Wagin townsite borefield: review of aquifer performance

Authors

Rockwater

Publication Date

11-2022

Publisher

Rockwater Pty Ltd

City

Perth

Abstract

The Wagin Borefield was established by the Department of Agriculture and Food, Western Australia in 2000-2007 to control groundwater levels in the town that had risen to critical levels as a result of increased recharge and runoff following the clearing of native vegetation for urban development and agriculture. Similar investigations were conducted as part of the Rural Towns Program and Rural Towns-Liquid Assets projects in 41 other wheatbelt towns, but none, except perhaps from Merredin, have been as comprehensively implemented, operated and monitored as Wagin.

The Wagin Borefield comprises 8 production bores, of which only 3 have been operated. To assist with definition of the townsite geology and hydrogeology, and for the measurement of water levels, 113 monitoring bores were installed throughout the town area.

The last review of pumping rates and water levels at Wagin was performed by Rockwater (2008), when only one of the production bores was in operation. Since then 2 other bores have been commissioned and the 3 bores have been pumped more or less continuously, resulting in a widespread amelioration of the shallow watertable problem.

In 2022, DPIRD engaged Rockwater to conduct another review of the Wagin Borefield, focussing on the effects of pumping on water levels and the sustainable yield of the aquifer.

This aquifer performance review is particularly important at Wagin because of the apparent inability of the borefield to supply sufficient water to operate a small reverse osmosis (RO) plant used by Unigrain for the processing of oat crops. The Unigrain RO plant ceased operation in November 2019, but could be recommissioned if groundwater were made available. Another option would be for Unigrain to purchase the permeate from the RO plant to be installed by WaterSmart Farms. The feed water requirement for the WaterSmart Farms RO plant is likely to about 150 kL/d, which at a recovery rate of 50%, should be sufficient to produce 25 kL/d of water for Unigrain and 50 KL/d of water for the Shire of Wagin.

Number of Pages

96

Keywords

groundwater monitoring, pumping, aquifer, hydrogeology, dewatering townsite, Wagin

Disciplines

Agricultural Science | Agriculture | Environmental Monitoring | Geology | Hydrology | Sustainability | Water Resource Management

Comments

The results of this Wagin borefield review will be used to help assess the viability of establishing a small reverse osmosis plant at Wagin as part of the WaterSmart Farms Project, which is being undertaken by DPIRD and the Water Corporation to trial the application of local, small-scale desalination systems to reduce dependence on scheme water.

This review builds on Groundwater study of the Wagin townsite.

Recommended Citation

Rockwater (2022) Wagin townsite borefield: review of aquifer performance, report to Department of Primary Industries and Regional Development, Rockwater Pty Ltd, Perth.

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