• 191 dams in various wilayats of the Sultanate of Oman until June 2024 with a storage capacity of 357.7 million cubic metres
• New dams are still under implementation in Muscat Governorate, most notable of which are: Protection Dam in Wadi Adai (G2), Protection Dam on Wadi Al Khoud, Majlas Dam in Quriyat, Al Ansab 2 and 3 dams in Wadi Al Ansab in Bawshar
• Dams are part of an integrated strategy that aims to preserve water resources and ensure a sustainable ecological balance
• There are three main types of dams. They are underground recharge dams, surface storage dams, and flood protection dams
Dams are major cornerstone of water resources management in the Sultanate of Oman, contributing to water sustainability and supporting agricultural and environmental activities through recharging groundwater and increasing the level of falajes and wells. Additionally, the storage of the extra water during floods to be used later to irrigate agricultural lands and achieve ecological balance.
The Ministry of Agriculture, Fisheries and Water Resources supervises 191 dams until mid-2024,with a storage capacity of 357.7 million cubic meters. It has reserved more than 3 billion cubic meters of floodwater, which reflects its strategic role in sustainability.
In Muscat Governorate, dams reduce the floods` risks from seasonal wadis and protect infrastructure. Dams also play a role in the water storage to prevent dryness and enhance groundwater recharge, within an integrated strategy to preserve natural resources and environmental balance. There are three basic types of dams, including groundwater recharge dams, surface storage dams, and flood protection dams.
Groundwater Recharge Dams
Groundwater recharge dams increase water storage in underground aquifers through the utilization of wadi floodwater, which would usually be lost to the sea or desert. This water is temporarily stored in the earth`s lower layers for later use for various purposes. Groundwater recharge dams are constructed on alluvial valley streams, where water is stored in dam lakes for a maximum of fourteen days, to reduce evaporative loss and health risks. Then, the water is slowly released to leak into the thick sedimentary layers under the dam, facilitating easy extraction when needed.
There are three of these dams in Muscat Governorate. These are Wadi Al Khoud Dam in Seeb, and the Upper and Lower Sarin Dam in Al Amerat. The total storage capacity of these dams is 1339 million cubic meters.
Surface Storage Dams
These dams aim to provide sustainable water resources and support the development of villages and communities in mountainous regions, especially on valley banks and mountainsides, where traditional water sources are rare. These dams also benefit distant areas that are difficult to reach by cars, which improves the social and economic conditions of the local residents and encourages them to stabilise in their areas. The Wadi Daiqa Dam and the Rabakh depth dam in Muscat are examples of such dams, with an estimated storage capacity of about100,004,000 cubic meters.
Flood Protection Dams
This type of dam aims to protect areas from flood risks and prevent seawater intrusion into agricultural land, an issue that often occurs during tides and can lead to soil degradation. These dams also reduce the salts` concentration in the soil by collecting floodwater and discharging it to the sea through specific channels, which preserves soil quality and supports agriculture. Additionally, dams help to recharge underground aquifers and increase the region`s water supply.
These include the Al Amerat Heights Flood Protection Dam (B15), Al Jafnayn Flood Protection Dam(JIF07), and the Al Jafnaina Flood Protection Dam in Al Amerat in Muscat Governorate (B6).
The ministry is also currently working on the construction of a flood protection dam on the mountain gorge in Wadi Adai (G2) in Al Amerat, which began construction on 17February and is expected to be completed on 16 August 2026. Implementation tender documents are also being prepared for the protection dam on Wadi AlKhoud in Seeb. While the Majlas Dam in Quriyat is still in the designs review and consultant supervision stage. The Al Ansab 2 and 3 dams in Wadi Al Ansab,in Bawshar, are currently in the implementation tender stage.
Wadi Daiqa Dam in Quriyat
The Wadi Daiqa Dam is one of the largest dams in Oman with a storage capacity of 100 million cubic meters. It was constructed in 2009. The project consists of the main dam with a length of 410 m and a height of 75.43 m, which is located on top of the AlMazara` village, and the side dam with a length of 360 m and a height of 49.16m. Both contribute to store the flood valleys` water and prevent its flow.
The dam has a central spillway to discharge floodwaters, a calming basin to protect the valley from erosion, and a water outlet tower with 11 pipes to control the water drainage. Its facilities include control and observation rooms, a SCADA system to monitor the processes, a tunnel for surveillance and drainage. A swell as, wells and devices to monitor movement and earthquakes. When full, the storage lake covers an area of 350 hectares and measures 6 kilo meters in length, with a circumference of 28 kilo meters.
The dam has become a popular tourism destination because of its design and geographical location. It is surrounded by stunning landscapes of mountains and valleys. Visitors` facilities such as car parking, seating and services are available, which makes it a popular destination for nature lovers and eco-tourism.
Wadi Al Khoud Dam in Seeb
The Wadi Al Khoud Dam was constructed in 1985 to store rainwater and reduce floods. The dam has a storage capacity of 11.6 million m³, a total length of 5,100 m, and a height of11 m. It plays an important role in protecting the surrounding residential districts from floods. Besides, contributing to the groundwater recharge in the region.
The dam was constructed using compacted soils, with a section of plasticized concrete to ensure efficient insulation, and a 3000m long gabion spillway to drain excess water. The dam is also equipped with a variety of monitoring devices. They include devices to measure groundwater levels, water levels in the lake, and arain monitoring station, which ensures effective management and accurate monitoring of water resources.
Lower and Upper Sarin Dam in Al Amerat
The Lower and Upper Sarin Dams in Al Amerat are part of a vital dam system that aims to manage water resources and protect them from floods. The two dams, designed with advanced technologies, contribute to preserve water, protect residential areas and enhance water security in the region. The Lower Sarin Dam has a capacity of 1.07 million m³, with a length of 249.75 m and a height of 19.5 m. While it includes a concrete spillway and 192 m of gabions. The Upper Sarin Dam has a storage capacity of 0.72 million m³, a length of 105.25 m and a maximum height of 18 m, and includes a 65 m concrete spillway, which enhances the dams` ability to protect the region from floods and store water for use when required.
Al Amerat Heights Flood Protection Dam
This dam is a strategic project in Al Amerat that aims to protect residential areas and infrastructure from floods caused by heavy rains and valleys. It absorbs water and directs extra flows to safe pathways, which reduces damages and increases groundwater recharge. It also helps to wash away salts from the soil via water discharge to the sea, and supplies the region`s underground aquifer.
The total storage capacity of the dam is (22) million m3 in 2012, and this dam is part of the proposed protection system on Wadi Adai. It aims to protect populated areas in the upper basins from the watershed, as well as to protect the Al Qurum Commercial District from floods’ risks. The length of the dam is about (2726 m)with a maximum height of (23 m), and the spillway is (489 m long).
Rabakh Depth Dam for Surface Storage in Quriyat
The Rabakh depth dam is a surface water storage dam, and its main purpose is to improve water security in the region. This dam is able to collect and store large quantities of rainwater that flows through the surrounding valleys. Thus, it provides an additional source of water that can be utilised during dry periods and contributes to reduce the pressure on underground water resources.
The design of the Rabakh depth dam is a model of modern technologies for surface water storage, featuring a strong structure and large capacity, which is appropriate to deal with large flows during the rainy season. The Rabakh depth dam for surface storage in Quriyat was built in 2014, with an approximate storage capacity of(4000 m3), a length of (18 m), and a height of (7 m).
Wadi Adai Dam
The Wadi Adai Damis a significant dam near capital city Muscat. It was constructed in this important location to intercept rainwater and floods from the six southern wadis of AlAmerat that flow from the upper basins to the Qurum area. It is the third dam in a protection system of six other dams that will protect the Al Qurum Commercial District and urban expansion in Al Amerat from rainfall.
The Ministry of Agriculture, Fisheries and Water Resources has started implementation of the Wadi Adai Dam project to protect against flood risks, located in the Wadi Adai stream in Mutrah in Muscat Governorate. The dam’s storage capacity is 23million cubic meters. The project includes the treatment of the dam`s foundations up to 50 meters deep underground in some parts, and the construction of a 220-metre long and 39- meter high cumulative dam made of stones and compacted soils. The project is estimated to cost OMR 38 million and is expected to last 30 months, to be accomplished by the end of 2026.
Projects Under Implementation
The Ministry of Agriculture, Fisheries and Water Resources, in coordination with Muscat Municipality, is currently working on various tenders for flood protection projects in Mutrah. These include the construction of four dams and drainage channels, with a period of 12 months for design and 18 months for supervision. Currently, an introductory report is being prepared that includes proposed scenarios for the construction of dams and spillways. Designs are also being upgraded for the drainage channels below Al Jafnayn Dam and Wadi Al Khoud Damin Seeb. While, work has also initiated on a flood mapping project to identify regions of high, medium and low risks. Moreover, the maintenance projects include the following dams. Wadi Daiqa in Quriyat, Wadi Al Khoud for underground recharge in Seeb, the Upper Sarin Dam 1 and 2 in Al Amerat, and the maintenance of the flood protection dam in Al Amerat.