Seeking out potential irrigation development in the Pilbara
The Transforming Agriculture in the Pilbara (TAP) project is currently undertaking land and water assessments, which will validate water resources and soils at a number of sites including Lower DeGrey River, Shaw River, north Newman and Karratha Hinterland.
Department of Primary Industries and Regional Development (DPIRD) soil scientist Henry Smolinski and senior technical officer Tim Pope recently completed surveying in the Shaw River area, North West of Marble Bar. They were on the lookout for free draining soils with good nutrient and water holding capacity that are highly suitable for irrigation.
Mr Smolinski said his team observed considerable areas of red loamy soils that have a sandy loam to clay loam soil texture.
“These loamy soils, particularly the coarser textured sandy loams, are better drained and can be irrigated with less potable water,” Mr Smolinski said.
“Matching soils with water supplies of varying quality is one of the challenges in determining site suitability for irrigation development.”
Further north in the Karratha Hinterland, Mr Smolinski surveyed the Horse Flat land system locally known as the Roebourne Plains.
He found red cracking clays being extensive on the alluvial plains between Karratha and Port Hedland and have a high water holding capacity but commonly have salt within the subsoil. However, when this soil type occurred near the main river systems and subject to more frequent flooding, they have been leached of salt and highly suitable for irrigation.
DPIRD hydrogeologist Bob Paul is collecting water samples from bores belonging to pastoral and mining companies in the area to determine the depth to groundwater and water quality.
Groundwater resources for irrigation are required to have low levels of total dissolved salts and must be found at relatively shallow depths below ground level in order to minimise pumping costs.
Project manager Chris Schelfhout said the soil and water information collected by the TAP project would allow developers to focus on locations that had good quality water and soils that were most suitable for irrigation.
This information will be shared with other agencies including the Department of Water and Environmental Regulation to enable more efficient decision making when processing water licence and development applications.
DPIRD has been working with pastoralists and aboriginal corporations in the TAP focus areas but is keen to engage with others in the Pilbara seeking to understand more about irrigation opportunities on their tenure.
Anyone interested are encouraged to get in touch with Chris Schelfhout or phone 9143 7011.