Mereenie Aquifer Alice Springs
Frequently asked questions
How was the Mereenie Aquifer formed?
Mereenie is the largest of several aquifers that make up the Amadeus Basin Rock Aquifer System. It is the major source of water for the public water supply borefield at Roe Creek, providing about 80% of the drinking water supply. The other 20% comes from the Pacoota, Shannon and Goyder formations.
Mereenie is made of natural sandstone, originally deposited as desert sands an estimated 430 million years ago. Over time the sand has become stone, full of fractures and cracks. This acts like a sponge, holding large volumes of water that can be accessed using deep bores.
The water that is stored in the aquifer is very old, dated 10 000 to 32 000 years old. This rain fell in a much wetter climate than our current experience, although some rainfall today reaches the aquifer following flows in the Todd River and Roe Creek.
How much does the Mereenie Aquifer hold?
Mereenie holds vast amounts of water but some of it is salty. It is estimated that the aquifer holds 5 to 6 million megalitres of water suitable for drinking, but only 1.3 million megalitres of this is high quality (similar to what you drink now).
One megalitre is about the amount of water in an Olympic-sized swimming pool.
How sustainable are our water supplies?
Unfortunately, much more water is taken from these aquifers than they receive from rainfall and river recharges. As a result water levels at the Roe Creek borefield (currently about 150 metres below the surface) are dropping about one metre every year.
The water in Mereenie Aquifer is considered non-renewable, as the rate of recharge from rainfall is insignificant compared to what is pumped out for public water supply. The water is basically being mined.
There is still a lot of water in the basin, but as levels drop bores have to be deepened and new bores drilled. This is expensive and uses more energy for pumping. The water will also be of lesser quality and will require extra treatment before use.
The life of the Aquifer depends on how we use the water now and in the future. At current rates of use, the water resource should last for a few hundred years, but this depends on everyone conserving water and finding new ways to be efficient with water.