May
2009 : As this is the actual submission lodged in
December 2007
there
is no change to this section
********************************************************
This
submission was made under the alternative section of the Environmental
Impact Study (EIS) on the 31st December 2007.
This
entire website also formed part of the submission.
It concludes that the harvesting of surplus water that now flows over the
spillway of
the Wivenhoe Dam in times of flood plus the expansion of the Borumba
Dam to
a 2 million ML storage Dam will prove to be a superior alternative to the
proposed
Traveston Crossing Dam.
It
will provide a buffer against the possible interruption to our water supplies
through
Climate Change. The size of the buffer,
being the expanded Borumba Dam, is 2 million ML
and that capacity is greater than the capacity of all Dams in South East
Queensland.
The Traveston Crossing Dam
Dam will provide no such insurance.
Index
First of all, this submission sets out
the grounds for the submission. They are :-
Pages 1-4.
My view of the fundamental flaws in the documents provided for the justification
of the Dam at the Traveston Crossing.
Pages 4-8
My view of the fundamental flaws in the hydrology report on the inter basin
transfers
I.E. The transfer of surplus water from the Wivenhoe/Somerset System in times of
major
Meteorology events to the expanded Borumba Dam and returned in times when they
are absent and the provision of additional water to the System collected in
the
expanded Borumba Dam. This aspect has already been dealt with in Qld
Govt Reports
in the previous section.
Pages 1-11
Climate change and other matters relevant to the submission.
The submission then explains important
aspects that need examination before the
alternative project is considered. They are :-
Pages 12-15
Uncommon events (Large Meteorology events such as Monsoons and Cyclones)
Pages 16-18
Concatenation (linking together) of uncommon events.
Page 19
This set the scene for
the project to replace the Traveston Crossing Dam
Page 20-26
Available surplus water
Page 27
Expected flow volumes
Page 28-30
Expected pumping requirements
Pages 31-41
Engineering applicable to the Pipeline
Dam construction and estimated costs (expanded Borumba Dam)
Pipeline construction and estimated costs
Hydro Plant
Operating costs of the Pipeline
Page 42
Summary
Attachments are integrated in this website.
Page 1
Grounds
of this submission
FUNDAMENTAL
FLAWS IN THE EIS
In my view the EIS is fundamentally
flawed in two aspects. They are:-
·
The justification of the Dam at Traveston
Crossing and
·
The justification for dismissing the Inter
Basin
transfer of surplus water from
the Wivenhoe/Somerset to the enhanced Borumba Dam in times of large scale
Meteorological events such as Monsoons, Cyclones or large rain
depressions.
The reverse transfer to occur in times such as we are now experiencing.
Flawed
Justification of the Dam at Traveston Crossing
This is drawn from two sections. The
overview on page 1-2 of Chapter one and the
Project overview- Need for the project- of
chapter two on pages 2-6 & 7.
The
flaws encountered in the “overview”:
(1)
“Consequently, the Traveston Crossing Dam Project has been identified as
one
of
Queensland
Government’s major new water infrastructure
initiatives for SEQ region….”
Response:
The matter of consequence was the comparison of the
Upper
Mary
Valley
catchment with the Wivenhoe and its catchment, the
Brisbane
River
.
The Somerset Dam and its catchment the Stanley River should have been
the
comparison. The
Somerset
catchment is the Stanley
River. It is 1/3 the size of
the Wivehoe catchment, the Brisbane
River, but 3 times more efficient. It
receives 30% more rainfall than the Wivenhoe (SEQWater information) which
converts to a higher inflow figure. The calculations of the foregoing are set
out
in attachments 6, 7 and 13.
That the Wivenhoe Dam and its catchment is our main source of water supply is
an elementary error which is adopted by a high percentage of lay people.
In
my view, the comparison used in the EIS has added credence to a common
misstatement of fact.
As a consequence of this misdirected
comparison, the
inefficiency of the
proposed Traveston Dam was masked. You will see that the
Somerset
and
its catchment provide some 260,000ML annualized with 10% less rainfall whereas
the Traveston all three
stages will provide a total of 150,000ML. It does not
provide beyond 2050 and there
is no additional storage facility to combat
natural and man made climate change.
This flaw, of itself, opens up the
consideration of other proposals
Page 2
The
flaws encountered in “need for the project”
There are several paragraphs in this “need for the
Project” which deal with the
perceived “drought” conditions of the last six to seven years. They are
largely contained
in the last 2 paragraphs in section 2.3 on page 2-6 and the first three
paragraphs on the
next page (2-7.)
To me they demonstrate the lack of understanding of the two types of rainfall that
occur in the catchments of all of South East Queensland Dams and as a consequence
solutions to the problem have been overlooked. The rainfall types are:
The normal summer rain that falls year
after year. The 4 summer months December to
March receive more than 50% of rainfall and this high rainfall tends to make the
creeks
flow. The remaining 8 months receive the balance and rarely provide major
inflow. The
overall catchment rainfall has never
been lower than 76.8% of the long term
average. This has been confirmed by Department of Natural Resources and
Water and
the Bureau of Meteorology email to me dated 25th August 2006 and
included in this
submission.
The large scale meteorological events known as
“uncommon events” by SEQWater.
They are Monsoons, Cyclones and large rain depressions. They generally cover all
of SEQ.
They have the capacity to fill the Dams in a
few days whereas the summer rains
provide an average annual fill of 11%.
The
flaws that the above produced are:-
(2) Comparison with the Federation Drought.
“The
Federation drought is the only comparable period…..”
This report was compiled by the Queensland Climate
Change Centre of Excellence (QCCCE)
and headed “The drought to 2007” being the period from February 2001 to
January 2007.
Response:
This report confirmed that the rainfall in the catchments had never been
less that 76.8% of the BOM long term average 1961 to 1990.
It was a qualified report as a hydrology report at that time distance was not available.
The
comparison was rainfall.
The overall rainfall was similar but that is
the only area that they were in agreement.
The summer rains that produce inflow were normal in the current period at
99.7%
for the Wivenhoe and 91.4% for the
Somerset. The deficiency was in the non summer
months that rarely create inflow.
The Federation drought period shows the rainfall evenly spread out over the
whole
of the period with little ability to create inflow. Refer attachment 4 & 5.
Page 3
All of the rainfall for all months in both periods is included in this
submission for general
viewing and support of this response. Refer attachments 4 & 5.
In my view, the use of this report to claim
vindication for a drought is a flawed argument.
(3)
Remaining drought related statements
There are five remaining drought related
statements intertwined. They are contained in
the two following statements.
“SEQ
is experiencing the compounding effects of the worst drought in more than
100 years, a booming population and the prospect of continuing irregular
rainfall due
to natural climatic variability and long-term climate change.
(Page 2 – 6)”
“Most
parts of SEQ have been affected to some degree by lack of reliable
rainfall
over recent years. Bureau of Meteorology (BOM) rainfall deficiency maps
show 1st July 2004 to 30th June 2007 as the driest three
year period on record for
inland parts of the Wivenhoe catchment. Other……”
Response:
Booming population
The Queensland Government graph and figures of
population growth show a steady
and predictable growth since 1984 at the start of the Wivenhoe Dam to the
current
date. The graph is included in this submission. (attachment 26) To suggest that
it
should be included in a compound effect is, in my view, erroneous.
The question not asked is: How did this
massive Dam manage to fill from scratch,
service this population growth until 2001 and then drop like a stone in a
period
when summer rains were quite normal at 99.7% in the Wivenhoe and 91.4% in
the
Somerset
? (Attachment 8 & 9)
Worst drought in 100 years, BOM rainfall deficiency
maps, climatic variables and
inland Wivenhoe deficiency maps.
Response:
The source of the term “worst drought in
100 years” is the BOM rainfall deficiency
maps. They are generally shown without the corresponding rainfall percentage
map
that is more informative and less misleading due to the consequences of the
next
two paragraphs.
The Bureau of Meteorology measures rainfall
against the long term average 1961
to 1990. This period includes the deluge of 1974 and two “uncommon
events”
of 1988 and
Page 4
1989 that filled the brand new Wivenhoe Dam.
Discussions with the BOM confirmed that
they do not make exception for these “uncommon events”.
The last six year period does not include
any of these “uncommon events” and naturally
produced a rainfall deficiency when all that really happened was the normal
walkabout
of these events. The graph in this submission is set out on page 14 and shows
the
yearly gaps created when “uncommon events” decide to depart the scene.
The six year decile recording for the last century is included in this
submission. Almost
all of the six year periods that did not have an “uncommon event” congregate
in the
lower half of the decile graph. (Attachment 12) Out of a total of 106 years
there is
only one exception in those 48 years without uncommon events.
To answer the question under Booming Population, the Wivenhoe had
five “uncommon events from 1988 to 1999 with a top-up in February 2001.
They
created spill over the Dam wall on four occasions.
The use of decile map to “prove” a
position in the catchment is fraught with difficulty
because of the BOM measurement method.
This is highlighted in the use by SKM of the
inland deficiency map of the Wivenhoe
catchment. In the first place, one will see from this submission that the
Wivehoe
is very much the junior partner in the provision of water that finds its way
into the
Wivenhoe Storage Dam. In the second place, the decile map is not
accompanied
by the percentage map. The same principles about “uncommon events”
enumerated
above, apply.
It should be obvious by now that the cause
of our current predicament is the
unpredictable timing of “uncommon events”. It raises the question
as to whether
the use of water from these events can be better managed particularly
through
inter-basin transfers.
Justification for dismissing inter-basin transfers
The
justification for dismissing the
Inter
Basin
transfer of surplus water from
the Wivenhoe/Somerset to the enhanced Borumba Dam -
-in times of large scale Meteorological
events such as Monsoons, Cyclones or
large rain depressions. The reverse transfer to occur in times such as we are
now
experiencing
Examination
of appendix “A” of Gilbert and
Associates and concurrence by SKM
INTER-BASIN TRANSFERS
In my view the subject of
inter-basin transfers ( Wivenhoe/Somerset to
Borumba and the reverse) the EIS of SKM is fundamentally flawed
Page 5
SKM’s only
reference to this particular Inter-Basin subject is the second last
paragraph on page 2-28.
“The
study also looked at the issue of inter-basin transfers between Borumba
Dam in the
Mary
Valley
Basin
and the Wivenhoe/Somerset System in the
Brisbane
Valley
. For inter-basin transfers to occur, two conditions need to be
simultaneously met, namely Borumba Dam needs to be overflowing and the
Wivenhoe/Somerset system needs to have freeboard capacity. The conclusion…”
You will observe
that their statement is a virtual quote from the Gilbert and
Associates appendix “A” assessment in lines 35 to 44. I am unable to find
where
SKM supplied any critical analysis. Therefore they rely entirely upon the
assessment of Gilbert and Associates contained in their Appendix “A”
“Preliminary
assessment of potential for inter-basin transfer” which, in my view, is
a fundamentally flawed document.
The reasons for my
conclusions that they are fundamentally flawed documents
follow:-
Gilbert and Associates appendix: “A”
Gilbert and
Associates Assessment of Inter-Basin Transfer (
Brisbane
River
and
Mary
River Basins
.)
(1)
This title, which may be technically correct, does not convey
the full intent
Conclusion: Approximately
65% of the water in the Wivenhoe/Somerset
System comes from the
Stanley
River. Refer to page 1 in this submission
(2) The McMah proposal Dam size
Line 50/51. The
size required under stage 3 of the McMah proposal ( between
1,500 and 2,000GL(2,000,000ML) ) and ….
Conclusion : The Dam required
under the McMah proposal is clearly 2,000 GL.
It is on page 1 of his submission to the Senate Enquiry which predates
this
assessment. This fact has an important flawed influence on conclusions
drawn by them and graphs supplied by them. For example, the graph on dam
levels was commenced at year 1900 instead of year 1890 which was the
commencement of their simulated model. The 1893 flood would have filled
the Dam to 2,000GL and the 1898 flood would have a further spill. Their
graph commenced at 1,450GL thus altering the balance throughout.
Page 6
The Engineers GHD
concluded that a Dam wall of EL 230m was feasible for a
2,000GL Dam and went further to say that a Dam wall of EL320m was also feasible.
Additional component of the McMah proposal
Line 2. Additional component. The Hydrology concentrated on the Mary
Valley
Weirs and the inter-basin transfers rated little mention particularly in
the
Engineering assessment and the cost assessment.
Conclusion: One does not build
a 2,000 GL( 2,000,000ML) Dam as an additional
component. It is the main thrust of the McMah proposal
The requirement for the Borumba to be overflowing before
transfers
could begin
Lines 7 to 9. Transfer would occur from Borumba to Somerset/Wivenhoe
during periods in which Borumba was
overflowing and sufficient freeboard
existing in the
Brisbane
River basin
storages.
Conclusion: The capacity of the
enhanced Borumba Dam is 2,000,000ML. The joint
capacities of the Wivenhoe/Somerset are 1,165,000ML Wivenhoe and 380,000ML
Somerset totalling 1,545,000ML. There is no apparent reason why this
condition
was placed on the transfer. The releases from the Borumba into the
Mary
Valley
would be unaltered. The return transfer of the water to the
Wivenhoe/Somerset
System would contain all of the water withdrawn in times of major
surpluses
and released in times when “uncommon events” were absent and the Dams
depleted as they are at this time.
Influence of large scale meteorological influences known
by the Dam
Managers as “uncommon events”
Lines 49 to 54. The
Borumba catchment is relatively
small ( approximately
465 km2 ) for a Dam required under stage 3 McMah proposal (between
1,500GL and 2,000GL) as such likely to fill and spill due to the influence
of
large scale meteorological influences which will almost always influence
the Brisbane River catchment at the same time. As such Borumba
is likely
to be overflowing generally during those times in which Wivenhoe &
Somerset are also close to Full Supply level.
Conclusion: This is an ideal
situation to have on our hands. The Borumba
enhanced to 2,000GL (2,000,000ML) filled to overflow on numerous occasions
and available
to replenish the depleted Wivenhoe/Somerset when “uncommon
events” depart for
Page 7
their quite normal
walkabout. This absence creates gaps for several years, the
last being 14 years 1974 to 1988.
Unfortunately it is
an elementary error if the DNR & W monthly stream discharge
volumes at Yabba Creek are to be believed. They are available on the DNR &
W
website and I have reformatted them to show their influence on the Dam
supply
level. Refer to Page 24. The highest peak was 1971 to 1975 when
1,091,290ML
became available. The total for 1964 to 2002, 38 years, was 2,541,685ML.
Draft Moreton WRP (Water Resource Plan)
Lines 68 to 83:
Based on NRW simulation modeling,
under a scenario of full
utilization of existing entitlements (i.e. full use of existing licensed
extractions)
there is little to no potential for additional extractions from the system
without
failing the MAF EFO of 68%. Notes:
NRW, Natural resources and Water: MAF,
Mean Annual Flow: EFO, Environmental Flow Objectives. The part of the
System that we are dealing with is the Wivenhoe/Somerset and their
catchments. The 68% is placed at the
Brisbane
end of the
Brisbane
River Basin
.
Conclusion: In my view, this statement
fails to recognize that the System
Dynamics have changed and that the required 68% is maintained and improved.
1.
The 80,000ML surplus water that goes over the spillway currently
in
times of “uncommon events” is to be transferred to and retained in
the Borumba Dam and returned at a more suitable time. This gives
no loss or gain.
Refer to pages 22-24.
2.
The Expanded Borumba Dam to 2,000GL now gives an annual yield
of
91,000ML. After the normal release into the
Mary
Valley
, there is
approximately 75,000ML available annually thus giving us an equivalent
net gain.
3.
The Grid system is designed to overcome some of the vagaries
of “Uncommon events”. At 500ML per day capacity, there is an addition
of most of this 182,500ML to the system. There is an annual net
gain
to the system of around 140,000ML after the Hinze Dam contribution
is deducted.
4.
With the Grid system
and Summer Rains providing approximately
1000ML per day, it is quite sufficient for our business as usual needs.
However, with no draw-down required for a decade or two, there is no
storage available for “uncommon events” when they return with the
exception of the first event and possibly part of the second. The
Summer rains have been quite normal for the last six years. The
“worst drought in 100 years” is the product of a misused decile map
with no uncommon events since February 2001 and normal summer
rainfall. There were 5 events in the short life of the Wivenhoe Dam
and we came to rely on them thus creating the observed stress on
the Moreton Region. With 20 events
Refer to page 16
Page 8
in the simulated
111 years and a multitude in the last 60 years of the
19th Century, they will return.
Refer to page
18
Because
there is no storage space and no requirement to draw on
them in the near future, a close run of uncommon events will mean that
the major portion of them will be lost over the spillway of the Wivenhoe.
The calculations of the last 30 years at Page 18 show that this
concatenation (linking together) of events will provide a loss of
113,096ML
a year over the spillway that cannot be retained in storage.
Refer
to page 15
With
the blocking off of the Borumba Dam to a mere 40,000ML
by the Traveston proposal, there will be no available space to contain
these events. It will result in a gain
to the
Brisbane
end of the
Brisbane
River Basin
and a loss to the Wivenhoe/Somerset System of 113,096ML.
This loss should be calculated in the effectiveness of the Traveston
thus reducing its supply to 36,904ML annually
(150,000ML – 113,096ML).
Our
proposal will collect most of this water but not all. It will occur
at the same time as our proposed retrieval of the GHD identified surplus
water of 80,000ML on an annualized basis. This will create pressure on the
safety level of EL 74m and thus a considerable quantity may be lost. The
capacity of the 2,000GL Borumba Dam will also be tested. This will create
a gain to the system of a volume not yet determined and may be
altered
by the Engineers if they increase the pumping capacity.
CLIMATE CHANGE
The
capacity of the enhanced Borumba Dam to 2,000GL provides
a suitable buffer to the natural
climate change of the first 70 years of
the 20th Century as evidenced in the charts provided in the
addendum
and the evidence of the Bureau of Meteorology flood information. It also
provides defense against perceived climate change created by the
exploding population of the World and its energy requirements. The
Engineers GHD have identified the suitability of the Borumba for a wall to
EL 320m which would retain most of the loss with suitable pumping gear.
Transfer from Brisbane river to Mary River
Lines 55 to 66:
There appears to be no argument about the proposal for the
transfer of water from the “
Brisbane
” River to the
Mary
Valley
.
The sole adverse
comment was in relation to the Moreton WRP already dealt
with. Therefore I will not offer scrutiny of the method employed. This
section
is added for completeness.
Page 9
FINAL ASSESSMENT OF THE PRECEEDING
DOCUMENTS
It should be apparent to the reader that the
basis of the selection of the Traveston
Crossing as a Dam site is predicated upon substantially flawed information.
The basis of my information is the monthly
rainfall figures of all Dam catchment Rainfall
Stations in the Wivenhoe,
Somerset
, North Pine, Borumba and the catchment of the
Mary
Valley
since Bureau records were kept. The information was in EXCEL spreadsheet
format which aided the production of information. Added to this was information
from
SEQWater website Annual Reports and various publications. Relevant
Government
websites were also examined.
ALTERNATIVE
PROPOSALS
This brings into focus to other methods of
managing our water supply requirements.
It is my view that it is the misunderstood
effect of “uncommon events” that created
the problem and hence my interest in their management through Inter-Basin
transfers.
INTER-BASIN
TRANSFER. WIVENHOE/SOMERSET DAMS AND ENHANCED
BORUMBA DAM
Additional
Summary of facts and circumstances
·
Engineers GHD in their June 2006 “desk top review of
identified Dam &
Weir sites” considered the Augmentation of the Wivenhoe Dam. In
that
section they considered the hydrology assessment of Department of
Natural Resources and Water (DNR & W) dated December 2005. An
increased Dam wall height would provide a further
yield of 80,000ML
on an annualized HNFY (historical no failure yield) basis if the Dam wall
was raised. This identifies the
surplus water at 80,000ML annualized
for 111 years 1890 to 2000 that occurs in times of “uncommon events”
( Monsoons, Cyclones and large rain depressions).
·
In the same section they considered the alteration
of operating
procedures to lift the current FSL of EL67m in the Wivenhoe. Safety
level is EL74m. This indicates sufficient time to withdraw all of the
water, referred to in the previous paragraph, from the flood compartments.
·
The surrounding evidence of the expanded
Borumba Dam to FSL 230m
and storage capacity of 2,000,000ML indicates a yield
in the region
of 90,000ML. The evidence of this yield will be considered in full in
this submission.
Page 10
·
Examination of the flood heights at
Brisbane
City
for the years 1840 to
1890 indicate that the 80,000ML calculated above rises to around 189,960ML
on an annualized basis for the 50 year period. It is also interesting to
note
that the last 30 years of the Twentieth century averaged 123,930ML on
an annualized basis.
·
The cost of the construction of the new Borumba Dam
wall to 230FSL with
the storage volume of 2,000,000ML has been supplied by the Engineers.
However it needs to be revisited as it was assessed in three stages. The
three stage cost is shown at $1,268 million whereas the GHD costing on the
dam to 197FSL, 23m less, was $324 million.
·
The pipeline requirements have been assessed
and running costs also
assessed both with engineering assistance. The preliminary engineering
requirements are in pages 33 to 36 of this submission. The overall costing
of this part of the project has been assessed at $500 million with
appropriate caveats at this early stage. This includes all pipes, pumping
equipment, access roads, electricity, land resumptions, easements,
intermediate stations etc. The pipe manufacturers indicate a cost of
pipes and fittings to be around $225 million.
·
Pumping main cost of electricity has been
calculated and is listed in the
Project costs. The cost of the Hydro plant has been assessed by JWP
engineers at $64 million. The output of the plant has been calculated by
JWP engineers at 2.8 megawatts. This compares with the output of the
Wivenhoe at 4.5 megawatts and the
Somerset
at 4.0 megawatts. This
output requires further consideration in the light of the capital cost.
·
The overall cost of the project depends on
the Dam costing. Including
the Hydro plant, it appears to be somewhat less than $2 billion. It is
difficult to obtain an accurate assessment of the Traveston proposal
including infrastructure such as road closing for the total project. The
most common figure used is $2.6 billion.
·
This submission should be read in
conjunction with a submission being
made by Mr R. McMah. It was he who pointed out the potential of the
Borumba Dam thus saving the
Mary
Valley
largely intact. My
concentration was on South East Queensland water supply. By a
happy coincidence both proposal eliminate the Traveston Dam.
·
I have no commercial or other interest in the outcome of this
submission
other than as a citizen of SEQ.
To gain an understanding of the proposal, it is necessary to understand the
action and consequences of “uncommon events”. We will retain the term used
by the Dam Managers.
Page 11
Page 12
Uncommon
events
We have seen above that uncommon events have
been identified by SEQWater as
Monsoons, Cyclones and large rain Depressions
that generally cover South East
Queensland. They have the capacity to fill the
Dams to overflow in a few days.
The official SEQWater “Historical Wivenhoe Storage Capacity” graph follows
on the
next page. It covers the period January 1990 to June 2006. I have added
the
known “uncommon events” that occurred in that period. I have estimated
the position
for the period 1986 to 1989 when the Dams filled to overflow.
The graph further illustrates that the population requirements were constant
throughout
the Dam life. With three refills through uncommon events, the angle
of the draw down
after these events was constant
It also illustrates that it was supplied by five uncommon events
to 1999 and a topup
in February 2001.
Using SEQWater requirements to identify an
event and confirming the result with BOM
flood data, 18 were identified in the
Twentieth Century. This chart also follows on the
next
page but one.
We had obviously come to rely on and accept “uncommon events” as a permanent
part of our water supply when their recorded history and name suggests
otherwise.
It
is the surplus water that flowed over the Wivenhoe Dam wall four times in its
21
year life that I am interested in and will be examining later.
Add to that all
previous events.
The
Somerset
sits atop the Wivenhoe and releases its water collected into the
Wivenhoe.
Page 13
Page 14
Page
16
Concatenation
(linking together of uncommon events)
Most people with the responsibility of our
water supply appear to believe that there is a
drought in the catchments. It has
been demonstrated that there are two types of rainfall
that fill our Dams,
normal summer rainfall and “uncommon events”.
Summer
rainfall has been quite normal in the last six years.
Any deficiency has
been experienced in the non-summer months that do not usually
provide inflow into
the Dams.
The most important aspect is that since 2001 “uncommon
events” are having time
off, as their history shows, and are living up to
their name “uncommon”.
As the “drought” breaks, one envisages
that normal flows begin and that is that.
In this case the normal summer rains that
produce a daily average of 500ML and
the
water grid which will contribute an average of 500ML
per day will provide for our needs
without water restrictions. It seems to
concur with the EIS report when other dams in
SEQ are added. Our current
requirements are 700ML per day with restrictions.
This joint contribution of 1,000ML per day
converts to 365,000ML annually. This
compares with the attached yield/water
allocation of the
Wivenhoe/Somerset dams in the stage 2 interim report of
SEQRWSS of 374,000ML.
Consequently the inflow into the dams is the same as the
withdrawals on
a “business as usual basis”.
So
where does the rain from “uncommon events” end up?
We have seen from
the graph that two such events filled the brand new
Wivenhoe dam to overflow
in 1988 and 1989.
With the Dam now full in 1989, the
historical graph of the Wivenhoe Dam levels
shows that the recoveries required
to full capacity
were 27% in 1992, 55% in 1996, 30% in 1999 and 10% in 2001.
That represents a total percentage of 122% of the dam’s capacity.
We have seen that the Summer rain and the
Grid supply our ” business as usual”
needs so there is no need to
withdraw water from the Dams. The Traveston proposal
is supposed to be for
population growth.
This water amounting to 122% of the Wivenhoe
full capacity will now go over the
dam spillway because there is no space
available. This calculates to 1,421,300ML
or, in the 12 year span, 113,096ML
annually with a 9,000ML a year reduction for
evaporation etc.
This water, of course, is lost if the
Traveston is built. The Borumba Dam will be
closed off and incorporated with the
Traveston in stage 2 for a very small 30,000ML
a year. This forms part of the
Traveston eventual supply of 150,000ML.
Page 17
On the other hand if this proposal is
adopted, this water can also be pumped into the
Borumba Dam from the Wivenhoe.
It could fill 71% of the expanded Borumba dam
of 2,000,000ML in a 12 year
period.
The main purpose of the Grid System was to insulate our
requirements from
unpredictable
uncommon events. The heart of the
problem was the inability of the Wivenhoe/Somerset
system storage to retain all water from these events.
With the Borumba dam being used to store surplus water
from this proposal, they could
then be brought into
predictable calculation.
800ML per day was the product
of these events from 1974 to 2006 and led to the
expansion of water allocations from the
Wivenhoe/Somerset system.
With the Wivenhoe “uncommon events”
being brought back into play with the next
uncommon event and, with the Grid
system in full operation, this water becomes
surplus to our current needs. It is
that water that could provide for our growth and
the Borumba Dam reservoir held
in reserve as and when required well into the
21st Century.
To illustrate the effect over the period 1974 to 2001, the next
page outlines the
calculations.
Page 18
Page 19
The
alternative project
Available surplus water
The following four pages illustrate the
volume of water that currently finds its way over
the spillway of the Wivenhoe
Dam. They clearly show a volume of 80,000ML a year on
an annualised basis.
The volumes do not flow on an annualised
basis. The volumes are calculated from
available data and crosschecked with the
known annual volumes. This information
follows in the next section.
They also have an important bearing on the
time to pump such large volumes of water.
Attachment A 14. Location of the Borumba Dam
Attachments 19, 20 and 21. Link to North
Pine Dam in this website.
Page 24
Page 25
Page 26
Expected
flow volumes
These calculated volumes are cross checked
in total with the annualised available
water. They follow on the next page.
There are known dam levels for the period
1988 to 2001. For other periods, the
Dam level is the same as reported by DNR
& W.
Years 1889, 1890, 1893 and 1974 are major
events and have been dealt with
individually. This is particularly so in years
1889, 1890 and 1893 because of the
concatenation effect.
The surplus water from the concatenation effect
is not included in these calculations.
This surplus amounts to 113,000ML a year
on an annualised basis.
The intention is to show that this project
exceeds the expectations of the Traveston
on a like for like basis. This additional surplus water is a major adverse
consequence of the
Traveston Proposal.
The expected flow volumes are on the next page and this available surplus water
and its pumping requirements follow in the next section.
Page
28
Expected
pumping requirements
The important aspects of this section are
the Flood holding capacities of the
Wivehoe/Somerset system and the time
required to reduce and relocate the flood holding.
The flow volumes listed in the previous page
have been reassembled into yearly order.
The fifty years 1840 to 1890 have also been
included. They have been assessed on the
basis of the BOM graph of flood heights
at Brisbane
city from 1840 to 2006.
We have seen in this submission that the
surplus water that now flows over the
spillway of the Wivenhoe is 80,000ML on an annualised basis. The contribution of
the Borumba Dam expanded to 2,000,000ML is
90,000ML per year making a total
of 170,000ML. This compares with the Traveston
target of 150,000ML for all three
stages. This 80,000ML does not occur in an orderly fashion each year. It is
best observed
in climatic averages set out below:-
Climatic averages
A schedule detailing these climatic averages is on the
next page and a summary of
them follows:-
1.
The fifty years 1840 to
1890 show that for the Wivenhoe, on an annualised
basis, the total is
189,960ML. An overall excess over the
Traveston of
129,960ML
(189,960 + 90,000 – 150,000). It requires 190 days pumping with
pumping at
1,000ML per day.
2.
The eighty years 1891 to
1970 show that for the Wivenhoe, on an annualised
basis, the total is
189,960ML. An overall excess over the
Traveston of 5,078ML
(65,078 + 90,000 – 150,000). It requires 65
days pumping with pumping at 1,000ML
per day.
3.
The thirty years 1971 to
2001 show that for the Wivenhoe, on an annualised
basis, the total is
189,960ML. An overall excess over the
Traveston of
63,930ML (123,930 + 90,000 – 150,000). It requires 124
days pumping with
pumping at 1,000ML per day.
Return
of water from the Borumba Dam and pumping of the “concatenation
effect” from
the Wivehoe/Somerset to the Borumba.
Page 29
The main purpose of the Grid System was to insulate our
requirements from
unpredictable
uncommon events. The heart of the problem was the inability of the
Wivenhoe/Somerset system storage to retain all water from these events. With the
Borumba dam being used to store surplus water from this proposal, they can now
be
brought into predictable calculation.
800ML per day was the product of these events
from 1974 to 2006 and led to the
expansion of water allocations from the
Wivenhoe/Somerset system.
With the Wivenhoe “uncommon events”
being brought back into play with the next
uncommon event and, with the Grid
system in full operation, this water becomes
surplus to our current needs. It is
that water that could provide for our growth and
the Borumba Dam reservoir held
in reserve for future use well into the 21st Century.
These
calculations show that there is little need to re-pump to the
Wivenhoe/Somerset
system.
With the “Uncommon events” coming on
stream as a predictable water supply in
conjunction with the expanded Borumba,
there will be a reducing need to pump
the
“concatenation effect” from the
Wivenhoe/Somerset to the expanded
Borumba Dam.
It also likely that the Engineers will see a
need to link the Borumba to the
Grid system to reinforce the North Pine
Dam and surrounds.
Page 31
Engineering
applicable to the pipeline
The engineering assessment of this proposal was lost
by a misunderstanding. It was
incorrectly assumed that it was normal water from
the stressed Wivenhoe/Somerset
system in the Moreton region that was the subject
of the proposal rather than
the surplus
water.
Mr McMah refused to sign off on the terms of reference because the yield of the
Borumba dam was stated as 51,000ML for a 1,000,000ML dam whereas a dam
of
2,000,000ML was envisaged and naturally a higher yield.
In these circumstances, the fact that it was
surplus water to the stressed Moreton
region system appears to have escaped
their attention.
The Engineers’ and Hydrologists’
approach appeared to be “if there is something to it,
we will look into it
further”.
This is confirmed by JWP Engineers report
which partly involved the construction of
the Borumba Dam new wall. Their scope
is now listed:-
