Groundwater Overextraction in the MENA Region: Scale, Drivers and Management Responses

The fossil aquifer problem

Unlike surface water systems that recharge seasonally, the deep aquifers underlying Saudi Arabia (the Saq–Ram system), Libya (the Nubian Sandstone Aquifer System, shared with Egypt, Sudan and Chad), and the Gulf states hold water deposited between 10,000 and 35,000 years ago under wetter Pleistocene climates. Current recharge rates are negligible — often quoted as below 1 mm/year across most of the Arabian Peninsula — meaning every cubic metre extracted is a permanent depletion.

Depletion rates and the saltwater intrusion frontier

GRACE satellite gravity data, calibrated against borehole records, indicate that the Arabian Aquifer System lost an average of 5.7 km³/year between 2002 and 2016. In coastal zones, the hydraulic gradient that previously pushed freshwater seaward has reversed in over 80 monitored boreholes along Saudi Arabia's Eastern Province, the Gulf coast of Kuwait, and the Batinah plain in Oman, resulting in progressive salinisation of previously potable supply wells. TDS values in some affected coastal boreholes have risen from below 500 mg/L in the 1980s to above 4,000 mg/L today.

Managed aquifer recharge: what is working

The Wadi Dayqah dam in Oman and associated spreading basins have recharged approximately 120 million m³ since 2012, measurably slowing the saltwater wedge along the Batinah coast. Treated wastewater injection trials in Riyadh's Wadi Hanifah corridor — using tertiary-treated effluent meeting WHO Class A reuse criteria — have demonstrated recovery rates of 60–80% after 18–24 months. These projects validate the technical feasibility of MAR in arid systems but highlight the governance challenge: recharge infrastructure competes for capital with desalination, which delivers water faster and more predictably.