Surface water

Surface runoff at dams is the main surface water resource in KSA.

There are 522 dams around the country, with a capacity of 2.3 billion cubic meters (BCM) to facilitate the storage and recharge of surface runoff. The total amount of the utilized water from dams is about 1.6 BCM/yr.

Groundwater

Renewable groundwater

Most of the runoff infiltrates the ground to recharge the shallow aquifers located along the river valleys and beneath the alluvial fans and plains in various areas. These aquifers are generally unconfined, small in size and have water tables that respond rapidly to local precipitation. The total renewable groundwater is estimated to be 2.8 BCM/yr.

Non-renewable groundwater

Groundwater in the deep sandstone aquifers is non-renewable or ‘fossil’ water, which is confined in sand and limestone formations of a thickness of about 300 meters at a depth of 150-1,500 meters. The deep rock aquifers are sedimentary in origin, usually sandstone and limestone, extending over thousands of square kilometers with poor natural recharge.

The average annual groundwater withdrawal rate is 20 BCM, while the annual recharge is only 2.8 BCM. 

The additional quantity of groundwater is extracted from the fossil groundwater in Saq-Ram aquifer, which has a proven reserve of 103,360 MCM.

During the last two decades, the water table in this aquifer has fallen by 60 meters due to heavy use by the agricultural and domestic sectors. Both renewable and non-renewable groundwater is used primarily in the agricultural sector, which constitutes about 85% of total groundwater withdrawal. If current withdrawal rates are maintained, the available reserves will be depleted within 50 years

Non-conventional water resources

Desalinated seawater

KSA is among the top producers of desalinated water. There are 35 desalination plants on the western and eastern coasts. Nearly 70% of the national water supply comes from desalination.

The Saline Water Conversion Corporation (SWCC) is considered the largest producer of desalinated water and owns the majority of desalination plants in KSA, accounting for 73% of the total production capacity. To meet the potable water demand, which is expected to be 8.5 MCM/d by 2025, the SWCC is aiming to increase its installed production capacity to around 8.8 MCM/d by 2030.