Water Strategy Management (WSII) of Aquifer Recharge (MAR) What are MAR's objectives and benefits? They include:

• Storing water in aquifers for future use;

• Smoothing out supply/demand fluctuations;

• Being part of an integrated water management strategy;

• Stabilizing or raising groundwater levels where Auja wells are over-exploited leading to high salinity concentration;

• Applying (them) when no suitable surface storage site is available;

• Reducing loss through evaporation and runoff;

• Impeding storm runoff and soil erosion;

• Improving water quality and smooth fluctuations;

• Maintaining environmental flows in streams/rivers;

• Managing saline intrusion or land subsidence; and

• Disposing/reusing of waste/storm water.

The CSA in the shallow aquifer is alluvial sediments; therefore, alluvium can consist of fluvial, marine and lacustrine deposits ranging in thickness from a few tens of meters to kilometers like Lisan formation. Major deposits are usually found in the lower reaches of river basins forming flood plains. The topographic relief will usually be low, as will natural hydraulic gradients. The sediments will range from highly permeable coarse gravel to impermeable fine-grained silt and mud. Groundwater levels will naturally be shallow where rivers are perennial, but may be deeper in arid regions or where pumping has lowered the water table. In the former case, there is little storage space available in the aquifer and the resources in the aquifer need to be exploited, which may result in river water being induced into the aquifer.

In light of the above MAR objectives, and in order for the GMS-Mod flow model results in the CSA, based on current scenario (WSII), investigation suggests several methodologies for MAR derived from UNESCO International Hydrological Programmed HP/2005. These methodologies could be applied on the second water strategy based on managing aquifer recharge (WSII). These selected strategy methodologies are as the follows:

Spreading methods which approach CSA as follows:

- Infiltration ponds and basins which usually could be more practical in case of controlled flooding by leaky dams. This is estimated to collect about 1 Mm³ during flooding events (6 days) in winter time (December- March) through Wadi Auja, which is closed to irrigated lands, (closed to Zones 4, 5, 6 and 7 by model Geometry). This recharging quantity is estimated at 0.5 Mm³/a.

- Soil Aquifer Treatment (SAT) is required in the area of irrigated vegetables (2,000 dounums), which has a high SAR build up through years of cropping, by flushing soil inside

for about one thousand dunums providing fresh water for flushing during night (7 hours) pumping 70 m³/hr, for one dunum of greenhouses intensive agricultures. It is 500 m³/night/donum. Flushing process is usually launched in 5 nights for preparing the soil. Water quantity used for flushing of the entire cropping area is about 2.5Mm³/a. Recharge is estimated at 95% of total flushing quantities (2.4 Mm³/a); so, in this manner recharge by irrigation is estimated at 10% of water used for irrigation.

Using Auja canal surplus for wells injection is a methodology for aquifer storage and recovery (ASR). There is about 12 Km long of Auja Canal which distributes water into irrigated lands of Auja area. In winter, water needs are minimum with maximum fluctuation of Auja Spring canal and in summer period large quantities of fluctuated water are lost due to irrigation mismanagement. Surplus fluctuated water is distributed into irrigated lands. It is estimated at 50% (about 2 Mm³ in wet years). 1Mm³ could infiltrate by the agricultural ponds located in the irrigated area. In this case, about 95% of total quantity could recharge the shallow aquifer (Marie, A., and Manasrah, K., 2012) (Pumping, Storage and Recovery, 2012) with 0.95 Mm³ and another 1Mm³ could be injected directly into 10 wells in the area.

Regarding the pumping test of well 19-015/019 (2012), 250 m³/day were injected and pumped (Marie, A., Manassrah. K., 2012). This research in particular leads to good assumption to inject all ten wells with 250 m/day over all the year in wet condition. This is used by model scenario WSII.

In this strategy (WSII), water surplus in wet winter season was assumed to recharge from Auja canal into agricultural ponds and by direct injection in agricultural Auja wells. The estimated recharged quantity was 2.5 Mm³. The Model shows the difference between current situation and MAR by injection and agriculture pond recharge by about 2 m increase in water table indicating ASR's ability during the irrigation system in the area. On the other hand, it is a good chance to improve water quality and decrease salinity in pumped water during next season (Summer Season). Figure 5.37 shows this difference with a calibrated target between -300 to -320. The simulated Head is around -312 along the historical period in 36 years comparing simulation with the current situation. It is about -314 to -315 head. This gives a clearer view for this technique of MAR in these CSA.

-10

1977/10/01 1979/03/01 1980/08/01 1982/01/01 1983/06/01 1984/11/01 1986/04/01 1987/09/01 1989/02/01 1990/07/01 1991/12/01 1993/05/01 1994/10/01 1996/03/01 1997/08/01 1999/01/01 2000/06/01 2001/11/01 2003/04/01 2004/09/01 2006/02/01 2007/07/01 2008/12/01 2010/05/01 2011/10/01 2013/03/01

Monthly surplus/deficit Mm3

Monthly water Buget Analysis Figure 5.37: Simulation of Well No.19/15-05 in the CSA

Monthly water budget analysis explains the new situation if MAR is applied; the accumulated budget increases in winter and spring months by about 2 MCM. This increase gives new vision for irrigated land extension by new 2,000 donums on average as irrigated lands. Figure 5.38 shows this increase of monthly water budget.

Figure 5.38: Water budget analysis applying MAR and ASR using direct injection and agricultural ponds infiltration in the CSA

Figure 5.39 explains continuity of water surplus in winter and spring periods as well as deficit during summer months (June to the end of August). This water shortage did not increase by MAR. On the contrary, it seems to decrease by about 1 Mm³ compared with the current situation for two seasons; but deficit still happen and irrigated land expansion is unable to irrigate at least 10,000 donums. In this case, MAR could provide surplus water with additional 1,500 donums irrigated lands by ponds' infiltration and direct wells injection.

Figure 5.39: Monthly Water deficit and surplus in the current situation and MAR

Using MAR and ASR approach strategy as well as the current situation (WSII), (Table5.15) will provide 7.23 Mm³ of water: 4.31 Mm³ from Auja Spring, 0.12 Mm³ from surface Run off, and 2.8 Mm³ from shallow aquifer wells. This strategy gives a new promising solution in the area in terms of water quality and quantity.

Table 5.15, Part 1: WSII, injection and Agricultural ponds infiltration from Auja canal .

Water Source WP Water Availability Water

Surplus CUWR

Actual Min. loss

Fresh Water (Mm³/a) (Mm³/a) (Mm³/a) (Mm³/a) (Mm³/a) 1.1 Auja Spring (WSII) 8.61 4.31 (WSII) 6.89 4.14 2.58 1.2 *Deep Carbonate wells

(West) 12 0.25 0.37 0.12 0.01

1.3 Surface Run off (WSII) 1.2 0.12(WSII) 0.9 0.78 0.78 Fresh Water Summary 21.81 4.68 (WSII) 8.16 5.05 3.37 Brackish Water

2.1 Alluvial Shallow

wells+MAR (Direct injection and Ponds infiltration ASR) (WSII)

2.8 2.8 (WSII) 0.0 0.0 0.0

2.2 *Carbonate East Wells

(Fashkha Wells) 3 0 0.9 0.9 0.9

Table5.15, Part2 : WSII, injection, and Agricultural ponds infiltration from Auja canal

5.8.3 Integrated Water Resources Management Strategy (IWRM), Water Strategy No. 3