Completed 2021 East Kimberley

The East Kimberley project built a greater understanding of groundwater systems in the onshore Bonaparte Basin within the Keep River Plains in the Northern Territory (NT) to enable informed decision-making for agricultural development.

The project focused on the Permian and Carboniferous rock units of the onshore Bonaparte Basin and their significance to groundwater in overlying Cenozoic sediments. This is because these geological units underlie most of the proposed agricultural development areas.

Current land use in the area includes grazing cattle on large pastoral properties (such as Legune and Spirit Hill stations), and irrigation of crops in the Ord River Irrigation Area (ORIA) north of Kununurra. In October 2020, the Northern Territory Government released 67,500 hectares of agricultural land to the north and east of the current ORIA, including on the Keep River Plains. The region has good road, port and energy infrastructure, with a local labour force based in Kununurra and Australia's second largest reservoir by volume (Lake Argyle). However, additional water security is required to support further agricultural development, particularly in upland areas.

Benefits

The East Kimberley project has provided baseline information about groundwater conditions and processes in the onshore Bonaparte Basin. By combining point-measurements of salinity with geophysical data from airborne electromagnetic (AEM) surveys, this project mapped fresh, brackish and saline groundwater resources across the Keep River Plains. Detailed elevation and vegetation data, combined with geomorphic and geological mapping, were used to determine likely areas of groundwater recharge and discharge. The results can feed into decision making relating to management of land and water resources, particularly as irrigated agriculture expands in the area.

Project objectives

The main objectives of the project were to:

• identify the location, quantity and quality of new and existing groundwater resources in sedimentary basin and palaeovalley aquifers
• identify potential hazards to agricultural development in the Keep River Plains where Cenozoic alluvial aquifers occur
• de-risk resource and agricultural investment, and inform water management options by providing baseline hydrogeological data.

Collaboration

Project collaborators included:

• The Northern Territory Department of Environment and Natural Resources (DENR), now Department of Environment, Parks and Water Security (DEPWS)
• The Kimberley Land Council
• The Northern Land Council