Chapter 15

Umm er Radhuma-Dammam Aquifer System (Centre)


Executive Summary 

The central section of the Umm er Radhuma- Dammam Aquifer System extends over a 400 km-wide structural platform that stretches across three Gulf States: Bahrain, Qatar and Saudi Arabia. In the western low-plateau areas, the aquifer system is dominated by the Umm er Radhuma, while in the eastern plains it becomes more complex as the Umm er Radhuma and the Dammam are separated by the Rus Formation and overlain by Neogene-Quaternary units. Limited recharge occurs mainly through the Umm er Radhuma outcrops. The general direction of groundwater flow in the aquifer system is from west to east in Saudi Arabia.

The aquifer system is heavily exploited for agricultural development projects in Saudi Arabia, with most water abstracted from the Dammam. The Dammam is also the main source of irrigation water in Bahrain, while the Umm er Radhuma supplies most of the water for domestic and industrial purposes. In Qatar, water is drawn from the Umm er Radhuma and Rus in the north. The Umm er Radhuma- Dammam Aquifer System in the Gulf region is increasingly threatened by salinization as a result of seawater intrusion and over-pumping.

  • Hofuf Oasis, Saudi Arabia, 2011. Source: Chris Helmkamp.
  • Agriculture in Bahrain, 2011. Source: Michele Solmi.
  • Jebel al Qarah, Saudi Arabia, 2011. Source: Chris Helmkamp.

Basin Facts 

Riparian Countries Bahrain, Qatar, Saudi Arabia
Alternative Names Alat, Khobar, Dammam, Rus, Umm er Radhuma
Renewability Very low to low (0-20 mm/yr)
Hydraulic Linkage with Surface Water Weak
Rock Type Fissured/karstic
Aquifer Type Unconfined to confined
Extent ~281,000 km2
Age Cenozoic (Paleogene)
Lithology Mainly limestone and dolomite, with some evaporites
Thickness Dammam: 35-180 m
Umm er Radhuma: 240-500 m
Average Annual Abstraction Bahrain:
Dammam: 97 MCM (2010)
Umm er Radhuma: 54.3 MCM (2006)

Qatar: 91 MCM (1983)
Saudi Arabia: ~608 MCM (2006)

Storage Bahrain: 90 MCM (safe yield)
Qatar: 2.5 BCM
Saudi Arabia: 235 BCM
Water Quality Fresh (mostly <1 g/L TDS) to hypersaline in some coastal areas
Water Use Mainly agricultural, also domestic, industrial and urban irrigational use
Agreements --
Sustainability Over-exploitation and salinization