Chapter 14

Umm er Radhuma-Dammam Aquifer System (South)

Rub' al Khali

Executive Summary 

The southern section of the Umm er Radhuma- Dammam Aquifer System extends from the Gulf coast in the north and the Oman Mountains in the south-east over about 800 km. It covers a total area of about 680,000 km2, stretching across the vast Rub' al Khali Desert, the Dhofar-Najd Plain in Oman, and the northeastern Hadhramaut-Al Mahra Plateau in Yemen. The aquifer system in this section comprises three Paleogene (Paleocene-Eocene) Formations: the Dammam, the Rus and the Umm er Radhuma, of which the Rus is the least important.

Groundwater flow is generally from the central Arabian Peninsula in the west towards the Gulf coast in the east. Further south and east, flow is mainly north and north-eastward from the Hadhramaut-Dhofar Mountains, and westand south-west from the Oman Mountains. Most of the groundwater entered the system during the pluvial periods between 20,000 and 10,000 years ago, although there are indications of limited present-day recharge through the Oman Mountains and the Hadhramaut-Dhofar Mountains. Natural discharge occurs through springs emanating from the Umm er Radhuma Aquifer along the edge of the Hadhramaut-Al Mahra Plateau escarpment, or in the form of saline to hypersaline waters that form sabkhas in the lowlands.

At present, the only use of this aquifer system takes place in the Dhofar-Najd region in Oman and United Arab Emirates (UAE) where the water is used for agricultural and domestic purposes, and, to a lesser extent, for recreational or industrial purposes such as water injection for the oil industry.

  • Liwa Oasis, Abu Dhabi, UAE, 2010. Source: Tom Olliver.
  • Lake Hatta in the Oman Mountains, UAE, 2010. Source: Maarten Schafer.
  • An aerial view of Jebel Hafit, with the city of Al Ain to the north, Abu Dhabi, UAE, 2010. Source: Tom Olliver.
  • Lake Hatta in the Oman Mountains, UAE, 2010. Source: Maarten Schafer.
  • Rub’ al Khali Desert, Oman, 2011. Source: Philipp Weigell.

Basin Facts 

Riparian Countries Oman, Saudi Arabia, UAE, Yemen
Alternative Names Umm er Radhuma/Dammam, Hadhramaut Group
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 ~680,000 km2
Age Cenozoic (Paleogene)
Lithology Mainly limestone and dolomite, with some evaporites
Thickness Dammam: 60-490 m
Umm er Radhuma: 50-550 m
Average Annual Abstraction Oman: 45 MCM
UAE: 7.7 MCM
Storage Najd area: 180-1,100 MCM
Water Quality Fresh to hypersaline
Water Use Agricultural, domestic and oil injection in Oman
Agreements --
Sustainability --