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Burnett Water Pty Ltd
Eidsvold Weir EIS
4. ALTERNATIVES TO AND NEED FOR THE
PROPOSAL
The Central Burnett Region (comprising Biggenden, Gayndah, Mundubbera and Eidsvold
Shires) is heavily dependent on the primary industries sector for economic prosperity and
growth, with over 42% of the workforce employed in Agriculture, Forestry and Fishing
(BIEDO, 1998). Irrigated horticultural and agricultural enterprises make a very important
contribution to the sector, particularly in the Mundubbera and Gayndah Shires. Some 64% of
the value of agricultural production in the Central Burnett is derived from irrigated land so that
the region is dependent on good quality water supplies.
The higher reliability of production and local employment associated with irrigation enterprises
as compared with rainfed enterprises is an important factor in maintaining investor confidence
in rural communities. Moreover, increased economic stability and growth prospects will also
have favourable social implications; e.g. through better retention of young people in the
community, reduced unemployment and availability of services in the town.
An appreciable proportion of the horticultural production, particularly citrus, is exported so
existing irrigation developments contribute to national export earnings as well as to the
Queensland economy.
In addition, urban and industrial developments are dependent on the availability of water
supplies. The three Shires of Eidsvold, Mundubbera and Gayndah have a total allocation for
urban use of 1,670 ML and 1,577 ML were delivered against this allocation in 1998-99 (State
Water Projects, 1999). This utilisation level of over 94% effectively leaves very little margin
(i.e. ~6%) available for future urban or industrial growth.
All water available from existing storages in the Burnett is committed already. Water
allocations, including those for urban centres, in the area served by the Upper Burnett Water
Supply Scheme total 27,954 ML and deliveries totalled 26,865 ML or over 96% of allocations
in 1998-99 (State Water Projects, 1999) again illustrating the lack of available supplies to
support further economic growth and underpin prosperity.
DNRM (2001) Report contains the results of a 1993 survey by the Steering Committee of the
Central Burnett 2005 Study to assess estimated future demands from existing and potential
water users. The total quantity of water requested in the section from Wuruma Dam to Degilbo
Creek over a ten-year period was 15,700 ML with 10,500 ML being a priority requirement
within five years. Because of failure of supplies from Wuruma Dam in 1995/96 and from the
start of 1999/2000 to the present, and restricted supplies over other periods since 1993, it is
highly likely that demands have increased substantially since the survey.
DNRM (2001) have estimated the potential demand for irrigation water based on full
development of irrigable soils. Estimates for the area within 5 km of the Burnett River between
the Nogo River and Degilbo Creek are given in Table 4.
Status – Final Draft 31 September 2001
Project Number – 831/000259 Our Ref − draftreport-vers04.doc
Burnett Water Pty Ltd
Eidsvold Weir EIS
Table 4. Potential demand for irrigation water based on full utilisation of available soils with
an average water use of 5.8 ML/ha
River reach Total area of Regulated Additional area Additional
irrigable soils licensed area for water
(ha) (ha) development requirement
(ha) (ML)
Nogo River to Mundubbera 7,850 2,220 5,630 32,650
Mundubbera to Gayndah 8,070 1,120 6,950 40,310
Gayndah to Degilbo Creek 10,240 770 9,470 54,930
Total 26,160 4,110 22,050 127,890
Source: DNRM (2001)
The 1993 survey of potential water users indicates that there is appreciable demand for the
water that will become available for irrigation as a result of the project and Table 4 shows that
there are more than adequate reserves of suitable land to use the water.
In addition, Mundubbera Shire Council has indicated that they have an urgent requirement for
an additional 200 ML of high priority water to remove the need for repeated annual negotiations
with Gayndah Shire Council for temporary transfers of allocation. Further supplies are likely to
be sought to support future urban developments.
Eidsvold Shire has a water allocation of 350 ML and water use is currently around 290 ML or
83% of the allocation. Thus it is anticipated that an increase in allocation or some reserve of
high priority water to be set aside as a result of the project will be sought. However, the matter
has not been considered by Council so that no estimate of volume is available at present.
Council will be seeking an allocation to support an integrated aquaculture/cabinet timber
production project as well. This project is anticipated to underpin a more permanent
employment base for the town in future. The majority of the town’s workforce is currently
employed seasonally in the fruit industry.
Alternatives to the project may be considered in terms of alternative sources of water and
alternative water storage options. The likely feasibility of a number of alternative sources of
water are summarised in Table 5. More detail on some issues may be found in DNRM (2001).
Available alternatives only yield small volumes of water in comparison with those from the
proposed project and/or provide water at a high cost.
Table 5. Feasibility of alternative sources of water
Source Notes on feasibility
Demand management § Water shortages in recent years have forced irrigators to improve
efficiency of water use through practices such as trickle or
microspray irrigation of tree and vine crops so potential gains are
small
§ Urban water use in the catchment is a small proportion of total water
use – DNRM state that a 20% reduction in urban demand across the
whole catchment would reduce water use by only 3,600 ML
Rainwater tanks § DNRM (2001) indicate that rainwater tanks could supply only 9% of
total urban demand at a capital cost of $56,000 /ML of yield
($56 /KL)
§ Quality of rainwater from tanks may be poor and first flush and
Status – Final Draft 32 September 2001
Project Number – 831/000259 Our Ref − draftreport-vers04.doc
Burnett Water Pty Ltd
Eidsvold Weir EIS
Source Notes on feasibility
disinfection systems may be required for potable use
§ Rainwater tanks are already used on almost all rural properties and
in some towns such as Mundubbera where aesthetic qualities of
reticulated water have been poor from time to time
Greywater reuse § DNRM (2001) indicate that greywater requires treatment before use
and that the capital cost of systems would be $23,000 to
$69,000 /ML of yield – 7,450 ML/a could be saved by full
implementation across the catchment by 2025
Wastewater reuse § Mundubbera wastewater is used for golf course irrigation already
§ Reuse of 90% of wastewater for irrigation would yield about
6,000 ML/a at present at a capital cost of between $4,600 and
$13,800 /ML (DNRM 2001)
Urban stormwater harvesting § Reliable estimates of cost are not available
§ Applicability in the Eidsvold to Gayndah area is limited because of
small urban centres
On-farm storages § Capital cost of ring tanks (1,454 ML capacity) is estimated at
$963 /ML of yield (DNRM, 2001)
§ Additional capital costs are incurred for high-capacity pumping
systems to fill storages
§ Additional operating costs are associated with the double handling of
water on-farm (filling then irrigating as a separate operation)
Alternative storage sites in the Central Burnett were examined by Hyder (1998). Their study
looked at the following proposals:
§ dam on the Auburn River at AMTD 14.4 km, 18.8 km or 22.5 km;
§ weir on the Auburn River at AMTD 4.64 km;
§ weir on the Burnett River between AMTD 290 km and 312 km; and
§ dam on the Burnett River between AMTD 317 km and 366.6 km.
Dam sites at AMTD 18.8 km and 22.5 km on the Auburn River were eliminated because any
dam with appreciable storage capacity at these sites would have a significant impact on
conservation values within the Auburn River National Park. A dam at AMTD 14.4 km would
be constrained by impacts on the National Park but could still increase system yield at Jones
Weir by an estimated 23,700 ML/annum at an estimated cost of $2,776 /ML.
It was found that a weir on the Auburn River at AMTD 4.64 km could yield 5,600 ML/annum at
low reliability of supply and an estimated cost of $1,100 /ML. However, it was concluded that
closer economic study was required.
Seven storage options along the Burnett River were examined by Hyder (1998) and the
outcomes of their evaluations are summarised in Table 6. Where more than one full supply
level was considered at any site, that with the lowest cost per megalitre of yield of high
reliability water is considered. The Consultant put the AMTD 300.4 km site forward as the
preferred weir option on the basis of similar performance and environmental impacts to the
AMTD 296.8 km site and lower cost. It was noted that further geotechnical investigations
should be undertaken before adoption of the site as a final choice.
Status – Final Draft 33 September 2001
Project Number – 831/000259 Our Ref − draftreport-vers04.doc
Burnett Water Pty Ltd
Eidsvold Weir EIS
Table 6. Summary of the evaluation of alternative storages in the Central Burnett
Site / Issue Evaluation
Dam at AMTD 366.6 KM
Engineering § Rock about 10 m under alluvium
§ Saddle dam required on left bank
Yield and cost § 19,400 ML at $3,206 /ML
Terrestrial flora and fauna § No extensive tracts of remnant native vegetation
§ Narrow and fractured riparian zone
§ Similar to weir sites near Eidsvold
Aquatic flora and fauna § Flood plain and a number of off-stream pools associated would provide
a wide diversity of high quality habitats
§ Natural flows downstream would be reduced appreciably
Cultural heritage § No sites of significance identified by study
§ Community consultation and an archaeological field survey would be
required
Socio-economic § Some 11,000 ha of land suitable for irrigation downstream
§ Appreciable resumption costs
Dam at AMTD 317.0 km
Engineering § Weathered rock outcrops on both abutments
§ Suitable for an RCC gravity dam
Yield and cost § 74,000 ML at $1,277 /ML
Terrestrial flora and fauna § No extensive tracts of remnant native vegetation
§ Narrow and fractured riparian zone
§ Similar to weir sites near Eidsvold
Aquatic flora and fauna § A number of off-stream water bodies (small tributaries) along the
waterway
§ Stream partly covered by riparian vegetation
§ Impoundment will result in loss of a number of high quality habitats
Cultural heritage § Impoundment would drown Ceratodus railway station
§ Community consultation and an archaeological field survey would be
required
Socio-economic § Severe impacts include inundation of current rail and road routes
requiring substantial diversions
§ Appreciable land resumption costs and loss of land already irrigated
Dam at AMTD 293.4 km
Socio-economic § Eidsvold to Theodore road would require diversion
§ Flooding of Eidsvold to Monto road and rail routes would limit storage
capacity
§ Site not investigated further
Weir at AMTD 295.3 km
Engineering § Up to 6 m of sand and gravel over decomposed or moderately
weathered rock
§ Right abutment would require extensive erosion protection works
§ River within Quaternary alluvium
Socio-economic § Road bridge would have to the carried over the weir with associated
costs
§ Site not investigated further
Weir / Dam at AMTD 296.8 km
Engineering § Site would be suitable for RCC weir
§ Site would be suitable for RCC dam with saddle dams up to 70 m long
and 21 m high
§ Longest saddle dam is 700 m
§ Up to 10 m of to hard rock in the streambed
Yield and cost § Dam 40,000 ML at $1,338 /ML
§ Weir 28,000 ML at $475 /ML or
Terrestrial flora and fauna § Tolderodden Conservation Park is downstream and unlikely to be
affected
Status – Final Draft 34 September 2001
Project Number – 831/000259 Our Ref − draftreport-vers04.doc
Burnett Water Pty Ltd
Eidsvold Weir EIS
Site / Issue Evaluation
§ Much of the impoundment area for the dam has been cleared or partly
cleared
§ Narrow strips of riparian vegetation remain
Aquatic flora and fauna § A number of off-stream pools associate with tributaries
§ Dam would result in loss of high quality off-stream pool habitats
reducing habitat diversity
§ Weir impacts would be confined to in-stream and riparian habitats
Cultural heritage § Close to Eidsvold Station homestead
§ Local waterhole believed to have cultural significance for Aboriginal
people
§ Community consultation and an archaeological field survey would be
required
Socio-economic § Weir would be within bed and banks without impacting on
neighbouring properties
§ Better dam sites are available
Weir at AMTD 300.4 km
Engineering § Materials are similar to those at the 296.8 km site with an alluvial
terrace extending about 400 m from the river on the right bank
§ Interpretation of seismic data indicated a dense layer, apparently
moderately weathered to fresh rock under the right bank alluvium
§ Further geotechnical investigations required
§ Site is suitable for a mass concrete or RCC weir
Yield and cost § 28,000 ML at $418 /ML
Terrestrial flora and fauna § Very similar to a weir at the 296.8 km site
Aquatic flora and fauna § Very similar to a weir at the 296.8 km site
Cultural heritage § Generally similar to a weir at the 296.8 km site
§ Site may be more acceptable to Aboriginal people than the 296.8 km
site
Socio-economic § Very similar to a weir at the 296.8 km site
Status – Final Draft 35 September 2001
Project Number – 831/000259 Our Ref − draftreport-vers04.doc
Burnett Water Pty Ltd
Eidsvold Weir EIS
Status – Final Draft 36 September 2001
Project Number – 831/000259 Our Ref − draftreport-vers04.doc
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