10 june 2005

10 June 2005
Dr Colin Terry
Infrastructure Planning Branch
Water Corporation
PO Box 100
Leederville WA 6902
Dear Dr Terry
WUNGONG CATCHMENT ENVIRONMENT AND WATER MANAGEMENT PROJECT
The Urban Bushland Council WA is an association of community groups with a common interest in the
conservation of urban bushland. We make the following submission on the above project.
Context
Urban Bushland Council (UBC) members have been concerned for some years at the damaging effects on
bushland health and biodiversity of declining ground water levels in the metropolitan region. This is due to a
combination of excessive drawdown of Water Corporation bores for potable supply, increasing commercial and
domestic use of bores, urban and commercial expansion and low rainfall. We are concerned that there does not
seem to be any overall and integrated planning to identify the total water resource available for the greater Perth
region and realistic limits to growth in the face of up to 60% less rainfall and 6-7 deg higher average
temperatures by 2070 (CSIRO predictions).
For the Wungong catchment we note the detrimental bushland impacts of the history of clearing and logging, the
mosaic of bauxite mining (Fig 9), various standards of revegetation (Fig 16), the history of regular burning, weed
invasion, and the very serious and widespread dieback infestation (Fig 10). For a potable water supply
catchment these disturbances are already extensive and less than ideal. We suggest the wider Perth community
is probably unaware of this history. However it is our belief that the community expects the very highest
standards of management and protection for our water supply catchments and would actually expect a 'no
disturbance' regime. The project proposed is a continuation of various disturbance practices.
Our specific comments are:
Biodiversity
We agree with the fundamental principles in the opening para of the Foreword (p iii) by Jim Gill and his
emphasis on biodiversity value. The best way to get high quality water is in fully protected catchments- where
'prevention' of degradation is the most cost effective and safest approach. However we do not believe that the
project follows this principle. Far too much disturbance is proposed.
The document is not about biodiversity conservation, although it could be more so. On page 62 it states
'There are few data available on the effects of non-commercial thinning on biodiversity in the northern jarrah forest.' . 'As there has been limited research specifically on the ecological impacts of non-commercial thinning, past thinning trials can be assessed to gather data' We do not believe that this can be done effectively many years later. It looks as if there is no data available. Earlier thinning trials were set up to look at changes in runoff, not to study effects on ecosystem functioning or biodiversity. The whole issue of impacts on biodiversity is glossed over with vague statements and weasel words. The discussion on p53 is meaningless 'management' chatter. For example: 'mitigate and minimise any potential adverse effects and maximise positive environmental benefits by the implementation of best practice prescription; 'monitor the effects of treatment on the specified environmental values and conduct appropriate longer term research;. 'review these results and incorporate the findings into revised best practice prescriptions (adaptive management); and'
If the Water Corporation were to be serious about 'minimising adverse environmental impacts' it would ensure
that there is no more bauxite mining in the catchment. The UBC does not support bauxite mining in the
Wungong catchment as it destroys biodiversity: of flora, fauna, and soil biota including the native fungi which
are essential to ecosystem functioning. Rehabiliatation after mining only replaces bits of the whole jarrah forest
ecosystem.
Sustainability
The concept of sustainability is not treated seriously in the document. Sustainability has become a fashionable
buzz word generally used to justify activities which are not truly sustainable or to make 'business as usual' sound
good. For example the phrase 'to achieve sustainable outcomes' is meaningless. Sustainability of what? We
would prefer to see the document written in plain english. For example it is really all about increasing the runoff
and hence yield of water from the catchment into potable supply. And this is a reasonable objective.
Serious consideration of sustainability of the water resource for human use would look at the water cycle of
nature over the next 50 years: volumes of rainfall, groundwater levels, how much is transpired, surface runoff,
infiltration, evaporation, and water quality in the environment etc and keeping all this in balance over time rather
than depleting the resource in any sector.
Streamflow (p 2)
Streamflow data should be more comprehensive: a table would be more revealing with comparison with rainfall
data for each year. Rainfall patterns and intensity and annual totals are related to runoff and streamflows. The
reduction in streamflows is substantial in recent years. We are not convinced that the expected increase in
streamflows and thus yield from thinning are realistic as there is no analysis or presentation of scenarios for
differing rainfall levels in future years.
Commercial logging and harvesting
The UBC objects strongly to the practice of logging or harvesting of forest products from bushland in a water
supply catchment. Indeed it is clear that past logging of the Wungong catchment has been counterproductive to
surface water yield. The catchment should never have been logged in the first place. Logging would also have
helped to spread dieback, increase weed invasion, and disturb soil resulting in stream degradation. Fauna
breeding habitat has been lost also in old trees and stags eg for Carnaby's Cockatoos, Red Tailed Black
Cockatoos and many other species. The latter are now increasingly under threat from loss of breeding habitat.
Thinning
Frank Batini gave a presentation to UBC members on the proposed catchment thinning trials and we appreciated
being given all the information. However UBC members are uneasy about the proposals. We are aware that
past thinning done by CALM and Alcoa are done for the purpose of maximising forest production. They are
certainly not done for the purpose of biodiversity conservation. The Wungong proposal is presented as a trial
when it is really a forest management plan for 12 years for the whole catchment in order to increase water yield
and production of commercial forest logs (see p 44), and to continue bauxite mining. This is akin to the
Japanese rationale of whaling for research purposes.
The UBC objects strongly to the use of all herbicides and other chemicals in a potable water supply
catchment. Thus we do not support the notion of the 12 year 'trials' or 'research' which depends on very
extensive use of chemical herbicides to kill trees and then to follow up in killing coppice regrowth, weeds,
and new undergrowth.
If there is adequate rainfall, after thinning the vegetative cover will tend to return to earlier levels. An increase in
the undergrowth is likely with more light penetration and access to soil moisture depending on rainfall. In other
words the system will tend to return to its own balance. It seems to us that the project proposes to keep reducing
the total foliage cover. Discussion of foliage cover in terms of data on NDVI changes and modelling of
scenarios would have been more convincing in showing expected changes.
The UBC does not believe that the proposal presents adequate evidence that runoff and yield is likely to
significantly increase under the expected drying of our climate. Climate change is an over-riding influence. The
proposal does not show how it calculates the extra 40GL/a expected. Loose wording suggests that it is based on
the 1980's research where rainfall was higher and runoff much greater. It is clear that thinning does increase
runoff but in this landscape surface runoff rates are not inherently high.
The project purports to hasten growth of an open mature forest (in rehabilitation areas), with higher runoff
characteristics. However we are not convinced that increased runoff can be maintained without extensive
reduction in undergrowth. The mistakes have already been made in past mining followed by rehabilitation with
so many trees. What is proposed is a costly, invasive and labour intensive exercise in killing vegetation. Other
alternatives could have at least been considered and compared. For example we support the harvesting and
removal of pine plantations and the timber may as well be used commercially. Pine plantations are ecological
deserts and could be replaced with another desert which would serves as a water shedding structure, such as
concrete. Not a pretty site but at least could be considered. We are aware of the small bitumen catchment on
Rottnest Island and concrete would be a safer substrate than bitumen. Please note we would not support
clearing of native forest for this purpose!
We note the extensive use of burning and practices such as scrub rolling proposed to reduce fire risk. These
have detrimental effects on biodiversity.
Pine plantation
As stated above the UBC supports the harvesting and removal of the pine plantations.
Fire risk and climate change
In a drier and hotter climate, fire risk will increase and this needs to be recognised. With large numbers of killed
trees left standing after thinning, presumably the risk of more intense fire in more standing dead wood will be
even greater. Excessive burning depletes biodiversity values significantly, and for this reason we do not support
the concept of a partly dead standing forest.
In the event of heavy rains soon after prescribed burning or major fires leaving a bare landscape, surface runoff
rates and erosion would be high. Any chemicals used or their breakdown products could be rapidly transported
to streams and the reservoir. This is an unsatisfactory situation and should be prevented by avoiding use of
chemicals. Such a string of events has occurred in Tasmania resulting in extensive ecological damage where
areas have been sprayed under 'forest management practices' and then burnt.

Dieback
The extent of dieback in the catchment is alarming. We note that dieback areas have higher runoff and water
yields. Continued mining, logging and thinning activities will increase the spread of dieback and is reason alone
to avoid these activities. All activities which result in bare landscapes will facilitate the spread of dieback during
rain events and for this reason should be avoided. Dieback has severe detrimental effects on biodiversity and we
submit that there is inadequate research and attention paid to this extensive problem. Dieback is a major
threatening process to biodiversity and the Water Corporation should pay much more attention to halting
spread by preventive means and to long term research on dieback and its management in water
catchments.

Bauxite mining
As stated the UBC objects to bauxite mining in the catchment and believes it should be stopped as it destroys
biodiversity values, results in soil movement and turbidity in runoff and waterways, spreads dieback and is a
generally destructive land use where the catchment should be left undisturbed. Mining removes nesting habitat
for endangered birds especially Black Cockatoos which require old mature trees for breeding. Mining totally
destroys the soil microflora and especially fungi. Enough damage has been done already and that is not
justification for continuing mining. Low water yield from mining rehabilitation areas is the major problem now
so there is no reason to continue 'making' them. The principle of prevention (of degradation) should be
employed.

Weed invasion
The UBC supports weed control in the catchment but only by either mechanical means or benign practices
such as steam spraying. We object strongly to the use of chemical herbicides in the catchment as these
compounds are estrogen mimics and should not be allowed to enter catchments for potable supply. We are
concerned that this practice is already in common use by CALM in water catchments (p71). We are also
concerned that Roundup may already be in use in the Wungong catchment. We submit that steam methods which
are available and are used elsewhere should replace all chemical use.
The spread of estrogen mimics (sometimes called zen estrogens) in wildlife and in the human population is an
increasing public health problem. The precautionary principle and principle of prevention dictate that potable
water supplies should not be exposed to any estrogen mimics such as Roundup and other chemical defoliants.
The Water Corporation and Health Department must surely be aware of health problems both human and
ecological caused by 'Agent Orange' and other chemicals.
Alternatives: reducing demand for water
The UBC believes inadequate attention is paid to demand management and its comparison with catchment
thinning in the document. Whilst it is mentioned we would prefer to see details of investment in reducing
demand in both domestic and commercial sectors compared with various scenarios of thinning by mechanical
means with up to 60% less rainfall.
SUMMARY

The primary and only land uses in the Wungong catchment should be regarded as potable water supply and
biodiversity protection as these uses are generally compatible.
However the purpose of the project is obviously to maximise both forest production and water yield. It should
not pretend to have 'improved environmental outcomes' when these are not clearly identified.
The UBC does not support the concept of a massive thinning program presented as a 'trial' and using Roundup to
produce questionnable increases in yield of 40GL in a fiercely drying climate.
We have little confidence in the expected 40GL yield. We suggest resources spent on the thinning project are
likely to result in insignificant extra yields of water in an increasingly drying climate and would be better spent
on 'demand management' and changing community attitudes. We need to accept that there is a finite supply of
water for Perth. We need to dramatically reduce per capita use, recycle what we do use, and most importantly
change our garden mindset away from lawns and European plants toward waterwise alternatives and use of our
unique local plants.
If you require any further information or clarification please contact me directly by phone on 9271 5707.

Yours sincerely
C Mary Gray
President
POP Box 326 West Perth 6872
tel 9420 7207

Source: http://www.bushlandperth.org.au/images/stories/PDF/Submissions/2005/Wungong%20Catchment%20EWMP%20Water%20Corp%20Jun%2005.pdf