Augmenting water bodies with Highly Treated Recycled Water (HTRW)

To improve water security, drought and environmental resilience of our water bodies many utilities and governments are exploring ways to augment natural systems with highly treated recycled water (HTRW). These can be used to improve environmental flows, secure yields through indirect potable reuse (IPR) and enhance environmental outcomes in urban waterways, including recreational access to water bodies, for urban cooling and liveability benefits.

Understanding the holistic short-term and cumulative long-term effects (positive and negative) and interactions arising from augmenting natural water bodies with HTRW in order to optimise integration of HTRW into the natural environment could deliver positive environmental benefits. This project focuses on research beyond environmental impact assessment and will enhance knowledge around the long term ecosystem changes that may occur beyond the current state of knowledge around augmentation with highly treated water.

Current knowledge includes best practice guidelines and frameworks around indirect augmentation of natural water systems. However, there are no established standards for indirect augmentation as each ecosystem may vary. There are also knowledge gaps for both short and long-term ecological changes of releasing HTRW. This includes the potential changes of releasing into natural environments, as well as benefits of releasing into more heavily disturbed (i.e., urban) environments. There is also limited understanding of ecosystem cascades from HTRW that may lead to unforeseen changes to the system that impacts on how we make decisions on managing HTRW into aquatic systems.