This National Groundwater Awareness Week we're shining a spotlight on this priceless resource. One which around 44% of the world's population depends on as its primary water source. In Australia, groundwater is about a third of our water use and much of it is still unused.
It's not only the human population that depends on groundwater - our flora and fauna, including many ecosystems, need it to survive. It hides beneath the Earth's surface, usually not in caves or lakes, but in tiny gaps. It's like wet sand at the beach, the water is there, but you cannot see it until you dig.
With all this in mind, it's clear we need to make every drop count. Lucky for us, Australia is tapping into the latest science and technology to ensure we can do just that. We're leading the way when it comes to brackish groundwater innovation.
Supported through the work of our National Water Grid science projects, we're also:
- mapping where it's located
- updating modelling guidelines so it can be sustainably used
- storing excess water underground for later use (for example, water captured from floods and storms) to prevent evaporative loses
- investing in new ways to treat it so it's safe for use.
We'll highlight this work in action as we follow a simplified process of groundwaters' 'lifecycle' - from finding it through to being able to use it.
To start, a case study focused on locating groundwater. Western Australia is our biggest state or territory by land size, so that would suggest it's home to a range of groundwater resources. Last year, CSIRO completed a deep dive into brackish groundwater in the state. They mapped where it can be found, including identifying around 4,000 gigalitres, or 4 trillion litres (around 8 Sydney Harbours worth) that could potentially be put to use.
As we continue to map groundwater, one key next step is to revise our modelling guidelines to ensure they are up to date. Right now, the guidelines are out of date, technology has changed and so have stakeholder needs.
These guidelines will contribute to a broader set of information available to decision makers. They will play a role in supporting more informed decisions, such as:
- directing investment toward the most effective infrastructure
- helping our regions plan long term projects
- ensuring groundwater remains available for environmental needs, such as keeping ecosystems alive
- supporting cultural connections to water.
Having national guidelines will also ensure consistency across states and territories. We're aiming to ensure everyone is on the same page that is centred around best practice.
With groundwater located and guidelines in place, we then need to use science to treat the water so it's safe for use. There are a range of options available, many advanced and some still on the newer side, including:
- using desalination technology, in other words, treating any form of salty groundwater and making it fresh and safe for use
- focusing on renewable energy to power the treatment process
- creating new underground water storages, allowing water to be pumped and stored during wet times, and then pumped back out for use during dry times
- using a special 'draw solution' technique that sucks water through a membrane, leaving behind salts and using less power
- electrodialysis reversal, which is the use of electric currents to remove dissolved salts from water.
While the process we've outlined above seems simple, it's far from it. These are just a few of the projects underway or completed. The list goes on, and is constantly growing, when it comes to understanding groundwater.
Through our National Water Grid projects, we're helping to fill in any information gaps and update what we know about this hidden gem.
