A concept for managed aquifer recharge using ASR-wells for sustainable use of groundwater resources in an alluvial coastal aquifer in Eastern India

Groundwater resources in coastal plains area are coming under increasing threat due to over extraction and unsustainable agricultural practices. Sustainable water resource management in these areas can potentially be facilitated through the use of a novel concept in groundwater management. This concept involves matching supply and demand for irrigation water by managing excess monsoon season runoff and making it available for managed aquifer recharge (MAR), thereby allowing potentially greater extractions during the dry season. This includes the deliberate lowering of the groundwater table during the dry season, resulting in more storage capacity for MAR. In a case study the excess water was calculated and a field layout including ASR-wells and canals was developed. This groundwater management concept shows an additional potential infiltration of nearly 220 mm/a could be developed but field experiments showed problems which may be related to clogging of the injection wells. Additional enhancement of the natural recharge allows providing enough groundwater to grow a second crop during a year throughout nearly the whole area.