From drought-risk bulletins and Sustainable Development Goals (SDGs) dashboards to national climate adaptation plans, one solution continues to surface: managed aquifer recharge (MAR).
Having evolved since its introduction in the 1960s, MAR involves using excess surface water to recharge aquifers for use during drier periods. Today, recharge schemes throughout the world collectively replenish an estimated 10 cubic kilometers of groundwater each year. However, despite its steady growth, MAR still accounts for only about 1% of global groundwater extractions.
According to the Global Inventory of MAR Schemes maintained by IGRAC, there are more than 1,200 documented MAR sites in over 50 countries which indicates that it has moved beyond isolated experiments, although its adoption remains irregular.
As climate change drives longer dry seasons, erratic rainfall and growing pressure on groundwater reserves, MAR is attracting greater attention, but its wider adoption seems to depend less on engineering and more on governance, financing and long-term planning.
Therefore, the debate is shifting from whether MAR works to whether governments are willing to invest in it at scale, regulate it effectively and integrate it with broader water management strategies.
Can MAR help to achieve the SDGs?
UNESCO highlights the ability of MAR to address several development challenges at once: improving water security and quality, strengthening drought resilience, supporting cities facing growing demand, and protecting groundwater-dependent ecosystems.
MAR is therefore relevant to SDG 6 for clean water and sanitation, SDG 13 for climate action, SDG 11 for sustainable cities, and SDG 15 for life on land.
For SDG 6, MAR can help to maintain water supplies when surface sources fail, while also improving water quality, preventing seawater intrusion, and supporting environmental flows. For climate adaptation, it offers a method of capturing excess rainfall during wet periods and storing this for use during droughts. In urban areas, MAR can help cities to manage stormwater and reduce pressure on conventional water sources. For SDG 15, MAR can help to keep rivers flowing during dry periods and prevent stress from groundwater decline.
As Dr. Alice Aureli, former head of UNESCO’s groundwater program, explains:
“Groundwater is the invisible part of climate adaptation. If we don’t manage recharge, we are only managing scarcity.”
However, its contribution to sustainable development depends on many more factors than the actual technology itself, with experts warning that its long-term success depends on the systems needed to govern it: groundwater monitoring, clear regulations, water-quality safeguards and effective management of extraction.
Who pays for groundwater resilience?
The argument for MAR is ultimately an economic one: can the cost of storing water underground be justified against the cost of drought, deteriorating aquifers and emergency water supplies?
Water scarcity already carries significant economic costs. Inadequate water supply and sanitation are estimated to cause US$260 billion in losses annually, while more than 2 billion people and 40% of agricultural production depend on overexploited groundwater reserves.
However, evidence suggests that the economics can still work. An analysis of 21 MAR schemes in 15 countries found that most had “positive or neutral effects” on groundwater storage and quality, demonstrating “strong returns on investment”.
The problem is therefore less about whether MAR can generate value and more about who captures that value. As groundwater economist Robert G. Maliva noted in his research paper, the challenge is that the costs involved in MAR are often upfront, while the benefits only accrue over time, and the beneficiaries are not always those who initially paid for the project. Cities can benefit from more reliable water supplies, farmers can avoid falling groundwater levels and governments can avoid the costs of drought response.
This means public investment is particularly important. For developing countries, external finance can also be vital. In South Australia, federal and state governments are jointly financing projects to test underground storage for drought and climate resilience, including a $4.8 million aquifer storage and recovery project in Loxton. Meanwhile, in Bangladesh, most MAR initiatives are supported by external funding.
MAR is not a standalone solution
MAR’s value becomes clearer when it is compared with other approaches to water security. Wetland and watershed restoration can protect natural water systems and deliver biodiversity benefits, while rainwater harvesting can provide a relatively simple, decentralized supply. Wastewater reuse can be a reliable source for recharge, while desalination produces freshwater when conventional sources are insufficient.
MAR has a different advantage: it can store water underground, reducing evaporation and allowing surplus water captured during wetter periods to be held for use during droughts. But it also depends on suitable aquifers, reliable recharge sources and effective groundwater regulation. Desalination, by contrast, does not depend on specific aquifers but does entail substantial energy and investment. Wetland restoration and watershed protection can provide wider ecosystem benefits but cannot by themselves guarantee water supplies during a prolonged drought.
The implication is that MAR should be judged as part of a portfolio of options rather than as a replacement for other measures with the appropriate combination dependent on local water availability, geology, infrastructure, costs and environmental pressure.
According to WRI’s Aqueduct Water Risk Atlas, 17 countries representing about a quarter of the world’s population face extremely high water stress. No single intervention is likely to address that level of pressure.
What would it take to scale MAR?
The evidence points to three conditions being necessary for wider adoption: investment beyond the infrastructure itself, effective groundwater governance and integration with other water-security measures.
Firstly, financing needs to cover more than the cost of the recharge infrastructure. Research into MAR highlights the importance of monitoring, risk assessment and institutional capacity in determining whether schemes will operate sustainably over time.
Secondly, groundwater regulation needs to keep pace with recharge technology. Clear rules on extraction, licensing, monitoring and water quality are essential if recharge is to translate into sustainable groundwater management.
Thirdly, communities and water users need a reason to support and maintain the MAR schemes. A 2026 review has identified that participation and co-management are the core social aspects of successful MAR, while research into its economic viability highlights a recurring problem: the people who benefit from groundwater resilience are not always those able or expected to fund the upfront investment.
A regional picture
MAR models also differ by region. In drought-prone parts of Africa, relatively simple systems for capturing seasonal runoff are more appropriate than capital-intensive infrastructure, whereas in densely populated parts of Asia, MAR is linked to agricultural water security and rapidly deteriorating aquifers. European schemes often place greater emphasis on water quality and highly monitored recharge, while in the Americas, aquifer storage is increasingly used alongside irrigation and drought-management systems.
There is therefore no single MAR model to scale. Its value lies in adapting the approach to groundwater storage to meet local water, climate and development needs.
The case for MAR
Managed aquifer recharge is no longer a niche experiment. It has expanded steadily for decades and is now being used across different regions for water security, drought resilience and water-quality management. But its future will not depend on proving that the technology works but on creating the conditions in which it can work at scale.
This means deciding who pays, who benefits, who regulates the groundwater and how MAR fits alongside wetlands, watershed protection, wastewater reuse, rainwater harvesting and desalination.
MAR may become an important part of climate adaptation, but its strongest advantage is not as a silver bullet. It is as one component of a broader strategy to make water systems more resilient in an increasingly less predictable climate.