Managed aquifer recharge (MAR) is the intentional draining or discharging of water directly or indirectly into a well (aquifer) for subsequent recovery or environmental benefit. If the intention is to extract the water post recharge, this process is referred to as Aquifer Storage and Recovery (ASR) (if the water is extracted from the same well it is drained or injected into). Or Aquifer Storage Transfer and Recovery (ASTR), is when the water that has been drained or injected is taken from a different well, generally where a hydraulic connection to the well in which the water was drained or injected has been determined.
MAR can help replenish depleted aquifers and is a way to store various sources of water until it is needed at a later date. In times of low rainfall, for example, water that has been stored in an aquifer can be extracted and used for irrigation or industrial use, to supplement water sourced from native groundwater sources or river water.
In South Australia, although initial MAR investigations can be traced back to the early 1950’s, MAR scheme investigation and implementation didn’t start until the early 1990s, mainly as a part of stormwater harvesting and reuse schemes. The Department for Environment and Water (DEW) Technical report ‘Managed aquifer recharge schemes in the Adelaide Metropolitan Area’ provides a useful summary of Adelaide’s MAR infrastructure as well as providing information to assist further optimisation of Adelaide’s alternative water infrastructure.
Find out how to plan, build and operate a MAR scheme or about MAR regulations.
Significant projects in South Australia
See the stormwater reuse projects happening in Greater Adelaide on the Natural Resources Adelaide and Mount Lofty Ranges website.
Established MAR schemes in South Australia include those run by:
To download technical reports and other studies in relation to aquifers and MAR schemes, visit WaterConnect groundwater.
How do MAR schemes work?
MAR schemes can be set up utilising surface water sources such as watercourse water, stormwater, and roof runoff, as well as treated wastewater under certain circumstances.
Many organisations, such as councils and golf clubs, use MAR schemes as a way to improve their water security, which includes improving their native groundwater quality. They are able to recharge and store excess water in winter and recover it in summer when irrigation needs are greater.
For a MAR scheme to be feasible, you will need:
• a suitable source of water
• an ability to adequately treat the water to a suitable quality to meet guidelines
• an appropriate aquifer in which to ‘recharge’ the treated water
• a potential end use if the water is to be extracted
MAR schemes can be categorised broadly under two types:
• Aquifer Storage and Recovery, where water is recharged into an aquifer via a well and later recovered for use from a well completed in the same aquifer
• Aquifer Storage Transfer and Recovery, where water is recharged into an aquifer via one well and later recovered via a different well
See also CSIRO’s website regarding using MAR in Australia for more examples of the types of MAR schemes.
Find out about different scales of MAR schemes, ranging in size from single-house to regional, or see the step-by-step stages of a MAR scheme.
Are there any risks?
MAR schemes have the potential to attract many hazards and difficulties. It’s essential that their planning, design, construction and operation is carefully thought out and managed.
Typical examples of the pitfalls to the establishment and operation of a MAR scheme include:
• a highly variable and unreliable supply of source water
• the absence of a suitable, local aquifer
• the inability to recover recharged water due to aquifer properties
• insufficient land for harvesting or pre-treatment of water prior to recharge
• the contamination of recharged water due to geochemical interactions in the aquifer
• the contamination of aquifer due to inadequate quality control of recharge water
• a non-competitive cost benefit of the scheme
• not fully understanding the regulatory requirements and timeframes around getting approvals from the regulators for the commissioning and operation of the scheme.