Investigating alternative water supply options for two Regional Communities, with a novel climate change sensitivity

Abstract

The townships of Miriam Vale and Bororen are small communities supplied with potable water by located Gladstone Regional Council (GRC). The communities often face water restrictions during drought conditions, and groundwater supplies can be limited by salinity. Engeny worked with GRC to define the current level of water supply security for both towns, then investigated a long list of possible water supply options. These options ranged from significant infrastructure solutions like supply pipelines, harvesting dams, weir raises, treatment plants and additional bores to lower investment options like leakage reduction and demand reduction measures. Alternative options like evaporation reduction and water recycling were also explored.

A review of Level of Service (LOS) objectives for water supply was undertaken and LOS objectives set for the communities. A key LOS objective is the frequency of water restrictions. They must account for local hydrology and demands.

To aid the assessment of benefit, water balance models were developed and calibrated for both Baffle Creek and the Bororen Borefield. A novel methodology was then developed to simulate the potential impacts of climate change on water supply security - by extracting publicly available but lesser-known datasets developed by CSIRO and DES (now DESI) for 11 Global Climate Models.

A Multi-Criteria Analysis was undertaken of the shortlisted options and clear recommendations made. Council have enacted various actions recommended by this work, with successful outcomes reported.

This methodology could be applied for other small communities that do not have well-understood and/or reliable water supply to help guide future planning and expenditure to achieve a cost-effective benefit for the communities, with consideration to ever-changing climate conditions.