basisof the modelling procedure, their quantitative natureensures that decisions based upon these methods aremore easily defended, provided the information uponwhich habitat criteria are based is rigorously collectedand analysed. Further reliance on these methods doesrequire strong validation of the relationship betweenhabitat structure, habitat use and fish assemblagecomposition, a significant knowledge gap for most areasof Australia.

Expert panel and holistic methodologies vary greatlyin the time and expense required to conduct them.Significant advantages of these techniques are that theyrecognise that the information base is deficient in someareas, that environmental flow decisions must consider arange of taxa other than just fish, and that importantecological processes must also be included.

The Expert Panel Assessment Method (Swales &Harris 1995) may have further utility in the initial phaseof an environmental flow process, particularly inestablishing areas of particular ecological concern.However, it suffers from a lack of defensibility due tothe subjective manner in which different flows areassessed, and a lack of transparency in the manner bywhich assessments are incorporated intorecommendations for a modified flow regime. TheScientific Panel Assessment Method (Thoms et al. 1996)is a significant improvement due to its more holisticoutlook and the fact that the decision-making process isbetter detailed and, to an extent, based on the collectionof quantitative data. An advantage of this method is theconsideration of habitat in an extended spatial hierarchy,such that habitat incorporates such off-stream features asfloodplains rather than habitat in a few supposedlyrepresentative critical reaches.

Holistic methodologies such as the Building BlockMethodology (King & Louw 1998), the HolisticApproach (Arthington et al. 1992a) and the FlowRestoration Methodology (Arthington & Zalucki1998b) seek to be more inclusive and, to differingdegrees, are founded on the development of a strong

4. R&D on methods for freshwater fish

9

R&D ON METHODS FOR FRESHWATER FISH

quantitative basis with relevance to the river in question,and on information on other rivers in the region. Theyare, therefore, more regionally oriented. The workshopcomponent of each is explicit, as are the mechanisms bywhich final flow recommendations are achieved by theparticipants. A significant advantage of these approachesis that they allow for the incorporation of a range ofmethods to address particular issues but, importantly,are not constrained to accept the recommendationsoffered by any one method without an assessment of itsadvantages or disadvantages compared with a range ofother methods and for other components of the riverineecosystem. The ability to include other ecosystemcomponents or processes such as the transfer of carbon isan advantage and increases the defensibility ofholistic approaches.

Tunbridge (1997) believed that there was only onecorrect method for assessing an environmental flowwhich presents a very low level of risk to the biota. Thatmethod required “... the collection of data whichidentifies species present, river hydraulics and structure,water quality, behaviour and biology of the biota andidentification of habitats” followed by “... examinationof the flow regime, identification of critical areas ofhabitat, river or environment that need to be protectedand the identification of factors that act adversely onhabitat useability or directly on biota”. Only then canthe necessary conditions required to protect biota beestablished. Obviously, additional areas of investigationsuch as community metabolism could, and should,be added.

Tunbridge (1997) recognised that this protocolrepresented a full environmental study and that it was anexpensive one in terms of time and money. It wasimportant to recognise, however, that deviation fromthis protocol represented a significant increase in risk tothe biota (Tunbridge 1997).

In conclusion, all of the methodologies orapproaches discussed above and in Pusey (1998) havedeficiencies to a greater or lesser extent. Methods thatare cost-effective and time-effective may ultimately befound to be environmentally expensive, because of aquestionable theoretical underpinning with respect totheir relevance to Australian conditions. Cost-effectiveness needs to be assessed with respect to thelong term rather than the short term.

4.2 R&D priorities for flowrequirements of fish

4.2.1 R&D on ecological issuesThere are seven distinct areas in which insufficientknowledge hampers ability to manage environmentalflows in a sustainable manner as they relate to freshwaterfish. These areas are as follows.

1. An understanding of the habitat requirements ofmany species of fish.

2. An understanding of basic life history and itsrelationship to hydrology for many fish species.

3. An understanding of patterns of fish movement andtheir relationship to hydrology.

4. An understanding and appreciation of the linksbetween freshwater and estuarine systems.

5. An understanding of the processes that governinter-specific interactions between freshwater fishand understanding of links between landscape,hydrology and community metabolism.

6. The absence of clear guidelines available to watermanagers on the day-to-day management of in-stream flows and ability to include flow variabilityin such a process.

7. An almost complete absence of validation ofthe sustainability of prescribed environmentalflow allocations.

It can be seen from this list that nearly all theseproblems are of an ecological nature, specifically, anincomplete ecological understanding. Four of theseseven points are addressed briefly below in relation tothe R&D required to improve assessment of the flowrequirements of freshwater fish. A full account can befound in Pusey (1998). Item 4 above is addressed inSection 5 of this report.

4.2.2 Habitat requirements of fishAll of the in-stream flow methodologies described inPusey (1998) deal in one way or another with therelationship between flow, habitat and fish, yet there isstill a great degree of uncertainty about the habitatrequirements of many of Australia’s freshwater fishes.This is particularly so for northern Australia but is also acharacteristic of south-eastern Australia. A synthesis ofthe ecology of Australia’s freshwater fishes is lacking,although regional variations on this theme have beenproduced, for example, Koehn and O’Connor (1990).

10


Harris and Gehrke (1997) collected data concerning fishdistributions and habitat structure (flow, depth, width,substrate, vegetation, cover, and so on) and thisinformation will be of considerable benefit when fullyanalysed and made available.

Current research undertaken by the Centre forCatchment and In-Stream Research at GriffithUniversity, is focused on defining the macro-habitatand micro-habitat requirements of about 60 species ofQueensland freshwater fishes. Whilst this may appearto be comprehensive, the data are limited in spatialextent, being collected mostly from seven rivers acrossa range of three distinct hydrologies, and limited tofishes occurring in small to medium-sized streams(ie. those efficiently sampled by back-packelectrofishing). Data for abut 55 species need to becollated into a reference manual.

The In-stream Flow Incremental Methodology(primarily the habitat modelling component,PHABSIM), despite its many potential drawbacks, hasbeen used in Australia and will probably increasein usage.

For the In-stream Flow Incremental Methodology tobe useful, the following issues require furtherresearch.1. Complete and publish regional summaries of the

habitat requirements of individual fish species.

2. Determine the relationship between dischargevariability and habitat fidelity or plasticity.Experimental examination of changes in habitat useunder conditions of differing discharge variabilitywill be required.

3. Develop methods to include the availability ofadditional critical habitat elements such as woodydebris or macrophyte beds in the modelling processusing PHABSIM.

4. Establish whether there is any congruence betweena reach’s modelled suitability and the actual biomassor density of fish over a range of river andhydrological types.

5. Explore use of the In-stream Flow IncrementalMethodology modelling package to generate habitatduration curves for individual species at a site. Suchapplications seem intuitively more useful given thatthere is little empirical evidence to suggest a linearrelationship between habitat suitability and fishdensity or biomass as implied by the In-stream FlowIncremental Methodology.

6. Develop methods that allow for the considerationof multi-species assemblages rather than forindividual species (see Arthington et al. 1992b forone approach). The risk assessment approach usedby Davies and Humphries (1995) warrantsfurther development.

7. In-stream Flow Methodology and multiple transectmethods are focused very narrowly on a restrictedrange of habitat types (generally riffles because theyappear to be the most affected by changes in flowvolume). A focus on riffle areas may be moreappropriate in some areas of Australia and types offlow regime (predictable versus unpredictable) thanothers. Information is needed to allow anassessment of the range of habitat types requiringattention in different river systems.

8. A national examination of regional variation indischarge patterns and variability is needed toidentify the characteristics of different river systemsand to provide a guide to the essential flow andhabitat conditions which must remain relativelyunchanged in any modified discharge scenario.

4.2.3 Fish life history and relationship tohydrologyThe definition of critical habitat and flow requirements isvirtually impossible without detailed life historyinformation. The freshwater fish fauna of many parts ofAustralia, particularly northern Australia, is essentiallyunstudied. Life history studies appear limited to thosesouth-eastern species of economic importance or to thosespecies that can be found close to major populationcentres. Few studies have addressed the interactionbetween hydrology and life history. No published studiesexist that compare how life histories vary within species orassemblages in regions of differing flow variability,although such work is under way in some parts of thecountry (eg. Victoria and Queensland).

The investigation of larval fish biology of freshwaterfishes is still in its infancy in Australia. It would seemthat the appropriate management of flows and habitatfor spawning and for larval fishes is a necessaryprerequisite for the management of overall stocks, yetthis aspect remains little studied.

Further examination of the environmental cues thatstimulate spawning is also warranted. Research is neededto distinguish the degree to which floods stimulatespawning and the degree to which floods enhancerecruitment through the provision of greater areas of

11

R&D ON METHODS FOR FRESHWATER FISH

habitat, thereby increasing survivorship. Harris andGerhke (1997) have highlighted the need for a betterunderstanding of the interaction between streamflowand recruitment in order to facilitate better managementof fish stocks.

This information is required in a range of differentriver types and flow regimes.

The R&D priorities are as follows.1. Complete and publish regional summaries of fish

life histories.

2. Determine the environmental cues that stimulatefish spawning using a range of methods (eg. fieldwork, experimental release studies).

3. Determine larval habitat requirements in a range ofdifferent river types and flow regimes.

4. Determine how fish life histories vary withinindividual fish species or fish assemblages in regionsof differing flow variability.

5. Collate existing data on fish population dynamicsin a range of different river types and flow regimesand assess their utility for developing modelspredicting fish abundance and recruitment. Identifyinformation gaps and establish R&D projects todevelop recruitment models for key speciesoccurring in focus catchments with different typesof flow regime around Australia.

4.2.4 Patterns of fish movement and relationshipto hydrologyMigration has traditionally been an area of concern inlarge rivers of south-eastern Australia and has been animportant factor in the environmental flow decisions ofmany of the studies reviewed by Pusey (1998). However,much of this research is limited in taxonomic extentand, even for such apparently important species asgolden perch, the dynamics of this process are still notfully understood (Mallen-Cooper 1996).

Research directed at assessing the efficiency offishways or the ability of fish to negotiate low-level weirshas yielded valuable information on patterns ofmovement. The compilation and synthesis of these datashould be encouraged in order to provide better accessto water managers. Moreover, empirical studies of theswimming abilities of adult and juvenile fishes areneeded (Harris & Mallen-Cooper 1994). Without suchdata, assertions that the passage requirements of onespecies of particular economic value are sufficient to

accommodate most others species (eg. Hogan et al.1997) or all life history stages remain unvalidated.

Migration, for whatever purpose, is an importantprocess in rivers of northern Australia but, with theexception of studies by Bishop et al. (1995), studiesrelated to this area have been limited to assessments ofthe efficiency of fishways (eg. Kowarsky & Ross 1981;Russell 1991; Hogan et al. 1997; Stuart 1997). Thesestudies have, however, revealed important insights intothe degree of movement exhibited by freshwater fishes ofnorthern Queensland. The report of Stuart (1997) onthe efficiency of a vertical slot fishway on the FitzroyRiver is particularly noteworthy, revealing that differentspecies migrate under different flow conditions. Stuartrecommended that fishway design must be able toaccommodate low flow conditions. The QueenslandDepartment of Primary Industries has commenced aninvestigation of fish passage in regulated rivers of thestate and these data will provide very considerableassistance to water managers when the programis completed.

The R&D priorities are as follows.1. Develop regional summaries of the movement and

migration requirements of individual fish species inrivers with different channel morphology and flowregimes. Identify information gaps and establishR&D projects to define movement and migrationrequirements of key species occurring in focuscatchments with different types of flow regimearound Australia.

2. Develop a protocol for assessing fish passagerequirements as part of environmental flow studies.

3. Review and develop methods for restoration/construction of critical reaches required to achievefish passage in regulated rivers.

4. Develop fishway designs to achieve successful fishpassage under the full range of flows likely to berecommended in environmental flow regimes.

4.2.5 Inter-specific interactions betweenfreshwater fishes and understanding of linksbetween landscape, hydrology and communitymetabolismThere has been (and probably will continue to be)considerable debate about the role of biotic factors inthe regulation of freshwater fish communities, and fewAustralian studies have examined fish trophic ecologyfrom a community ecology perspective. The extent of

12


species interactions is of considerable importance inassessing the potential impacts of river regulation. Forexample, most regulation results in an increase in theconstancy and predictability of downstream flows. If thetrophic structure of a fish assemblage occurring in a riverhas evolved under conditions of flow variability and ispresumably characterised by trophic generalism, whatare the expected outcomes of an increase in flowpredictability with respect to species richness andassemblage structure? This question has not beenaddressed in depth in any of the world literature,although it has been alluded to previously(Grossman et al. 1990; Arthington et al. 1992).Experimental evaluation of this problem will proveuseful in predicting the impacts of flow regulation onfish assemblages.

Identification and quantification of the linksbetween fish trophic structure and sources ofproduction, particularly with respect to the importanceof off-stream sources such as floodplains and theirassociated water bodies, will prove a useful aid indefining environmental flow strategies, especially withrespect to the need for and characteristics of largeflushing flows. For example, if it can be shown that themajor role of floodplain inundation with respect toriverine food webs is the transport of terrestrial carbonto the riverine environment and that this occurs rapidly,then the appropriate strategy may be one of a singleshort flood flow. If, however, such transfer occurs slowlyor is mediated by the passage of organisms from theriver to the floodplain and back again, then theappropriate strategy may be one of either multiple ormore prolonged single flood events. The incorporationof flows large enough to result in floodplain inundationis likely to be the most expensive and contentious issuein many environmental flow studies. Therefore it iscritical that the need for such flows be unequivocallydemonstrated and quantified.

The analysis of spatial and temporal patterns ofcommunity metabolism has only recently been appliedto an environmental flow study, but is likely to achievegreater significance in the future. For example, such linesof investigation in rivers in south-western Australia andthe Border Rivers region of south-western Queenslandhave revealed surprising links between in-stream primaryproduction and higher level food webs (S.E. Bunn, pers.comm.). These links are potentially sensitive to changesin flow to the extent that a failure to consider them inany modified flow regime would probably result insignificant and widespread impacts post-regulation.

The R&D priorities for flow-driven floodplainprocesses are as follows.Flow-driven floodplain processes should be addressed ina series of focus catchments selected through aconsultative process involving Environment Australia,water management agencies and relevant researchgroups. Research in a series of focus catchments must becarefully planned to ensure integration of a series oflinked and interacting processes (eg. effects of floodflows on physical habitat structure, the responses ofvegetation, invertebrates and fishes, and consequences interms of key ecosystem processes).

This research should be conducted in unregulatedand minimally disturbed catchments selected to serve asreference areas for comparison with systems that areregulated in various ways and to various degrees. Aresearch strategy in relation to regulated rivers isoutlined in Section 7.3.

13

Stuart E. Bunn

5.1 Limitations of existingmethodsIt is apparent from the review by Bunn et al. (1998) thatvery little quantitative information is available on therelationships between river flows and coastal fisheries,and that this constrains our ability to predict theconsequences of flow regulation for coastal ecosystems.Additional research is required to develop predictivemodels from existing catch and flow data that:

• identify which attributes of the flow regime appear tobe important (this is likely to be species-specific andregion-specific, though generality should be sought);and

• can quantify likely changes to fish stocks (andassociated economic implications) if the flow regimeis altered.

At the same time, research is needed to establish thecausal mechanisms that underlie observed relationshipsbetween flow and catches in order to improve theknowledge base upon which coastal fisheriesare managed.

5.2 R&D priorities: River flowsand coastal fisheries

5.2.1 Development of predictive models

Very little quantitative information on the relationshipsbetween flow and fisheries is available and much of this(eg. from recent flow management studies on the Loganand Fitzroy Rivers in Queensland) should at best beconsidered as preliminary. Further studies are requiredto build on these studies and to extend them to otherriver systems.

A broader geographical coverage of estuarine andcoastal systems is needed and should include:

• temperate south-western Australia, comparingestuaries permanently open to the sea with those thatare periodically or frequently closed;

• temperate south-eastern Australia;

• subtropics (building on work in Moreton Bay);

• wet tropics;

• wet-dry tropics (eg. building on work in the Fitzroyand Gulf of Carpentaria, as well as north-western Australia).

This will capture not only the full range of climaticconditions, flow regimes and habitat types, but also abroad range of target species.

Additional issues arise in estuaries or embaymentswith multiple rivers, where the potential impacts of flowregulation in one river may be offset by maintenance ofnatural flows in the other(s). However, it is possible thatone river may have a disproportional influence oncatches in the embayment, even if it does not dominatethe total run-off. For example, flows from the LoganRiver in south-east Queensland explain more variationin total fish catches in Moreton Bay (Loneragan &Bunn, in press) than do flows from the Brisbane River(Bunn & Loneragan 1998). There may be severalreasons for this, including a more concentrated fishingeffort in the southern bay or greater presence ofjuvenile habitats.

The search for time-lagged effects, which may beindicative of enhanced recruitment or survivorship ofjuveniles through increased productivity, should begiven a high priority. These effects are likely to representreal changes in fish/crustacean population size ratherthan flow-induced variations in catchability. Thepotential additive (or multiplicative) effects of thesefactors must also be resolved.

No attempts have been made in the above studies tolink anomalies in size (age)-frequency data on long-livedspecies to particular flow events that can be associatedwith the cohort (age-class) in question. This couldprovide additional evidence of flow-driven changes inpopulation dynamics and identify the range of flowevents that lead to enhanced (or failed) recruitment.

Little emphasis has been placed on the indirecteffects of river regulation on coastal fisheries throughchanges in coastal geomorphology resulting fromchanges in flow regime and the delivery of sediment.The long-term consequences on the distribution of fishhabitats (eg. mangroves and seagrass beds) and physicaland chemical conditions (eg. in estuaries thatperiodically are closed) should be addressed.

5. Influence of river flows on coastal fisheries

14


In the case of species that make extensive use offresh or brackish water habitats as part of their life cycle(eg. barramundi), the impact of flow diversions(including levee bank construction) on habitatavailability should be quantified.

5.2.2 Research on causal mechanismsThe presence of time-lagged effects in the relationshipbetween flow and catches of certain long-lived species(eg. barramundi) indicates actual variation in populationsize, rather than a simple change in catchability(resulting from increased movement or concentration ofindividuals in particular areas, for example). Tounderstand the implications of flow regulation andeffectively manage stocks of these species, it will beimportant to understand the causal mechanism(s) thatunderlie this flow-driven response.

For example, if recruitment success is linked toavailability of juvenile habitat (eg. floodplain wetlands),is it a consequence of the area of inundation, theduration or perhaps enhanced production of foodsources stimulated by catchment-derived nutrients?Alternatively, is enhanced recruitment the result ofgreater access of adults to spawning sites?

What evidence is there of a transfer of energy fromprimary production (stimulated by high flow andcatchment nutrients) into secondary production incoastal systems? Simple relationships between algalproduction and flow could be examined in the same wayas for fisheries data (as above). Transfer of increasedprimary production into coastal food webs is likely onlyif catchment nutrients stimulate production of palatableforms of benthic or pelagic algae. Under whatconditions (eg. flow, nutrient load and turbidity) doesthis occur? Alternatively, are there particular conditionsunder which production is shifted into unconsumableplant biomass?

The degree to which increases in catchabilityassociated with river flow equate to increases in stockabundance is unclear. Indeed, it may be that duringtimes of high flow, fish stocks are susceptible to over-harvesting as a result of high catchability, and ecologicalsustainability may be threatened at such times.

Further research in this area will provide betterinformation upon which to base principles of coastalfisheries management. It is conceivable that thestrategies of fisheries managers may need to change fromyear to year in response to patterns and magnitudes ofriverine flow, ensuring that fish stocks are not over-exploited during times of vulnerability induced byvariations in riverine flow.

15

Ivor Growns

The research issues and needs identified by Growns(1998) are summarised in Table 1 (page 16). A smallproportion of the information necessary to developenvironmental flow methods for invertebrates is beingaddressed by current research. Some of the research isrequired to further develop some specific methods, suchas the In-stream Flow Incremental Methodology.However, the majority of the research that is required ismore general in nature. This is because there is currentlya lack of information on the specific flow requirementsof the vast majority of invertebrates. Information on theflow requirements of invertebrates would enhance theability of most flow allocation methods to provide flowsfor invertebrate species. Some flow requirements ofinvertebrate species are obvious, such as the currentspeed necessary to maximise the feeding potential offilter feeding animals. However, it is likely that manyflow requirements may be more subtle. For example, theabundance of a population of a species or invertebratecommunity structure may be influenced by flows thatoccurred previously in the river.

6. R&D on methods for invertebrates

16

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17

Angela H. Arthington

7.1 Limitations of existingmethodologiesHolistic methodologies for assessment of environmentalflows may take one of two fundamentally differentapproaches, or may combine both approaches(Arthington 1998; Brizga 1998):

• a bottom-up approach where the environmental flowregime is built up by flows requested for specificpurposes, from a starting point of zero flows;

• a top-down approach where the environmental flowregime is developed by determining the maximumacceptable departure from natural flow conditions.

The review of holistic methodologies currentlyapplied in Australia concluded that construction ofmodified flow regimes using a bottom-up process of theHolistic/Building Block type seems likely to form thebasis of most Australian environmental flow assessmentsinto the foreseeable future (Arthington 1998).

There are several reasons for this. Perhaps the mostimportant is that water managers have generallyaccepted the idea that some features of the ‘natural’ flowregime are more important than others and must bemaintained as environmental flows to protect aquatichabitat, biological ecosystem ‘components’ andecosystem ‘values’. These important flows are beingdefined from the bottom up as low, medium and highflows of various magnitudes and temporal attributes(frequency of occurrence, timing, rate of rise and fall offlood hydrographs, and predictability). All holisticmethodologies in use in Australia aim to construct (or torestore) modified flow regimes using a bottom-upprocess (see Arthington 1998).

Construction of an environmental flow regime in abottom-up, step-wise fashion requires a soundunderstanding of the flow requirements of ecosystem‘components’ and this understanding is limited in manyAustralian catchments. Bottom-up holistic approachesalso depend upon historical flow data for the catchmentand accurate hydrological models with a daily time step.The successful use of the ‘natural’ historical flow regimeas the basis for constructing modified flow regimes will

be limited by the accuracy and precision of hydrologicalmodels and their capacity to simulate extended historicalflow sequences. Furthermore, flow regimes must beanalysed in a consistent manner to describe flow-ecologyrelationships, yet there is no uniformity of approachthroughout Australia. A further significant impedimentis the lack of a suitable, user-friendly computer packagefor the analysis of flow data in ecologically meaningfulways. There are various programs in use within variousresearch groups and agencies, and limited opportunitiesto share expertise.

Environmental flow strategies need to betransformed into day-to-day operating rules for watermanagers, and mechanisms are needed by which flowvariability can be factored into water release strategies toan appropriate degree. The establishment of a processthat directly links operating rules with forecastedweather patterns may be useful in this regard. In orderto be useful, however, the establishment of flowconditions within individual rivers must be shown tobe correlated with such indices as the SouthernOscillation Index.

A phase of monitoring and adjustment of initialenvironmental flow strategies is a key feature of allholistic methodologies. However, there is no setmethodology and spatial/temporal framework forassessing the beneficial outcomes of environmentalflows, and for follow-up adjustments. Interimrecommendations made in good faith by expert panelstend to become final recommendations by default. Apractical process is required to ensure that the outcomesof monitoring are used to achieve adjustments and finetuning of interim environmental flow regimes.

7.2 R&D priorities to improve‘bottom-up’ holisticmethodologiesTo improve the construction of modified flow regimesfrom the bottom up using holistic methodologiesrequires R&D to improve fundamental understandingof flow-driven geomorphological and ecologicalprocesses, and R&D to improve various steps in theholistic process itself. The following prioritiesare suggested.

7. R&D priorities to improve holisticmethodologies

18


1. Considerable R&D is required to improvefundamental understanding of thegeomorphological and ecological processes drivenby flow regimes in a range of river types throughoutAustralia, using focus catchments andmultidisciplinary research teams to ensure adequatecoverage and integration of key issues. R&Dpriorities relating to geomorphology, channelmorphology, sediment processes, wetland andriparian vegetation and fish, and flow-drivenecological processes have been identified above.

2. Research is needed on other issues of importancethat tend to be neglected in environmental flowassessments for want of adequate understandingand suitable assessment methods:

• water and flow requirements of water-dependentvertebrates other than fish;

• flow and water quality relationships;

• surface and groundwater relationships;

• the water requirements of all waterbodies ina catchment.

3. Information on the water and flow requirements ofwater-dependent vertebrates other than fish (frogs,reptiles, waterbirds) should be collated into a seriesof regional documents relevant to river types andflow regimes. Knowledge gaps should be identifiedand R&D commissioned to fill key gaps. Existingreviews of information on platypus (Scott &Grant 1997; Zalucki & Arthington 1998) shouldbe combined with advice on methods for gatheringessential data to support new environmentalflow assessments.

4. R&D is required to support the inclusion offlow-driven water quality processes intoenvironmental flow assessments. An assessment ofexisting methods and water quality models shouldbe commissioned, and a process developed tointegrate water quality assessment and managementinto the proposed best practice framework formanagement of river flows. Some water qualityproblems may need to be addressed throughcatchment management, point-source remediation,and so on.

5. Methodologies are required to ensure that surface-groundwater relationships and the waterrequirements of all waterbodies in a catchment areadequately assessed and incorporated into water

management strategies. These issues may require afundamentally different approach to conventionalenvironmental flow assessment, such as thedevelopment of a water budget for the catchment,and independent but linked consideration offlowing and standing waterbody requirements.

6. Research is needed to assess the sensitivity ofhydrological simulation models to various factorsand processes (eg. how do rainfall run-off modelsrespond to variability in soil infiltration rates; whatare the effects of vegetation clearing, afforestationand different forms of land use on flow regimes indifferent climatic zones; do off-stream storages havea significant effect on flow regimes; are the levels ofaccuracy of simulation models across the full rangeof flows acceptable given their uses inenvironmental flow assessments?).

7. Australia needs a robust Windows-based computerpackage for flow data analysis incorporating a widerange of flow statistics and graphical formats fordisplay of flow characteristics. Work already inprogress in Australia (eg. Cooperative ResearchCentre for Freshwater Ecology, CooperativeResearch Centre for Catchment Hydrology, Centrefor Catchment and In-Stream Research) should bereviewed to define the most suitable statisticalmethods, flow indices and graphical formats. Thecapacity of the Environmental Flows DecisionSupport System (Young et al. 1995) to provide thisanalytical and graphical package should also bereviewed. A new project may need to becommissioned to develop a stand-alone Windows-based computer package accessible to researchgroups, agencies, community groups, and so on.

8. The mechanisms and processes now in use totransform environmental flow strategies intooperational rules for water managers (eg. the use ofenvironmental flow nodes within the IntegratedQuantity Quality modelling framework) should bereviewed, and an acceptable set of processesdeveloped that directly links operating rules withforecasted weather patterns (eg. SouthernOscillation Index).

9. A small workshop is needed to develop a protocolfor monitoring the outcomes and benefits of flowreleases from dams, and of the whole environmentalflow regime at suitable spatial and temporal scales.Monitoring should be linked to the key

19

R&D PRIORITIES TO IMPROVE HOLISTIC METHODOLOGIES

geomorphological and ecological processes to bemaintained by the environmental flow regime, andmeasured using robust, responsive indicators (eg.habitat structure, biological diversity, recruitmentprocesses, P/R ratios).

10. Mechanisms for including a process of adaptiveenvironmental management into flow managementprocedures need to be investigated andimplemented in Australia.

7.3 R&D priorities to improve a‘top-down’ process ofbenchmarking against modifiedflow regimesThe most rigorous approach to holistic environmentalflow assessment is considered to be a combined bottom-up – top-down approach, where an environmental flowregime is initially developed using a bottom-upapproach, and is then evaluated by cross-checkingagainst a top-down assessment incorporating abenchmarking process to assess the ecologicalimplications of various water management andenvironmental flow scenarios (see ComparativeEvaluation of Environmental Flow Assessment Techniques:Best Practice Framework, Arthington et al. 1998).

Benchmarking against levels of degradation in othercatchments with similar types and levels of flowregulation appears to be the strongest top-downapproach in use in Australia. The Environmental FlowsDecision Support System (Young et al. 1995) appears tobe developing a somewhat similar general approach bydeveloping models of flow regulation impacts. However,its focus on the Murray-Darling system and the limitednumber and scope, and possibly the relative simplicity,of the flow-ecology models, may limit its utility as a toolfor use throughout Australia. Certainly, flow-ecologymodels must be developed for different climatic zones,regional river types and flow regimes, and for a range ofkey species and issues. Benchmarking against levels ofdegradation in other catchments is a new approach, andrequires critical evaluation in terms of fundamentalecological issues, the best techniques for assessing riverdegradation, the selection of key flow statistics todescribe and quantify levels of flow regulation, and thedevelopment of models to predict responses to differenttypes and levels of flow regulation.

A focused Australia-wide R&D strategy is requiredto address these topics in a coordinated manner.

The recommended steps in the R&D strategy are asfollows.1. Undertake a national examination of regional

variation in river discharge patterns and variabilityin order to identify river systems with similar flowcharacteristics and flow regimes. Then analyse theextent to which these flow regime types have beenmodified in both unregulated (but modified) andregulated systems, to identify the most importantcategories of change in flow characteristics withineach regional flow category. These flow regimeclassifications would form the basis of a nationalprogram to assess the feasibility of benchmarking indifferent areas of Australia, as part of a nationalapproach to environmental flow assessment usingthe proposed bottom-up – top-down approach.

2. Assemble all existing data sets on the effects of flowregulation on river systems throughout Australia,collating types of river flow regime, types of changein flow regime, types of data available(eg. geomorphology, plants, fish), length of datasets, and reliability of the data. Categorise data setsinto those that report responses to flow regulationalone and those that are confounded by other typesof disturbance (eg. loss of riparian zone functions,presence of barriers to fish migration,water pollution).

3. Commission analyses of the strictly flow-relateddata sets to determine and summarise the types ofresponses of key indicators to flow regulation. Thenrun a workshop to review how each river system hasresponded to flow regulation, and the types ofresponses observed (eg. do river systems changefrom one state of dynamic equilibrium to anotherwhen the flow regime is changed beyond somecritical level, or do some systems respond todisturbance gradually and in a linear fashion(Figure 1)?)

The workshop would address this question for keyecosystem components (geomorphological featuresof rivers, algae, aquatic plants, riparian plants,invertebrates, fish, attributes of water quality). Eachparticipant would present response curves based onkey indicators (eg. fish diversity, an index ofrecruitment, abundance of particular species,proportion of native versus exotic species) and levels

20


of departure from ‘natural’ key flow statistics (eg.size of flows required to trigger spawning, frequencyof riparian, wetland or floodplain inundation). Theworkshop would produce a national summary ofthe impacts of flow regulation on a catchment,regional, state and national spatial scale, andidentify critical knowledge gaps.

4. Use the workshop summary of critical knowledgegaps to establish a coordinated national program tocollect field data and build predictive models ofresponses to flow regulation in regional river typeswith different types of flow regime. Field siteswould be selected to provide a range of levels ofchange in key flow statistics, so that a gradedecological response to flow regulation could bedocumented. This field research and modellingprogram would produce a series of modelsquantifying how much change in key flow statisticsis possible before key ecological indicators reach acritical point. Models could be tested using theAUSRIVAS protocols, that is, by developing eachmodel using a reduced set of sites, and testing itagainst other sites in the same catchment and insites from an adjacent catchment to determine therange of applicability of the model.

Outcomes would have three major uses:(i) identification of changes in flow regimes thathave severe ecological impacts and should never beimplemented in new development schemes;

(ii) identification of the potential impact of flowregulation in new development schemes before anyparticular environmental flow scenario isimplemented; and (iii) identification of the criticalfeatures to be restored in rivers with modified andregulated flow regimes.

5. Models defining critical response curves could thenbe built into the environmental flow nodes ofhydrological models such as Integrated QuantityQuality Model and be used to identify acceptableand unacceptable flow scenarios. Whenunacceptable flow scenarios are identified by sometrigger process built into the Integrated QuantityQuality Model, the next step would be to run aseries of flow scenarios wherein alternative strategiesare tested as a means of providing bothconsumptive and environmental waterrequirements. This approach has been taken inQueensland Water Allocation and ManagementPlanning studies and in the Flow RestorationMethodology. Alternatives might involve differentwater infrastructure, physical interventions todeliver water, provision of critical habitat areas forriverine biota, or fish stocking, and so on.

6. The final stage of the R&D program would be toimplement a series of demonstration flowrestoration projects in focus catchments aroundAustralia with significant problems due to flowregulation and realistic opportunities for flowrestoration. Each case study would be run accordingto a standard format for monitoring and assessingcritical variables related to flow and flow-drivenecological processes. The monitoring andassessment program would be designed todetermine the outcomes of particular changes inkey flow characteristics (described by key flowstatistics) representing the major types of changesbeing made in flow regimes in different areas ofAustralia. Such trials are essential to validate themodels relating change in flow to geomorphologicaland ecological response. The Campaspe RiverProject is an example of this approach.

Figure 1: Pressure-State-Response (PSR)curve

Note: Curve shows the ‘edge of the cliff ’ (arrow) where condition suddenlyand significantly deteriorates as a result of pressure. The thinner lineindicates more gradual deterioration with increasing pressure.

STAT

E

low PRESSURE high

good

bad

21

R&D PRIORITIES TO IMPROVE HOLISTIC METHODOLOGIES

7.4 R&D strategy to support thebest practice frameworkThis study has described a single overarching bestpractice framework for environmental flow assessment(Arthington et al. 1998). The framework presents:

• a structured and systematic methodology fordeveloping environmental flow recommendations,incorporating the three-tiered hierarchyof assessment;

• a process for considering of factors other thanflow which may influence river condition andthe effectiveness of flow allocations andflow management;

• a process for addressing human use and waterinfrastructure constraints in a realistic fashion;

• a phase of social and economic evaluation;

• an ongoing interface with stakeholders;

• a monitoring phase to assess the outcomes andbenefits of environmental flows, plus a phase ofspecial investigations and/or research, with a feedbackloop to ensure that flow management strategies arerevised and adjusted as new information becomesavailable.

Within the framework, environmental flowassessments can be undertaken with various degrees ofscientific rigour. A three-tiered hierarchy of assessment issuggested:

Level 1: Rapid methods for basin-wide assessment ofdevelopment options, or scoping of opportunities torestore environmental flows in rivers with modified flowregimes.

Level 2: Holistic assessment of flow requirements atsub-catchment scale.

Level 3: Quantitative assessments at any scale, plusspecial investigations and research.

A standard but flexible best practice framework forenvironmental flow assessments in Australia would haveseveral advantages. The most obvious is that outcomesfrom many case studies would be amenable tocomparison of outcomes in many different catchmentsand types of flow environments around Australia.Regional principles for river flow management might beexpected to emerge, and any such principles wouldstrengthen basin-wide assessments and other rapidassessment processes based on less rigorous methods.

The following R&D strategy is recommended tosupport the best practice framework.1. A combined bottom-up – top-down approach

should be incorporated into existing holisticmethodologies used in Australia (eg. ScientificPanel Assessment Method, Flow RestorationMethodology), and at least considered as anelement of the Environmental Flows DecisionSupport System (Young et al. 1995), by adaptingand improving the benchmarking methodsdeveloped in Queensland.

2. Several trials of these combined bottom-up – top-down approaches should be run in association withexisting holistic methodologies.

3. These trials should be evaluated to determine thefeasibility and utility of developing a standardmethodology and prescriptive approach forAustralian environmental flow assessments.

4. The trials should be run within the broaderstructure of the proposed best practice framework,and the utility of the best practiceframework evaluated.

5. If appropriate, the best practice framework, thethree-tiered hierarchy for environmental flowassessment and the most useful combinedbottom-up – top-down approach, and any otheruseful innovations, should be developed into a setof standard procedures for routine applicationin Australia.

22

Appendix

Author contact detailsProfessor Angela H. ArthingtonCentre for Catchment and In-Stream ResearchGriffith UniversityNathan Qld 4111Telephone: (07) 3875 7403Facsimile: (07) 3875 7615Email: [email protected]

Dr Sandra O. BrizgaBrizga and Associates Pty LtdPO Box 68Clifton Hill Vic 3068Telephone: (03) 9859 7403Facsimile: (03) 9482 6885Email: [email protected]

Associate Professor Stuart E. BunnCentre for Catchment and In-Stream ResearchGriffith UniversityNathan Qld 4111Telephone: (07) 3875 7402Facsimile: (07) 3875 7615Email: [email protected]

Dr Ivor O. GrownsAustralian Water TechnologiesPO Box 1357Albury NSW 2640Telephone: (02) 6058 3878Facsimile: (02) 6058 3888Email: [email protected]

Robert O. McCoskerLANDMAX19 Bell StreetKangaroo Point Qld 4169Telephone: (07) 3217 4348Facsimile: (07) 3392 2672Email: [email protected]

Dr Bradley J. PuseyCentre for Catchment and In-Stream ResearchGriffith Universityc/– DPI FisheriesKennedy HighwayWalkamin Qld 4111Telephone: (07) 4092 9924Facsimile: (07) 4093 3903Email: [email protected]

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Arthington, A.H. (1998). Comparative Evaluation ofEnvironmental Flow Assessment Techniques: Review ofHolistic Methodologies. LWRRDC Occasional PaperNo. 26/98. (LWRRDC: Canberra.)

Arthington, A.H., S.O. Brizga and M.J. Kennard(1998). Comparative Evaluation of EnvironmentalFlow Assessment Techniques: Best Practice Framework.LWRRDC Occasional Paper No. 25/98.(LWRRDC: Canberra.)

Arthington, A.H., J.M. King, J.H. O’Keeffe, S.E. Bunn,J.A. Day, B.J. Pusey, D.R. Blühdorn andR. Tharme. (1992a). Development of an holisticapproach for assessing environmental flowrequirements of riverine ecosystems. In Proceedingsof an International Seminar and Workshop on WaterAllocation for the Environment. (Eds J.J. Pigram andB.P. Hooper.) pp. 69–76. (Centre for Water PolicyResearch, University of New England: Armidale.)

Arthington, A.H., D.L. Conrick and B.M. Bycroft.(1992b). Environmental Study: Barker-BarambahCreek. Volume 2. Scientific Report: Water Quality,Ecology and Water Allocation Strategy. 457 pp.Report for the Water Resources Commission,Queensland Department of Primary Industries.(Centre for Catchment and In-Stream Research,Griffith University: Brisbane.)

Arthington, A.H. and B.J. Pusey. (1993). In-stream flowmanagement in Australia: Methods, deficienciesand future directions. Australian Biologist 6: 52–60.

Arthington, A.H. and J.M. Zalucki. (Eds) (1998a).Comparative Evaluation of Environmental FlowAssessment Techniques: Review of Methods.LWRRDC Occasional Paper No. 27/98.(LWRRDC: Canberra.)

Arthington, A.H. and J.M. Zalucki. (Eds) (1998b).Environmental Flow Requirements of the BrisbaneRiver Downstream from Wivenhoe Dam. 760 pp.Final Report to the South East Queensland WaterBoard. (Centre for Catchment and In-StreamResearch, Griffith University: Brisbane.)

Bacon, P. (1996). Relationship Between Water Supply,Water Quality and the Performance of Eucalyptuscamaldulensis in the Macquarie Marshes of NSW.Report for the Macquarie Marshes Unit.(NSW Department of Land and WaterConservation: Dubbo.)

Bacon, P.E., C. Stone, D.L. Binns, D.J. Leslie andD.W. Edwards. (1993). Relationships betweenwater availability and Eucalyptus camaldulensisgrowth in a riparian forest. J Hydrol 150: 541–61.

Bishop, K.A., R.W. Pidgeon and D.J. Walden. (1995).Studies on fish movement dynamics in a tropicalfloodplain river: Prerequisites for a procedure tomonitor the impacts of mining. Aust J Ecol20: 81–107.

Bren, L.J. (1987). The duration of inundation in aflooding river red gum forest. Aust For Res17: 191–202.

Bren, L.J. (1988). Flooding characteristics of a riparianred gum forest. Aust For 51: 57–62.

Bren, L.J. (1992). Tree invasion of an intermittentwetland in relation to changes in the floodingfrequency of the River Murray, Australia.Aust J Ecol 17: 395–408.

Bren, L.J. and N.L. Gibbs. (1986). Relationshipsbetween flood frequency, vegetation andtopography in a river red gum forest.Aust For Res 16: 357–370.

Brewsher, A., D.J. Macleod, R.I. Francis, J. Tilleard andR. Elphinstone. (1991). Water Management of theBarmah-Millewa Forests. Proceedings of theInternational Hydrology and Water ResourcesSymposium, Perth. pp. 880–885. (Institution ofEngineers: Barton, ACT.)

Brizga, S.O. (1997) Barron River WAMP: TheGeomorphology of the Barron Delta – Implications forEnvironmental Flow Requirements. FinalDraft Report for Department of Natural Resources,Queensland. (S. Brizga & Associates Pty Ltd:Melbourne.)

References

24


Brizga, S.O. (1998). Methods addressing flowrequirements for geomorphological purposes. InComparative Evaluation of Environmental FlowAssessment Techniques: Review of Methods.(Eds A.H. Arthington and J.M. Zalucki.)pp. 8–46. LWRRDC Occasional Paper No. 27/98.(LWRRDC: Canberra.)

Brizga, S.O. and N.M. Craigie (1997). FluvialGeomorphology of the Yarra River. Report forMelbourne Water Corporation. (S. Brizga &Associates Pty. Ltd: Melbourne.)

Bunn, S.E. and N.R. Loneragan. (1998). River flowsand estuarine ecosystems. In Environmental FlowRequirements of the Brisbane River Downstream fromWivenhoe Dam. (Eds A.H. Arthington andJ.M. Zalucki.) pp. 461–482. Final Report to theSouth East Queensland Water Board. (Centre forCatchment and In-Stream Research, GriffithUniversity: Brisbane.)

Bunn, S.E., N.R. Loneragan and M. Yeates (1998).The influence of river flows on coastal fisheries.In Comparative Evaluation of Environmental FlowAssessment Techniques: Review of Methods. (EdsA.H. Arthington and J.M. Zalucki.) pp. 106–114.LWRRDC Occasional Paper No. 27/98.(LWRRDC: Canberra.)

Burgess, G.K. and T.L. Vanderbyl. (1996). HabitatAnalysis Method for determining environmentalflow requirements. In Water and the Environment.Proceedings of the 23rd Hydrology and WaterResources Symposium, Hobart. pp. 203–206.(Institution of Engineers: Barton, ACT.)

Chesterfield, E.A. (1986). Changes in the vegetation ofthe river red gum forest at Barmah, Victoria.Aust For 49: 4–15.

Craig, A.E., K.F. Walker and A.J. Boulton. (1991).Effects of edaphic factors and flood frequency onthe abundance of lignum (Muehlenbeckia florulentaMeissner) (Polygonaceae) on the River Murrayfloodplain, South Australia. Aust J Bot39: 431–443.

Davies, P.E. and P. Humphries. (1995). AnEnvironmental Flow Study of the Meander,Macquarie and South Esk Rivers, Tasmania. 151 pp.Report to the National Landcare Program.(Tasmanian Inland Fisheries: Hobart.)

Dexter, B.D., H.J. Rose and N. Davies. (1986). Riverregulation and associated forest managementproblems in the River Murray red gum forests.Aust For 49: 16–27.

Erskine, W.D. (1996). Geomorphic input to thedetermination of environmental flows on the SnowyRiver below Jindabyne Dam. In Expert Panel (1996)Environmental Flow Assessment of the Snowy Riverbelow Jindabyne Dam. pp. 37–50. Report for theSnowy Genoa Catchment ManagementCommittee. (Centre for Water Policy Research,University of New England: Armidale.)

Gomes, A.R.S. and T.T. Kozlowski. (1980). Effects offlooding on Eucalyptus camaldulensis and Eucalyptusglobulus seedlings. Oecologia 46: 139–142.

Grossman, G.D., J.F. Dowd and M.C. Crawford.(1990). Assemblage stability in stream fishes: Areview. Environmental Management 14: 661–671.

Growns, I.O. (1998). Methods addressing theenvironmental flow requirements of aquaticinvertebrates. In Comparative Evaluation ofEnvironmental Flow Assessment Techniques: Review ofMethods. (Eds A.H. Arthington, and J.M. Zalucki.)pp. 115–140. LWRRDC Occasional PaperNo. 27/98. (LWRRDC: Canberra.)

Harris, J.H. and P.C. Gehrke. (Eds) (1997). Fish andRivers in Stress: the NSW Rivers Survey. 298 pp.(NSW Fisheries Office of Conservation: Cronulla.)

Harris, J.R. (1988). Demography of Australian bass,Macquaria novemaculeata (Perciformes:Percichthyidae) in the Sydney Basin. Aust J MarFreshw Res 39: 355–369.

Harris, J.H. and M. Mallen-Cooper. (1994). Fishpassage development in the rehabilitation offisheries in mainland south-eastern Australia.In: Rehabilitation of Freshwater Fisheries.(Ed I. Cowx.) pp. 185–193. (Fishing NewsBooks: Oxford.)

Haworth, R. (1996). Comments on the geomorphicinput of the expert panel environmental flowassessment of the Snowy River below JindabyneDam. In Review of the ‘Expert Panel’ Process as aMechanism for Determining Environmental Releases.12 pp. Report for the Snowy Mountains Hydro-Electric Authority. (Centre for Water PolicyResearch, University of New England: Armidale.)

25

REFERENCES

Hogan, A., P. Graham and T. Vallance. (1997). Re-designof the Clare Weir Fishway: Identification of FishMovement. 11 pp. Report to the QueenslandDepartment of Natural Resources.

Jolley, I.D. and G.R. Walker. (1996). Is the field wateruse of Eucalyptus largiflorens F. Muell. affected byshort-term flooding? Aust J Ecol 21: 173–183.

King, J.M. and D. Louw. (1998). Instream flowassessments for regulated rivers in South Africausing the Building Block Methodology. AquaticEcosystem Health and Restoration. 19 pp.

Koehn, J.D. and W.G. O’Connor. (1990). BiologicalInformation for Management of Native FreshwaterFish in Victoria. 165 pp. (Victorian Department ofConservation and Environment: Melbourne.)

Kondolf, G.M., J.W. Webb, M.J. Sale and T. Felando.(1987). Basic hydrologic studies for assessingimpacts of flow diversions on riparian vegetation:Examples from streams of the eastern SierraNevada, California, USA. EnvironmentalManagement 11: 757–769.

Kowarsky, J. and A.H. Ross. (1981). Fish movementupstream through a central Queensland (FitzroyRiver) coastal fishway. Aust J Mar Freshw Res32: 93–109.

Loneragan, N.R. and S.E. Bunn. (in press). River flowsand estuarine ecosystems: Implications for coastalfisheries. Aust J Ecol.

Mallen-Cooper, M. (1996). Fishways and Freshwater FishMigration in South-Eastern Australia. 377 pp.plus appendices. PhD Thesis. (University ofTechnology: Sydney.)

McCosker, R.0. (1998). Methods addressing the flowrequirements of wetland, riparian and floodplainvegetation. In Comparative Evaluation ofEnvironmental Flow Assessment Techniques: Review ofMethods. (Eds A.H. Arthington and J.M. Zalucki.)pp. 47–65. LWRRDC Occasional Paper No. 27/98.(LWRRDC: Canberra.)

Mensforth, L.J., P.J. Thorburn, S.D. Tyerman and G.R.Walker. (1994). Sources of water used by riparianEucalyptus camaldulensis overlying highly salinegroundwater. Oecologia 100: 21–28.

Mitsch, W.J. and J.G. Gosselink. (1986). Wetlands.(Van Nostrand Reinhold: New York.)

Pusey, B.J. (1998). Methods addressing the flowrequirements of fish. In Comparative Evaluation ofEnvironmental Flow Assessment Techniques: Review ofMethods. (Eds A.H. Arthington and J.M. Zalucki.)pp. 66–105. LWRRDC Occasional PaperNo. 27/98. (LWRRDC: Canberra.)

Raine, A.W. and J.N. Gardiner. (1995). Rivercare –Guidelines for Ecologically Sustainable Managementof Rivers and Riparian Vegetation. LWRRDCOccasional Paper No. 03/95. (LWRRDC:Canberra.)

Richardson, B.A (1986). Evaluation of in-stream flowmethodologies for freshwater fish in New SouthWales. In Stream Protection: The Management ofRivers for Instream Uses. (Ed I.C. Campbell.)pp. 143–167. (Water Studies Centre, ChisholmInstitute of Technology: Victoria.)

Russell, D.J. (1991). Fish Movements through a fishwayon a tidal barrage in subtropical Queensland river.Proc Roy Soc Qld 101: 109–118.

Scott, A. and T. Grant (1997). Impacts of watermanagement in the Murray-Darling Basin on theplatypus (Ornithorhynchusanatinus) and the waterrat (Hydromys chrysogaster). Unpublished report.

Slavich, P.G., G.R. Walker, I.D. Jolley, T.J. Hatton andW.R. Dawes. (in press) Dynamics of Eucalyptuslargiflorens growth and water use in response tomodified watertable and flooding regimes on asaline floodplain. J Hydrol.

Stalnaker, C.B. and S.C. Arnette. (1976). Methodologiesfor the Determination of Stream Resource FlowRequirements: An Assessment. 199 pp. (US Fish andWildlife Service, Office of Biological Services,Western Water Association: Washington DC.)

Stuart, I.G. (1997). Assessment of a Modified Vertical-slotFishway, Fitzroy River, Queensland. 82 pp. Report tothe Queensland Department of Primary Industries,October 1997. Q097023.

Swales S. and J. Harris. (1995). The Expert PanelAssessment Method (EPAM): A new tool fordetermining environmental flows in regulatedrivers. In The Ecological Basis for River Management.(Eds D. Harper and A. Ferguson.) pp. 125–134.(John Wiley and Sons Ltd: London.)

26


Tennant, D.L. (1976). Instream flow regimens for fish,wildlife, recreation and related environmentalresources. Fisheries 1: 6–10.

Thoms M.C., F. Sheldon, J. Roberts, J. Harris andT.J. Hillman. (1996). Scientific Panel Assessment ofEnvironmental Flows for the Barwon-Darling River.161 pp. Report for the New South WalesDepartment of Land and Water Conservation.(New South Wales Department of Land and WaterConservation: Sydney.)

Thorburn, P.J., L.J. Mensforth and G.R. Walker.(1994). Reliance of creek-side river red gums oncreek water. Aust J Mar Freshw Res 45: 1439–1443.

Tunbridge, B.R. (1997) Environmental Flows: Review ofthe Environmental Flow Methodology used by theFreshwater Ecology Section – Including Comparisonwith United States Instream Flow Methodology.22 pp. Report for the Victorian Department ofNatural Resources and Environment.

Walter, A.C., G.K. Burgess and P.J. Johnston (1994).Assessment of a process for determiningenvironmental flows. In Environmental FlowsSeminar Proceedings. pp. 195–201. (AWWA Inc.:Artarmon.)

Young, W.J., J.R. Davis, K.H. Bowmer and P.G. Fairweather (1995). The Feasibility of aDecision Support System for Environmental Flows.Final Report to Murray-Darling BasinCommission. CSIRO Division of Water Resources,Consultancy Report No. 95/19. (CSIRO Divisionof Water Resources: Canberra.)

Zalucki, J.M. and A.H. Arthington (1998). Habitatand flow requirements of the platypus. InEnvironmental Flow Requirements of the BrisbaneRiver Downstream from Wivenhoe Dam. (Eds A.H.Arthington and J.M. Zalucki.) pp. 443–459. FinalReport to the South East Queensland Water Board.(Centre for Catchment and In-Stream Research,Griffith University: Brisbane.)

Comparative Evaluation of Environmental Flow Assessment ... · geomorphological significance through their effects on vegetation growth. Vegetation affects channel morphology by altering

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