A number of (43) underground recharge dams were completed and distributed in the various governorates of the Sultanate with total storage capacity of (93.5 million cubic meters). (15) dams of them in Al Batinah, (7) dams in Al Dakhliyah, (6) dams in Al Buraimi, (6) dams in Musandam, (4) dams in Al Sharqiyah, (3) dams in Muscat and one dam in both Al Dhahirah and Dhofar. Establishment of other dams in some governorates is still under study.
Economic return of Recharge dams
1. Undergound recharge dams store about (1174) million cubic meters of water since its construction until mid of 2006. This quantity equals twice the amount of water used in the agricultural sector by falaj, which represents a significant addition to the limited water resources in the Sultanate.
2. Recharge the aquifer to provide more water for the counuity of various development projects.
3. Contributed effectively to mitigate phenomenon of saltwater intrusion to underground freshwater in coastal parts.
4. Have a significant role in reducing small and medium floods risks to residential areas and properties downstream the dams.
5. They are less expensive compared to other water sources in the Sultanate
Most current surface storage dams in the Sultanate were constructed in Al Jabal Al Akhdar and Dhofar Mountains. Al Jabal Al Akhdar which its name indicates its green area is known by its facienating landscapes and exquisite villages. Water was a concern controlled the lives of its communities. The conducted studies and surveys have shown that the best methods to increase water resources in that area is by constructing surface storage dams.
The number of surface storage dams that were constructed is (90) dams distributed in Al Jabal Al Akhdar, Jabal Shams, Jabal Al Kawr and Jabal Aserah and Dhofar Mountains. Their storage capacities range between (500 - 20000) cubic meters, while the total storage capacity is about more than (137) thousand cubic meters. The height of surface storage dams ranges between (4-8) meters.
Economic returns of surface storage dams
1- Develop water resources for the inhabitants in remote villages who did not have the conventional water sources.
2- Encourage inhabitants to stable in their places and improve their social and economic conditions.
Wadi Dayqah Dam
Components of the project
The project involves construction of two dams located just upstream of Mazara Village. The main dam which was constructed on the main stream of Wadi Dayqah and the saddle dam on the left depression of the reservoir. The spillway was built in the middle of the main dam to pass flood waters, also a stilling basin was built downstream to reduce the energy of water flowing from the spillway.
- Length of dam 410
- Dam height 75.43 m
- Design flood 18.39 m3/s
- Spillway length 201.74m
- Spillway hight 67.5m
- Number of outlets 11
- Outlet diameters 1-1.6m
- Reservoir 350h
- Storage capacity 100 million cubic meter
- Available water quantity 35 million cubic meter/annum
- Surface flow rate 50.97 million cubic meter
The project also includes construction of intake tower to control discharge of water from dam's lake. In addition, the project includes a control and monitoring system of the dam and a water discharge tower. In addition there are (18) wells monitoring aquifers in the dam area to follow up the groundwater level.
The Project of Wadi Dayqah Dam included the establishment of a visitors centre in an area of about (1281 m2) on the plateau near the main dam, where the visitor can have a top overview sighting. The center includes a documentary and educational exhibition that focuses on everything related to the project.
The second phase of the project - water supply components
This phase consists of a modern water treatment and supply system, where about (35) million cubic meters of water will be pumped annually in order to distribute water in the dam reservoir to supply wilayat Quriyat and other wilayats of Muscat Governorate with water for drinking and other uses.
The economic returns of the project
According to 2006 estimations of construction and operation of the Wadi Dayqah Dam, the cost of water supplied to all users in wilayat Quriyat and other wilayats in Muscat Governorate will be some 225 Bz per cubic meter. Noting that the irrigation water supplied to the existing downstream users for free.