Underground water key to quenching region’s thirst
UNDERGROUND water sourced from Alstonville, Newrybar, Tyagarah and Woodburn is part of the water security plan for the Northern Rivers.
Rous County Council this week adopted its draft document called Future Water Project 2060
Integrated Water Cycle Management Plan, to go on public exhibition on July 1.
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The plan explained a possible Dunoon Dam will take at least nine years to build, so underground water could keep the region hydrated until then and remain as an important source of the element.
The idea includes the reinstatement of bores at Woodburn and Alstonville, plus new borefields at Tyagarah, Newrybar and Alstonville.
This location expands on an existing scheme, licences and land, but has low yield and high cost.
An existing bore supply at Woodburn consists of three bores in the coastal sands aquifer which supplies to the Lower Richmond River supply area (Woodburn, Broadwater, Evans Head and Coraki) during dry periods.
In 2007/08 the borefield produced 46 ML.
The existing borefield has a licence entitlement of 726 ML/a. Bores 1 and 2 were compromised by the development of the Pacific Highway and are no longer used.
Bore 3 has been replaced and is used as an emergency supply.
Water quality was determined to be suitable for drinking water if appropriate treatment is
The concept design for the Woodburn borefield includes four production bores (the existing No. 3 plus three new ones).
Two options for groundwater supply at Newrybar have been identified (north and south) which may be combined to reduce costs.
The groundwater supply from these two sources would be combined with existing supplies to the Knockrow reservoir.
This location means relatively high cost groundwater but high yield, and requires a new
The site would mean the need for brackish water desalination to produce drinking water quality.
This location offers relatively low-cost groundwater and high yield, but requires a new
scheme in two parts.
Scheme 1 would transfer the treated groundwater to the Ocean Shores reservoirs and Rous retail customers. Scheme 2 would transfer the water to the St Helena reservoir.
The report suggests initial construction of Scheme 1, with future expansion to include Scheme 2 with an ultimate capacity of 12.5 ML/d.
The future scheme would supply all of the Byron Shire, apart from Bangalow.
Alstonville / Wollongbar
The report explains that the expansion of Marom Creek Water Treatment Plant and the use of Alstonville groundwater is the preferred first action by Rous County Council, as it will achieve the short-term secure yield outcomes required from existing assets owned by the community.
The existing Alstonville borefield consists of two production bores, one at Lumley Park and one at Converys Lane, which extract groundwater from fractured basalt to augment supply during dry periods.
This option proposes that the bore at Lumley Park be retained while the bore at Converys Lane would be replaced with a new bore adjacent to the existing bore.
A new water treatment plan and a transfer pump station and pipeline, to transfer the groundwater to the Wollongbar reservoir, would be required.
The estimated long-term capacity of the two bores is 4.5 ML/d.
Initial capital costs for the Woodburn plan would cost $36.4 million, while the Integrated
Newrybar plan would reach $63.1 million.
The Tyagarah (Scheme 1) initial capital costs would be around $50.8 million; with further $30.4 million for Tyagarah (Scheme 2).
The Alstonville plan's total initial capital costs were estimated in the report at $25.9 million.
Implementation of groundwater options will have a lead time of approximately 2.5 to 4.5
years (to allow for additional investigations, approvals and construction).