THE PROJECT

As a result of increased recharge following the clearing of native vegetation in the wheatbelt of Western Australia, many low-lying rural towns, such as Wagin, have become adversely affected by secondary salinity caused by rising water tables.

Recharge can be limited by re-vegetation and improved surface water control, but the most effective method of lowering water tables is to implement a dewatering scheme.  At Wagin, this was achieved by installing a network of eight production bores into a widespread zone of permeable “saprolite grit” located at the base of the granitic weathering profile.

Extraction from three of the main bores since 2008 has resulted dewatering of the town to the extent that sallow water tables and secondary salinity are no longer a problem.

The Wagin dewatering scheme funded by the Department of Primary Industries and Regional Development (DPIRD) as part of the Rural Towns – Liquid Assets Programme.

Much of the exploration and drilling and testing of the production bores was performed by Rockwater under contract to DPIRD.  We also designed the pumping and piping infrastructure, which transfers the dewatering water to a nearby salt lake for disposal by evaporation.

Rockwater was also largely responsible for the establishment of a similar dewatering scheme at Merredin.

• Geological interpretation
• Field investigation reporting

• Gravity surveys
• TEM surveys
• RAB exploration holes
• Mud-rotary production bores
• Pumping tests
• Dewatering trial