Sixty years of global progress in managed aquifer recharge

TLDR

Over the past six decades, groundwater extraction and overdraft have surged while new water‑treatment technologies have enabled managed aquifer recharge (MAR) as a key strategy to sustain stressed aquifers amid climate change and rising extremes. This study aims to be the first global quantification of MAR volume and to map the evolution of its major types in relation to research and regulatory progress. The authors compile and analyze worldwide MAR data, categorizing major recharge methods and linking their adoption to advances in hydraulic design, tracer studies, and governance. MAR has accelerated at about 5 % per year, reaching roughly 10 km³ yr⁻¹ (≈2.4 % of reported groundwater extraction) and is projected to exceed 10 % of global extraction, yet it still lags behind the growing demand for groundwater.

Abstract

The last 60 years has seen unprecedented groundwater extraction and overdraft as well as development of new technologies for water treatment that together drive the advance in intentional groundwater replenishment known as managed aquifer recharge (MAR). This paper is the first known attempt to quantify the volume of MAR at global scale, and to illustrate the advancement of all the major types of MAR and relate these to research and regulatory advancements. Faced with changing climate and rising intensity of climate extremes, MAR is an increasingly important water management strategy, alongside demand management, to maintain, enhance and secure stressed groundwater systems and to protect and improve water quality. During this time, scientific research—on hydraulic design of facilities, tracer studies, managing clogging, recovery efficiency and water quality changes in aquifers—has underpinned practical improvements in MAR and has had broader benefits in hydrogeology. Recharge wells have greatly accelerated recharge, particularly in urban areas and for mine water management. In recent years, research into governance, operating practices, reliability, economics, risk assessment and public acceptance of MAR has been undertaken. Since the 1960s, implementation of MAR has accelerated at a rate of 5%/year, but is not keeping pace with increasing groundwater extraction. Currently, MAR has reached an estimated 10 km3/year, ~2.4% of groundwater extraction in countries reporting MAR (or ~1.0% of global groundwater extraction). MAR is likely to exceed 10% of global extraction, based on experience where MAR is more advanced, to sustain quantity, reliability and quality of water supplies.