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Etheridge Shire Council to pursue Gilbert River Irrigation Scheme

For some time, Council has been promoting the Gilbert River Irrigation Scheme (based on the Green Hills dam) to facilitate a more intensive agricultural development in the Shire. Through this proposal, the Etheridge Shire sees an opportunity to progress orderly development of the Gilbert River area in accordance with Government policy and through accessing funds currently available under the Federal Government’s National Water Infrastructure Development Fund, the National Water Infrastructure Loan Facility and the Northern Australia Infrastructure Facility. The successful implementation of this project will promote employment opportunities, development of new agricultural industries and economic development generally.

Council intends to:

  1. partner regional stakeholders in developing a clearer and focussed development vision for land and water resources within the catchment;
  2. determine appropriate equity principles for future allocation of water (e.g. allowance for one to two significant developments, framework for innovative pastoral intensification, strategic Indigenous reserves reviewed and supported, etc) over time;
  3. evaluate and set guidance for progression of preferred water development supply options (including impact standards); and
  4. establish an Area Vegetation Management Plan under the VMA to allow for orderly and streamlined tree clearing arrangements to be proactively developed.  

With seven million dollars already spent through the CSIRO on studying the Gilbert, it is opportune to narrow the focus of interest to the single most viable alternative: the Green Hills dam (due to the level of documentation and access to suitable land (adjacent to the river, approximately 25 km immediately downstream)).  Sources from within the Federal Government have indicated that the latest a submission could be considered for the funding currently available is August this year.

Using the considerable CSIRO studies already completed, it is believed that a credible business case can be prepared and submitted within this timeframe based on the well proven Tasmanian Irrigation model which includes business case approvals being based on three conditions: viz. environmental and other approvals being achieved, private investment being raised through the sale of water entitlements and live tenders being in place to show that the infrastructure can be built within the budget provisions of the business case.  Only after demonstrating the fulfilment of these conditions is funding released against the milestones of the Federal / State funding agreement.

Council will be advertising for a Project Manager to lead the establishment of the Gilbert River Irrigation Scheme and gain the necessary approvals for this project.

Project Description

The project is based on the Green Hills dam located on the Gilbert River with the full supply level at approximately 30 metres above the natural riverbed, giving an impoundment volume of approximately 300,000 ML and yielding 200,000ML for irrigation under an existing allocation.  This is one of the dams proposed by the CSIRO studies conducted between 2010 and 2013. Delivery of the water is via the natural water course to one or more weirs on the Gilbert and a pump station on each weir delivering water via a pipeline approximately eight kilometres long to the boundaries of properties subdivided into lots of between 200 and 500 hectares. The lots will be subdivided from existing cattle stations where there is already approximately 12,000 hectares of cleared highly fertile land.  It is estimated that fertile land together with water at 8 ML/ha could be offered at between $4,500/ha and $6,500/ha.  It is proposed to raise between $90 million and $120 million of private sector investment in this way.  Throughout Australia, there is currently considerable investor interest in water if the right products are made available. 

Electrical power for the disaggregated blocks and pump stations will be reticulated from a new substation.  This land has already been mapped for soil quality and biodiversity.  It is intended to apply for permits to clear another 3,000 or 4,000 hectares once an Area Vegetation Management Plan is in place.

The Mareeba Dimbulah Water Supply System was established on tobacco in the mid-1950s but over time transitioned into high-value agriculture and horticulture and yielded $552M output in 2015 according to DAF, so it is proposed to use cotton as a host for Gilbert Irrigation.  Based on this approach, preliminary economic modelling by Marsden Jacobs and Associates has shown that the proposal is economically viable yielding an economic NPV of between $136 million and $267 million (depending on capital in the range of $220 million to $360 million) based on 84.5% of the water going to cotton, the complementary crop and the remainder going to a mix of higher value yielding crops.

The establishment of a water trading framework will ensure that the water migrates to higher value production over time and the economic performance is higher than modelled.

For more information contact Warren Devlin, Etheridge Shire Mayor on 0458 621 233.

Access the Preliminary Findings Report to view the Economic and Financial Assessment for the GRIS.