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QUARTERLY OUTCOMES NEWSLETTER | JANUARY– MARCH 2020

LACHLAN RIVER MONITORING, EVALUATION AND RESEARCH

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LACHLAN RIVER MONITORING, EVALUATION AND RESEARCH

Welcome to the March 2020 quarterly newsletter of the Lachlan Monitoring, Evaluation and

Research (MER) Program. This newsletter forms part of the reporting activities undertaken in

the Lachlan river system under the MER Program and provides a regular update on our moni-

toring activities and observations.

In this issue we put a spotlight on our fish community monitoring which occurs each year in

early Autumn. We then take a look at the weather conditions we’ve experienced in the

catchment during the quarter we well as the volumes that have been flowing down the river.

We provide an update on our fish community monitoring field trip and the progress of our

research project on monitoring reedbeds in the Cumbung Swamp. Finally, in our latest instal-

ment of the Lachlan Diaries, Adam Kerezsy introduces us to one very pretty, small and endan-

gered fish which is found in Brewster Weir Pool.

We hope you enjoy the read!

The Lachlan MER Team

Lake Brewster Weir Pool (Photo: Mal Carnegie)

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INDICATOR SPOTLIGHT

Fish Community Monitoring

Autumn is fish community monitoring time for the

Lachlan MER team. Why autumn? Well most of the

native fish spawn in the second half of the year, so by

the following autumn the offspring are large enough to

be captured using standard fish capture techniques,

but small enough so that they can be identified as

young-of-year.

Juvenile Murray cod

captured in the Lach-

lan River during the

fish community sur-

veys in 2020 (Photo:

DPI Fisheries)

Adult golden

perch being

returned to the

river after measuring during fish community surveys in the

Lachlan River in 2020 (Photos: DPI Fisheries)

Flow plays an important role in the life-cycle of

native fishes from larval through to adult life

stages.

Water may inundate habitat needed to breed, trigger a

spawning response; create a boost in food resources

that improves recruitment success; improve habitat

condition by moving sediment and improving water

quality; or stimulate and facilitate in-stream migration.

Some fish species need certain types of flow to initiate

spawning. For example, research has shown us that

golden perch (Macquaria ambigua) need variable win-

ter-spring flows followed by an increase in river height

combined with water temperatures of more than 19

degrees to spawn. This means that seasonality of the

flow is critically important.

Spawning is just the start of the life-cycle of fish and to

successfully grow to be adult fish, young fish need

food resources which can be provided by nutrients

which are transferred into the river when flows inun-

date banks and floodplains moving leaf litter and other

organic material into the river.

Fish also need good quality habitat and this means

that sediment transport and scouring during high flow

events is essential for maintaining deep pools and con-

tributing woody debris and large wood to the river to

provide habitat. Flushes of fresh water (freshes) also

helps to maintain water quality and provide move-

ment triggers and facilitate longitudinal connectivity

within the system.

For all fish species, access to high quality refugia dur-

ing drought is critically important for survival as, unlike

many other taxa, fish have limited ability to move to

new areas and cannot survive with the loss of habita-

ble water for even very brief periods of time.

Supporting native fish in the Lachlan river system has

been a major focus of environmental water delivery

over the past five years. Environmental water has

been delivered to support fish outcomes, either direct-

ly (through the provision of spawning flows) or indi-

rectly (through improvements to water quality or habi-

tat access) in every year of the program.

What is a fish community?

In ecology, a community is a group or association of

individuals of two or more different species occupy-

ing the same geographical area at the same time. A

healthy fish community is made up of a number of

native fish species, each with juveniles and adults

present. We single out ‘Young-of-year’ as a special

group of juvenile fish that were born within the past

year as they give us information about recent

spawning.

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Monitoring

To monitor fish communities, the team uses elec-

trofishing and netting. Electrofishing uses electrici-

ty to stun fish allowing fish to be captured and

brought aboard for assessment. Electrofishing pos-

es little harm to fish, with most individuals recov-

ering within seconds of being stunned. The team

also uses a variety of nets to capture fish, including

collapsible bait traps and fyke nets. Once captured,

fish are identified, measured for length and weight

and returned to the river.

Data collected from the fish community monitor-

ing program provides an assessment of the health

of the fish community and provides a robust da-

taset to detect change in response to environmen-

tal flow releases over time. Critical components

assessed as part of MER relate to recruitment

(how many young-of-year individuals there are)

and native species composition compared to alien

species.

DPI Fisheries electrofishing boat (Photo: DPI Fisheries)

Monitoring results under LTIM and MER since

2015 indicated that there are fluctuations in fish

community composition in the Lachlan River with

flow, particularly in relation to the large floods in

2016/2017. The number of adult Murray cod cap-

tured during sampling in the Lachlan River de-

creased following this flooding, likely because of

the subsequent blackwater related mortality.

Numbers of Murray cod caught per site in the fish com-

munity monitoring undertaken during the LTIM program

The team has also detected the threatened fresh-

water catfish while monitoring, which is a good

sign that this species is holding on in this reach.

This is supported by other sampling higher in the

catchment, where catfish have been sampled at

four off-river creeks and wetlands. The team has

yet to detect natural recruitment of golden perch

in the lower Lachlan River, despite some efforts to

create favourable spawning conditions using envi-

ronmental water. Facilitating natural golden perch

recruitment in the catchment is under considera-

tion for future years.

What about carp?

The delivery of environmental water in warmer months to support native fish species runs the risk of pro-

moting a common carp spawning event, particularly if wetlands are inundated. In the Lachlan river system,

the use of Commonwealth environmental water has generally been confined to in-channel flows. This was a

successful approach in 2014-15, 2017-18 and 2018-19 with low levels of common carp spawning detected in

these years and minimising connections with wetlands during warmer months remains a strategy to be used

within the catchment.

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Catchment conditions January to

March 2020

Rainfall across the catchment had been well below

average since June 2019, but in the first quarter of

2020 the conditions became wetter. February and

March were the wetter of the three months, with

41.4 mm falling at Hillston in February and 68.6

mm falling in March. The majority of the March

rainfall fell in one big event with 54.2 mm on the

5th of March. The total rainfall amount for this

quarter was 133.6 mm surpassing the long term

median rainfall which is only 49.6 mm.

Average daily maximum and minimum tempera-

tures at Hillston for the first quarter of 2020 were

slightly below average. January was an exception,

was the warmest, with a highest daily maximum at

46 degrees and an average temperature of 35.6

degrees which is 2 degrees warmer than the long-

term average.

These daytime temperatures were accompanied by

minimums for this quarter that were equal to the

long-term averages.

Graphs showing rainfall and maximum and minimum

temperatures for the first quarter of 2020. Data are for

the weather station number 075032 and are sourced

from the Bureau of Meteorology.

OBSERVATIONS AND OUTCOMES

What is median rainfall?

Median rainfall is the mid-point of all observed rainfall records when they are sorted in

order of magnitude (from the lowest to the highest). The median is the preferred measure

of 'typical' rainfall from a meteorological point of view. This is because of the high varia-

bility of rainfall; one extreme rainfall event will have less effect on the median than it will

have on the average.

For more information see: http://www.bom.gov.au/climate/cdo/about/about-stats.shtml

Conditions became wetter

in the first quarter of 2020

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Hydrology

The four watering actions using Commonwealth environmental water for 2019-20 were delivered be-

tween October and December 2019. The peak of the spring pulse occurred in mid October at Willandra

Weir at just under 1100 ML/day. The peak of the spring pulse took almost 4 weeks to reach the edge of

the Great Cumbung at Four Mile. By the time it reached Four Mile, the spring pulse had become attenu-

ated—this means that the peak flows were lower (only 330 ML/day) and the pulse was almost twice as

long (occurring over 6 weeks instead of 3 weeks).

OBSERVATIONS AND OUTCOMES

Hydrographs showing flow in the Lachlan River downstream of Willandra Weir and at the edge of the Great Cumbung. Com-

monwealth environmental water spring pulse is shaded green. Data from Water NSW (http://waterinfo.nsw.gov.au/).

Water from the spring pulse which delivered water to the Great Cumbung in November, peaked in late

November and had fully receded by the 1st January.

Sentinel imaging showing water (false colour

blue) in the Great Cumbung on the 5th De-

cember 2019 (above) and the 1st January

2020 (right)

Further information about the watering actions can be found at:

http://www.environment.gov.au/water/cewo/catchment/lachlan/water-use

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Fish community monitoring

University of Canberra and NSW DPI Fisheries staff

recently completed annual fish community surveys

between Wallanthery and Hillston. A range of spe-

cies were captured (and returned to the water after

being measured), including a number of large Mur-

ray cod and reasonable numbers of young Murray

cod (new recruits). The team also caught numer-

ous 40-50 cm golden perch and a range of other

native fish species including bony herring, carp

gudgeon, Australian smelt, flatheaded gudgeon and

unspecked hardyhead.

OBSERVATIONS AND OUTCOMES

Bony herring caught during fish community surveys in

the Lachlan River in 2020. (Photo: NSW DPI Fisheries)

Sentinel imaging showing water (false colour

blue) in the Great Cumbung on the 5th De-

cember 2019 (above and the 1st January 2020

(right)

Flatheaded gudgeon caught during fish

community surveys in the Lachlan River in

2020. (Photo: NSW DPI Fisheries)

The Lachlan River at Hunthawang, one of the regular fish monitoring sites (Photo: Ben Broadhurst)

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Research

The University of Canberra, Centre for Applied Wa-

ter Science team has been conducting research to

develop techniques to monitor the response of

reedbeds to environmental water. As part of this

research we have undertaken four field trips over

Spring and Summer (2019-20) monitoring the

reedbed of the Great Cumbung Swamp. During

these trips we have collected a range of data

through on-ground monitoring and the use of

drone imagery.

The reedbed of the Great Cumbung Swamp, domi-

nated by the reed species Phragmites australis or

common reed, is the largest stand of common

reed in NSW, and provides important habitat for a

range of bird species, particularly in periods of

drought. Within the Great Cumbung Swamp, thick

patches of common reed occur along the main

channel of the Lachlan River and surrounding low-

er lying open marsh lakes. These open marsh lakes

intermittently connect with the Lachlan River

channel during high-flow events, where water

floods across the swamp before inundating the

surrounding reedbeds depending on the magni-

tude of inundation.

Common reed is a species of grass (Poaceae)

which primarily grows over the warmer months

(September-April) of the year. New reed shoots

start to grow in late winter/early spring and con-

tinue to grow over summer. During Autumn

shoots start to senesce, kind of like the leaves of a

deciduous tree. These (senescent) brown reeds

will remain on the plant into the next growing sea-

son, while the young green shoots start to grow.

RESEARCH

Location of the Great Cumbung in the Lachlan Catchment

Nest built in the

reeds (Photo: Will

Higgisson) and

healthy looking

reeds (Photo: Matt

Young)

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The once natural flow of the Lachlan River has been

extensively modified by river regulation and extrac-

tion. These changes to river flow patterns have re-

duced the frequency, duration and extent of inun-

dation which now occurs in the Great Cumbung

Swamp. Common reed along with other flood de-

pendent species which occur in the Great Cumbung

Swamp depend on these inundation events to per-

sist in the landscape. For this reason, the reedbeds

of the Great Cumbung Swamp have been targeted

with Commonwealth environmental water to main-

tain the current extent and increase periods of

growth.

The reedbed of the Great Cumbung Swamp re-

ceived Commonwealth environmental water twice

in 2019. The first occurred in July, with the greatest

extent of the Cumbung Swamp inundated on the

2nd July, and the second event occurred in Novem-

ber, with the greatest extent of the Cumbung

Swamp inundated on the 10th November. 2019 was

a particularly dry period in the lower Lachlan Catch-

ment resulting in low river levels apart from the

Commonwealth’s environmental watering actions.

These events inundated the open marsh lakes of

the Great Cumbung Swamp and parts of the sur-

rounding reedbed.

While our team have set out to develop techniques

to monitor reedbeds and their response to environ-

mental water, in the process we have collected val-

uable and interesting data on how reedbeds grow

and their response to flooding. Preliminary analysis

has shown that the environmental watering events

have resulted in increased height of reeds and the

presence of flower heads for sites which received

flooding compared to sites which had not received

flooding which were much smaller and produced no

flower heads. This result demonstrates the im-

portance of flooding to the growth and reproduc-

tion of common reed and the important role of en-

vironmental water during dry periods.

Changes to river flow patterns

have reduced the frequency,

duration and extent of inunda-

tion which now occurs in the

Great Cumbung Swamp.

Environmental water reaches the Great Cumbung—November 2019 (Fiona Dyer)

A developing seed head (Photo: Will Higgisson)

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Stories from monitoring and community

events in the Lachlan catchment

Adam Kereszy, fish biologist at large

Olive Perchlet in the Lachlan catchment

Olive perchlet are one of the rarest fish in the

Lachlan, and are currently found in only one

location – upstream of a weir, halfway be-

tween Lake Cargelligo and Hillston.

The rare olive perchlet, currently known from a single

population in the Lachlan catchment (Photo: Adam Ke-

rezsy)

Olive perchlet belong to a family called Ambas-

sidae that are collectively referred to as

‘glassfish’ because of their translucent bodies.

There are several species that occur in north-

ern and central Australia, and also in New

Guinea, but the species in question here – Am-

bassis agassizii – although common in coastal

rivers on the eastern seaboard, appears to

have declined in the Murray-Darling Basin in

the time since Anglo-European colonisation

and associated river regulation. Their common

name gives an indication of their stature: they

are a perch, like much bigger distant relatives

like cod and yellowbelly, but they are consid-

ered massive at 50 mm and old at two years,

so ‘perchlet’ is very appropriate.

It’s difficult to pinpoint reasons why olive per-

chlet are rare. Along the coast, the species ap-

pears to compete successfully alongside alien

fish like live-bearing guppies and their relatives

(such as platys, swordtails and gambusia). In

the rivers of far western Queensland like the

Cooper and Diamantina, a closely-related spe-

cies is mostly present and booms after floods.

In other words, fickle rivers and a fair amount

of competition don’t seem to be limiting fac-

tors to the success of the species in other plac-

es, and it’s reasonable to assume – as many

fish ecologists do – that olive perchlet used to

be more widespread and abundant in the me-

andering rivers of the MDB.

As with many MDB species, it seems likely that

the combination of negative factors has con-

tributed to the apparent decline. River regula-

tion disrupted flows and breeding cues and

cycles. Barriers like dams and weirs prevented

up and downstream migration. Following the

carp explosion, in-stream vegetation – a fa-

voured habitat – diminished, and introduced

predators like redfin perch would almost cer-

tainly enjoy a mouthful of olive perchlet when

the opportunity presented itself.

THE LACHLAN DIARIES

Olive perchlet are one of the

rarest fish in the Lachlan,

found only in one location.

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But all that said, we really don’t know. This is

because – unfortunately – by the time we col-

lectively started working out what did and did-

n’t live in the MDB, the rivers were already

compromised. You could say the horse had al-

ready bolted.

What we do know is that we still have at least

one population of olive perchlet in the Lachlan,

so it’s likely they are more widespread, it’s just

that we haven’t found them yet. Even so, this

population is not always easy to find. They are

mostly present, but there have been a couple

of sampling trips in the last few years that

failed to detect them.

In mid-March 2020, two members from ANGFA

– the Australia and New Guinea Fishes Associa-

tion – travelled to the weir pool with their small

box traps and dip nets to assist DPI Fisheries

and State and Commonwealth environmental

water managers (DPIE–EES and CEWO) gauge

the status of the Lachlan River olive perchlet

population. The timing was important given the

recent water shortages within the catchment.

As Commonwealth and NSW environmental

water has been (and will continue to be) used

to assist the olive perchlets through drought, I

went along with a set of funnel-shaped fyke

nets at the request of the Lachlan environmen-

tal water manager to conduct a formal popula-

tion and habitat assessment.

ANGFA members are a diverse group, but they

all have one thing in common: they absolutely

love fish. As soon as I arrived, I remembered

NSW President David Matheson from talks I

had given at ANGFA meetings in the past. His

accomplice this time was Lachlan Nevinson, a

fish-obsessed shearer from Holbrook. Dave and

Lachy had already done a bit of fishing and had

already found a few olive perchlet and other

local native species, but they were extremely

keen to pull on their waders and head out to

set the bigger fyke nets and see what turned up

overnight.

We still have at least one popu-

lation of olive perchlet in the

Lachlan.

(L-R) Nathan McGrath (DPIE), Dave Matheson and Lachy Nevinson (both ANGFA) set a fyke net during fish sampling in

the mid Lachlan in 2020 (Photo: Adam Kerezsy)

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Setting and retrieving nets and taking samples is

ok by yourself, but the time always passes much

faster when there are like-minded people to

share the work with and chat to: on this trip

there was Dave and Lachy, and also Nathan

McGrath from the DPIE–EES environmental wa-

ter team and carp-fisher Keith Bell, so no prizes

for guessing the general content of the conversa-

tions. In fact, Dave, Lachy and Nathan were so

keen they even went out fishing again long after

the sun had set in order to improve the accuracy

of our species list.

The population of olive perchlet in the MDB is

listed as endangered. Given their rarity this is

probably a good thing, but it presents challenges

for hobbyists/naturalists/conservationists like

Lachy and Dave.

As much as they would love to be directly in-

volved in taking immediate action and breeding

up our endangered species in captivity, there are

complex processes and legislation to be navi-

gated which can dampen some of the enthusi-

asm. This is a bit of a shame, because those of us

who work professionally on fish mostly don’t

have the time, the facilities or – in some cases –

the expertise to care for and breed fish under

captive conditions. We all love fish too – but in a

slightly different way.

As we dragged the nets in the following morning

we were all gratified to find a juvenile olive per-

chlet that was only 17mm long. This meant that

the community in the weir pool had spawned

with at least some success in spring and summer

2019/2020, but we all agreed their future was

still hard to predict. With a bit of luck, people like

Lachy and Dave will stay interested in conserving

our threatened native species, and with a bit

more, hopefully at some stage they may be able

to take a more active role in breeding popula-

tions for re-release in other suitable locations.

The population of olive perchlet in

the MDB is listed as endangered.

The olive perchlet community in

the Brewster weir pool has

spawned with at least some suc-

cess in spring and summer 2019-

2020.

Nets set in Brewster Weir pool (Photo: Joanne Lenehan)

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ACTIVITY SUMMARY

The following summary provides information about the contracted activities undertaken between October and

December 2019 as part of the Lachlan Monitoring, Evaluation and Research (Lachlan MER) Project. Activities that

will be undertaken between January and March 2020 are listed as upcoming activities.

ACTIVITIES PROGRESS TO DATE UPCOMING ACTIVITIES

Monitoring activities

Ecosystem type Data collection complete and suggested Australi-an National Aquatic Ecosystems (ANAE) types for all sites included in the Monitoring and Data Management System (MDMS).

No more data collection required

Fish (river) Adult fish community sampling completed in March

Data processing, QA/QC and data entry

Fish (larvae) Larval fish samples processed, data entry and analysis commenced

Data entry continuing

Water quality and stream metabolism

Data processing commenced Downloading and servicing loggers if possible

Vegetation diversity Data processing commenced Data processing, QA/QC and data entry

Evaluation activities

Monitoring data entry Data entry continuing Data entry continuing

Research activities

Research Two rounds of data collection Commenced data and image processing

Data and image processing Further data collection (if possible) Assessment of sites and data col-

lection to date

Communication and engagement

Selected Area Working Group (EWAG and TAG meetings)

Hay EWAG meeting Online EWAG meeting May

Project team teleconference None Project team teleconference

Other Stakeholder Engage-ment

Robinson Crusoe Island Down the Track Weekend Robinson Crusoe Island Down the Track Weekend

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ABOUT THIS DOCUMENT

The Commonwealth Environmental Water Holder (CEWH) is responsible under the Water Act 2007

(Cth) for managing Commonwealth environmental water holdings. These holdings amount to more

than 2,700 gigalitres (as at July 2019) of water entitlements across the Murray-Darling Basin. The hold-

ings must be managed to protect or restore the environmental assets of the Murray-Darling Basin, and

other areas where the Commonwealth holds water, to give effect to relevant international agree-

ments.

Monitoring and evaluation are critical for supporting effective and efficient use of Commonwealth en-

vironmental water. Monitoring and evaluation also provides important information to ensure the

CEWH meet their reporting obligations. Between 2014 and 2019, the Commonwealth Environmental

Water Office (CEWO) has undertaken monitoring and evaluation of the ecological outcomes of envi-

ronmental watering through the Long Term Intervention Monitoring Project (LTIM Project). At the

same time, the CEWO has undertaken research which seeks to improve the science available to sup-

port environmental water management in the Murray-Darling Basin through the Murray-Darling Basin

Environmental Water Knowledge and Research Project (EWKR Project).

The Monitoring, Evaluation and Research Program (MER Program) builds on the work of the LTIM and

EWKR Projects to undertake monitoring, evaluation and research activities within seven Selected Are-

as and at the Basin-scale between 2019 and 2022. One of the seven Selected Areas is in the Lachlan

river system and a team of researchers, agency staff and contractors led by the Centre for Applied Wa-

ter Science at the University of Canberra are monitoring, evaluating and conducting research in the

catchment.

This newsletter forms part of the reporting activities undertaken in the Lachlan river system under the

MER Program. It will be produced quarterly and highlights the activities, observations and outcomes

that have occurred in the river system in relation to environmental water.

In conducting the monitoring evaluation and research project in the Lachlan river system, the project

team as well as the Commonwealth Environmental Water Office respectfully acknowledge the tradi-

tional custodians of the land on which this work is conducted, their Elders past and present, their Na-

tions of the Murray-Darling Basin, and their cultural, social, environmental, spiritual and economic

connection to their lands and waters. The Lachlan River flows through the lands of the Nari Nari,

Ngiyampaa, Waradjuri and Yita Yita Nations, and we acknowledge these people as the traditional own-

ers of the land on which this publication is focused.

More information can be found at:

https://www.environment.gov.au/water/cewo/monitoring/ltim-project

https://www.environment.gov.au/water/cewo/monitoring/ewkr

https://www.environment.gov.au/water/cewo/monitoring/mer-program

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INQUIRIES REGARDING THIS DOCUMENT SHOULD BE ADDRESSED TO:

This document was prepared by Fiona Dyer, Will Higgisson, Ben Broadhurst (CAWS-UC), Jason Thiem and

Daniel Wright (DPI Fisheries) and Adam Kerezsy (Dr Fish).

Cover Photo: Returning an adult Murray cod to the river following capture using electrofishing. (DPI Fisheries)

Document history and status

Distribution of copies

Copyright © Copyright Commonwealth of Australia, 2020

‘Lachlan River, Monitoring, Evaluation and Research, Quarterly Outcomes Newsletter’ is licensed by the Commonwealth of Australia for use under a Creative Commons By Attribution 3.0 Australia licence with the exception of the Coat of Arms of the Commonwealth of Australia, the logo of the agen-cy responsible for publishing the report, content supplied by third parties, and any images depicting people. For licence conditions see: http://creativecommons.org/licenses/by/3.0/au/

Disclaimer

The views and opinions expressed in this publication are those of the authors and do not necessarily reflect those of the Australian Government or the Minister for the Environment and Energy. While reasonable efforts have been made to ensure that the contents of this publication are factually cor-rect, the Commonwealth does not accept responsibility for the accuracy or completeness of the contents, and shall not be liable for any loss or damage that may be occasioned directly or indirectly through the use of, or reliance on, the contents of this publication.

Version Date Issued Reviewed by Approved by Type

Draft 1 3 April 2020 Project Team Fiona Dyer DRAFT

FINAL 24 April 2020 CEWO Fiona Dyer FINAL

Version Type Issued to

FINAL Electronic Commonwealth Environmental Water Office

Damian McRae

Commonwealth Environmental Water Office

Phone: 02 6274 2524

e-mail: damian.mcrae@environment.gov.au

Dr Fiona Dyer

University of Canberra

Phone: 02 6201 2452

e-mail: Fiona.Dyer@canberra.edu.au