CHAPTER 5 GROUNDWATER DEVELOPMENT

Transcription

1 CHAPTER 5 GROUNDWATER DEVELOPMENT In the previous Chapters, all the field work results were described. In this Chapter, groundwater development potential is to be estimated roughly from a recharging potential based upon the existing hydrogeological data/information, field work results and examinations thereof. Given the basic purpose of this Sub-project, groundwater development potential in each site is to be estimated, and then the development potential will be examined in detail using MODFLOW simulation model only for the site(s) having promising high potential on the future development. Groundwater development scenarios are then examined, following which a conceptual development design will be formulated. A monitoring system on the groundwater table in the target sites will also be presented. 5.1 Estimation on Groundwater Development Potentials Groundwater is one of the renewable natural resources, whereby we can develop it in a sustainable way if we keep exploiting groundwater within the volume it renews every year. Renewing groundwater volume in a certain groundwater basin takes place mostly by precipitation, which is called as Perennial Yield of the basin. Though renewing of the groundwater volume varies depending upon the annual precipitation, the sustainable groundwater development potential therefore settles almost same as the average perennial yield of the groundwater basin. This Sub-project tries to estimate the average perennial yield of each target groundwater basin as a sustainable 1 development potential roughly as the first step. The perennial yield of a groundwater basin shall be estimated through examinations on the direct groundwater recharge by precipitation in a certain groundwater basin and the indirect recharge by seepage from river-bed or canal bottom passing through the target basin. The precipitation data available in and around the survey area are only the observation records at the Kabul Airport. Based on the observation at the Airport, average annual precipitation for the current six years was found at around 303 mm/year (see Figure 5.1.1). Exactly saying, groundwater development potential is not equal to the perennial yield since it must take existing groundwater usage in the groundwater basin into consideration. It follows that the groundwater development potential in a certain groundwater basin is the perennial yield minus the existing level of groundwater exploitation. The existing groundwater exploitation, current groundwater usage in other words, is difficult to exactly grasp on quantitative basis. Annual Precipitation, mm 600 Average: 303 mm/year Figure Annual Precipitation from However, most of the existing groundwater usages are observed on domestic water use, periodical irrigation use for a period of roughly 3 months in a year, and also some industrial use especially for brick factories at the Bakhtyaran site and Daneshmand-Pymonar site. The current use of groundwater 1 Short-term Development Potential may be referred to as the groundwater development volume we expect to be allowed to exploit, beyond the sustainable development volume, only for short period such as three or four years. However, there is no such allowable groundwater development volume which can be exploitable beyond the perennial yield, nor such term of Short-term Development Potential hydro-geologically. Continuous over exploitation beyond the perennial yield causes rapid groundwater depletion and finally dries up or destroys the aquifer. No one knows a certain aquifer once destroyed can recover or not. With this in mind, this Sub-project is to examine the sustainable amount of groundwater development. JICA 5-1 DCDA

2 Afghanistan might be compensated from the groundwater development system to be constructed, except for the Tangi Kalay site which already has large scale production wells owned by an investor. Following discussion centers on the maximum perennial yield in each target site while current water usage is discussed in the following sub-chapter: Development Potential in Site-1 (Tangi Kalay) In Site-1 (Tangi Kalay area), there are large scale production wells already along with the north bank of the Kabul River. Therefore, it is unlikely that there is chance to develop groundwater furthermore. In the site, taking this condition into account, only groundwater quality analysis on the existing production well was conducted. No other hydrogeological investigation works such as geophysical prospecting and test well drilling have been conducted. The groundwater development potential is therefore roughly estimated based on the existing data and information. 1) Direct recharging The north bank of the Kabul River has its own catchment area in its further north of around 19.5 km 2 (see Figure 5.1.2). The infiltration ratio in this catchment area can be evaluated at 0.06 to because the catchment area is composed of relatively course materials due to its rather high average inclination. Thus, the direct recharging through the own catchment area is calculated as: 19.5(km 2 ) x 10 6 x 0.303(m) x = 354, ,680 m 3 /year....(a) 2) Indirect recharging In the Tangi Kalay area, Kabul River is passing through around 5km before it enters the steep and narrow gorge. The area is located at the low end of the Kabul Basin, and therefore results of a previous groundwater study on the Kabul basin; Study on Groundwater Resources Potential in the Kabul Basin (2011) conducted by JICA, can be applied. In accordance with the study, the low end of the Kabul River is recharging groundwater through seepage from the bottom by around MCM/km/year. Based on the data, the groundwater recharge through the river is estimated as: Catchment Boundary Tangi Kalay Pol-e Charkhi Figure Catchment area of Tangi Kalay Area 5.0 (km) x (MCM/km/year) x 1,000,000 = 1,610,000 m 3 /year... (b) 3) Groundwater development potential Groundwater development potential, thus calculated, shall be added together and resulted as (a) + (b); 354, ,610,000 1,964,500 m 3 /year 2 Under the Study on Groundwater Resources Potential in the Kabul Basin, simulations were carried out dividing the target Kabul Basin into more than 130 sub-basins wherein infiltration ratio and coefficient of permeability were so evaluated as to meet the field observation results of groundwater tables. In so doing, 10%, 7% (or ), 5% (or ), and 3% (or ) were identified as the infiltration ratios of area with high infiltration rate, e.g. fan or talus, area covered by coarse materials with rather high ground inclination, area of normal alluvial plain in the Kabul Basin, and area covered by fine materials e.g. silt or silty clay respectively. DCDA 5-2 JICA

3 5,380 m 3 /day 62 liter/sec 472, ,610,000 2,082,680 m 3 /year 5,700 m 3 /day 66 liter/sec Groundwater development potential in the site is roughly estimated as from 5,300 to around 5,700 m 3 /day. It is rather excellent potential but it may have more development potential because the area can be recharged from its southern bank too. As evidence, production wells for irrigation purpose existing in the north bank of the Kabul River can yield around 45 to 40 liter/sec with 6.0m drawdown Development Potential in Site-2 (Pol-e Charkhi) At the site-2, Pol-e Charkhi area, one of the tributaries of the Kabul River, named Buthkhak River joins together. The Buthkhak River has a large catchment area of some hundreds sq.km but the catchment which can replenish the groundwater is confined at its lower middle stream (at the east of Atal Ghar) by a natural underground dam 3. Direct recharging by precipitation can therefore be expected from only the downstream catchment area from the natural underground dam point. Even though it is less than 1/4 of the total catchment, the available Buthkhak catchment area comes to around 66.5 km 2 (see Figure 5.1.3). 1) Direct recharging Figure Catchment Area of Pol-e Charkhi Area As explained in the previous section, a yearly average precipitation observed at Kabul Airport in current 6 years is m/year. An infiltration ratio of precipitation in the Buthkhak River basin is, however, not so high as the northern catchment of Tangi Kalay because the catchment area is mostly flat and covered by fine materials such as silty soil. In this area, infiltration rate from 0.04 to 0.06, which is almost average infiltration ratio of Alluvial deposits in Kabul Basin, shall be adopted. Thus, direct recharge in this area is; 66.5 (km 2 ) x 10 6 x (m) x = 805,980-1,208,970 m 3 /year...(c) 3 At this point of the Buthkhak River, hard foundation which has very low permeability comes up preventing the groundwater flow from upstream to downstream or simply saying such very low permeable foundation forms a natural underground storage in its upstream side, which is called underground dam. With this condition at the midpoint of Buthkhak River, only downstream area is counted as the catchment area which can replenish the groundwater of the Pol-e Charkhi area. JICA 5-3 DCDA

4 2) Indirect recharging Afghanistan In this area, the Kabul River runs through around 3.0km length. As mentioned above, the Kabul River recharges groundwater through seepage at around the rate of MCM/km/year. With the rate, the site can be recharged through the Kabul River as: 3.0 (km) x (MCM/km/year) x 1,000,000 = 966,000 m 3 /year... (d) 3) Groundwater development potential Groundwater development potential in Pol-e Charkhi area is now estimated by adding (c) and (d); 805, ,000 1,771,980 m 3 /year 4,850 m 3 /day 56.2 liter/sec 1,208, ,000 2,174,970 m 3 /year 5,960 m 3 /day 69.0 liter/sec Thus, groundwater development potential in this site is roughly estimated from 4,850 to 5,960 m 3 /day, nearly same as the potential of Tangi Kalay area. It shows also excellent development potential. In addition, the site may have an extra recharging through an old river route of the Logar River which was to join the Kabul River at Pol-e Charkhi area for some period in an ancient time. The effect of the old Logar is, however, not taken into consideration because AUWSSC and KfW are planning to develop groundwater in the lower Logar sub-basin, just upstream of the old river route Development Potential in Site-3 (Bakhtyaran) Bakhtyaran site lies in the Dehsabz Basin and there is no major river. Only a Bakhtyaran canal is passing through along the western edge of the target site. Rather small but Bakhtyaran site also has a catchment area in it eastern side. The site can be recharged by precipitation and also by the Bakhtyaran canal, though the recharge from the canal may not be so noticeable. 1) Direct recharging Catchment area of Bakhtyaran site extends toward east to the Figure Catchment Area of Bakhtyaran Area Mount Gharib Ghar. The mountain is of the watershed at its eastern side and the catchment is enclosed by the Bakhtyaran canal at its western side. Catchment area of the site is estimated at only 16.0 km 2 (see Figure 5.1.4). The area near the site where groundwater development is planned is widely covered by worked Loess, which is composed of very fine materials such as clay or silt, and the infiltration ratio of rain in this area is estimated at 0.02 to Thus, the direct recharging by precipitation in this site is as small as: DCDA 5-4 JICA

5 16.0 x 10 6 x x = 96, ,920 m 3 /year...(e) 2) Indirect recharging Bakhtyaran canal, passing through along the western edge of the site for around 3.0 km, is not perennial and the averaged flow rate is very small. The previous study on the Kabul Basin, Groundwater Resources Potential in the Kabul Basin, 2011, surveyed the flow sourced from Kabul River. The average yearly runoff of the canal was around 7.7 MCM/year, and this is only less than 2.0% the runoff of the Kabul River at Pol-e-Charkhi point. The condition of the canal bottom is also different from that of Kabul River, less permeable than that of Kabul River. Taking those into account, indirect recharging rate of the canal is set at only 1% of that of Kabul River: 3.0 (km) x (MCM/km/year) x 1,000,000 x 0.01 = 9,660 m 3 /year... (f) 3) Groundwater development potential Groundwater development potential in Bakhtyaran area shall be estimated by adding (e) and (f); 96, , ,620 m 3 /year 292 m 3 /day 3.4 liter/sec 193, , ,580 m 3 /year 558 m 3 /day 6.5 liter/sec There is an observation relating to the above potential. An observation well by AGS exists near the Bakhtyaran site. Yearly fluctuation of the groundwater table in the observation well is around 3.0m in average. When the area of target site is estimated at 1.8 km 2 (3.0 km x 0.6 km) and effective porosity of the aquifer at 0.03, the volume of renewable groundwater can be estimated as follows, indicating quite similar calculation results: 1.8 (km 2 ) x 1,000,000 x 3.0 (m) x 0.03 = 162,000 m 3 /year 434 m 3 /day 5.1 liter/sec As aforementioned, estimated groundwater development potential in Bakhtyaran site is very low as only several hundreds cubic meter per day. When considering the water demand in the new Dehsabz city, it may be concluded that there seems little groundwater development potential in Bakhtyaran site Development Potential in Site-4 (Pymonar - Daneshmand) Daneshmand site is located in a quite flat plain in between Pymonar village and Daneshmand village. Some small drainages are passing through the plain forming gullies from the west to the east. There is neither perennial river in this area nor canal. Therefore, resources of the groundwater here is only precipitation. 1) Direct recharging The area is widely covered by worked Loess on its ground surface, making difficult to infiltrate rain water into the ground. Infiltrate ratio in this area is set at less than 0.03 as the maximum estimation. The target site is confined at its western side by low mountain range separating the Dehsabz basin from the Parwan basin. Total catchment area of this site is estimated at 53.0 km 2 (see Figure 5.1.5), and thus direct recharging by rainfall is calculated as: 53.0 (km 2 ) x 10 6 x (m/year) x 0.03 = 481,770 m 3 /year... (g) JICA 5-5 DCDA

6 2) Indirect recharging Indirect recharge through river or canal does not exist in this site. Afghanistan 3) Groundwater development potential Thus, the total groundwater recharging amount estimated for the area is 481,770 m 3 /year, which is converted into 1,320 m 3 /day and 15.3 liter/sec. Figure Catchment Area of Daneshmand-Pymonar Area Though the estimated groundwater development potential in Pymonar - Daneshmand site is much better than Bakhtyaran site, there is still not enough recharging to develop at a certain scale. Farther, groundwater quality analysis also identified that the water quality was no good showing very high EC value and high Mn contents. Thus, groundwater development in this area located between Pymonar village and Daneshmand village will hardly be possible Summary of the Development Potential As discussed so far, the averaged perennial yield in each target site varied from only 425 m 3 /day to more than 5,000 m 3 /day. Groundwater development potential in the two sites of Bakhtyaran and Pymonar - Daneshmand are very small while sites along the Kabul River show large potential thanks to the huge groundwater recharge through the seepage from the river bottom. Sustainable groundwater development potential in these target sites are summarized in Table 5.1.1: Table Summary of Groundwater Development Potential Site Direct Indirect Development Catchment Area, km 2 Recharge, Recharge, Potential, m 3 /Yr m 3 /Yr m 3 /day Feasibility Tangi Kalay ,510 5,380 5,700 1,610, ,680 (ave 5,500) Hard Pol-e Charkhi ,980 4,850 5, ,000 1,208,970 (ave 5,400) High Bakhtyaran , ,920 9, (ave. 420) Daneshmand , ,300 No Source: JICA Sub-project Team Note: Average annual precipitation is 303 mm. No Remarks Existing large yielding wells High potential, not much current use Very little water, poor water quality Very small water resource available As shown in the above table, only the sites along the Kabul River have groundwater resources potential feasible to develop. However, Tangi Kalay site has already large scale production wells mainly for irrigation purpose owned by an investor. Therefore, the Tangi Kalay site may be said not to be much feasible in terms of development unless there is a water-trade agreement with the well owner. On the other hand, candidate sites of Bakhtyaran and Daneshmand-Pymonar, located in Dehsabz Basin, have a little groundwater resources and what is worse the water quality is not so good. It is therefore concluded that the groundwater development potential for the 2 sites is poor. DCDA 5-6 JICA

7 5.2 MODFLOW Analysis on Potential Sites As discussed so far, only Pol-e Charkhi site has high feasibility on further groundwater development, and Tangi Kalay site has the next feasibility depending upon the negotiation with the investor having large scale irrigation wells. In this section, groundwater development potential on these two sites are examined more detail through MODFLOW simulation, whether it is feasible to pump up the estimated development amount in these two sites MODFLOW Simulation on Pol-e Charkhi Site (1) Concept of MODFLOW Model Concept of MODFLOW model for Pol-e Charkhi site is shown in Figure As shown in the figure, not all of the Buthkhak River basin was modeled but only the area underlain by Alluvial aquifer. The cross section model was simplified by two layers structure and the flat bottom from the northern end to the half of the total area. Figure MODFLOW Model for Pol-e Charkhi Site The extent of area is around 30.1 km 2, and depth of the aquifer is set from 12m to 30m below the ground surface. However, the upper 2m is already dry. Materials of aquifer are estimated as Sand and Gravels of river-bed deposits. Southern half of the model area (the Buthkhak river basin) is omitted JICA 5-7 DCDA

8 Afghanistan from the analysis because there is no groundwater system in its area. Widths of the cells are set 20m at the minimum (near the New Production Wells) and 100m in the other areas. MODFLOW model, thus built up, is shown in ANNEX-VIII.1. (2) Assumptions For MODFLOW analysis, physical properties of layers consisting of the model, boundary conditions, and hydrogeological information on the site are required. Among them, some of hydrogeological information was obtained through the investigation and data collection under this Sub-project, but the other physical properties were assumed by general practices facing the little data availability. Physical properties of the layers, assumed Table Assumed Physical Properties of Layers in the analysis, are summarized in Table Permeability and Specific Storativity on the aquifer were estimated from the Particular Permeability, K (m/sec) Sandy Clay (GL m) 1.0 x 10-6 Aquifer (GL m) 2.46 x 10-3 Specific Storativity Ss (m -1 ) 1.0 x x 10-4 results of Pumping Test conducted in the Specific Yield Sy (%) 5 25 existing well in the National Radio Station Source: JICA Sub-project Team (T=3,400 m 2 /day, S=0.0036). The northern end of the model, which is the Kabul River was set as fixed head boundary, and the both sides of the Buthkhak River catchments area were set as no flow boundaries. Precipitation on the area is m/year from the 6-years average rainfall at Kabul Airport Station, and 0.05 of infiltration rate was applied. Those measured data or assumptions were given to the model, and four (4) wells of equivalent existing wells were assumed to evaluate the current groundwater balance through a try and error trial. The trial has changed the pumping rates from these assumed wells in order to adjust the groundwater table near the New Production Wells being around GL. -14m. As a result, a current groundwater table was assumed as Figure To adjust the groundwater table near the production wells, total 1,400 m 3 /day of pumping from those assumed equivalent wells were required. Figure Current groundwater Balance of target Area DCDA 5-8 JICA

9 (3) Case Study Two new production wells were assumed in the Radio Station at Pol-e Charkhi site, and pumping simulations were carried out for several cases. The cases of Pumping Simulation are summarized in Table (Results of MODFLOW Case simulation, estimated drawdown at each production well by the time-series and distance, and estimated groundwater contour maps in time series at every one year are attached in ANNEX-VIII.2). (4) Results of MODFLOW analysis: Groundwater Level in the Well Groundwater drawdown in the Buthkhak basin is relatively small (refer to ANNEX-VIII.2); drawdown only from a few centimeters to several tens of centimeters even near the production wells were simulated. These small scales of drawdown may be brought about by the influential interference of the Kabul River at the northern edge of the simulation area. Then, the groundwater drawdown in the production wells during pumping was examined. The model was not dispersed enough to reproduce the water level in the pumping well (the minimum cell width was 20m). The water level at the just pumping well was calculated using the following empirical equation by Anderson and Woessner (1994): h w = h ij Q (ln r e ln r w ) / 2 πt Where h w: Water head in the well, h ij: calculated water head at the node, Q: pumping rate, re: distance between the node and equal head point, (equal well radius) rw: radius of the well, and T: Transmissivity. Equal well radius was calculated as follows: re = SQRT( x y/π) E where, x, y: size of cell, E: Coefficient in the right table, and α= MAX( x/ y, y/ x) Table MODFLOW Case Study Pumping from No.1 Pumping from No.2 well, m 3 /day well, m 3 /day Total Pumping Rate, m 3 /day Case-1 1,000 1,000 2,000 Case-2 1,500 1,500 3,000 Case-3 2,000 2,000 4,000 Case-4 2,500 2,500 5,000 Case-5 3,000 3,000 6,000 Source: JICA Sub-project Team α E α E Groundwater drawdown in the production wells (No.1 well for eastern one, and No.2 for western one), thus calculated, are summarized in Table 5.2.3, and shown in Figure Groundwater contour map of the site, in Case-4 (total 5,000 m 3 /day pumping) and at after 5 years from the time the pumping started, is shown in Figure JICA 5-9 DCDA

10 Afghanistan Table Groundwater Table at Production Wells in Pol-e Charkhi Site Time Case.1 Case.2 Case.3 Case.4 Case.5 Q=1,000 2(m 3 /day) Q=1,500 2(m 3 /day) Q=2,000 2(m 3 /day) Q=2,500 2(m 3 /day) Q=3,000 2(m 3 /day) (days) No.1 No.2 No.1 No.2 No.1 No.2 No.1 No.2 No.1 No , , , Source: JICA Sub-project Team, MODFLOW Simulation Unit: GL -m As shown in the table, groundwater drawdown caused by the pumping in the production wells, from each 1,000 to 3,000 m 3 /day are small, only from 81 cm to 2.45 m at the longest period (5 years) in Case-1 to Case-5. G.W Table GL.(m) Production Well No Time after pumping started (day) Supposedly, they Figure (1) Changing of Groundwater Table at the Production Well No.1 may be also due to the influence by Production Well No.2 constant recharge Case.1 from the Kabul Case.2 River. The Case.3 maximum drawdown of 2.05 m from the original groundwater table in Case.4 Case.5 Case-4, which is the estimated groundwater potential in the site, Time after Pumping started (day) Figure (2) Changing of Groundwater Table at the Production Well No.2 is enough small comparing to the thickness of the aquifer which is around 16m (less than 13%), and it suggests that the pumping up of total 5,000 m 3 /day of groundwater through two production wells in this site shall be feasible. G.W Table GL.(m) Case.1 Case.2 Case.3 Case.4 Case.5 DCDA 5-10 JICA

11 Groundawter Contour Pol-e Charkhi Case.4: Q=5,000m3/s (No.1+No.2) Well Point : No.2 5 Years After Kabul River : GL.-14m Drawdown Contour Pol-e Charkhi Case.4 : Q=5,000m3/s (No.1+No.2) Well Point : No.2 Kabul River : GL.-14m Years After Well Point : No Well Point : No Figure Estimated Groundwater Contour at Pol-e Charkhi Site, Case-4, after 5 years (5) Results of MODFLOW analysis: Groundwater Drawdown in the Village Aforementioned section estimated the groundwater level in the well. MODFLOW simulation gives not only the groundwater level in the well but also all the groundwater levels at each nodal point of the model. Table summarizes the groundwater drawdown with total 5,000 m 3 /day pumping (Case 4) by location such as 30 m away from the well, 100m, 200, etc. to 5 km away and by time such as 1 day, 10 days, 100 days, 200 days, 1 year, etc, to 5 years later. At a glance of the table is that the drawdown is not so much as exampled in the level at the time of 5 years after the pumping started, which is only meter even at the 30 m from the well. If the location is 5 km far from the well, the drawdown becomes only m. Table Groundwater Drawdown at Different Location by Time, Case 4: 2,500 m 3 /day x 2 wells Days 30m 100m 200m 300m 400m 500m 1km 2km 3km 5km X-coord. (m) 2,090 2,130 2,170 2,220 2,300 2,380 2,700 2,900 3,500 4,300 Y-coordi.(m) 12,730 12,670 12,580 12,500 12,420 12,350 11,900 11,300 10,500 8, (1 yr) (2 yrs) ,095 (3 yrs) ,460 (4 yrs) ,825 (5 yrs) Source: JICA Sub-project Team, by MODFLOW simulation Unit: m JICA 5-11 DCDA

12 5.2.2 MODFLOW Simulation on Tangi Kalay Site (1) Concept of MODFLOW Model Concept of MODFLOW model on Tangi Kalay site is shown in Figure As shown in the figure, all of the northern catchments area of this site (19.5 km 2 ) was fully modeled but its upstream zone was reduced to Afghanistan Figure MODFLOW Model on Tangi Kalay Figure Mr. Omarzay s Well the depth of aquifer, from the full depth of 42m to the upstream end, as shown in the cross section model. The cross section was built up from Lithological log of Mr. Omarzay s Well No.1 shown as Figure Southern edge of the model is the Kabul River as a fixed head boundary and the other sides are set as no flow boundary. (2) Assumptions Aquifer structure in this site was simply modeled as one layer structure. Physical properties on the aquifer, applied in the simulation, are the same as the ones for Pol-e Charkhi site (see Table 5.2.5). To estimate the current groundwater balance, current recharging and discharging were firstly evaluated. For recharging, a yearly average precipitation was set at Table Assumed Physical Properties 0.303m same as that of Pol-e Charkhi site, but an infiltration ratio was assumed as 0.07 in this site. Then, the Kabul River was set as fixed head boundary. For discharge, two equivalent wells with each 1,014 m 3 /day Particular Permeability, K (m/sec) Specific Storativity Ss (m -1 ) Aquifer (GL m) 2.46 x x 10-4 Specific Yield Sy (%) 25 of pumping rate were assumed at near around the Kabul Source: JICA Sub-project Team River. Thus, the current groundwater balance (Groundwater Contour Map) was simulated as shown in Figure As shown in the figure, the current groundwater table near the new production well was around 5.0m below the ground surface. (3) Case Study A new production well was assumed at near the Kabul River, in between the two equivalent assumed wells. MODFLOW simulation was conducted as case study changing the pumping rates of 1,500, 2,000, 2,500, and 3,000 m 3 /day, at an interval of 500 m 3 /day. DCDA 5-12 JICA

13 (4) Results of MODFLOW analysis Results of MODFLOW analysis are attached in ANNEX-VIII.3. Only one results of the case on 3,000 m 3 /day of discharge rate, 5 years after the pumping had started, is shown in Figure As easily readable from the figure, groundwater drawdown in the site, Tangi Kalay northern catchments area, is very small as only some centimeters in the nearest simulation cell to the production well. In this site too, groundwater drawdown at Figure Current Groundwater Contour Map the production well itself was estimated. As explained in previous section (Chapter (3)), the model dispersion is not enough small to reproduce the water level in the pumping well (the minimum cell width was 20m). The water level at the pumping well was calculated using the equation by Anderson and Woessner (1994). Estimated groundwater drawdown in the new production well, in time sequence and discharge amounts, are shown in Table As shown in the table, the maximum drawdown in the production well is, even in the Case-4 (the maximum discharge of 3,000 m 3 /day), less than 1.4m which does not cause any problem for discharging groundwater in this site because the drawdown is only 3.5% of the aquifer thickness. Thus, the groundwater development potential in Tangi Kalay site shall be at least 3,000 m 3 /day on condition that the investor s two wells are in operation as designed. Groundwater isobathic map on Tangi Kalay site at 5 years after the pumping started in Case-4 is shown in Figure Table Groundwater Level in New Production Well in Tangi Kalay Days after Case 1 Case 2 Case 3 Case 4 Pumping Q=1,500(m 3 /day) Q=2,000(m 3 /day) Q=2,500(m 3 /day) Q=3,000(m 3 /day) Remarks , , , Source: JICA Sub-project Team, MODFLOW simulation Unit: GL -m JICA 5-13 DCDA

14 Afghanistan Well Point : No Kabul River : GL.-5m Figure Groundwater Isobathic Map in Tangi Kalay (Case-4, 5 years after) (5) Results of MODFLOW analysis: Groundwater Drawdown in the Village In addition to the groundwater level in the well, MODFLOW analysis estimated the groundwater levels at all the nodal point. Table summarizes the groundwater drawdown with 3,000 m 3 /day pumping (Case 4) by location and by time up to 5 km away from the well. The table shows the drawdown is not so much as exampled in the water level at the time of 5 years after the pumping started, which is only meter even at the 30 m from the well. If the location is 5 km far from the well, the drawdown becomes only m. Table Groundwater Drawdown at Different Location by Time, Case 4: 2,500 m 3 /day x 2 wells Days 30m 100m 200m 300m 400m 500m 1km 2km 3km 5km X-coord. (m) 1,530 1,475 1,475 1,550 1,550 1,550 1,675 2,450 3,350 5,250 Y-coordi.(m) ,050 1,150 1,650 2,450 3,050 4, (1 yr) (2 yrs) ,095 (3 yrs) ,460 (4 yrs) DCDA 5-14 JICA

15 Days 30m 100m 200m 300m 400m 500m 1km 2km 3km 5km 1,825 (5 yrs) Source: JICA Sub-project Team, by MODFLOW simulation Summary on MODFLOW Analysis unit: m MODFLOW Analysis was conducted for the two candidate sites of Pol-e Charkhi and Tangi Kalay. In both sites, physical properties were assumed in Table Table Assumptions on Physical Properties Property Aquifer Surface Cover Permeability k (m/sec) 2.46 x x 10-6 Specific Storativity Ss (m -1 ) 2.25 x x 10-4 Specific Yield Sy (%) 25 5 Catchments Area (km 2 ) Pol-e Charkhi 0.08 Tangi Kalay: 19.5 Infiltration Ratio (%) Pol-e Charkhi: 0.05 Tangi Kalay: 0.07 Source: JICA Sub-project Team Model was built up in 20 to 100m disperse, 20m cells near around the production wells (refer to Figure for Pol-e Charkhi area). Two new production wells in Pol-e Charkhi and a new production well in Tangi Kalay sites were set near the Kabul River. The Kabul River in both sites was set as a fixed head boundary and the other sides were set as a no flow boundary. Current groundwater balance was estimated to adjust the groundwater table to the observed levels of around -14m in Pol-e Charkhi and -5m in Tangi Kalay site. Simulation was carried out as Case Study; changing the discharge amount and estimating the groundwater drawdown in the target Figure MODFLOW Model on Pol-e Charkhi Site area, and the drawdown in the production wells (pumping wells) was estimated through the equation by Anderson and Woessner (1994) because the minimum cells are not enough fine to estimate the drawdown in the well. As a result, the groundwater drawdown in the new production wells in Case-4 (discharge amount: JICA 5-15 DCDA

16 Afghanistan 2,500 m 3 /day/well totaling 5,000 m 3 /day in Pol-e Charkhi and 3,000 m 3 /day in Tangi Kalay) at the longest period (after 5 years since the pumping started) was estimated at only around 2.04m and only 1.3m in each site, respectively. The extent of drawdown is small comparing to the aquifer thickness 4 in both sites: sharing 12.7% and 3.5% of the thickness of the aquifer in the respective sites of Pol-e Charkhi and Tangi Kalay. This means 2,500-3,000 m 3 /day/well of groundwater discharge is quite feasible. On top of this, the groundwater development at the maximum potential estimated by simple balance calculation on recharging, around 5,400 and 5,500 m 3 /day in the sites of Pol-e Charkhi and Tangi Kalay, are also feasible. 5.3 Development Scenarios of the Groundwater Potential Discussions so far made have identified the groundwater potential by site based on simplified balance calculation referring to hydrogeological characteristics studied and the results of the pumping test. This sub-chapter explores development scenarios of the groundwater potentials; namely how the groundwater development should be explored in order to meet the population s demand for the new city of Kabul. Discussions below start with how much water the new city will require based on the projected population and the water demand per capita, and then the scenarios or alternatives are to be presented in order to meet the urban water requirement by the groundwater Water Requirement During the discussions on the Inception Report, DCDA clarified its stance in terms of the scale of the groundwater development as stipulated in the Minutes of the Meetings on the ICR: DCDA stated that the groundwater to be surveyed under the Sub-project should target not only the Parcel-1 - Phase I area but also the Phase I development area of Dehsabz South, covering till the year DCDA further stressed that the Phase I development is planned to accommodate 400,000 population with stage-wise incremental unit water requirement, whereby the groundwater development should be targeted according to the scale of development. Per-capita-water requirement has not been specified so far, but there may be an understanding that the requirement ranges from 25 liters per capita per day as the smallest case to as much as 150 liters per capita per day according to the development stage. Taking the per-capita requirement into account together with the step-wise population increase to the maximum 400,000, the total water requirement per day is resulted as shown in Table and Figure Water Required, CUM/Day 60,000 50,000 40,000 30,000 20, l/day/capita 50 l/day/capita 90 l/day/capita 120 l/day/capita 150 l/day/capita Table and Figure 5.3.1, as examples, simply indicate that population 400,000 will require a total 10,000 m 3 /day under the per-capita requirement of 25 liters per day per capita while the same population will require as much as 60,000 m 3 /day with the highest water requirement of 150 liters per 10, , , , , , , ,000 Population 400,000 Figure Water Requirement by Different Per-capita Water Requirement and Population 4 Usually it was said that the drawdown up to 1/4 (around 25%) of the aquifer thickness was allowable as a safe discharge not to harm the aquifer. DCDA 5-16 JICA

17 day per capita. On the other hand, if population of only 150,000 is projected by the time, the requirement will be 3,750 m 3 /day and 22,500 m 3 /day, respectively. Table Water Requirement by Different Per-capita Water Requirement and Population, m 3 /day Population 25 l/day/capita 50 l/day/capita 90 l/day/capita 120 l/day/capita 150 l/day/capita 50,000 1,250 2,500 4,500 6,000 7, ,000 2,500 5,000 9,000 12,000 15, ,000 3,750 7,500 13,500 18,000 22, ,000 5,000 10,000 18,000 24,000 30, ,000 6,250 12,500 22,500 30,000 37, ,000 7,500 15,000 27,000 36,000 45, ,000 8,750 17,500 31,500 42,000 52, ,000 10,000 20,000 36,000 48,000 60,000 Source: JICA Sub-project Team Exploitable Groundwater Potential Chapter 5.1 Groundwater Development Potentials explored the groundwater potential by site as once again summarized in Table In addition, the table indicates the current use of the groundwater such as domestic use for the population, irrigation, and also brick making factories. To estimate the current use of the groundwater, following were assumed with reference to the inventory survey and also interview results: 1) To estimate newly exploitable amount of groundwater, current use of groundwater should be taken into account. These are; 1) domestic use mainly composed of drinking and laundry, 2) irrigation, and 3) brick factories use to mold bricks. 2) For the domestic use of water, mainly drinking and laundry water, per-capita requirement per day is set at 50 liters per capita per day while the population refers to the bigger number, either the estimated population based on number of households given by CSO or what was reported by the village representatives. Not all the residential areas are to be affected by the future groundwater development, e.g. almost half the Pol-e Charkhi area is segregated by different catchment, only small parts of Bakhtyaran site and Pymonar site are to be affected since the residential areas are far from the groundwater development area. Daneshmand area is replenished by a stream coming from upstream whereby no effect is foreseen. 3) Concerning irrigation by groundwater, irrigation wells are found in Pol-e Charkhi area, Pymonar area and Daneshmand area, numbers of which are 14, 22 and 30 respectively. These wells are operated during spring season mostly from May July. According to the inventory survey, an average of 40 m 3 /day/well can be taken as the irrigation use for a well, converted in throughout the year pumping discharge as per day. 4) There are brick factories in Bakhtyaran area and the area between Pymonar village and Daneshmand village. To mold bricks, they use groundwater ranging mostly from 40 to as much as 150 m 3 /day for the period of half a year to throughout the year. Converting them into the throughout-year discharge, 48 m 3 /day/well and 52 m 3 /day/well are employed as the unit use by the brick factories in Bakhtyaran and Pymonar-Daneshmand area, respectively. 5) There are three large-discharge wells in Tangi Kalay owned by an investor. The discharges are reported at 45, 40 and 40 liters per day per well and one of the three wells is taken as emergency whereby two wells work in full operation during spring season, say 3 months, for irrigation purpose. Converting the 3 months discharge of the 2 wells, 45 liters plus 40 liters, into discharge throughout the year, an amount of 1,836 m 3 /day is estimated as the private investor s water use. JICA 5-17 DCDA

18 Afghanistan Following table shows, after subtracting current use of groundwater, that there are still exploitable potentials in Tangi Kalay and Pol-e Charkhi areas but not in Bakhtyaran and Pymonar-Daneshmand areas. For the latter 2 areas, the estimated total amount of current use indicates an already over-exploited situation, and therefore no further development would be foreseen. Table Groundwater Potential in Comparison with Current Use Site Tangi Kalay Pol-e Charkhi Bakhtyaran Pymonar Daneshmand Total Gross Potential, m 3 /day 5,500 5, ,300 Average Current Use, m 3 /day 2, Max. Compensation % of to-be-affected area Assumed by MODFLOW Population 3,840 3,590 5,000 4,800 4,800 simulation results. Domestic Use, m 3 /day l/day/capita No. of Irrigation well Irrigation Use, m 3 /day m 3 /day/3months/well No. of brick factories Brick Factory Use, m 3 /day m 3 /d/fac. (thr. Yr) Private investor s well, m 3 /day 1, (45+40) l/s/2 wells/3 m Net Exploitable Pot l, m 3 3,472 5,172 /day Say 3,000 Say 5, Source: JICA Sub-project Team In Tangi Kalay area, gross potential can be 5,500 m 3 /day while total amount of current use is estimated at 2,028 m 3 /day leaving net exploitable potential at about 3,000 m 3 /day. In fact, this exploitable amount is very much dependent on what extent the private investor is going to use his wells. In fact, should all the 3 wells owned by the investor be fully operational throughout the year, the total discharge would be 10,800 m 3 /day (( ) x 86,400/1,000), overweighing the gross potential by far. On the contrary, should the investor be willing to provide the water to the new City under a water trade-agreement, DCDA would be able to exploit as much as about 5,300 m 3 /day (5, ). Therefore, in this Tangi Kalay site, negotiation between DCDA and the investor is recommend as the first stage towards concluding in an agreement whereby the water right owned by the investor can be traded to DCDA. Otherwise, the net exploitable potential of only about 3,000 m 3 /day may remain in the Tangi Kalay. Pol-e Charkhi site shows the most promising exploitable potential amongst 4 sites. The net exploitable potential amounts at about 5,000 m 3 /day after subtracting domestic water (90 m 3 /day) and irrigation water (138 m 3 /day). Adding the exploitable potential at Tangi Kalay site, the total exploitable potential comes to about 8,000 m 3 /day, and should the agreement with the investor be made thereby DCDA could utilize his water right, the exploitable potential could Water Required, CUM/Day 25,000 20,000 15,000 10,000 5, , , l/day /capita 50 l/day /capita 90 l/day /capita 120 l/day /capita 150 l/day /capita 5,000 cum/day 8,000 cum/day 10,000 cum/day 150, , , , ,000 Population 400,000 Figure Water Requirements and Exploitable Potential DCDA 5-18 JICA

19 be as much as about 10,000 m 3 /day. Figure superimposes development potentials on the water requirements, in which the potentials of 5,000 m 3 /day only from Pol-e Charkhi, 8,000 m 3 /day from combined use of Pol-e Charkhi and Tang Kalay, and 10,000 m 3 /day from the combined use of Pol-e Charkhi and total potential of Tangi Kalay including the one owned by the investor are assumed. From this figure, following are indicated: In case of only Pol-e Charkhi being developed, population of approximately 200,000 could be served at the rate of 25 liters/day/capita, that of 100,000 at the rate of 50 liters/day/capita, and approximately 50,000 at 90 liters/day/capita. In case of Pol-e Charkhi and Tang Kalay being developed excluding the investor s water use, population of approximately 300,000 could be served 25 liters/day/capita, that of 150,000 at the rate of 50 liters/day/capita, that of approximately 75,000 at the rate of 90 liters/day/capita, and about 50,000 at the rate of 150 liters/day/capita. In case of Pol-e Charkhi and Tang Kalay being developed including the investor s water right, population of around 400,000 could be served with 25 liters/day/capita, that of 200,000 at the rate of 50 liters/day/capita, that of approximately 110,000 at the rate of 90 liters/day/capita, and about 70,000 with 150 liters/day/capita. JICA 5-19 DCDA

20 Afghanistan 5.4 Conceptual Development Designing Based on the simple balance calculation by employing a concept of perennial yield carried out in the aforementioned sub-chapter 5.1 and 5.2, it was found that only Pol-e Charkhi can be the potential candidate site for the groundwater development amongst 4 sites. Though Tangi Kalay area has presented almost same potential as that of Pol-e Charkhi, there should be prior negotiation with the investor who owns large scale wells if DCDA wishes to exploit the groundwater therein. If the negotiation is settled with a success, it would be a better option to buy water from the existing wells rather than establishing new wells. Therefore, conceptual design is to be done for the Pol-e Charkhi area only Groundwater Development Potential and Production Wells Groundwater development potential in the Pol-e Charkhi site was estimated from around 4,800 to 5,900 m 3 /day as a gross development potential, and around 230 m 3 /day 5 shall be left from the development for the existing water use including both irrigation and domestic uses. Thus, a net groundwater development potential comes to a level of about 5,000 m 3 /day. Then, based on the results of pumping test in Pol-e Charkhi site, it was confirmed that the aquifer in this site was excellent as indicating 3,400 m 2 /day of Transmissivity (T), of Storativity (S) and liter/sec/m of specific yield. The specific yield suggests that a proper designed production well in this site can yield more than 29 liter/s inducing 5.0m of drawdown, and this yield in terms of liter per second is equivalent to 2,516 m 3 per day. When considering the net groundwater development potential, only two production wells have enough capacity to exploit the potential as suggested by 2,516 m 3 /day x 2 wells = 5,031 m 3 /day, almost equal to the 5,000 m 3 /day of net potential Drawdown by the Production Well Accordance to Theis theory, when a well penetrating an extensive confined aquifer is pumped at a constant rate, the influence of the discharge extends outward with time. The rate of decline of head times the storage coefficient summed over the area of influence equals the discharge. Because the discharged water must come from a reduction of storage within the aquifer, the head will continue to decline as long as the aquifer is effectively infinite; this is called as Unsteady Radial Flow. In a case of unsteady radial flow in a confined aquifer, the drawdown is shown as a following solution: Q s = W ( u) 4πT 2 r S u = 4Tt (1) where: s is drawdown (m), Q is discharge (pumping) rate (m 3 /day) T is Transmissivity (m 2 /day) W(u) is Well function, u is an indicator of W(u), r is distance from pumping well (m), S is Storativity, and t is time of pumping (day) 5 In Pol-e Charkhi area, 90 m 3 /day for domestic water and also 138 m 3 /day for irrigation water are estimated now in use, totaling 228 m 3 /day. With this rough estimation, rounded amount of 230 m 3 /day is left for the domestic use and irrigation use for the population. DCDA 5-20 JICA

21 The equation was introduced for a confined aquifer but it can be applied to an unconfined aquifer as well if the drawdown is not so large as compared to the depth of aquifer, of course under the assumption that the aquifer is completely homogeneous and extending infinitely. As the equation indicates that the drawdown grows with the pumping rate and diminishes with the increase of the distance from the pumping well but it continues increasing steadily while pumping is continued. Table shows a drawdown of sample calculation in case of a production well in Pol-e Charkhi site under the conditions of 2,516 m 3 /day of pumping rate, 3,400 m 2 /day of Transmissivity, of Storativity. As shown in the table, drawdown after 1 day pumping at the point 30m far from the pumping well is only 46 cm, but it increases up to 90 cm at 5 years later. Whereas after 5 years continuous pumping, drawdown is 90 cm at the point 30 m apart from the pumping well, it is still less than 36 cm at a far point 3 km away from the well, if the actual aquifer condition is enough wide and homogeneous. Table Calculation of Drawdown by Theis, Pol-e Charkhi Site Time 4Tt S/4Tt u=r 2 S/4Tt r=30m r=100m r=200m r=300m r=400m r=500m r=1000m r=2000m r=3000m 1day E-07 u= W(u)= s= day E-08 u= E W(u)= s= mon E-09 u= E E W(u)= s= mon E-09 u= E E W(u)= s= year E-10 u= E E E E W(u)= s= y E-10 u= E E E E E E W(u)= s= y E-10 u= E E E E E E W(u)= s= y E-10 u= E E E E E E W(u)= s= y E-10 u= E E E E E E W(u)= s= Source: JICA Sub-project team Interference to the Existing Wells Where a cone of depression between two nearby pumping wells appears, as the case of Pol-e Charkhi, one well interferes with the other because of its increased drawdown by pumping lift. For a group of wells forming a well field, the drawdown can be determined at any point if the well discharges are known, or vice versa. From the principle of superposition, the drawdown at any point in the area Figure Interferences of Drawdown of influence caused by the discharge of several wells is equal to the sum of the values of draw-down caused by individual wells. Thus, s T = s a + s b + s c + + s n (2) where T is the total drawdown at a given point and sa, sb, sc, sn are the values of draw-down at the point caused by the discharge of wells a, b, c,, n, respectively. The situation is shown in JICA 5-21 DCDA

22 Figure Afghanistan Where a well is pumped near an aquifer boundary, the assumption that the aquifer infinitely extends is no longer valid. An example seen in the site is the situation of a well near a perennial stream. Because of the continuous recharging from a perennial flow, pumping water level (cone of depression) is modified as if there is an imaginary well system at the opposite side of the flow. Sectional view is exampled in Figure Figure Sectional View of Discharging Well near a Perennial Flow Taking these conditions; interference of production wells and recharging from perennial flow, into consideration, drawdown of groundwater taking place around the production wells was estimated through MODFLOW model simulation. Figure shows a sample of drawdown contour map 5 years after two of the wells started pumping, shown in meter. In this simulation, the production wells have been operated at the rate of 2,500 m 3 /day each. In the figure, the contour lines are 0.1m interval, and water level of the Kabul River is GL m Design of New Production Wells Pol-e Charkhi Case.6 : Q=5,000m3/s (No.1+No.2) 5 Years After Well Point : No Kabul River : GL.-14m Well Point : No.1 As explained above, two newly drilled production wells are required, which must yield more than 2,500 m 3 /day under at least m of water-head ((S.W.L 14m + D.D 5m) x 1.5). However, one new large scale Test Well which can be converted to a production well later Figure Groundwater Contour under pumping shall be drilled at first in order to confirm the well yield more precisely. Pumping rate of more than DCDA 5-22 JICA

23 2,500 m 3 /day means nearly 30 liter/sec, rather large amount of yielding, and to pump up such large amount of groundwater at least φ10 well must be required. To make up 10 well, drilling by 18-1/2 bit is needed. Thus, the structure of the production well shown in Figure is recommended. As shown in the figure, drilling diameter shall be 18-1/2 throughout the drilling, excepting an uppermost span of conductor pipe (6.0m), and the well depth shall be at least 40 m considering the geological condition of the site. Screen Figure Structure of New Test Well must be a wired type, so called Johnson s Screen to obtain enough open ratio of more than 25%. Since the screen is set from the depth of 25m to 35m, the submersible motor pump shall be set at around 25m, just upper point from the screen pipes. Two production wells will be drilled in the premises of Pol-e Charkhi Radio Station to avoid any land ownership conflict with the villagers, and shall be 1.0 km apart each other so as not to make a heavy interference. One of the two wells shall also work as a new test well, location of which can be at / in UTM (1K unit) as recommended in Figure Production well No.2 (New Test Well) Production well No.1 Compensation for the villagers may have to be considered. To identify such influence by the Figure Location of New Test Well pumping at an earliest date, a monitoring system on groundwater level must be established before a full scale development is to commence. A monitoring system is therefore to be discussed in latter sub-chapter (Sub chapter 5.5) Conceptual Design of Pipeline If the proposed water resources site were selected in the Dehsabz sub-basin, it might have been much JICA 5-23 DCDA

24 easy to transport the water to the new city. However, possible groundwater resources development site is only Pol-e Charkhi site within the Kabul Basin. On top of this, the recommended production wells are to be installed inside of the Radio Station located at southern bank of the Kabul River. It means that the pipeline to carry the water shall pass across the river along with the newly constructed road and bridge joining the Jalalabad road. Afghanistan Pipeline will pass across the road after crossing the bridge, then go west along with the northern side of the road. At a location around 3 km west from the joint with the road, the pipeline will turn to north along with the by-pass road to the Bagrum Road, just along with the district boundary between District 9 and District 19. After joining the Bagrum Road, the pipeline shall go further north along with the Bagrum Road approaching the new city. Total pipeline length is to be around 17 km. The rough route map of the pipeline is shown in Figure As shown in the figure, the pipeline starts at the two production wells to be established in the Radio Station and the ends at a reservoir near the new city just beside the road. Figure Outline of the Pipeline 5.5 Monitoring System for Groundwater Table There are two categories of monitoring systems in this project; one is to monitor the natural ground water level of the three target sites for a basic hydrogeological data in Dehsabz Basin and another is to observe groundwater drawdown to be caused by the pumping inside the Radio Station influencing the outside Monitoring of Natural Groundwater Table For the drilled three (3) wells under this Sub-project, after having placed concrete made basement (see photo as an example), they are to be so arranged that regular measurement of the groundwater level can be done. The frequency of groundwater level measurement can be as a rule once a month. This measurement may be carried out by DCDA supported by the Project on the Promotion of Kabul Metropolitan Area Development. Concrete made basement placed at the well for Bakhtyaran site DCDA 5-24 JICA

25 This Sub-project is therefore to provide them with a manual showing procedures of the measurement and items to be taken. If the measurement is to be entrusted to a third party, the Sub-project Team is to prepare a standard contract form and the TOR Monitoring the Interference to be caused by Production Wells In the previous section, draw-down to be caused by pumping at the production wells was explained. As shown in Figure 5.5.1, large parts of Pol-e Charkhi village will be affected by the pumping from the production wells but the influence is not anticipated serious judging from the result of the MODFLOW simulation. However, natural hydrological condition is not homogeneous, not infinitely equal. Therefore, it is quite important to monitor the values of actual groundwater draw-down in and around the production wells. Major purpose of the monitoring is to evaluate an influence of the groundwater drawdown to be caused by operations of the production wells, so that the monitoring must be done to the directions most affective and must be commenced before the production wells start pumping. The proposed locations of the monitoring wells are shown in Figure (Drawdown contours shown in the figure are only a reference). As shown in the figure, total three monitoring wells are required to observe the state of draw-down at the north, east, and south directions. The proposed locations are: M1: E/ N M2: E/ N M3: E/ N Figure Location Map of Monitoring Wells Depths of the monitoring wells are to be the same as that of the production wells, 50m, but drilling diameter is to be 7 to 8 and completed by 4 screen and casing. Rough design of the monitoring well is shown in Figure In case of observation wells, PVC casing and slotted screen can be applied. Screen depth shall be fixed from 25 to 35m in depth, the same as that of the new test well. Figure Structure of Monitoring Well JICA 5-25 DCDA

26 5.6 Way-forward to the Population s Consent for Groundwater Exploitation Afghanistan The prime target is Pol-e Charkhi area for the groundwater development of the Dehsabz new city. Secondary target may be Tang Kalay area, however in this area there are already 3 large wells owned by an investor. Therefore, the development in this Tangi Kalay area will firstly depend on the result of the negotiation with the owner since there is no more potential to further exploit the groundwater other than those large wells. To this end, the way-forward to develop the groundwater including EIA clearance and the population s consent should center on the Pol-e Charkhi area Groundwater Development in line with Legal Aspects There is a law stipulating water related issues in Afghanistan, called Water Law 6 issued at a Gazette No , February In addition, there is environmental related law called Environmental Law, official Gazette No.912 dated 25 January 2007, and its relevant Environmental Impact Assessment Regulations (Gazette No.939, 10 March 2008). This session refers to these 2 laws to know the legal aspects to be required for the groundwater development: 1) Water Law The Water Law has total 40 articles and governs not only surface water development but also groundwater development. The project for the groundwater development shall refer to the law especially for securing water right to develop and utilize the groundwater. Relevant articles in the law are cited and presented as below: The water is defined as a public property and the government is responsible for its protection and management by Article 2 - Ownership and Management of Water. The Article 3 defines the definitions and terminologies used in the Law wherein groundwater is governed under this Law defining that groundwater is all waters beneath the ground surface at different depths (aquifer) including springs, Karezes, deep and ordinary wells. Article 8 - Responsibilities of Governmental Institutions stipulates that the ownership of all waters in the country belongs to the people of Afghanistan and the government is responsible for their protection, control, management and effective use in accordance with the law. With this article, practical enforcement is stated as that MEW is responsible for planning, management and development of water resources in collaboration with concerned ministries and agencies, and for the groundwater the MoM shall be responsible in close collaboration with MoPH 7 and also NEPA. Aside from the line ministries, the Law stipulates under Article 13 River Basin Council (RBC) that the MEW shall establish a River Basin Committee composed of members representing water users, relevant national and local agencies and other stakeholders in the river basin (as at July 2011, no RBC has been established, though). The article further says that the MEW may delegate, when appropriate, some of its powers to the RBC in accordance with the law, after improving the required working capacity and capability through technical trainings. To this end, the one who shall issue water permit is the RBC, if already established, as stipulated under No.5 provision of Article 14 Functions of the RBC, i.e.; Issue, register, change or cancel permits and maintain relevant documents. 6 Referred to in an Unofficial English Translation by EIRP (Emergency Irrigation Rehabilitation Project) /FAO, Edited by UNEP and KRBP (Kunduz River Basin Programme) - July 6, Though the provision of Article 8 does not specify how to collaborate with MPH and NEPA, there is an understanding that the MPH should provide recommendations for the safe water quality in terms of chemical and bacteriological compositions. NEPA is the responsible agency for EIA clearance where required. In addition, NEPA is relevant with the protection of any water sources to be developed in Afghanistan. DCDA 5-26 JICA

27 The Law states necessity of carrying out an environmental impact assessment in the Article No Adverse Effects on the Environment. The article stipulates that the owners/proponents of any substantial water resources development projects shall be responsible for conducting Environmental Impact Assessment (EIA) at their own cost in accordance with Environmental Law and policy. Though the level of substantial is not stated in the Law, the envisaged groundwater development for the new Dehsabz city will be categorized under this substantial water resources development projects since the scale of the development goes beyond what the ordinary individual households require for their domestic purpose. There is an article stipulating deep well drilling, namely, Article 38 - Deep Wells Drilling. This article states that the deep wells may be drilled only after obtaining an authorization from MoM for agriculture, commercial, industry and urban water supply purposes. Digging ordinary wells to meet the need for drinking water and livelihood purposes is exempted from this provision. 2) Environmental Law and its Regulations The Environmental Law was enacted on January 25, 2008 by the National Assembly, and has total 78 provisions, following which Environmental Impact Assessment Regulations was gazetted on March 10, Relevant articles that shall refer to in developing groundwater are: National Environmental Protection Agency (NEPA) is designated as an independent institutional entity responsible for coordinating and monitoring conservation and rehabilitation of the environment, and for implementation of the Environmental Law under Article 3. This NEPA is therefore the sole agency to authorize on the advice of the EIA Board of Experts the project submitted by a proponent, provided that any significant adverse impact on the environment takes place. There is an article under the Law specifying public participation Article 19 Public Participation. The article states that the NEPA shall not reach a decision on any application for the permit until such time that the proponent has demonstrated to the satisfaction of the NEPA that the proponent has distributed copies of the document to affected persons, informed the public that the document is being made available for public review by advertising the document and display a copy of it for inspection, and convened and recorded the proceedings of a public hearing. The Article 19 under the Law further says that after the NEPA has reviewed the conditions set in the aforementioned statement, the NEPA shall reach a decision and inform the pubic of that decision and make available any relevant documentation or information for public review. In line with the Law excerpted above, the Regulations elaborates procedure of application in order to acquire permission for a project which may affect environment and its screening. Regulation 4 Applications states that an applicant shall submit to the NEPA an application form in accordance with schedule specified in the Regulations. Regulation 5 Screening 8 points out that the proponent shall conduct a screening process and complete a screening report consistent with international best practice, which is to be submitted to NEPA for its decision for the permission. Then, the NEPA may require the applicant to carry out environmental impact assessment process. If the applicant is instructed to do so by the NEPA, the applicant shall prepare environmental impact statement, which statement shall contain all the information required for the NEPA to 8 In relation to this, activities are categorized in 2; Category 1 and Category 2. No groundwater related activities are listed in the categories, however there is an activity of water supply and treatment. With reference to this category, a water supply scheme with a total cost of US$ 400,000 or more is categorized under Category 1 Activities while less than that water supply projects under Category 2 Activities. JICA 5-27 DCDA

28 make a decision if it is permitted or not. Afghanistan 2) Procedure to EIA Clearance and Water Right to Secure Taking account of above cited provisions of the Laws and Regulations relating to this groundwater development, DCDA is required to take following actions: 1) The production wells are to be constructed in the premises of Pol-e Charkhi Radio Station which is placed under the supervising authority of the National Radio and Television of Afghanistan (NRTA) of the Ministry of Communication and Culture. To construct the production wells within the premises, DCDA should start discussing with the Ministry of Communication and Culture for the permission of constructing the well(s), though this is not directly related to the requirement of the environmental law. 2) At the same time, DCDA to hold a public hearing meeting(s) inviting the population of the Pol-e Charkhi village (refer to Box). The size and contents of the development including the volume of the groundwater exploitation will be explained to the villagers. Expected drawdown of the groundwater table shall also be thoroughly explained with its monitoring system (For the procedure and the contents of the meeting are discussed in the following section). 3) In line with above 1) and 2) processes, DCDA to prepare for Screening of the groundwater development project required under the Environmental Law which is also a part of EIA. The contents of this Sub-project shall fully be People s involvement/participation in EIA: In line with EIA procedure, the people who may be affected by the project should at least be given all the relevant project information (level-1), which is usually called involvement of the population. This also requires the implementing agency to discharge the responsibility of accountability to the people. On top of the involvement, there may be 2 levels in which the people participate. One is the participation to decide which alternative plans to be provided by the implementing agency shall be the best (level-2), and the other is that the people themselves participate in the design of the alternative plans and decide on them by themselves (level-3). utilized especially for the design of the works, scale of the groundwater development, level of expected negative impacts represented by drawdown of the groundwater table and mitigation measures including monitoring system. The EIA should incorporate the discussion results with and the consent from the villagers of the Pol-e Charkhi for the development of the groundwater. 4) Upon the consensus by the Pol-e Charkhi population and permission for the construction of the wells within the premises by the Ministry of Communication and Culture, DCDA will complete the EIA statement and submit to the concerned authority, NEPA, for authorization of the project. Upon approval, DCDA to prepare for and submit an application form of the water work, which here means the groundwater development works composed mainly of 2 deep wells construction, to the MEW. In fact, though the application is supposed to go to the River Basin Committee, the committee has yet to be established whereby to the supervising authority, namely, to the MEW. In addition, DCDA has to submit the plan/design for the deep well(s) to MoM for the authorization of the work. 5) Upon the granting of the permission, the DCDA may proceed with the construction of the deep well(s) in the premises of the radio station. The premises is a government property, and therefore no financial compensation for occupying a land, approximately 5m square each per well, for the construction of deep well(s) may be required on condition that the DCDA and the Ministry of Communication and Culture are in agreement. DCDA 5-28 JICA

29 5.6.2 Consensus on Groundwater Development from the Pol-e Charkhi Population From the viewpoint of accepted customs and traditions, there are some statements given by some of the Shura members during the explanatory meetings arranged for the purpose of arriving at consensus on the conduct of the surveys under this Sub-project. The custom and tradition may suggest that the property right of the landowner does not govern that of the groundwater beneath his/her land. It means that as far as the new development does not negatively affect the present use of groundwater, the villagers shall not claim any compensation for the groundwater exploitation according to costmary practices. This custom is also in accordance with the Water Law wherein water is specified as public property under Article 2 - Ownership and Management of Water. According to the Water Law, DCDA is required to conduct EIA for this groundwater development project. The EIA procedure, according to the Environmental Law, requires DCDA to conduct public hearings from the Pol-e Charkhi population who may be affected by the project. Though the well(s) are to be constructed within the government premises, it is still necessary to hold the public hearing meetings with the Pol-e Charkhi villagers for the groundwater development as far as there is a possibility that they may be affected, otherwise the EIA procedure can not be completed. Taking above conditions into consideration, following procedures are recommended to arrive at the consensus with the Pol-e Charkhi villagers for the development of the groundwater: 1) DCDA to invite village representatives such as CDC members and Shura members through Malik for the public hearing meeting(s). The meeting should also invite some villagers concerned who are heavily dependent on the groundwater, e.g. farmers with irrigation wells and nearby households who are dependent on the groundwater for their domestic uses. Villagers who reside outside the radius of 2 km may not be requested to attend the meeting since the impact will be negligible. 2) During the meeting, the DCDA will explain the plan/design of the groundwater development and also its relevant impact. DCDA will also request the village representatives who attended the meeting to hold small meetings in their areas to further discuss and explain the information provided by the DCDA. DCDA will inform the participants in the meeting of the following, and at the same time shall make all the relevant documents and information public/ available: Rationale and the purpose of the groundwater development in the Pol-e Charkhi area, Timeframe of the groundwater exploitation, which refers to the time when the water resources at the Panjishir fan is to be developed, Development plan/design and the volume of the groundwater to be exploited by development stage (by year) in correspondence with the exploitable potential which exists in the Pol-e Charkhi area, Expected impact especially in the form of drawdown of the groundwater table, Monitoring system, and Measures to cope with negative impact such as drawdown of the groundwater table which goes beyond allowable level. 3) DCDA and the village representatives will prepare record of discussions including issues and agreements made. The document should clarify the consensus with the villagers on the groundwater exploitation and also the measures to be taken in case that unallowable negative impact happens. JICA 5-29 DCDA

30 Afghanistan DCDA should have in mind that as regards drawdown by more than 50cm from the present groundwater level it should notify the water users of what is happening on their groundwater through general communication practices. In case that groundwater level goes down by more than 50 cm from the original level, the users can feel that the pumping gets harder bit by bit due to the increased load and also the escalated time lag between starting the pumping and the moment the water starts pouring out. However, this situation does not instantly require the users to seek compensation since users still can avail of groundwater. According to the well structure in the Pol-e Charkhi area, the level of drawdown which makes existing wells very hard to pump up groundwater would be from 2-3 meters or more. In fact, if the drawdown reaches as much as 5m, there will be many wells that will dry up. However this situation would hardly take place according to the simulation results by MODFLOW. MODFLOW analysis has identified the drawdown of the groundwater under different pumping ratios of groundwater exploitation. Table summarizes the drawdown of the groundwater table in case of total 5,000 m 3 /day pumping (2,500 m 3 /well x 2 wells) with time of lapse and by distance from the wells. From the table, it can be said that the present users would hardly be affected to a level at which they would have great difficulty of pumping up groundwater whereby needing compensation: Table Drawdown of the Groundwater, 2,500m 3 /day x 2 Wells Day/Year Distance from the Well 30 m 100 m 1.0 km Day Day Day Year Year Year Year Year Year In detail, after a year since the pumping started, the groundwater drawdown will be only 66 cm even at a distance of 30m from the pumping well and only 27 cm at a place 1 km away from it. Likewise, 5 years later since the pumping started, the drawdown will be 74 cm and 42 cm at the place of 30 m away and at the place of 1 km away, respectively. From these results, though user villagers would notify the drawdown of the groundwater to at least some extent, they would have very little difficulty in pumping up the water. For the compensation should the case take place, the best way may be to install public taps sourced from the production well(s). The public taps, if needed, should be installed along existing village roads. Of course, the positioning of the taps should fully incorporate the users views. To provide the compensation water to about 50% of all the Pol-e Charkhi population as an example, there would be about 90 m 3 /day of domestic water based on a per-capita water requirement of 50 liter per day. Aside from this domestic use, there are 14 irrigation wells in Pol-e Charkhi area. One well usually provides about 40 m 3 /day during the irrigation period of 3 months. Though it is not likely for all the wells to be affected, the maximum compensation, if needed, would reach 560 m 3 /day for the 3 months from May to July. DCDA 5-30 JICA

31 CHAPTER 6 GROUNDWATER DEVELOPMENT -2 (ADDITIONAL TEST WELL) 6.1 General As explained in Chapter 4 and Chapter 5, the target site No.2, Pol-e-Charkhi area is the only site which has substantial groundwater development potential, on which present level of groundwater use is estimated below the annual rechargeable amount among total four candidate sites in this Sub-project. However, as described in Section Test Well Drilling General, the test wells drilled in the study were finalized by 6 casing and screen, and also as shown in Section 4.2,3 Pumping Test Results, the size of test well drilled in Pol-e-Charkhi site was not enough to set a submersible pump with large discharge amount. On the other hand, total groundwater development potential in Pol-e-Charkhi site was estimated as 5,960 m 3 /day (Section 5.1.2), and exploitable groundwater potential was evaluated as around 5,000 m 3 /day (Section 5.3.2). The volume can be exploitable by only two production wells (2,500 m 3 /day/well, nearly 28.9 lit/sec/well) because of very excellent hydrogeological condition of the site. However, actual pumping rate in the Constant Discharge Test in TW-Pol was only 3 lit/sec, and alternative pumping well (existing well in RTA compound) had rather enough discharge rate at around 24 lit/sec though no well design nor aquifer information were available. Thus, an additional test well was required to be drilled which had enough large casing diameter for setting submersible pump yielding around 30 lit/sec, and can be diverted to a Production Well after completing series of tests as a test well. Based on such requirement, an additional test well with 10 inches casings and screens which were enough to yield around 30 lit/sec of groundwater was planned out, and implemented. The new test well (hereinafter called as TW-N) was sited by field reconnaissance around RTA compound (Radio Station), because two of previously planned production wells, decided to be drilled inside of the RTA, were cancelled due to security reasons. In TW-N, a series of pumping tests and water quality analysis were conducted, and MODFLOW analysis was carried out again using the up-dated aquifer constants. Because these two production well sites were selected outside RTA compound, monitoring system of groundwater table was also reconsidered. Details of such siting, test well drilling work, groundwater analysis, and so on are described in the following sections. 6.2 Siting of the Test Well Introduction Through the investigation previously made, two production well sites were selected inside the Radio Station in Pol-e-Charkhi (refer to Figure Location of New Test Well, p.5-23). Use of these two points was finally refused by RTA through long and hard negotiations between RTA and DCDA. Since June 2011, more than 8 months in total were wastefully spent without any substantial work on groundwater survey. In November 2011, DCDA requested to the Consultants to select the production well sites outside the Station, even though the negotiation was still being continued at that time. In late November 2011, two Consultants and one DCDA Engineers made a field reconnaissance around the Radio Station. In the reconnaissance, the Consultants recommended three candidate sites for production wells. Later, after DCDA gave up the effort on the negotiations with RTA, Engineer of DCDA selected also three candidate production well sites around the Radio Station, one among them is the same as the previous selection while two were different new sites. Then, the Consultants agreed on the two sites among the three, in the north and the east of Radio Station through additional reconnaissance survey. JICA 6-1 DCDA

32 6.2.2 Required Conditions of Test Well Site Afghanistan Through the hydrogeological study on Pol-e-Charkhi area, it was found that the highest groundwater development potential could be obtained in the zone where groundwater was recharged from the Kabul River and the Buthkhak River as well. On Figure 6.2.1, the former zone is enclosed in between thick blue dotted lines, and the latter zone is also enclosed by pinkish line. Therefore, it was considered that the test well and production wells shall be drilled in the small zone overlapped by those two zones, fetched by thin red lines. 23 C 22 Possible Production Well Site A B 21 Indirect Recharge by Kabul Direct Recharge by Buthkhak Figure High Groundwater Development Potential Area As shown in the Figure, almost central part of the high groundwater potential zone is occupied by the Radio Station, and the alternative test well site must be sought in the west side (marked A ), south-west side ( B ), and in the north-west of the Station ( C ), because eastern half of the potential zone is almost filled by housings of the villagers. The site C is, however, not so favorable compared with the other two points because there are many small irrigation wells around Site Selection In early March 2012, DCDA made another field reconnaissance survey on Test Well sites around the Radio Station. Through the reconnaissance, they omitted the candidate sites A and B because the land owner did not agree to make a lease agreement on the land. Only the site C was available to obtain long term land lease agreement from the owner. Aside from these sites, DCDA found other two possible sites for production well sites, one was east side of point C and another was near the main gate of Radio Station. In the middle of March, the Consultants and DCDA Engineers made a joint final reconnaissance on the area, and finally selected two proposed production well sites, as point TW-N and PW-2 as shown in the Figure Locations of these well sites are as follows: TW-N: E / N PW-2: E / N DCDA 6-2 JICA

33 TW-N PW-2 Figure Location Map of TW-N & PW-2 Figure Location Map of TW-N & PW-2 The point of TW-N was in the same site of C in Figure There were some private irrigation wells around the site but open space could be found which gave enough space to drill the Test Well and an observation well (refer to the next section), a pump station as well, in the farm land a little far from the existing wells. The well, TW-N, shall be drilled as a test well at first, and then it shall be converted to a production well after all tests in the well would be completed. Therefore, the same well structure was designed as that of the standard production well that had been proposed during the last study period (refer to Design of New Production Wells: p5-23). PW-2, the other production well, shall be drilled at the space in between the wall of Radio Station and local road from Pol-e-Charkhi to Bagrami town (Province 8), and near the main gate of Radio Station. The land of PW-2 point was owned by RTA, which means a national land, and no need to negotiate a land lease agreement with any private sector Test Well System TW-N Ob-1 approx. 20m To obtain hydrogeological information on the aquifer, it is important to conduct a pumping test with at least an observation well. Without the test, a Storativity (S), which is the most significant aquifer constant needed to estimate the groundwater drawdown by pumping water out of the well, cannot be evaluated. Distance between the Test Well and the Observation Well shall be around 20m, with an allowance of error less than one meter. Direction of the observation well from the test well can be optional, but it shall be convenient to set these wells in parallel with the surrounding road of Radio Station from a viewpoint of access of drilling rig. Depths of the wells were both set to 40m. A simplified model of test well and pumping system is shown in Figure Depth 40m 10" Dia. Figure Test Well System Figure Test Well System 4" Dia. JICA 6-3 DCDA

34 approx. 50m Afghanistan Thus, two points for drilling (Test well TW-N and Observation Well Ob-1 ) had been selected in the above mentioned site C zone. Yard required for the drilling work had an area of around 20m x 50m for the drilling of two wells (refer to Figure 6.2.4), and the area was checked for mines and UXO by UNMACCA, before starting the drilling work. 20m TW-N Ob-1 20m 25m 25m Figure Required Area for for Drilling Work 6.3 New Test Well Introduction The additional new test well was drilled and tested to know whether it can actually yield designed discharge and how it affects to the surrounding area. Drilling of the new test well (and observation well) were carried out under Sub-contract between the Study Team and Prism, a local contractor. Prism made a preparation work from 16th to 19th, and brought a drilling rig to the site on 21st April. TW-N was drilled at first, then, Ob-1 was drilled continuously. These drilling works were conducted under supervision of Drilling Expert of the Team, Mr. Sasaki, with assistance of a local Hydrogeologist employed by the Team. Drillings works were made rather smooth, completed within less than two weeks. Then, development of both TW-N and Ob-1 were carried out in early May (4th May). Results of the drilling are shown in ANNEX-VI.9 and simplified figure is shown in Figure Based on the news on the completion of drilling works, Mr. Kawasaki (Leader of the SP) had arrived at Kabul on 13th May, Upon the arrival of Kawasaki, Mr. Sasaki returned to Japan on 17th May. TEST WELL DRILLING RESULT Well No. TW-N Drilling Diameter: 18-1/2" Pumping Rate: Location Pol-e-Charkhi Casing Diameter: 10" Dynamic Water Level: X Drilling Depth: 40.8m Completion Date: Y Well Depth: 40.0 m Drilled by: Prism Z 1, Static Water Level: GL.-5.77m Log Geology Color Age Drilling St. Well St At the beginning of pumping test in TW-N, Gravel 20 Alluvium very small groundwater yield, only 6 to 7 Gravel Packing /2" Drilling lit/sec, had been measured and the well was involved into a special strong development to 25 Gravel 25.15m φ10"jhonson Screen 27 recover the yield. However, such development Gravel with Clay could not recover the yield, and it was decided 31 Sand with Gravel that the well should be re-made under another 35 well design. After the re-making of the well, Gravel with Clay another pumping test was conducted in Blank Casing 37.15m re-made TW-N, and satisfactory groundwater 40 40m 40.8 Bottom Plug yield of 30 lit/sec was obtained through the test. The details of such special development and Figure Original Well Design of TW-N re-making of the well are explained in the next section. Re-making of TW-N was completed on 28th May, and pumping test in the well was conducted from 29th May to 3rd June, These situations DCDA 6-4 JICA Clay 22"Drilling φ20"steel Casing m 6 6m Muddy Clay Remarks Cementation Cementation 12 12m Clay Seal Gravel 14 Gravel with Clay 16 φ10" Blank Casing

35 are also explained in the following sections Re-making of TW-N On 16th May, a preliminary pumping test was conducted in the site. During this test, very low yield on TW-N had been found out, as only 6.0 lit/sec with lower than 24m of dynamic water level, it s around 19m of drawdown. The Consultants stopped pumping test immediately and instructed to make a special large scale development work, because normal development had been conducted for around 4 days already. The special development included an air-lift and an air-blow the water inside the well. Especially, air-blow blew groundwater to the ground surface through the annular space between the casing and well wall filled by filter gravel. After a half day of air-blow, a normal development by air-lift was carried out, then, another air-blow was conducted. For two days, the special development, both air-lift and air-blow, was conducted, and then, a preliminary pumping test was conducted again. The result was, however, almost the same as that obtained in the previous test, showing only 7.0 lit/sec with around GL-19.0m of dynamic water level (around 13.7m of drawdown). TEST WELL DRILLING RESULT (4/5) Well No. TW-New Drilling Diameter: 18-1/2" Pumping Rate: 27.4 lit/sec Location Pol-e-Charkhi Casing Diameter: 10" Dynamic Water Lev GL X Drilling Depth: 40.8m Completion Date: Y Well Depth: 40.0 m Drilled by: Prism Z 1, Static Water Level: GL φ20"steel Casing m m m 16 Gravel 20 Alluvium 22 Log Geology Color Age Well St. Clay Muddy Clay Gravel Gravel with Clay Well Logging Results Under the situation, the Consultant finally decided to re-make this well, because such low yield of the well should be attributed to the well structure itself, not due to work qualities such as shortage of development. Re-making of the well means a) pulling out the casing and screen, b) reaming the well by 19 bit (enlarging the well diameter), c) re-installation of casing and screen but different program, then, d) gravel filling again, and e) re-development. Original well design has come from the production well theories as: 25 Gravel 27 Gravel with Clay Sand with Gravel Gravel with Clay 23m 33m 36m 38.5m a) The screen shall not be exposed in the air through drawdown of dynamic water, to avoid deterioration of the screen. b) The submersible motor pump shall not be set in the span of screen pipes, to avoid harming the pump through sucking down sand grains. c) Submersible motor pump is Figure Re-Made Well Design of TW-N designed to absorb groundwater from its middle body and motor is assembled at its bottom, so the pump should be set above the screen pipes for effectively JICA 6-5 DCDA

36 cooling the motor. Afghanistan d) When the pump was set lower than the screen portion, it needs to be set a flow sleeve to cool the motor effectively by groundwater flow. Based on the condition a) mentioned above, the screen pipes cannot be installed at the position of main aquifer of GL-12m to 22m, because the dynamic water level in the well was supposed at nearly 19m, and therefore, the top of the screen must be lower than 20m. Since the submersible pump that can yield around 30 lit/sec usually has rather long vertical length, the top of the screen must be lower than the dynamic water level plus the length of submersible pump based on the condition b). Thus, mainly based on these two conditions and also on the condition c), the casing program of TW-N was designed as Figure On the reviewing of the first TW-N, three screen pipes (@3.0m x 3 = 9m) were installed at the position of main aquifer (GL-14m to 23m) in the re-made TW-N, to make it easier to develop the screen and to get full groundwater of the main aquifer directly. Through full activation of the main aquifer, it can be expect that the drawdown of dynamic water level may be reduced significantly. Even though such mitigation was not so much, and the filter top was exposed somewhat to the air by this design, it can be allowed because the production well is just a temporary one for only 5 years. Another screen pipe was set at the lower sub-aquifer (GL-33m to 36m). Between these two screen portions (GL-23m to 33m), four blank casing pipes (@2.5m x 4 = 10m) were installed as a pump chamber on which the pump shall be set. By this structure, above mentioned condition c) can be satisfied. Besides, it can also prevent all amount of groundwater yielding from upper layers. However, it can be recommendable to set a flow sleeve to the discharge pump when the well is completed as a production well. Then, 6 pieces of blank casing pipes were installed above the top of screen pipes (GL-14m), and thus, the top of the casing was set up around one meter above the ground surface. The well structure of re-made TW-N is shown in Figure Re-making of TW-N was completed by 28th May, 2012, and a series of pumping test were carried out from 29th to 3rd June, After completing it, the headwork of TW-N was constructed by a reinforced base concrete, overhead casing with flange, and steel cap fixed with flange by bolts and nuts with two locks (refer to Figure ) Figure Headwork of of TW-N Pumping Test A series of pumping test were conducted in the system of TW-N and Ob-1, such as; preliminary, step drawdown, constant discharge, and recovery test. The pumping test was a kind of empirical test to show that the well can yield planned volume of groundwater and how it influences the groundwater drawdown in the surrounding area. For this purpose, besides the series of the said test, groundwater level monitoring in three of the existing irrigation wells was also carried out in the term of constant discharge test to evaluate the influence of discharge from the production well. (1) Preliminary Pumping Test A preliminary test was conducted on the 29 th to 30 th of May, First of all, Static Water Level (SWL) was measured in both TW-N and Ob-1. SWL of TW-N was 5.78m below the ground surface DCDA 6-6 JICA

37 (BGS), and that of Ob-1 was 5.60m BGS. However, the groundwater level was measured from the top of casing pipe standing on the ground in the following test for the easiness to measure. Casing heights of TW-N and Ob-1 were 0.90m and 0.70m, respectively. Then, all of the system components such as submersible pump, raiser pipes, sluice valve, flow meter, electricity delivery board and water drainage system were checked carefully, and set up as the test system. Then, the pump was run in the condition of full discharge, and the discharge volume and drawdown were measured for around 30 minutes. Then, the sluice valve was closed to reduce the discharge volume and the groundwater drawdown in the well was measured, for around 15 minutes to 30 minutes. Thus, the groundwater drawdown in the well was measured occasionally, changing the discharge volumes, to know the relation between discharge and drawdown roughly. In the first day (29 th May), it was found that the maximum pump yield of the submersible pump provided in the site was less than 24 lit/sec, not enough to make a constant discharge test with the pumping rate of nearly the same as that planned as a production well. Planned pumping rate of the Production Well is 2,500 m 3 /day (28.9 lit/sec). Thus, the Consultants instructed the Sub-contractor to replace the submersible pump with other pump with larger yielding capacity. On 30 th May, the Sub-contractor brought another submersible pump which had a capacity of 100 m 3 /hour of yield at 15m of water head. The pump yield was improved to around 27.8 lit/sec, near around the planned yield, and higher yield can be expected when the water head is far less than the defined height. Thus, the Consultants accepted this pump for the following test. Results of the preliminary test were as follows: Discharge (lit/sec) Dynamic Water Level (GL-m) Drawdown (m) No discharge SWL= As shown above, the maximum discharge in the Preliminary Test was around 27.5 lit/sec, a little less than the planned discharge level of the production well, but the Team judged as allowable. Result of the test is figured out as Figure 6.3.4, shown below DD (m) Q (lit/sec) Figure Result of Preliminary Test JICA 6-7 DCDA

38 Afghanistan Based on the result of preliminary test, the frame of following pumping test plan was decided as follows: The pumping rate in Constant Discharge Test shall be around 27.5 lit/sec. The steps of Step Drawdown Test shall be from 13.0 to 27.5 lit/sec. The preliminary test was completed early afternoon in 30 th May, then, the pump was stopped to recover the groundwater level in the well. (2) Constant Discharge Test On the next day (31 st May), the Step Drawdown test was skipped out and the Constant Discharge Test was carried out from 10:00 in the morning, because of the schedule of Team s Engineer. Before starting the test, the groundwater levels at both TW-N and Ob-1 were checked out whether they were recovered to the original level (SWL). Referring to the results of the preliminary test, the discharge volume in constant discharge test was set as 27.5 lit/sec, which was around the maximum pumping capacity of the pump. The pumping rate was a little lower than the daily discharge of planned production well of 2,500 m 3 /day. DWL,s (m) TW-N Constant Discharge Test t (min) Figure Constant Discharge Test (TW-N) DWL-t s-t Q-t Q(l/sec) Results of the test are attached in ANNEX-VI.10, and the hydrographs are shown in Figure For analyzing the pumping test, not only for the Constant Discharge Test but for all other tests also, GWW which was the official application on pumping test analysis developed and issued by UNDP, was applied. Based (t/r 2 ) on the GWW analysis, the 0 Transmissivity (T) calculated from TW-N data was around 4,000 m 2 / day 0.1 (Theis and Jacob). However, the Storativity (S) based on Ob-1 data could not be analyzed. It may come from different aquifer structure of (t/r 2 ) s=0 = 1.6 x 10 5 a=0.228 Ob-1 (it has rather thick aquifer than TW-N) and influences from other pumping up for irrigation purpose (to be explained in the later section but S=2.25T(t/r 2 ) s=0 = western monitoring well was pumped 0.6 up during the test). Fortunately in this Figure Figure Storativility Storativility Analysis Chart s (m) 1.E 05 1.E 04 1.E 03 1.E 02 1.E 01 DCDA 6-8 JICA

39 site, groundwater level drawdown in three existing wells at different distance from TW-N was observed. Therefore, other approaches to evaluate the Storativity were conducted: so-called s-log 10 (t/r 2 ) plot method by Jacob. Figure shows one of the analysis chart on this method, in case of Ob-1/West well. Based on the chart S (west) was evaluated as around (no dimension). Transmissivity was calculated from the Ob-1 observation data also, but it was by far higher value than the one obtained from TW-N well, possibly because of different aquifer condition. Water Sampling In the late approach of the constant discharge test, in-situ water quality tests were made consisted of ph, water temperature, and EC. Then, one litter of water sample was taken for a laboratory water quality analysis. Besides the water sample for laboratory analysis, 100 ml x 2 sterilized bottles of water samples for micro-biological analysis were simultaneously taken. (3) Recovery Test After completion of the constant discharge test (by stopping the motor pump), groundwater levels in both wells were measured to observe their recovery situation, called as Recovery Test. The recovery test was continued to the following day, up to 10:00 on 1st June. Results of Recovery Test are shown in ANNEX-VI.10 together with the results of other tests, and shown roughly as Figure above, continuously from Constant Discharge Test. The Transmissivity (T) was analyzed as 2,680 m 2 /day by Recovery analysis. (4) Step Drawdown Test Through reviewing the results of preliminary test, discharge steps were decided as 13, 18, 21, 24, and 27.5 lit/sec. Results are shown in ANNEX-VI.10 in detail, and simplified figure is shown in Figure Results of the Step DD Test are summarized as following table (Table 6.3.1): DWL,s (m) TW-N Step Drawdown Test DWL-t 4 s-t t (min) Figure Step Drawdown Test (TW-N) Q-t Q-t(l/min) Table Results of Step Drawdown Test in TW-N Discharge (lit/sec) Drawdown (m) Aquifer Loss Well Loss Efficiency (%) As shown in the table, aquifer loss was 0.83 in an average and well loss was very small as around 0.01, well efficiency was nearly 98%. Relation between the pumping rates (Q) and drawdown (s) was almost linear and there was no inclination changing point which indicates change of specific yield. JICA 6-9 DCDA

40 (5) Analysis on Groundwater Level Monitoring Wells Afghanistan Besides the series of pumping test, groundwater tables were measured in the three existing wells (monitoring wells) in almost same time intervals with the pumping test (the details on the monitoring wells shall be described later). Among them, the west well, which was the nearest well to TW-N, was clearly disturbed by the pumping of groundwater in itself but other two wells were not disturbed by the other pumping operations. Thus, the groundwater measurement data in these two wells, north-east and east wells, were available to analyze hydrogeological constants of T and S, for only reference because they were located too far from the pumping well. The data on these two wells were also analyzed through GWW as a reference, and the results were as follows (Table 6.3.2), showing too much large Transmissivity and small Storativity. Table Hydrogeological Constants analyzed from Monitoring Wells Monitor Wells Distance T (m 2 /day) S (-) West 129.5m 11, North-east 164.6m 10, East 126.4m 14, (6) Summary Results of the pumping test were summarized as Table There were some differences in the values of Transmissivity (T) by the wells and analysis methods but the T value of the main aquifer shall be represented by approximately 4,000 m 2 /day, based on the Theis analysis of TW-N and considering the value obtained in the last pumping test. The value of Storativity (S) could not be obtained from Theis method in GWW analysis. A kind of Jacob method, so-called s-t/r 2 method using data of Ob-1 and from groundwater level monitoring wells, figured out Storativity from to Thus, several (S) values were obtained from several analyzing methods but the representative S value in this area shall be around , which was total averaging of these and also the value obtained through previous pumping test inside the Radio Station. Table Summary of Pumping Test Well Constants Analysis Method Represent Note Theis Jacob Recovery ative Value TW-N T (m 2 /day) 4,006 4,006 2,678 Sp. Yield 23.2 by Const T 4,000. Ob- 1/West T (m 2 /day) 1,901 15,887 Well S AWLR data West M. T (m 2 /day) 11,750 S Well S East M. T (m 2 /day) 14,783 Well S North M. T (m 2 /day) 10,008 Well S Based on the T value of TW-N, the permeability of the aquifer is calculated as 2.43 x 10-1 cm/sec (around 365 m/day). Specific yield calculated from the result of Constant Discharge Test was very large as 23.2 lit/sec/m. Based on the value, expected drawdown shall only be 1.24m when the pump is operated by 2,500 m 3 /day (28.9 lit/sec). DCDA 6-10 JICA

41 6.3.4 Groundwater Level Monitoring Throughout the constant discharge test period, groundwater levels in the selected three existing wells were measured at the same time interval as that of the pumping test. This measurement was called as groundwater monitoring in the existing wells. It was conducted for the purpose of understanding the influence of large groundwater discharge through production well. Locations of the monitored (existing) wells were as follows and shown below. Table Coordination of Existing Wells Direction Coordination Distance (m) West E/ N Northeast E/ N East E/ N As a result (refer to ANNEX-VI.10), influences to the groundwater in these three wells (drawdown in these wells in other words) were only from 0.11 to 0.14m from their SWL at the maximum, not so much. Figure shows groundwater hydrograph of those existing monitoring wells throughout the Constant Discharge Test in TW-N. As shown in the figure, the groundwater levels of wells nearby, such as Western and Eastern wells, responded to the pumping up at TW-N quickly, within 2, 3 minutes. On the contrary, the water level in a rather far well (Northeast well) responded to the pump up at TW-N very slowly. And, in this well, the drawdown of groundwater was the largest among the three monitored wells though it was located farthest. It suggested that the aquifer condition in the Northeast well would not be the same as that of other two wells. Then, in the West Well, groundwater level was remarkably down in the early stretch of the observation from 140 to 600 minutes and in the last stretch after 1290 minutes. The former test was conducted from 12:30 to 20:00 and throughout the time a private irrigation pump in the well was operated. The later test started from 7:30 of 1 st June and during this time most of the existing irrigation wells should start pumping. Thus, the groundwater drawdown in the Western well, caused by pumping up in TW-N, was estimated at 8cm. Figure Location Map of GW Monitoring Wells JICA 6-11 DCDA

42 Afghanistan Drawdown s (m) East Well Nort Well West Well Pumping in this well t (min) Figure Figure Monitoring Monitoring Wells Wells Drawdown Drawdown Pumping in otherwell As explained above, since groundwater level monitoring was conducted at the same time interval with the pumping well (it was a misunderstanding of the Engineer), the data of this monitoring was applicable to analyze it by Theis method through GWW analysis. The results were already explained in the above section (Section (5)) Water Quality Analysis (1) Introduction Associated with the pumping test, two categories of water quality analysis were carried out in the last period of constant discharge test; in-situ water quality test and laboratory water quality analysis. Water sample for laboratory water quality analysis was sent and actually analyzed in the Water Quality Laboratory which belongs to the Department of Geo-Engineering and Hydrogeology (DGEH), under the Ministry of Mines. (2) In-situ Test Three items, namely a) water temperature, b) ph, and c) EC value, were tested in the site, at the end of constant discharge test. In-situ water qualities were as follows: Water temperature: 16.0 Celsius Degree ph: 7.65 EC: ms/m Water temperature in this well was enough cool as groundwater, and ph value showed a little alkaline condition similar to most of groundwater in Kabul Basin. EC value was somewhat high as compared with the groundwater inside the Radio Station. It was not an obligation under the Specification but DO was also measured together with the other DCDA 6-12 JICA

43 in-situ water qualities, and a result of DO was 5 mg/l. (3) Laboratory Test Following items of the water qualities were analyzed in laboratory: COD, BOD, Anionic surfactant Ions of Sodium, Potassium, Calcium, Magnesium, Ammonia, Nitrite, Nitrate, Bicarbonate, Chloride, Sulfate, Manganese, Iron (total), Fluoride and Arsenic, and Total Coliform, Fecal Coliform, and General Bacteria. Results of the water quality analysis are shown in Table 6.3.5, together with the results of previous water analysis in other three candidate sites (Details are shown in ANNEX-VII.4). Bakhtyaran TW-1 Table Results of Water Quality Analysis Daneshman d TW-1 Tangikalay TW-1 Polecharkhi TW-1 Polecharkhi TW-OBS Polecharkhi TW-N Sampling Point Name Items Date Unit Tempurature is better. Electrical Conductivity (EC) μs/cm at DO mg/l COD mg/l BOD mg/l Anionic Surfactant mg/l Guide line: 1,900 μs /cm TDS 1,200mg/l by WHO;2500μS/cm by EU CFU/ml Coiforms CFU/ml Fecal Coliform CFU/ml (E. Coli) Standard Plate Count CFU/ml Bacteria Turbidity NTU <5 is better Alkalinity mg/l as Bicarbonate (HCO - mg/l 3 ) Ammnoia (NH 3) mg/l as NH3-N Nitrite (NO - 2 ) mg/l as NO 2 -N Guideline value (WHO): for short term, 0.06 for longterm Nitrate (NO - 3 ) Hardness Sodium (Natrium) (Na + ) Potassium (K + ) Magnecium (Mg2+) Calcium (Ca2+) Iron, Total (T-Fe) Manganese (Mn 2+ ) Chloride (Cl - ) Sulfate (SO 2-4 ) Fluoride (F - ) Arsenic (As) mg/l as NO 3 -N Guideline value (WHO): mg/l as mg/l <200 is better mg/l mg/l as mg/l as mg/l <0.3 is beter mg/l mg/l mg/l mg/l mg/l Guideline value (WHO): <250 is bettrer <500 is better Remarks Guideline value (WHO): Guideline value (WHO): JICA 6-13 DCDA

44 Figure shows a Piper Diagram (Tri-linear Diagram in other word), which marks water qualities of TW-N and two other wells drilled inside of the Radio Station (TW-Pol and TW-Obs). These three qualities are plotted in almost the same portion; Type-II, CaHCO 3 type to somewhat close to Type-I, CaSO 4 CaCl 2 type. As a tendency, these water quality types are typical water quality of river water and shallow groundwater. Afghanistan (4) Conclusion In the previous water quality analysis, somewhat high Nitrate content was found but Nitrate (NO 3 ) content was normal level in the analysis this time. Then, Manganese (Mn 2+ ) content was also found as lower than WHO guidelines. The water quality was classified as Interim Type near Type-II; CaCO 3 type Figure Piper Diagram typical to river water or shallow groundwater. Thus, the water quality of TW-N can be said as good enough for drinking. 6.4 Groundwater Development Introduction As discussed in previous Chapter (Chapter 5, to 5.1.4), groundwater development potential in the two sites of Bakhtyaran and Pymonar - Daneshmand were evaluated as very small, while sites along the Kabul River showed large potential with groundwater recharge through the seepage from the river bottom. Sustainable groundwater development potential in these target sites were summarized in Table (reinsert): Site Tangi Kalay 19.5 Pol-e Charkhi 66.5 Bakhtyaran 16.0 Catchment Area, km 2 Table Summary of Groundwater Development Potential Direct Indirect Development Recharge, Recharge, Potential, Feasibility m 3 /Yr m 3 /Yr m 3 /day 354, , ,980 1,208,970 96, ,920 1,610, ,000 9,660 5,380 5,700 (ave 5,500) 4,850 5,960 (ave 5,400) (ave. 420) Daneshmand , ,300 No Source: JICA Sub-project Team Note: Average annual precipitation is 303 mm. Hard High No Remarks Existing large yielding wells High potential, not much current use Very little water, poor water quality Very small water resource available As shown in the above table, only the sites along the Kabul River had groundwater resources potential and feasible to be developed. However, Tangi Kalay site had already large scale production wells mainly for irrigation purpose, therefore, the Tangi Kalay site was evaluated as not to be feasible in terms of a new development. Thus, the site of Pol-e-Charkhi was selected as the production well field. In the previous study term (refer to ITR 2), MODFLOW simulation was applied to two sites at Pol-e-Charkhi and Tangi Kalay. This time, only Pol-e-Charkhi site was simulated for evaluating the drawdown of groundwater level and influence of such large discharge of 2,500 m 3 /day/well through DCDA 6-14 JICA

45 production wells to the surrounding area by MODFLOW MODFLOW Analysis In the previous study (before June, 2011), MODFLOW analyses were carried out targeting both Pol-e-Charkhi and Tangi Khaley. This time also, MODFLOW analysis was conducted but targeting only Pol-e-Charkhi site, using newly obtained aquifer conditions and constants. Major differences were both Kabul River water level and groundwater level around the test well. The aquifer model was also modified slightly, as the aquifer changed its thickness and cropped out to ground surface in the upstream. (1) MODFLOW Modeling Figure Plane model of MODFLOW was not so different from the one previously made, but the locations of production wells and representative existing wells were updated. Two planned production wells were located outside of the Radio Station, and therefore, locations of representative existing wells were modified their positions. Total target area, the Buthkhak River catchment area, was rather wide or wider than 66 km 2. The area was, however, roughly divided into three zones, namely Kabul River recharge zone, Buthkhak River recharge zone and basement (no recharging) zone. These situations are shown in Figure Cross section model of the site was also revised slightly, based on the results of the drilling of new test well. Thickness of the aquiclude (Sandy Clay layer) had been constant throughout the model in the previous model but it was changed into the Figure MODFLOW Plane Model transition zone to basement zone. In accordance with the change, the aquifer was cropping out to the ground surface, in front of the basement zone. Bottom of the aquifer, and the model, was set as GL -30m, the same as that in the previous model. These conditions are shown in Figure (2) Assumptions Physical Properties For MODFLOW analysis, physical properties of layers consisting of the model, boundary conditions, and hydrogeological information on the site were required. Among them, some of hydrogeological information was obtained through the investigation and data collection under this Sub-project, Kabul River GL.-6m Seepage from River to Aquifer Infiltration from Rain Gravel Clay No infiltration from River to Clay Layer GL.-12m Basement (Out of the study) MODFLOW Cross-section Model Figure MODFLOW Cross-section Model GL.0m GL.-30m JICA 6-15 DCDA

46 Afghanistan but the other physical properties were assumed by general practices due to the limited availability of data. Table Table Assumed Assumed Physical Physical Properties Properties of Model of Model Permeability k (m/sec) Sp. Storativity Ss (m -1 ) Sp. Yield Sy (%) Sandy Clay GL.0m~GL.-12m Gravel GL.-12m~GL.-30m Physical properties of the layers, assumed in the analysis, are summarized in Table Permeability (k) on the aquifer was estimated from the results of Pumping Test conducted in TW-N (T=4,000 m 2 /day, d=19m). Storativity (S) was estimated at the same as adopted in the last time, around and Specific Storativity (Ss) was calculated as 2.25 x 10-4 (m -1 ). This time, groundwater table in the three existing irrigation wells, surrounding TW-N, were monitored throughout the constant discharge test. These hydrographs were available to check the assumed physical properties. Figure shows the results of verification on the assumed physical properties of four cases; 1) both k and Ss were the largest value derived from the test, 2) k was the largest, Ss was the same as the last time value, 3) both k and Ss were the same as shown in Table 6.4.1, and 4) k was the smallest, Ss was the same as shown in Table As shown in the figure, case 3 shows groundwater drawdown in surrounding area as around 7.5 cm at West and North-East wells and around 11.5 cm at East well, nearly the same as the actual drawdown of 8 cm in the West, or of 11 cm in the East well. Only the actual drawdown in North-East well was different, presumably because of some other reasons. Case 1 and 2 show too small drawdown, and case 4 shows too large drawdown. Thus, case 3 which means assumed values set shown in Table should be appropriate assumption Drawdown s(m) Verify-1 k= (m/sec) [Laegest] Ss= (m -1 ) [Largest] Northeast West East Drawdown s(m) Verify-2 k= (m/sec) [Largest] Ss= (m -1 ) [Last time] Northeast West East t(min) t(min) Drawdown s(m) Verify-3 k= (m/sec) [This time] Ss= (m -1 ) [Last time] Northeast West East Drawdown s(m) Verify-4 k= (m/sec) [ Smallest] Ss= (m -1 ) [Last time] Northeast West East t(min) t(min) Figure Varification Verification of Assumed Physical Properties DCDA 6-16 JICA

47 Boundary Condition The northern end of the model, which is the Kabul River was set as fixed head boundary as GL -6.0 m, and the both sides of the Buthkhak River catchments area were set as no flow boundaries. Precipitation and Recharging Ratio For precipitation data on the area, daily precipitation data measured at the Kabul Airport for five years since Jan up to Dec were adopted. Based on the data, yearly average precipitation of mm/year was applied in the calculation for a steady flow analysis. In the steady analysis, infiltration ratios of 0.07 and 0.05 were applied in the Kabul River recharge zone and Buthkhak River recharge zone, respectively. While in a transient flow analysis, infiltration volumes in both zones were estimated through so-called Tank Model which were built up in the Study on Kabul Basin Groundwater Resources Potential (refer to Figure 6.4.4). Those measured data or assumptions were given to the model Buthkhak 50% Infiltration (mm/day) % 4 30% 15% /1/1 2004/2/1 2004/3/1 2004/4/1 2004/5/1 2004/6/1 2004/7/1 2004/8/1 2004/9/1 2004/10/1 2004/11/1 2004/12/1 2005/1/1 2005/2/1 2005/3/1 2005/4/1 2005/5/1 2005/6/1 2005/7/1 2005/8/1 2005/9/1 2005/10/1 2005/11/1 2005/12/1 2006/1/1 2006/2/1 2006/3/1 2006/4/1 2006/5/1 2006/6/1 2006/7/1 2006/8/1 2006/9/1 2006/10/1 2006/11/1 2006/12/1 2007/1/1 2007/2/1 2007/3/1 2007/4/1 2007/5/1 2007/6/1 2007/7/1 2007/8/1 2007/9/1 2007/10/1 2007/11/1 2007/12/1 2008/1/1 2008/2/1 2008/3/1 2008/4/1 2008/5/1 2008/6/1 2008/7/1 2008/8/1 2008/9/1 2008/10/1 2008/11/1 2008/12/1 Figure Daily Precipitation & Infiltration in Buthkhak Current groundwater Balance To estimate the current groundwater balance around the site, five (5) virtual wells which are equivalent to the existing ones were allocated surrounding the production wells. Estimation of the current groundwater balance was carried out through a steady analysis changing their discharge rates until the groundwater level near the site fits to actually observed groundwater level (GL -6.0m). As a result, distribution of groundwater level in the model area was estimated as shown in Figure In the trial, 9000 groundwater discharge volume in these virtual wells was estimated at around 300 m 3 / day/ well, or ,500m 3 / day (17.4 lit/sec) in total. (3) Case Studies Two new production wells were allocated just outside of the Radio Station at Pol-e-Charkhi site, and pumping simulations were carried out for total ten (10) cases. The cases of Pumping Simulation are summarized in Table Pumping rates were set as four (4) cases; 1) no pumping, 2) 2,000, 3) 2,500, and 4) 3,000 m 3 /day/well, and pumping scenes were individual pumping of each well and dual pumping. Results of the simulation, estimated drawdown at each case by the time-sequence and distance, and Figure Current Groundwater Balance JICA 6-17 DCDA Figure Current Groundwater Balance GL.(m)

48 Afghanistan estimated groundwater contour maps in time sequence at every year are attached in ANNEX-VIII.2). (4) Simulation Results Table Case Studies Table Case Studies Case Discharge (m 3 /day) Discharge (m Case /day) TW-N PW-2 Total TW-N PW-2 Total Case Case.5 0 2,500 2,500 Case.1 2, ,000 Case.6 0 3,000 3,000 Case.2 2, ,500 Case.7 2,000 2,000 4,000 Case.3 3, ,000 Case.8 2,500 2,500 5,000 Case.4 0 2,000 2,000 Case.9 3,000 3,000 6,000 In each case, groundwater level in the well and at several points at different distances from the pumping well was simulated, and groundwater drawdown (differences of groundwater level between pumping and no pumping condition) was calculated. All results are shown in ANNEX-VIII.4, and results of some significant cases are roughly explained below: Case 0 Case-0 is a case of no pumping from both wells, meaning current groundwater balance in the area in time sequence, under simulated groundwater recharge for five years. Table shows simulated groundwater table at different distances from TW-N, for 5 years. Groundwater hydrograph drawn from Table was shown as Figure As shown in the figure, groundwater levels in several points fluctuate in both dry and rainy seasons though the level does not change significantly. Case 2 Pumping at only TW-N is this case. Simulated groundwater drawdown, which is the water level difference from groundwater level in case-0, is shown in Table Based on the drawdown, groundwater hydrographs in time sequence, at different points, are shown in Figure The Table shows that the groundwater level shall go down around 17cm at the point of 100m far from the well, around 6.9cm at the point of 500m far, and around 4.7cm at the point of 1.0km far from the pumping well, after a year of constant pumping at 2,500 m 3 / day. Figure indicates the groundwater drawdown at every point. Drawdown shall not fluctuate in time sequence, only different by the distance from TW-N, the pumping well. Although groundwater table fluctuates depending upon the seasons, as drawdown is calculated as the water level difference from no pumping condition, it does not so much fluctuate. Case 8 Case-8 is the most significant simulation case that both production wells discharge 2,500 m 3 /day of groundwater, which is the routine pumping activity. Table shows estimated groundwater drawdown at different distances from TW-N in time sequence. As shown in Table, groundwater table shall draw down around 21.3cm at the point of 100m far from TW-N, about 16.5cm at 500m far and 19.2cm at 1.0km far from the TW-N, at a year of constant pumping by both production wells. The drawdown escalates in parallel with the pumping duration and it shall be 21.0cm at 1.0km point and 19.0cm at 5.0km points in its maximum. In this case, groundwater level shall go down more than 30cm at around 30m far from TW-N in 5 years later from pumping started. It means groundwater drawdown caused by these production wells in most part of Pol-e-Charkhi town shall be less than 30cm, and the level can be said as not so high. DCDA 6-18 JICA

49 Table Groundwater Level at Different Points from TW-N Case.0:PW1= 0 m3/day (The lowest Level in the Period) PW2= 0 m3/day 1st Year TW-N at 30m at 100m at 200m at 300m at 400m at 500m at 1km at 2km at 3km at 5km Note X Y Dist. Before pump , Jun , Jul , Aug , Sep , Oct , Nov , Dec , Jan , Feb , Mar , Apr , May nd Year Dry season ~ ~ Rainy Season ~ rd Year Dry season ~ Rainy Season 4th Year Dry season ~ ~ Rainy Season 5th Year Dry season ~ ~ Rainy Season Days ( 非表示 ) Unit:GL.(m) Groundwater Table GL.(m) Figure Groundwater Hydrograph at different points from TW-N TW-N at 30m at 100m at 200m at 300m at 400m at 500m at 1km at 2km at 3km at 5km Before pump 2004, Jun. 2004, Jul. 2004, Aug. 2004, Sep. 2004, Oct. 2004, Nov. 2004, Dec. 2005, Jan. 2005, Feb. 2005, Mar. 2005, Apr. 2005, May ~ Dry season ~ Rainy Season ~ Dry season ~ Rainy Season ~ Dry season ~ Rainy Season ~ Dry season Figure Simulated Groundwater Hydrograph at different points from TW-N JICA 6-19 DCDA

50 Afghanistan Table Groundwater Level at Different Points from TW-N Case.2:TW-N= 2,500 m3/day (The lowest Level in the Period) PW-2= 0 m3/day 1st Year 経過日数 ( 非表示 ) TW-N at 30m at 100m at 200m at 300m at 400m at 500m at 1km at 2km at 3km at 5km Note X Y Dist. Before pump , Jun , Jul , Aug , Sep , Oct , Nov , Dec , Jan , Feb , Mar , Apr , May ~ nd Year Dry season ~ Rainy Season ~ rd Year Dry season ~ Rainy Season ~ th Year Dry season ~ Rainy Season ~ th Year Dry season Unit:GL (m) ~ Rainy Season ( m ) d o w n D r a w TW-N at 30m at 100m at 200m at 300m at 400m at 500m at 1km at 2km at 3km at 5km p. m n l g p t v c n b r r y u u u u e c o e a e a p a p J J A S O N D J F M A M e,,,,,,,,,,,, r o f e B. 1 n o s 5 a 0 e s `2 y r 6 D n 5 o. s 6 a 0 e S `2 y n 2 i. 1 a R n o s 6 a 0 e s `2 y r 6 D n. o 7 s 0 a e `2 S y 2 n. 1 i a 6 R n o s 7 a 0 e s `2 y r 6 D n. o 8 s 0 a e `2 S y 2 n. 1 i a 7 R n o s 8 a 0 e s `2 y r 6 D Figure Simulated Groundwater Hydrograph at different points from TW-N ` DCDA 6-20 JICA

51 Table Groundwater Level at Different Points from TW-N Case.8:TW-N= 2,500 m3/day (The lowest Level in the Period) PW-2= 2,500 m3/day TW-N at 30m at 100m at 200m at 300m at 400m at 500m at 1km at 2km at 3km at 5km Note X Y Dist. Before pump , Jun , Jul , Aug , Sep , Oct , Nov , Dec , Jan , Feb , Mar , Apr , May st Year 2nd Year 3rd Year 4th Year 5th Year ~ Dry season ~ Rainy season ~ Dry season ~ Rainy season ~ Dry season ~ Rainy season ~ Dry season ~ Rainy season Unit:GL.(m) Before pump 2004, Jun. 2004, Jul. 2004, Aug. 2004, Sep. 2004, Oct. 2004, Nov. 2004, Dec. 2005, Jan. 2005, Feb. 2005, Mar. 2005, Apr. 2005, May ~ Dry season ~ Rainy season ~ Dry season ~ Rainy season ~ Dry season ~ Rainy season ~ Dry season ~ Rainy season Drawdown (m) TW-N at 30m at 100m at 200m at 300m at 400m at 500m at 1km at 2km at 3km at 5km Figure Simulated Groundwater Hydrograph at different points from TW-N JICA 6-21 DCDA

52 Afghanistan Groundwater hydrograph (drawdown) in this case is shown in Figure In this case, groundwater level continuously goes down as time passes, even in the 5 th year since pumping started. (5) Conclusions MODFLOW simulation on the groundwater drawdown caused by pumping of planned production wells in Pol-e-Charkhi area, on the Buthkhak River catchment area in more exact term, was conducted, based upon several assumptions and daily precipitation data of last five years. Both plain model and cross section model were modified through the new study and investigation. At first, the current groundwater balance in the area was estimated through trial simulation setting five fictional wells surrounding the production wells, which represented the existing wells, through steady flow analysis. Then, groundwater table in the area after the start of pumping was simulated under the recharging condition by daily precipitation estimated by Tank Model. Groundwater drawdown was calculated by comparison of simulated groundwater level and current groundwater balance. Simulation was conducted mainly under 1) no pumping, 2) pumping by individual well, and 3) pumping by both production wells. Cases of pumping were set as 0, 2,000, 2,500, and 3,000 m 3 /day, thus, total ten (10) cases were studied. As a result, fluctuations of groundwater level through a year were not so much in the area, maximum around 20cm. When only one production well was operated by a routine pumping rate of 2,500 m 3 / day, groundwater level was drawn by around 17.1cm at the point 100m far from the well in a year later, 6.9cm at 500m point, and 3.7cm at 2.0km point. Thus, the influence of pumping up by one production well shall not be so much significant. In this drawdown level, it was less than 10cm in the major part of Pol-e-Charkhi town, for which no need arises to compensate. However, when two of the Production wells are operated, groundwater level at around 500m apart from TW-N shall be drawn down by 16.5cm a year later, lowered by 19.2cm at 1.0km far from the TW-N. The drawdown shall increase to 17.5cm and 21cm after 5 years, respectively. Groundwater drawdown of more than 20cm shall be somewhat significant, however, it is in almost the range as the extent of the seasonal fluctuation. It shall be not severe when thinking from the MODFLOW simulation. At any rate, it shall be the most important to monitor the groundwater level actually in the monitoring wells surrounding the production wells, and the pumping rates shall be adjusted based on the monitored groundwater level Monitoring System of Groundwater Table (1) Allocation of Monitoring Wells During the constant discharge test conducted this time, groundwater level in the three existing irrigation wells around the test well were measured to find the influence of such large discharge in the production well to the groundwater level in the surrounding area (refer to 6.3.4). As a result, the influence (groundwater drawdown by the pumping) in the area was not so Figure Location Map of Proposed Monitoring DCDA 6-22 JICA

53 significant, less than 18cm at the maximum. However, in the actual project term, at least two of production wells shall pump up around 5,000 m 3 / day (about 28.9 lit/ sec/ well) of groundwater continuously, throughout a year. Even though it might not so large, pumping up shall induce some drawdown at groundwater table around the wells. To identify the occurrence and extent of such adverse effect, as early as possible, at least four monitoring wells shall be provided; in the north, east, south, and west of the production wells. The recommended locations of these monitoring wells are shown in Figure Their coordinates (in UTM) are roughly as follows (however, detail position must be selected through reconnaissance): M-1: E/ N M-2: E/ N M-3: E/ N M-4: E/ N However, if MoIC accepts to set the Monitoring Well system inside the Radio Station, previous Test Well of TW-Pol can be used as one of the Monitoring Wells instead of M-3, and M-4 can be shifted inside the RTA compound, as shown in Figure In this case, Monitoring Well locations are to be as follows: M-1: E/ N (same to above) M-2: E/ N (same to above) M-3: E/ N (TW-Pol) M-4: E/ N (new Monitor Well) (2) Monitoring Well Structure Design of the monitoring wells was already discussed in the previous study (refer to 5.5.2), however it shall be further Figure Location Map of Proposed Monitoring Wells (alternative) modified a little. Depths of the monitoring wells are enough to cover the main aquifer, so to as to be 30m, but drilling diameter is to be 8 and completed by 4 screen and casing. Rough design of the monitoring well is shown in Figure In case of observation wells, PVC casing and slotted screen can be applied. Screen depth shall be fixed from 10 to 25m in depth to catch up a small fluctuation of groundwater table. (3) Monitoring System A daily measurement of the groundwater levels in these monitoring wells shall be done at fixed time, at 10 o clock every morning for example, for the first one year since the initiation date of routine pumping. During the groundwater monitoring, pumping rates in production wells shall be reduced so that the groundwater level in any monitoring well goes down to the prescribed level. The prescribed groundwater level shall be decided through a discussion with villagers, before starting a routine pumping operation. Around 30cm drawdown of groundwater table in monitoring wells shall be reasonable for the prescribed water level, based on the results of pumping test including groundwater monitoring in the existing wells and MODFLOW analysis. JICA 6-23 DCDA