Al-Wihdeh Dam

Construction of the Dam commenced on 26/5/ 2003 and will continue until late 2005. 

Located on Yarmouk River, which forms part of the northern boundaries of Jordan with Syria, at about 120 Km from Amman the Capital.

It is a gravity Roller Compacted Concrete (RCC) dam and to be constructed in two stages.  The first stage is to bring the dam’s crest to Elevation 116 m a.s.l and the maximum normal water level to El. 110.  The total storage capacity would be about 110 MCM (Million Cubic Meters).  The second stage is to raise the dam, in the future, to Elevation 140 m a.s.l with a total storage capacity of about 225 MCM.

The dam will capture the floods and available base flow in the Yarmouk basin and hence will:

• Provide about 30 MCM of water to irrigate 31000 dunums (1 dunum = 1000 m²) of cultivated land.
• Supply Amman and its vicinity by about 50 MCM/ year of potable water.
• Generate yearly about 18,800 Megawatt/hr of electricity after the second stage is completed.

Expected Construction Cost and Financing of the Project:

Cost and time for construction of RCC dams is noticeably low, hence in 1999 Jordan Valley Authority (JVA) awarded three RCC dam projects namely Almujib, Wala and Tannur.  JVA reconsidered RCC for Al-Wehdah dam design and based on the cost of above projects it is estimated that the expected cost of the first stage of construction, i.e. building the dam to El. 116 only, is about 66 MJD (Million Jordan Dinars) including consultants’ fees for change of design and supervision over construction.

The following agencies will finance the project with about 89 Million JOD (MJD):

• The Arab Fund for Economic and Social Development (shall cover 80% of the total cost of the Project),
• Abu Dhabi Fund for Development (10%) and
• The Government of Jordan.

The Consultant:

On 18/3/2002 Harza Engineering was awarded the contract for the redesign and later the supervision over the construction of the project for a total cost of 3687550 JD.

The Construction Contract:

On 20/7/2002 seven Contractors were prequalified to apply for the construction of Al-Wehdah dam project.  Six Contractors purchased the Contract documents and Five Contractors applied for bidding on 1/12/2002.  The Contract was awarded to the Turkish Company Özaltin in February 2003 for about 62 million Jordanian Dinars.  The Contract agreement was signed with them on 6/4/2003 and the order to commence the Construction works was issued on 26/ 5/ 2003.

Principal Features of the Project

The Al-Wehdah Dam Project consists of the following principal features:

• An Existing Diversion Tunnel in the right abutment Length = 950 m, modified horseshoe shape, Diameter = 7.75 m, slope = 0.0138 and Capacity (Design Flood) 825 m³/s.
• Excavation.
• A Roller Compacted Concrete (RCC) dam, Crest El. 116 raisable in the future to El. 140.
• Grouting and drainage galleries.
• Grout curtain.
• An Ungated stepped Spillway over the RCC dam with an Ogee crest, invert El. 110.
• A multi level intake tower structure on the upstream face of the dam.
• A discharge structure downstream of the dam.
• Conduits, 3.0 m diameter each, for irrigation supply and future power generation.
• Instrumentation for monitoring dam behavior.
• Access roads to major features of the project.
• Employer- Engineer Site Offices and Accommodation.

AlWehdah Dam Description: 

For further information contact

Jordan Valley Authority Secretary General

Eng. Zafer Alem                   E-mail: Zafer,alem@mwi.gov.jo