Northern Stuart Corridor
The Northern Stuart Corridor Project includes two project areas: the Daly River Basin and Howard East area.
Daly River Basin
Groundwater in the Daly basin supplies 80% of the water extraction in the region for a range of applications including town supply and water consumptive industries like agriculture, horticulture, stock supply and forestry. Additionally, groundwater provides baseflow to the Daly River during the dry-season and is critical for sustaining eco-systems, tourism and for indigenous culture. Groundwater is predominantly extracted from the Cambrian Tindall limestone and Oolloo dolostone. However the geometry of these aquifers is poorly constrained in areas where borehole information is sparse.
As part of the Exploring for the Future program, a ~3,500 km2 airborne electromagnetic (AEM) and magnetic survey was flown over the Daly River Basin (see Figure 1) in 2017 for reconnaissance-scale mapping of the groundwater system. The AEM data has been used to model the interfaces between the Jinduckin and Oolloo Aquifers and image basin scale structures. These mapped products can be used to build more accurate groundwater-surface water flow models to underpin informed water management decisions in this region.
Borehole geophysical and hydrochemical data were also collected in the Daly River Basin and are available via the Exploring for the Future portal.
Up to 90% of Darwin’s town water supply is sourced from Darwin River Dam. The remainder comes from groundwater supplied from Howard East and McMinns Borefields in the Koolpinyah Dolostone Aquifer (KDA) and contributes of up to 15% of the city’s water supply. Groundwater from the KDA is also essential for domestic use in rural areas and for irrigated agriculture. Increasing demand coupled with a number of low-rainfall wet seasons has put pressure on groundwater resources.
Previous investigations in the Howard East area indicated a potential seawater intrusion (SWI) hazard to the existing groundwater resource (Fell-Smith and Sumner, 20111; Tan et al., 20122). Seawater intrusion can impact water quality in aquifers, rivers and estuaries, and floodplain and wetland ecosystems. As part of the Exploring for the Future program, new groundwater and surface water chemistry, salinity monitoring, airborne electromagnetic (AEM) and borehole geophysical data have been collected. The findings from project will contribute to building a complete conceptual understanding of the KDA near the Howard East Borefield.
- Borehole geophysical and hydrochemical data;
- Groundwater level and salinity data (Howard East only);
- Hydrostratigraphic surfaces (Daly River Only);
- Technical reports describing key results from the two study areas.
New data acquisition
The project collected:
- 5,423 line-kilometre airborne electromagnetic and magnetic survey
- 59 boreholes logged for induction and gamma.
The Northern Stuart Corridor project was undertaken collaboratively with the Northern Territory Department of Environment and Natural Resources.
Other key stakeholders include NT Power and Water Corporation, Northern Land Council (NLC), Tindal RAAF Base, NT Cattleman's Association, local indigenous groups and landholders.