Dams in Jordan, a fresh resource to think about! Dr. Alsharifa Hind Mohammad Dr Taleb odeh Dr. Maisaa Shammout Arab Water Week, Dead Sea, 21/3/2017

Introduction Jordan is an arid to semi-arid country, with a land area of approximately 90,000 km². The mean annual rainfall in Jordan ranges between 50 mm in the southern desert region to about 600 mm along the western mountains adjacent to the Jordan Valley.

Problem Jordan suffers from water scarcity, which poses a threat that would affect all sectors that depend on the availability of water for the sustainability of their activities for their development and prosperity. Normal population growth is very high in addition to the high rate flux of refugees that hosted by the Jordanian community . Treated wastewater is a very important nonconventional water resource; in Jordan; the reuse of wastewater is highly common in agricultural and industrial sectors, treated wastewater is collected in different dams in Jordan.

objectives merging of wastewater and floods water should be retaken into consideration, in this work; the effects of the merging these waters are studied, quality of the effluents and dams before and after diversion of the outflow of treatment plants were done. Two important dams in Jordan were studied, those dams collect water from the high rainfall areas, important wastewater treatment plant discharge its outflow within the stream of these dams.

Study area Realizing all drastic natural conditions, Jordan has built many dams of various storage capacities in order to store it for different purposes such as domestic, agriculture and industry uses and to control floods, improve drainage, collect water from rivers and streams. Among these artificial surface water bodies is King Talal Dam (KTD); it is an earth-fill dam that was constructed in the period 1972-1978. The storage capacity of the dam is about 85 million cubic meters (MCM). Dam Flood flow MCM/yr Base flow MCM/yr Total MCM/yr KTD 37.49 33.4 70.89 Ziglab 2.2 8.3 10.5

Study area The area of catchment of Wadi Ziglab measures 106km² and extends from the valley of Jordan eastwards towards highlands. Different springs issue beside Wadi Ziglab with an entire release of some 5 MCM/year. Additionally, Wadi Ziglab depletes another floodwater of 5 MCM/year. In 1966, in Wadi Ziglab, a dam was built with a capacity of around 4.3 MCM, and with the objective of utilizing its water for the purpose of irrigation. 

Materials and methods Samples of water were collected from different sites along the studied dams are wadis area (Fig. 3), the streams just before enter targeted dams, in addition to the main body of the targeted Dams. Also; an old data for the chemical analysis for KTD dam before the diversion of the different wastewater treatment plants were collected and comprised with the new data.

Results and discussions: Comparison using EC The figure shows the electrical conductivity of the different samples water; it is highly clear that the water from the dam lake before and after diversion of the treated wastewater into the dam lake; this highlight the importance of the separation of treated wastewater from fresh water collected into the dams.

Results and discussions:

Results and discussions:

Wilcox diagram Another method for determination of suitability for agricultural use in groundwater is by calculating Na+ percentage (Wilcox, 1955), because Na+ concentration reacts with soil to reduce its permeability (Todd, 1980). Percentage of sodium values of according to Ragunath., 1987 SAR calculated as:

Wilcox for the stream of the dam Ziglab dam: S1C2: which is low sodium hazard with medium salinity hazard King Talal dam: S1C3:which is low sodium hazard with high salinity hazard

Wilcox for the dams before diversion Ziglab dam: S1C2: which is low sodium hazard with medium salinity hazard King Talal dam: S1C3:which is low sodium hazard with high salinity hazard Kelley et al., (1940) have suggested that the sodium problem in irrigational water could very conveniently be worked out on the basis of the values of Kelley’s ratio. water having Kelley’s ratio more than one is generally considered as unfit for irrigation. The Kelley’s ratio has been calculated for all the water samples of the study area. The formula used in the estimation of this ratio is expressed as: All ions in meq/l.

Wilcox for the dams after diversion Ziglab dam: S1C2: which is low sodium hazard with medium salinity hazard King Talal dam: S1C3:which is low sodium hazard with high salinity hazard

Kelley's ratio Kelley et al., (1940) have suggested that the sodium problem in irrigational water could very conveniently be worked out on the basis of the values of Kelley’s ratio. water having Kelley’s ratio more than one is generally considered as unfit for irrigation. The Kelley’s ratio has been calculated for all the water samples of the study area. The formula used in the estimation of this ratio is expressed as: Na/(Ca+Mg) All ions in meq/l.

Recommendations: As become very clear from the chemical analysis and plotting as resent in the discussion part, the stream water which contains higher amounts of pollutants coming from the wastewater treatment plants that discharge their flows down to the targeted dams increase the potentiality to the stored water which is of higher quality and could be a very importance resource to such country like Jordan By considering the major quality changes which have taken place in the waters of dams originally designed to store flood and base flows of wadis and streams; it becomes clear that this policy has deprived the country of ten million cubic meters of good quality flood and base flows, which can be used for higher quality use such as drinking. The mixing of these waters with treated wastewater rendered the mixture only useful for irrigation purposes. Of course the quality of the mixture improved compared with quality of the treated wastewater, but it is a more severe fact that the good quality of flood and base flow has deteriorated, in a country keen to obtain higher quality water for drinking purposes.

Recommendations: This mixing process of good quality base and flood flow with treated wastewater is also occasionally not sounding because separation offer wards or treatment becomes very expensive and non feasible. If the two types of water are stored separately, mixing remains a viable option when needed. It is recommended to study separate storage of both types of water, which will guarantee storage of good flood and base flow waters for higher quality water use