The Lower Gascoyne plan area is located approximately 900 km north of Perth.
Groundwater resources in the plan area
Groundwater is the main water source in the plan area. There are three groundwater sub areas within the Gascoyne area – Subarea A, Subarea B-L and Yandoo subarea.
The Gascoyne groundwater area overlies the Lower Gascoyne Alluvial aquifer and the lower Gascoyne surficial aquifer.
Surface water resources in the plan area
Surface water in the lower Gascoyne area is accessed during river flow events like cyclones. The Carnarvon surface water irrigation district is within the plan area.
Water planning in the Lower Gascoyne plan area
Groundwater salinity is a critical issue in the Lower Gascoyne area and the allocation plan is integral to managing abstraction to prevent significant or permanent degradation of the aquifer. Historical water quality trends and groundwater modelling indicate that salinity is best managed with a combination of allocation limits and salinity thresholds.
The plan sets allocation limits and local licensing rules that define how much water can be sustainably abstracted from each resource annually.
The Lower Gascoyne water allocation plan for public comment was open for submissions from the 30 November 2010 to1 April 2011. This included a two month extension to allow for the disruption caused by flooding during the comment period. The final plan was amended where appropriate to take into account the formal comments and feedback during the public comment period. We have released a statement of response document which details how individual comments were considered in plan finalisation.
The Lower Gascoyne allocation methods report describes how we determined the allocation limits in accordance with the departments allocation planning process.
Why has the department prepared a water allocation plan?
Water allocation planning in the Lower Gascoyne is needed to:
- support the increasing agricultural potential of the region being driven by the cross government priority, the Gascoyne Foodbowl Initiative.
- increase the precision of management arrangements set out in Managing the groundwater resources of the Lower Gascoyne River (Carnarvon) WA (WRC 2004) to allow for more water to be accessed by individual growers in Subarea A while managing the risk of increased salinity.
Since the 2004 strategy we have collected new information and undertaken groundwater modelling to improve the accuracy of the yield range, so that we can be more certain about how much water we should allocate for abstraction.
Stakeholders are actively involved in managing abstraction in the Lower Gascoyne and extensive consultation during the planning process benefited from the historical knowledge held by the community.
How can I access any of the information on the Lower Gascoyne that the department has produced?
We are committed to making the information that we use in the planning process publically available.
Please click in the links to access the following documents:
Allocation plan and supporting documents
Lower Gascoyne water allocation plan
Publish Date: 2011
Lower Gascoyne allocation methods report
Publish Date: 2011
Lower Gascoyne water allocation plan : statement of response
Publish Date: 2011
Hydrogeological reports
Groundwater recharge from the Gascoyne River, Western Australia,
Publish Date: 2002
The assessment of groundwater resources of the Gascoyne Aquifer System using GASFAMS Volume 1
The assessment of groundwater resources of the Gascoyne Aquifer System using GASFAMS Volume 2
Further information
For licensing information please contact our Mid-West Gascoyne Regional Office in Carnarvon. Phone 08 9941 6100.
For planning information, please contact the Department’s Water Allocation Planning Branch. Phone 08 6364 7600 or email allocation.planning@water.wa.gov.au