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Newsletter and Technical Publications Case Study 3: Water Harvesting in Wadi Al-Mwaqquar, Jordan The water-harvesting project in Wadi Al-Mwaqquar was implemented to serve agricultural and research purposes in a region with a climate currently categorized as dry. The annual rainfall rate ranges between 100-200 mm, and can change substantially from year-to-year. The topography in the area is characterized by a wavy surface with some isolated hills. The depth of the soil section changes with changes in slope. Shallow soils exist at slopes higher than 5%, while deep soil sections exist in areas of mild slopes. The soil also is characterized by a low content of organic carbon, low aggregate soil, silt contents, and the presence of a strong surface crust. It generally has low permeability and a low water-retention capacity. Technology Description This project utilizes the following technologies :
The main method of increasing the quantity of irrigation water is by increasing the surface water runoff, via two means:
For this project, appropriate topographic maps were used to select suitable sites for the earthen dams, and as a base map for the soil survey. Three dams were constructed, with a total capacity of 8,500 m3. Observations indicated it is possible to fill the dams at least 4 times during the season, meaning 340,000 m3 of water can be provided annually. Appropriate systems for providing supplemental irrigation water were completed, including pumps, PVC and PE pipes for water conveyance and distribution. Flood control systems also were constructed with a series of stone walls, including the wide Wadi (Marab), which is covered with a highly-productive soil for agriculture. Extent of Use Water harvesting is often practiced in
arid and semi-arid regions. The basic technology requirements are availability
of at least 80 mm annual rainfall, availability of extended land areas, and
absence of sharp topographical variations.
Historically, the technology was practiced long time ago by the
Nabtieens in the south of Jordan (Petra) and the Romans. Operation and Maintenance Implementing water harvesting projects requires well-trained staff (e.g., agricultural engineers) to collect and process, measure and/or computer the following types of required information:
Establishing the water harvesting system (or the project) is the most difficult part of using this technology. When the system is carefully designed and properly implemented, the required maintenance is simple, and should be done at the beginning of each rainfall season and, in the case of heavy rainfall, occasionally after its cessation. Level of Involvement The government has a major role to play in water-harvesting projects, especially macro-catchment projects. In addition, research institutes ( universities, National Center for Agricultural Research and Technology Transfer, etc.) also have potentially-useful inputs regarding micro-catchement projects. Recently, a few farms (private sector) have adopted this technology, whereby farmers have established several harvesting structures (e.g., Abu Settah Dam). Some farmers have applied water harvesting technologies on the farm scale and in small watersheds to cultivate fruit trees and grazing plants. In fact, a project proposal has been developed with the objective of introducing these technologies to farmers. Implementation of this project will begin by mid-1999, with financial assistance from the European Community and Jordanian government. Cooperation also is underway with the Al-Badyah project (Al-Safawy) to introduce water harvesting technologies of Haffir and small watersheds for livestock watering and cultivation of grazing plants in the Al-Safawy area. Costs The costs of implementing water harvesting systems varies considerably, dependent on factors such as the site, topography, soil, type of crop to be planted, labor and required machinery. Nevertheless, the most important factor is the positive environmental impacts, whereby dry lands can be transformed into sustained productive farms in arid and semi-arid regions. It is noted that an economic study has indicated that the cost of one cubic meter of dam water is less than US$ 0.10. Effectiveness of the Technology The construction of dams, and utilization of flood waters, to irrigate crops in the project area, have demonstrated the positive potential of developing and improving the area, improving the financial positions of farmers and livestock grazers, and improving the state of the environment by increasing and improving the water supply and vegetative cover. Studies have shown that using supplemental irrigation technology, and the addition of materials that improve the physical properties of the soil, have increased the productivity of these areas. The field visits organized for farmers have also shown that the farmers have adopted the project technologies, thereby highlighting their effectiveness. The project area represents 13% of the Jordanian Kingdom. Thus, its development will doubtless result in a positive change in the field of agricultural production, especially the livestock component. In addition, the project reduces demands for groundwater for irrigation purposes, thereby saving at least 20 million m3 that can be used to augment freshwater sources in other sectors. Technology Suitability The study area is characterized by limited rainfall (100-200 mm) and suitable soil conditions to utilize water-harvesting technologies. In addition, watershed studies utilizing Geographic Information Systems (GIS) have shown that application of these technologies in this area of Jordan will lead to its agricultural development and improvement. The construction of dams also will reduce groundwater demands, thereby also reducing groundwater depletion and deterioration. The technology can also be applied in many similar watersheds due to their topographic nature (slopes less than 8%) and its low economic cost (the capital cost of a dam with a capacity of 30,000 m3 does not exceed US$ 10,000). Thus, the long-term cost of water does not exceed US$ 0.10/m3. The construction of a series of dams, as exhibited in the Al-Mowaquar project (series of three dams), will result in reduced dam construction costs, and simpler design and construction, as well as allowing the storage of larger volumes of water. The management of the dams also will become more efficient, since the water is pumped after floods and stored in the soil section in orchards and field crops (supplemental irrigation). In turn, this leads to increased utilization of surface runoff water. All of these factors indicates that this technology is suitable for the prevailing environmental, social and economical conditions in Jordan. Advantages Water harvesting is considered an effective tool for creating a sustainable, productive farming system, based on the following considerations:
Disadvantages The major disadvantage of this technology is that its application requires experienced technical staff, specialized in design and construction fields. Cultural Acceptance The large participation of farmers in field visits, and their requests for application of these technologies on their farms, demonstrates their acceptance of these technologies. Information Sources Contacts Abdel Naby Fardous Awny Teaimah Botrus Haz References Fardous, A., T. Oweis, and M. Jitan. 1998. Indigenous water harvesting systems in Jordan. Technical report.
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