Final Report Executive Summary · 2011. 6. 15. · Executive Summary 3 basin because the Paghman,...

Ministry of Mines The Islamic Republic of Afghanistan

THE STUDY

ON GROUNDWATER RESOURCES POTENTIAL

IN KABUL BASIN

IN THE ISLAMIC REPUBLIC OF AFGHANISTAN

Final Report Executive Summary

March 2011

JAPAN INTERNATIONAL COOPERATION AGENCY (JICA)

SANYU CONSULTANTS INC.

GEDJR

11-077

North

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Photo-Album (1) Kabul City

Photo-1: Looking North Kabul and far Pol-e-Charkhy sub-basins

Photo-2: Central Kabul City

Photo-3: Darlaman sub-basin

Photo-Album (2) Geophysical Work and Water Measurement

Photo-4: Preparatory Work of TDEM Photo-5: Setting Transmittal Loop

Photo-6: TDEM Measuring Photo-7: Measuring VES

Photo-8: Measuring Groundwater Depth Photo-9: Measuring Groundwater Quality

Photo-Album (3) Test Well Drilling

Photo-10: Inauguration Ceremony Photo-11: Drilling Rig (TOP-750) Minister of MMI cutting the tape provided under the Project (center left of photo)

Photo-13: Drilling Site (TW-3)

Photo-12: Deep Aquifer Drilling Scene (TW-4)

Photo-14: Preparation of Drilling at MW-1 Photo-15: Drilling Scene at CW-1

Photo-Album (4) Well Completion & Pumping Test

Photo-16: Well Logging Scene Photo-17: Screen and Casing Installation

Photo-19: Air Lift Development

Photo-18: Gravel Packing Scene

Photo-20: Pumping Test Scene 1 Photo-21: Pumping Test Scene 2

Photo-Album (5) Joint Technical Committee & Capacity Development Program

Photo-22: Addressing Team Leader in the 1st JTC Photo-23: Scene of JTC

Photo-24: Scene of Capacity Development Program Photo-25: Seminar Scene on (Pumping Test Site) Capacity Development Seminar

Photo-26: Field Training on VES Photo-27: Scene of Capacity Development Seminar

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Table of Contents Location Map of the Study Area Photos Table of Contents List of Figures and Tables Abbreviations

Page

CHAPTER 1. THE STUDY GENERAL ............................................. 1 1.1. The Kabul River and Kabul Basin ................................................................................1 1.2. The Study General...........................................................................................................1

1.2.1. Previous Studies .......................................................................................................2 1.3. Groundwater Condition of the Study Area ...................................................................2

1.3.1. Current Situation of Groundwater Sector.............................................................2 1.3.2. Institutional Situation of Groundwater Sector......................................................3 1.3.3. Mandate of MoM and DGEH .................................................................................3 1.3.4. Situation of Water Supply in Kabul City ...............................................................4

CHAPTER 2. FIELD STUDIES........................................................... 7 2.1. Field Study General.........................................................................................................7 2.2. Geophysical Prospecting.................................................................................................7

2.2.1. Geophysical Work......................................................................................................7 2.2.2. Analysis and Interpretation ......................................................................................7 2.2.3. Outcomes of Geophysical Work................................................................................8

2.3. Test Well Drilling.............................................................................................................9 2.3.1. Outline.........................................................................................................................9 2.3.2. Test Well Drilling......................................................................................................10 2.3.3. Pumping Tests...........................................................................................................12 2.3.4. Water Quality on Deep Aquifer ..............................................................................13

2.4. Water Measurement......................................................................................................13 2.4.1. Outline.......................................................................................................................13 2.4.2. Water Resources Inventory Survey........................................................................14 2.4.3. Simultaneous Groundwater Measurement ............................................................14 2.4.4. Continuous Groundwater Measurement ...............................................................15 2.4.5. Water Quality on Shallow Aquifer .........................................................................15 2.4.6. Surface Water Measurement...................................................................................15

2.5. Joint Technical Committee ...........................................................................................16 2.6. Capacity Building Program..........................................................................................16

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CHAPTER 3. GROUNDWATER ANALYSIS .................................. 17 3.1. Shallow Aquifer Analysis ..............................................................................................17

3.1.1. Outline.......................................................................................................................17 3.1.2. Introduction of Synthetic Storage Model (SSM) ...................................................17 3.1.3. Synthetic Storage Model Analysis...........................................................................18

3.2. Deep Aquifer Analysis ...................................................................................................22 3.2.1. Outline.......................................................................................................................22 3.2.2. MODFLOW Analysis ..............................................................................................22

3.3. Evaluation of Groundwater Development Potential ..................................................25 3.3.1. Shallow Aquifer Development Potential ................................................................25 3.3.2. Deep Aquifer Development Potential .....................................................................25

CHAPTER 4. IMPLICATIONS FOR GROUNDWATER

DEVELOPMENT IN THE FUTURE....................... 27 4.1. Water Resources Development under Limited Potential...........................................27

4.1.1. Approach to the Supply Side...................................................................................27 4.1.2. Approach to the Demand Side ................................................................................27 4.1.3. Expected Role of DGEH..........................................................................................28

CHAPTER 5. RECOMMENDATIONS............................................. 29 5.1. Further Groundwater Development............................................................................29 5.2. Capacity Development of DGEH .................................................................................30

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List of Figures

Figure 1. Workflow of the Study ..................................................................................2 Figure 2. Pattern Analysis of TDEM ...........................................................................8 Figure 3. Isobathic Map of Basement by TDEM All & PASSPORT ........................9 Figure 4. The final Deep Aquifer Investigation Plan................................................10 Figure 5. Concept of SSM...........................................................................................17 Figure 6. Final Sub-basin Division of Kabul Basin ..................................................18 Figure 7. No Pumping Simulation (Passive Verification) ........................................20 Figure 8. Total Water Balance of Kabul Basin (Recent 10 year average) ..............21 Figure 9. MODFLOW Cross Section Model.............................................................23 Figure 10. Dispersal and Boundary Condition of Deep Aquifer Model ...................23

List of Tables

Table 1. Survey on Existing Water Supply Facilities (as of September 2006) .............5 Table 2. Plan and Achievement in Number of Wells (Final) .......................................10 Table 3. Simulation Cases for MODFLOW Analysis ..................................................24

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ABBREVIATIONS

AGS: Afghanistan Geological Survey AIMS: Afghanistan Information Management Services ANDS: Afghanistan National Development Strategy AUWSSC: Afghanistan Urban Water Supply and Sewerage Corporation AWLR: Automatic Water Level Recorder BGR: Bundesanstalt für Geowissenschaften und Rohstoffe CAWSS: Central Authority of Water Supply and Sewerage DGEH: Department of Geo-Engineering and Hydrogeology DIWS: Department of Irrigation and Water Supply, MEW DRWSS: Department of Rural Water Supply and Sanitation, MRRD EIA: Environmental Impact Assessment GIS: Geographical Information System GTZ: Gesellschaft fur Technical Zusammenarbeit IA: Irrigation Association ICRC: International Committee of the Red Cross IMF: International Monetary Fund ISAF: International Security Assistance Force JBIC: Japan Bank of International Cooperation JICA: Japan International Cooperation Agency JTC: Joint Technical Committee KfW: Kreditanstalt fur Wiederraufbau (German Development Bank) KM: Kabul Municipality KMA: Kabul Metropolitan Area MAIL: Ministry of Agriculture, Irrigation and Livestock MBA: Mirab Bashi Association MEW: Ministry of Energy and Water MoBTA: Ministry of Border and Tribal Affairs MoCI: Ministry of Commerce and Industry MoF: Ministry of Finance MoFA: Ministry of Foreign Affairs MoI: Ministry of Interior MoM: Ministry of Mines MoPH: Ministry of Public Health MoTCA: Ministry of Transportation and Civil Aviation MoUD: Ministry of Urban Development Affairs MPW: Ministry of Public Works MRRD: Ministry of Rural Rehabilitation and Development NDE: National Department of Environment NEPA: National Environmental Protection Agency NGO: Non-governmental Organization RBA: River Basin Association RBC: River Basin Council SBC: Sub-basin Council

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SCWAM: Supreme Council for Water Affairs Management SEA: Strategic Environmental Assessment SSM Synthetic Storage Model TBR: Trans-boundary River UN: United Nation UNDP: United Nations Development Programme UNESCO: United Nations Educational, Scientific and Cultural Organization UNHABITAT: United Nation Human Settlements Programme UNHCR: United Nation High Commission for Refugees UNMACA: United Nations Mine Action Centre for Afghanistan USAID: United State Agency for International Development USGS: United States Geological Survey WHO: World Health Organization WUA: Water Users Association Exchange Rate (February, 2011) Afg 1.0 ＝ JPY 1.817

US$ 1.0 ＝ JPY 82.16

The Study on Groundwater Resources Potential in Kabul Basin in the Islamic Republic of Afghanistan Executive Summary

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CHAPTER 1. THE STUDY GENERAL

1.1. The Kabul River and Kabul Basin

The Kabul River is one of rivers located at the extreme upstream portion of the Indus River. The Kabul occupies around 12% of the national territory of Afghanistan but it alone drains more than one-forth (26%) of the total annual water flow of Afghanistan. Total catchments area of the Kabul River in Afghanistan is 76,908 km2 consisting of eight (8) major watersheds. Kabul City is located in the central part of the River and has an area of around 480 km2.

The Study Area covers the Kabul Basin where the Kabul City exists. The basin is enclosed by low but quite steep mountain ranges, and divided into two sub-basins by also low but steep mountain range with NW-SE direction. Its western sub-basin is called the Darlaman sub-basin, and in its eastern side the North Kabul, Pol-e-Charkhy, and Logar sub-basins are located. These sub-basins are separated by low, gentle and flat-topped hills.

1.2. The Study General

Purposes of the Study were: 1) to evaluate the potential of groundwater resources exploitable for drinking use in the study area; 2) to collect, review, and rearrange the basic data/information for formulating the plans of groundwater development and water utilization/supply in the Study Area, and to identify the problems and to provide recommendations; and 3) to transfer technology and methodologies of the Study on groundwater resources to the C/P (Counterpart Personnel) of the former MMI (Ministry of Mines and Industry), the implementing agency of Afghanistan, which had been reorganized into the MoM (Ministry of Mines) during the Study period, and relevant organizations during the Study. The flow chart of the Study is shown in Figure 1 below and each study items are described as follows.


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Data/Information collect

・Water Reources Inventory

・Remote Sensing Predicted

・Field Reconnaissance Hydrogeologic Map

・Geophysical Worl Plan

・Test Well Drilling Plan

　　　・TW-1

　　　・TW-2

　　　・TW-3

　　　・MW-1

　　　・MW-2

　　　・CW-１

　　　・CW-2

　　　・OW-１

　　　・TW-４

　　　・Shallow Aquifer Analysis

　　　・Deep Aquifer Analysis

　　　・Evaluation of Development Potential

：Field Work ：Reporting ：Technical Meeting

Joint Technical Committee


Deep Aquifer Investigation 1



Water Measurement 2

Water Measurement 3

Water Measurement 4

Deep Aquifer Investigation Plan ing

Geophysical Prospecting




Water Measurement 1

The FirstYear

TheSecondYeear

TheThirdYear

TheFourthYear

PreparatoryWork

Incpection on Rig,

Equipment

Receiving Rig,

Equipment

The FourthField Study

The FirstHomework

Provision/Discussion on Progress Report -2

The FirstField Work

The SecondField Study


The ThirdField Study

Elaboration of

Principles &

M h d l

Explanation Inception Report

Review on Deep Aquifer Invest Plan


Inception Reporting

Collection/Review of Existing Data

Provision of Final Report

Provision of Draft Final Report

Submission/Dicussion on DF/RThe Fifth

Field Study

The SecondHomework

Figure 1. Workflow of the Study

1.2.1. Previous Studies

There were many studies/investigations related to water resources availability and/or groundwater development potential in the Kabul Basin. Among them, a hydrogeological investigation conducted by ex-USSR from 1979 to 1982 targets deep aquifer in the lower Neogene deposits in North Kabul, Pol-e-Charkhy and a part of Darlaman. More than 50 holes of core-boring were carried out, and simple pumping tests were performed.

1.3. Groundwater Condition of the Study Area

1.3.1. Current Situation of Groundwater Sector

Although the Kabul Basin is situated in semi-arid to arid zone, it had been a groundwater-blessed


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basin because the Paghman, the Kabul, and the Logar rivers flow into the basin bringing enough water to recharge groundwater in the basin. People living in the basin used to enjoy clean and enough amount of groundwater anywhere with springs, karezes and dug wells. However, due to increasing population and chaotic groundwater development, the quality and quantity of groundwater in the basin deteriorated rapidly in the past two or three decades. Over pumping condition of the groundwater was highly-publicized recently, however, actual evidence of over-pumping was not ascertained.

Through the survey by former USSR (PASSPORT), it was found that Conglomerates and unconsolidated gravel layers containing groundwater were underlying in the deep of Upper Neogene which was believed as practical impervious basement of the Kabul Basin. This deep formation, containing groundwater, was called as “Neogene Aquifer” or simply as “Deep Aquifer”. The deep aquifers were distributing widely in North Kabul and Pol-e-Charkhy sub-basins, and partly in Darlaman sub-basin. This aquifer was, however, not yet developed nor investigated since that was reported. Thus, the deep aquifer was focused as the main target of the Study.

The groundwater sector in Kabul has been beset by many problems as stated below:

- Improper latrine facilities in houses, unregulated refuse disposal, and opened sewerage channels are causing contamination in the shallow groundwater.

- Waste water from both domestic and industrial uses is freely released to Kabul River, and pollutes river water and groundwater consequently.

- Only the groundwater is the resource for water supply of the city. However, majority of the citizen of Kabul City do not know the severe situation of groundwater resources and apt to abuse or stretch much water.

- The government agencies responsible in managing groundwater development do not have long-term perspective (master plan) and are rarely equipped with necessary information, equipment and technologies.

1.3.2. Institutional Situation of Groundwater Sector

There are many agencies concerning to water resources or groundwater in Afghanistan. Major ones are seven (7) agencies. They are:

- Ministry of Energy and Water: MEW - Ministry of Mines: MoM - Ministry of Agriculture, Irrigation and Livestock: MAIL - Ministry of Urban Development: MoUD - Ministry of Rural Rehabilitation and Development: MRRD - National Environmental Protection Agency: NEPA - Ministry of Public Health: MoPH

1.3.3. Mandate of MoM and DGEH

Department of Geo-Engineering and Hydrogeology (DGEH), under Ministry of Mines (MoM) is


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counterpart agency of the Study. Mandate and mission of MoM is to execute the mining sector’s development and steward of all mineral, hydrocarbon and groundwater resources. Reportedly, MoM is to be re-structured from the current structure with two vice-ministers to the new structure with three vice ministers. The three sections are: “Administration and Finance,” “Regulation and Coordination,” and “Policy and Programs.” DGEH, which have taken a responsibility of actual works in drilling and water survey in the Study, is to be attached under “Regulation and Coordination” section.

In the groundwater sector, MoM has the responsibility to plan and implement surveys, detections, investigations, researches and identification of groundwater storage, and to monitor and protect against contamination and determining chemical and bacteriological composition in close collaboration with MoPH and NEPA. The MoM is also authorized to certify deep well drilling for agriculture, commercial, industry and urban water supply purposes.

DGEH is the division in charge of all groundwater matters and geo-engineering sector under MoM. The authorization to administer deep well drilling also belongs to DGEH. Further, DGEH is the sole responsible agency to undertake ground investigation, soil mechanical test, rock test, and material test in Afghanistan.

In accordance with the restructuring plan of MoM, DGEH is also to be reorganized, reportedly from April 2011, to a bigger organization, having five sections under the president: “Groundwater-Development Licensing”, “Hydrogeology Research”, “Groundwater Planning”, “Drilling and Services” and “Geoengineering”. Although it has been an executing agency, it is anticipated that DGEH be an agency for policy planning in the future.

1.3.4. Situation of Water Supply in Kabul City

There were eleven (11) water supply systems with 1 to 11 production wells in Kabul City. Each system has a reservoir with only 180 to more than 10,000 m3 of capacity Also there are three (3) pump stations and a booster pump station. Estimated groundwater discharge in the area ranged from 1,300 to 13,500 m3/day with 300 to 13,500 house connections. Table 1 summarizes the existing water supply facilities and their beneficiaries in Kabul city, which have been identified in 2006.


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Table 1. Survey on Existing Water Supply Facilities (as of September 2006) y g pp y ( p )

Name of Water Supply System Logar Nasaji Allau

Din Kabul Univ. Afshar Khair

KhanaKarghaKoshar

Plu arital

Wazir abad

Para wan

Microrayan

Managing Office Logar, Zone 1 KWSS

Zone 4 KWSS

Afshar, Zone 5KWSS

Zone 2KWSS

Zone 3 KWSS

Zone 6 KWSS

PAO,MUD

Number of Well 10 2 6 2 8 6 Spring1

+well21 +

1(OOS) 3 1 11

Number of Pump Station 1 1 1 0 0 0 0 1(BPS) 0 0 0

Amount of Reservoir (m3) 5,000 1,200 7,500 1,000 10,000

+5,000 500 1,200 1,200 180 180 3,000

Number of HouseConnection 6,000 5,000 16,000 3,900 3,000 3,000 9,000

Estimated Lifted Water (m3/day) 12,000 2,600 6,700 6,000 13,500 3,800 10,000

+40 1,400 1,000 300 11,300

PAO, MUD : Protection of Area Office Microrayan, Ministry of Urban Development BPS: Booster Pump Station KWSS : Kabul Water Supply and Saniation, Central Authority of Water Suuply and Sanitation, MUD OOS: Out of Service Total numbers of wells and pump stations are 52 (including spring) and 3 (excluding booster pump station), total amount of the reservoir is 35,960 m3.

Former Central Authority of Water Supply and Sewerage (CAWSS) under the Ministry of Urban Development (MoUD) was the major executing body in charge of water supply in Kabul City. CAWSS was conducting the Project of Extension of the Water Supply System of Kabul (Kabul II) cooperating with KfW. Today, all of the projects on the water supply and sewerage in the urban were managed by Afghanistan Urban Water Supply and Sewerage Corporation (AUWSSC) established in 2009, and CAWSS is now organized as an executing body of AUWSSC. Beside AUWSSC, water supply in some parts of Kabul City is managed by Macrorayon Maintenance Department (MMD) under MoUD.

The Project of Extension of the Water Supply System of Kabul by AUWSSC/KfW is aiming toe develop 21 new production wells with 35 – 60 lit/s of yield in Kabul and Logar areas; capacity of existing Allaudin Pump Station (from 600 to 1,500m3/hour) is being increased; a new pump station and 7 reservoirs (23,000m3 of total capacity) are being constructed in Logar area; and trunk pipe lines, setting of 60,000 house connections, are being extended.

Thus, the service population of Kabul water supply would be 140,000 by 2015 when the project is completed.


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CHAPTER 2. FIELD STUDIES

2.1. Field Study General

Since the summer of 2006, the Study has been carried out in four years. Major components included: water measurement, geophysical work, deep aquifer investigation (Test Well Drilling), capacity development program and Joint Technical Committee (JTC) to share the information on methodology, schedule, progress, and results of the studies, and to obtain mutual understanding on these matters between the Study Team and groundwater related agencies of Afghanistan.

2.2. Geophysical Prospecting

2.2.1. Geophysical Work

Based on the existing data/information and a predicted geological map prepared, the study area was divided into four hydrogeological sub-basins, namely North Kabul, Pol-e-Charkhy, Darlaman, and Logar Sub-basins. Beside from such geo-morphological setting, Actual geo-physical prospecting work had been conducted in the late 2006 and middle of 2007, under the prospecting plan with several objectives: to reconfirm the distribution of deep Neogene aquifer in North Kabul and Pol-e-Charkhy sub-basins; to check the extension of Neogene deposits at the west side of Darlaman sub-basin; and to determine whether sufficient thick Neogene deposits are existing in Logar sub-basin.

Because depth of the targeted prospecting is very deep, about 600m or more from the ground surface, a Time Domain Electro-Magnetic Prospecting (TDEM) was applied as a main prospecting method. As a secondary prospecting methodology, Vertical Geo-electric Sounding (VES) was also applied. Around 80 % of all measuring points were accurately analyzed. A total 20 points of vertical geo-electric sounding were conducted as a supplemental geophysical work where TDEM work was difficult or uncertain. For VES, ABEM Terameter 300 was used.

A total of 211 points of TDEM prospecting were carried out. They were divided into two steps; a rough survey stage of 131 points (step-1) and accurate survey stage of 80 points (step-2). A total of 53 points of TDEM were allocated to supplement the existing investigation boring in the North Kabul/Pol-e-Charkhy sub-basins, 38 points were extended in the western Darlaman, and 40 points were allocated in the Logar sub-basin in an orderly manner as a grid. Based on the results of rough survey, 19 points in North Kabul, 19 points in Pol-e-Charkhy, 20 points in Logar and 22 points in Darlaman were carried out during the accurate survey period.

To conduct the TDEM, around 230 proposed sites were selected through a satellite image reading, and each site was explored by United Nations Mine Action Centre for Afghanistan (UNMACA). Besides the TDEM, 20 points of VES were conducted in the four sub-basins, 10 points in North Kabul, 4 points in Pol-e-Charkhy, and 6 points in Darlaman sub-basin.

2.2.2. Analysis and Interpretation

All of the measurement records were interpreted into a combination of “Time-Resistivity Curve” and “Geoelectric Section”. Geoelectric sections obtained in all of the sites in Kabul basin were classified


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into three (3) typical patterns (see Figure 2 below). The most popular type was “Type A” sharing around 80%, followed by “Type B” of around 14%. The other types were few, about 2.1% and 1.6% of the total analysis for “Type C” and neglected “D” respectively. All of the Geoelectric sections consisted of three major portions; the surface, the middle, and the base layers.

Resistivity (Ω-m) Resistivity (Ω-m) Resistivity (Ω-m)1 2 3 5 7 10 20 50 100 300 1 2 3 5 7 10 20 50 100 300 1 2 3 5 7 10 20 50 100 300

5 5 Surface 5

50 50 50

　Middle 　　Middle

500 500 500Base

1000

100

200

Surface

10

Dep

th (m)

20

11000

2

BaseBase

1000 1000

100 100

Middle200 200

Dep

th (m)

20

Dep

th (m

)

20

2 2

Surface

10 10

11000

11000

Type A Type B Type C

Figure 2. Pattern Analysis of TDEM

Geoelectric section Type-A consisted of surface resistivity layer with middle resistivity, some of middle layer with low resistivity, and base resistivity layer with high resistivity. The resistivity layer structure can be interpreted as top layer of mostly Alluvial deposits, a middle layer of Neogene deposits, and base layer of Basement. The surface and middle resistivity layers of Type-B section were interpreted as same as Type-A, Alluvial deposits and Neogene deposits underlying, but the base resistivity layer does not mean Basement. It means completely weathered rock (like a fault zone), or the point that could not be detected as the base-rock because of insufficient power supply or by some other obstacles. Type-C was a rare case; signals were hardly detected and thus most part of it could not be analyzed. Then, Type-D is characterized by a transitional zone of the basement such as thick weathered zone.

2.2.3. Outcomes of Geophysical Work

Based on around 110 points of TDEM result from Type A (and a few D) Geoelectric sections, an isobathic map of the bedrock surface was projected. From the map, it was found that the deep Neogene deposits distribute in the E-W direction from North Kabul to Pol-e-Charkhy sub-basins. The map also shows the deep Neogene distributions in Darlaman and Logar sub-basins. Also, the maximum depth of the bedrock surface is estimated more than 900m, as compared to more than 600m


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suggested by the preliminary information. Through the geo-physical prospecting work, then, the scale and distribution of Neogene aquifer was grasped based on the isobathic map.

The data of the PASSPORT report by ex-USSR were also found consistent with the contours drawn from TDEM step-1 survey. Lastly, around 60 points of the results of TDEM step-2 survey were added in this data set. These two maps have almost the same figures as a total, but the areas of the deepest deposits and their surrounding became more accurate and remarkably steep underground ridge in the central portion of North Kabul and deadly steep slope in the west Pol-e-Charkhy became visible.

Besides the isobathic contour map of base-rock, an isobathic contour map on the bottom of Quaternary deposits was carried out with almost the same procedure mentioned above, but mainly based upon TDEM shallow analysis and VES. Based on the isobathic map at the bottom of Quaternary deposits, the contour map revealed some underground valleys, which were considered Ancient River routes passing through the old Kabul Basin (Figure 3).

Source：Study Team

Figure 3. Isobathic Map of Basement by TDEM All & PASSPORT

2.3. Test Well Drilling

2.3.1. Outline

Based on the “Deep Aquifer Investigation Plan” a total of eight (8) Test Wells and an Observation Well were drilled. “Deep Aquifer” means the aquifers, semi-consolidated “Sand and Gravel” or “Conglomerate”, distributed at the bottom of the Neogene Tertiary deposits. Test Wells were originally classified into three (3) categories: the shallow, middle, and deep test wells of 200, 400, and 600m classes, respectively. Later, a 450m class observation well for additional pumping test and a 1,000m class Test Well to check the deepest basement condition were added. Table 2 summarizes the number


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of test wells drilled in the Study and Figure 4 shows the location of those wells.

Table 2. Plan and Achievement in Number of Wells (Final) Categories of Test Well Original Plan Achievement Remarks

1,000m wells 0 well 1 wells TW 4

600m wells 6 well 3 wells TW 1, 2, 3

400m wells 4 well 2 wells MW 1, 2

200m wells 4 well 2 wells CW 1, 2

Source: Study Team

Source：Study Team

Figure 4. The final Deep Aquifer Investigation Plan

2.3.2. Test Well Drilling

(1) Test well drilling General

A total of eight (8) test wells and one observation well were drilled in four years of the Study period. Throughout the drilling work, cutting sample was taken at every one meter, and samples at every three meters were stored in a sample bottle. Most of the test wells were drilled until they reached the bedrock except at TW-1, TW-4 and CW-2 where the depths of bedrock were deeper than expected.

Immediately after each drilling work was completed, well logging was conducted to make a casing


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program, and a casing/screen installation was conducted. For all test wells, a wired screen usually called as “Johnson type screen” was used. Through gravel packing, clay ceiling and cementation, all test wells were completed and developed (washed) by air. In these test wells, a series of pumping tests and water quality analysis were conducted.

At TW-1 site, the pumping test with 450m class observation well had been done. In the site, the groundwater table of the existing shallow well near TW-1 was measured to check the influence of deep aquifer pumping to shallow aquifer. All the test wells were completed as production well with φ24” conductor pipe, φ13-3/8” pump housing, and φ6-5/8” screen and casing. Items of the well logging were electric logging of short normal and long normal, SP, and a natural gamma ray (N-γ ray).

(2) The Deep Test Wells

Three deep (600m class) test wells were drilled. These were located along the E-W extended deep trough of Neogene deposit. TW-1 was drilled until the depth of 640m but did not reach the bedrock. Because the results of geo-physical work indicated that the depth of Neogene Aquifer was more than 700m, an attempt was made to drill to around 700m. Drilling at TW-3 was planned to be at the depth of 600m, however, drilling works stopped at the depth of 570m because it has already reached the bedrock at 554m. The estimated depth of drilling for TW-2 point was around at 550m. However, the bedrock actually reached 534m and drilling stopped at 554m. Thus, the results of Test Well Drilling were considered in conformity with the isobathic map projected.

In all test wells, alluvial deposits consisted of unconsolidated silt, sand, and gravels including clayey zone partly, cover the Neogene with thickness ranging from 34.5 to 44.0m. Below the Alluvial cover, very thick Neogene deposits are distributed widely. Neogene deposits in the Kabul Basin were divided into two formations of Upper Neogene (N2) and the Lower Neogene (N1). The Upper Neogene consisted mostly of unconsolidated clay or massive mudstone (consolidated clay). Sometimes it intercalated sandstone layers and includes gravels partially. Lower Neogene consisted of hard clay with gravels, unconsolidated sand and gravels, and consolidated sand and gravels (conglomerates). Thickness of the Upper Neogene was from 259 to 356m, while that of the Lower Neogene were from more than 252m (at TW-1) to 159m (at TW-3).

(3) The Middle Test Wells

Two middle depth test wells (MW-1 and 2) were drilled. MW-1 was drilled at the southeast corner of North Kabul sub-basin, where a large structural line passes through. MW-2 was located at the west of Logar sub-basin where the bedrock surface sloped down toward the deepest point. MW-1 reached the bedrock at the depth of 208m, proving the accuracy of the analysis of geophysical work. Though MW-2 was targeted to reach its bedrock at 450m, the bedrock was hit at depth of 488m.

The alluvial cover at the MW-1 site was more than 60m in thickness while that at MW-2 site was only 20m. Alluvium consisted of unconsolidated gravely layer including thin clayey zones on both sites. Upper Neogene in MW-1 was quite massive and homogeneous mudstone with only 130m in thickness. Lower Neogene in this well was very thin, only less than 16m but consisted of pure sand-gravel and


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bolder layers. Complete leakage of mud-water occurred in this zone suggesting a negative piezometric head of the aquifer. In the MW-2, Upper Neogene was very thick, at 390m and was mainly composed of hard mudstones but includes partial gravels or thin sand layers. Lower Neogene was gravel and bolder with 73m thickness. Bedrock in MW-1 site was Diabase while MW-2 was Amphibolites.

(4) Shallow Test Wells

The shallow depth test wells, CW-1 and 2, were drilled at the front of the northern mountain range and at the south of the small outcrops of bedrock in Kat-e-Naw area, Logar sub-basin. Alluvial cover was around 30m thick in both sites consisting of unconsolidated clayey layers but including gravels. CW-1 was drilled through only Upper Neogene up to the depth of 152m and reached its bedrock without drilling Lower Neogene. It means that the aquifer in this well was not a Neogene aquifer but a weathered rock aquifer, a kind of shallow aquifer. CW-2 was drilled only through Neogene and did not reach its bedrock at the depth of 230m. Upper Neogene was consisted of unconsolidated clayey layer and consolidated clay (mudstone) sometimes including gravels.

(5) The Deepest Test Well (1,000m class Well)

The deepest test well of 1,000m class (TW-4) was drilled around one of the deepest points of Neogene Deposits in Darlaman area. Actual drilling point was, however, a bit far from the exact deepest point of Neogene. As a result, TW-4 was expected to reach bedrock at depths between 850m to 900m based on the isobathic contour map of Bedrock surface. However, when drilling at depth of 677.7m, drill pipe (drilling rod) was cut at the depth of 455m. Therefore, the well was completed as 455m depth Test Well, then, pumping test and water quality analysis were conducted.

The hard Conglomerate at shallow depth was distributed from GL-7.5m to around 80m. After the depth, clayey formations or mudstones sometimes including thin gravely layers, which were classified as Upper Neogene (N2) appeared continually at the depth of 360m. From that depth, Lowe Neogene consisting of gravel or sand continued to appear until it reaches the drilling bottom of 677.7m.

2.3.3. Pumping Tests

(1) Pumping test general

Pumping test was conducted in each well, which consisted of primary, step draw-down, constant discharge, and recovery tests. Because of their depth, an observation well was not provided except at TW-1. As a principle, primarily test and step drawdown test were done in a day, constant discharge test lasted for full three days, and recovery test for at least one day. In-situ water quality tests such as water temperature, pH and EC were measured and two set of water samples were taken for laboratory analysis for chemical and isotopic water quality.

(2) Sole Well Pumping Test

Static water tables were rather shallow as less than 8m from the ground surface on average. Nevertheless, the depths of the aquifers were very deep. It indicates that the confined pressures of these deep aquifers are very high. Specific yields were moderate ranging from 7.2 to 27.3m3/day/m,


13

12.4m3/day/m on average. However, Transmissivity were very low, around 8m2/day on the average except TW-4 (10.44 m2/day on average with TW-4).

(3) Additional Pumping Test

In the course of the deep aquifer investigation, it became clear that the aquifer must be “fossil Water”, without connecting to a natural water circle. In this case, it is important to determine Storability to estimate the existing groundwater volume and development potential. Thus, additional pumping test with an observation well was conducted. The observation well was drilled beside TW-1, about 20m far with the depth of 450m by which Neogene aquifer was to be penetrated for more than 50m.

Procedures of the test were the same with the normal pumping test but dynamic water level was measured both in pumping well (TW-1) and the observation well. Transmissivity calculated from the data on observation well are much higher than the ones from sole pumping well. Storability was then calculated as 1.32 x 10-3 (by Theis method) to 3.49 x 10-3 (by Hantush method).

The Storability values obtained from Theis and Hantush methods are far different from common values on confined aquifers, which are normally ranging in 10-4 order. However, both T and S obtained here were only the results of one sample and too different from the sole test. Therefore, when these values are to be applied, some safety ratio should be applied.

2.3.4. Water Quality on Deep Aquifer

Results of the water quality test are compared with the WHO Guideline; some of test wells show rather high EC value and Manganese contents beyond the WHO guideline. Also, chemical components were generally high. Results of ionic analysis were rearranged as “Tri-linear Diagram” (or “Piper Diagram”). Based on the diagram, groundwater in TW-1, CW-1, and most of investigation boring in PASSPORT were classified as type-I, “Calcium Non-Bicarbonate Type,” characterized by rich Calcium and less Bicarbonate. TW-2, TW-3, MW-1, MW-2, and CW-2 were classified as Type-IV, “Sodium Non-Bicarbonate Type,” with rich Sodium and less Bicarbonate. Type-I is a typical water quality of a hydro-thermal water or fossil water, out of a natural hydraulic circle. While, Type-IV is a typical water quality of groundwater originated from sea water.

All the samples were sent to stable isotopic analysis. Water qualities of deep test wells (TW-1 to TW-4) were quite similar, strongly suggesting they came from the same aquifer. The isotopic ratios of both deuterium and oxygen in these four wells were much lower than the ones used as reference data (shallow wells) and other test wells (MW and CW). This indicates that the groundwater in these wells was recharged in very high-land or under very cold climates such as the last glacial age.

2.4. Water Measurement

2.4.1. Outline

Water measurements have been carried out for both ground and surface water. Groundwater measurement includes water resources inventory survey, simultaneous groundwater level measurement, continuous groundwater level measurement, and water quality analysis. Surface water measurement


14

means river or canal runoff measurement. Initially, an inventory survey on existing water resources and water supply facilities were conducted to grasp the current status on water supply and groundwater use.

Of the187 wells inventoried by the Study Team, 110 wells were selected as the observation wells for simultaneous groundwater level measurement. 50 wells of the 110 wells were selected as the sampling wells for water quality analysis, and finally 10 wells (+ 2 wells as a standby wells) were selected as the targets for continuous groundwater level measurement. The simultaneous groundwater measurement was conducted on a monthly basis, while the continuous measurement was done at one hour interval. Water quality analysis was carried out to a total of five times in different seasons.

In the second Study year, the rivers flowing in and out the Kabul Basin were re-surveyed and total 12 points were selected as gauging stations to measure the runoff as follows; nine points in three rivers for flow-in and three points of flow-out in one river/two canals. Two of these stations were the same with the gauging stations of MEW so the Study Team did not install the gage. As a result, runoff measurement was performed by the Team at a total of 10 stations on a monthly basis but the measurement by MEW was done on a daily basis.

2.4.2. Water Resources Inventory Survey

The state of water sources are surveyed including existing wells, springs and Karez in Kabul Basin and a well inventory and a traditional water source inventory were compiled. A total of 187 wells were filed in the inventory and, of which 110 of these wells were surveyed for their well-mouth elevation. As traditional water sources, two springs and a Karez were surveyed. An inventory survey on the existing water supply facilities was also conducted.

2.4.3. Simultaneous Groundwater Measurement

Since November, 2006, the simultaneous groundwater level measurements had been carried out on a monthly basis. For all the observation wells, the depth of groundwater table, temperature, pH and EC of the groundwater were measured. Depths of the groundwater table in all observation wells were converted to elevations. Based on the groundwater level, contour map of groundwater tables and groundwater hydrograph were prepared. From the figures, it was found that groundwater flows down from the west to east almost along with the inclination of ground surface. However, there is a groundwater valley passing through slightly in the northern part of North Kabul sub-basin.

Groundwater hydrographs indicate smooth seasonal fluctuations and the difference of the groundwater depths during the rainy and dry seasons were from less than 1m to more than 6m. Seasonal fluctuation is larger in the Logar sub-basin as compared to the other sub-basins. Groundwater table is at the highest level in May. Depths of the groundwater table ranged from less than 1.0m to around 46m from the ground surface, deeper in the west (Paghman river basin) and northwest (Khai Khana area) Kabul.

Groundwater temperature changes smoothly along with the air temperature; high in summer and low in winter, but the fluctuation range is small at about 15 degree C ±2.0 degree C. On the groundwater temperature, there is no obvious spatial tendency but it is slightly higher in the upstream of the


15

Paghman. On pH and EC of the groundwater there is no clear fluctuation in time series.

The pH value of water has no clear spatial tendency some wells shows extreme value controls. EC value also indicates no clear spatial tendency but the upstream (western side of the Basin) shows slightly low value as compared to what are located in the lower stream. The EC also shows few wells with extremely high EC value that controls the isohyets contours.

2.4.4. Continuous Groundwater Measurement

Automatic Water Level Recorders (AWLR) for continuous observation of groundwater level was installed in the selected 10 observation wells in Kabul Basin in October, 2006. Then, all test wells drilled under the Study were also installed by the AWLR immediately after they had completed. The data measured by AWLR were modified based on air pressure measured throughout the observation period by anther AWLR set in the office.

Groundwater hydrographs were obtained from continuous groundwater measurement. According to the graphs, the yearly fluctuation of groundwater level ranged from 1.6m to7.5m, with average of 2.67m. Some of measured wells belong to city water supply by CAWSS were operated even during the night and thus the pumping effect of those wells was not completely eliminated.

The piezometric heads fluctuates regularly in three different cycles of daily, monthly and yearly ranges. These fluctuations are synchronized in all test wells and not same with the yearly fluctuation of existing wells. This fluctuation indicates a tidal effect; showing a spray and neap tide. The situation suggests that these deep aquifers have no relation with shallow (Alluvial) aquifer, in other words, it is fossil water.

2.4.5. Water Quality on Shallow Aquifer

A total of 50 wells of the 110 observation wells were selected as the targets for the water quality analysis for shallow aquifer. The analysis was planned to be conducted five (5) times; two each in dry and rainy seasons and one in May when the water table is highest in a year. Results of the analysis were rearranged as “Piper Diagram.” Based on the diagram, water qualities of the most of wells were located in the zone of Type-II: “Bicarbonate Calcium Type, but roughly 30% were allocated in Type-I: “Non Bicarbonate Calcium Type” or in between the Type II and I.

The former is a typical water quality of common shallow aquifer fed by rain-water; however, the latter is a rather special water quality of so-called “Fossil Water”, which is outside of the natural hydraulic cycle. It means that some of the observation wells have reached deep aquifer, or have some mixture of groundwater of shallow and deep aquifers. Water quality of the wells classified into Type II are mostly fresh water but the wells classified as Type I or intermediate between II and I are rather saline water with more than 1,500 μS/cm, or more than 3,000μS/cm of EC value at times.

2.4.6. Surface Water Measurement

A total 8 of inflow points into Kabul Basin and a total 3 of outflow points from the Basin were selected as measuring points (gauging stations). Also, one gauging station in Pagman basin was


16

established to build up a surface runoff model. However, gauging stations were not installed in two stations because of the presence of gauge stations established by MEW. The maximum inflow to the Kabul Basin through the Paghman River (P-1, P-2 and P-3) was around 4.0 m3/sec. The result at the upper Kabul River was 2.7 m3/sec, and at the Logar River was around 48 m3/sec. The maximum outflow from the Kabul Basin to the lower Kabul River was around 150 m3/sec.

2.5. Joint Technical Committee

To share the schedule, progress and results of all studies carried out in the Study as well as for managing the progress of and for reconfirming propriety of the Study, Joint Technical Committee meetings have been held between the Study Team and related agencies in Afghanistan. Three JTC meetings were held during the each of first and second year, once in the third year and three times in the last study years. Members of JTC are the representatives of: Ministry of Mines (chair), Department of Geo-Engineering and Hydrogeology, Afghanistan Geological Survey, Ministry of Urban Development, Central Authority for Water Supply and Sewerage, Ministry of Energy and Water, National Department of Environment, Urban Service, JICA Afghanistan Office.

2.6. Capacity Building Program

Based on the request from Afghanistan government, “Capacity Building Program on Groundwater Development” was included in the Study item. Themes and specific items of capacity building were as follows: “Planning: Groundwater Development Plan”, “Exploration: Geophysical Prospecting”, “Drilling Technology: Drilling, Logging, and Pumping Test”, “Administration: Cost Estimation, Bidding and Supervision”, “Examination: Evaluation of Construction”.


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CHAPTER 3. GROUNDWATER ANALYSIS

3.1. Shallow Aquifer Analysis

3.1.1. Outline

The shallow aquifer, which is same as “Alluvial Aquifer” in the Kabul Basin, is distributed in almost all areas of the basin but thicker along the current and old river routes. Since the aquifer is the main water resource of current water in Kabul city, several studies on the groundwater resources potential had been done. In this Study, the groundwater resources potential of the shallow aquifer was analyzed using Synthetic Storage Model (SSM).

3.1.2. Introduction of Synthetic Storage Model (SSM)

Basic concept of SSM is, as shown in Figure 5, the faithful embodiment of natural water circulation on the Earth. The model equips every unit basin with functions of precipitation (RF), evapo-transpiration (ET), surface runoff (SF), infiltration (PC) or recharging (RE) and groundwater flow (GR). In the model, the water circulation starts with (RF). Some part of the precipitation is lost through (ET). Some portions is captured in the soil as retention water (SR), other portions are percolated into the deeper unsaturated zone (PC), and the remaining portions flows out to the downstream zone (SF).

Non-groundwater Basin Groundwater Sub-Basin 1 Groundwater Sub-Basin 2

RF ET Groundwater Sub-Basin 3

S. Dam RF ET Sea h SF RF ET

h SF　　　　A(1,2) RF ET

SI h SF　　　　　A(1,2)

SR SI 　　　　　A(1,2)

SR

ET 　　　A(1,1) SR SF

PC SF　　　 A(2,2) ET 　　　　A(1,1) SR OF

SI PC SF　　A(2,2) ET 　　　　A(1,1)

SI PC SF ET

SI PC

SR

　　　A(2,1) SR SF

　　　A(2,1) SR OF

　　　A(2,1)

RE

RE AR

DF1 DF1 RE

H1 H1 　Spring

H1 　　　　　SP

SY1 　　　　　GA1 SY1 　　　　　GA1 　　　　GA1 　Ground Surface

SeaGR1 GI1 GR1 GI1 GR1

　　L(1/2) H2 　　L(1/2) H2 　　　L(1/2) Sea-bottom Spring

DF2 DF2 DF2 H2 　　　　　　SPS

LR1 LR1 LR1

　　　　　GA2 　　　　　GA2 GA2

GR2 GI2 GR2 GI2 GR2

H3 　L(2/3) H3 　L(2/3)

　　L(2/3) 　　DF3 H3

LR2 LR2 LR2

　　　GA3

　　　　　GA3

GR3 GI3 GR3 GI3 GR3

Surface System

SY

3

SY

3

SY

3

SY

2

SY

2

Unconfined Aquifer

Confined Aquifers

SY

2

Source：Study Team

Figure 5. Concept of SSM


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The Model (SSM) makes a quite simple calculation: in every sub-basin at daily basis, “(RF) – (ET) – (SR) － (SF) = (RE)”. They are calculated through the relations with orifices high of the side and bottom, runoff coefficients of these orifices, and water level in the tank.

Groundwater system starts with the recharge from the surface tanks. In the groundwater tank, the recharge amount is converted into the increase of the groundwater level in accordance with a Strativity (or Specific Yield: SY) of the ground, such as: “(RE) / (SY) = increasing groundwater level (⊿H)”. Groundwater flow is decided by the comparison of groundwater levels (H1) in between neighboring sub-basins, and groundwater runs from high to low level sub-basin, in accordance with Darcy’s Law.

3.1.3. Synthetic Storage Model Analysis

(1) Model Construction

SSM analysis starts from building up the physical model. Physical model means a plain model (sub-basin division) and cross section modeling based on topographical and hydrogeological information. At first, the study area was enclosed with the line connecting watershed on the topographic map with a proper scale. The target basin was, at first, divided into major 4 zones based on the surface geology, then, the divided into main two parts by the inter-basin small mountain range. After that, the basin was further divided into several small catchments areas tracing small relief. Finally, the rivers of Paghman, upper Kabul, middle and lower Kabul, and Logar were set as individual sub-basins but cut into some blocks. Thus, the target basin was cut into 133 sub-basins. The outside of the basin was set as Dummy basin all in one as No.134 sub-basin (see Figure 6).

Figure 6. Final Sub-basin Division of Kabul Basin


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After the plain modeling was completed, a cross section model was prepared based on geological profiles and cross sections. Bottom elevation and distribution of aquifer, shape and area of groundwater connections can be clearly understood through the cross section model. From the model, up-and-down stream relations in surface system, groundwater connections in subsurface system of every sub-basin have been clearly identified.

(2) Data Arrangement

To make a simulation using SSM, daily precipitation, evapotranspiration, river runoff and groundwater hydrograph are also required as input and verification data. In addition, data on river intake and groundwater discharge are needed to make the water balance analysis.

From the data collected under the Study, both river runoff and precipitation had data deficits from the early 1980’s to early 2000’s. Thus, the dummy data were applied for the missing two decades. Although the necessary rainfall data are daily basis, only monthly data were available data for old times. Thus, the old monthly data was configured into daily data without changing the total monthly amount. Based on this data, a series of 45-year rainfall data was built up, using dummy data for the lacking 20 years (repeating use) as well as new daily rainfall data in recent four years.

Evapotranspiration data were taken from “Agromet Report” by USGS. The data were also on a monthly basis, and therefore divided into daily value. Groundwater hydrograph were provided by the Study Team and DGEH as verification data. 110 observation wells had been measured on a monthly basis (some were hourly) since the late 2006 to late 2009. Also, the DGEH had groundwater hydrograph data for the 1980’s in cooperating with ex-USSR.

(3) Strategy on the analysis

Because of the difficulty of estimation of groundwater discharge in recent years, firstly the simulation model was established under the condition that there was almost no pumping in Kabul Basin where people avail of only river water and/or groundwater from springs, karez or dug-well. Under this situation, the simulation shall be done under the premise that the groundwater levels is kept at reasonable depths, not inundated nor vanishing for long periods. This method is so-called “Passive Verification” in SSM.

Thus, a simulation analysis was conducted “without pumping” condition, or passive verification. Then pumping conditions were added step by step until the groundwater level, as outputs from the model, fits to the current groundwater hydrograph. Through this process, the number of wells (or discharge) was estimated reversely.

(4) No pumping Analysis

Simulation analysis using SSM model starts with the establishing “Try File” that represents tank structure of the surface system. Through a step of trial-and-error approach of the SSM simulation, typical tank structures of the surface system were figured out. All surface tanks were defined as one story structure. Tanks of Mountain and Neogene sub-basins have no bottom orifice, and tanks of Fan and Alluvial sub-basins have bottom orifice for infiltration. Every river basin has a bottom orifice for


20

groundwater recharging.

As an example, a result of no pumping analysis is shown in Figure 7. As shown in the Figure, the average water balance of the surface system for the period of 45 years was found minus (-1.76MCM/year), while the balance of groundwater system is a little plus (0.68MCM/year) condition because of no pumping condition.

Source：Study team

Figure 7. No Pumping Simulation (Passive Verification)

(5) Pumping Analysis

Groundwater hydrograph from the late 1982 to 1986 was compared to that of the data gathered during the Study period, showing that groundwater levels in Kabul Basin were decreasing at high rate. During the 24 years from 1982 to 2006, some of the decreases recorded 9 to 10m, others were from 1 to 2m, averaging around 5m drawdown. This is one of the concrete evidences of over withdrawal of shallow groundwater in the Kabul Basin.

Before starting pumping simulation, pumping amounts were reconsidered. Taking the pumping amounts in CAWSS’s production wells into consideration, pumping amounts of common hand-pump equipped wells were estimated: 9.6 m3/day (16 lit x 60 min x 10 hour /1,000 lit). Then, pumping amounts were reallocated in seasons of winter, summer and the others with reference of CAWSS pumping plan.

Using the groundwater model identified through the no-pumping simulation, a pumping simulation was conducted. Among total 78 groundwater sub-basins, the sub-basin which has the largest number of wells was sub-basin No. 103 with 390 wells, and the sub-basin from which the largest withdrawal was estimated was of 6,511.2 TCM/year at sub-basin No.116.

(6) Water Balance

The water balance of surface system in the recent 10 years on the average was found a little minus (-734 TCM/year, 0.5% of the rainfall). Major surface water supply was Inlet (river flow-in) of 351.8


21

MCM/year (70.2%) followed by Rainfall of 146.6 MCM/year (29.2%). Major losses were Runoff of 325.2 MCM/year (64.8%) followed by Evapotranspiration of 115.4 MCM/year (23.0%). Recharge from the surface system was 25.2 MCM/year, around 5% of the total surface loss and 17.2% of the rainfall.

In the subsurface system (groundwater), major source was the Recharge from the surface system of 25.2 MCM/year (85.2%) followed by Groundwater Inflow of 4.4 MCM/year (14.7%). Major losses from the groundwater system were Pumping-Out of 25.0 MCM/year (79.8%), and followed by Groundwater-Outflow of 3.2 MCM/year (10.2%). The total groundwater storage volume was 7,860MCM. The total water balance of the groundwater system was minus condition of 2.7 MCM/year on average for the 10 years period, and this is around 9.2% of total groundwater supply and 1.9% of Rainfall.

The total water balance of Kabul basin mentioned above is illustrated in Figure 8. The total water volume of the surface system is far larger than the one of subsurface system. The minus portion of groundwater system was supplied from the groundwater storage and the groundwater level was, thus, drawdown as a total.

Unit: MCM/y

Canal-of

Surface System

Recharge Inundate

GroundwaterGroundwater Subsurface System OutflowInflow

（7,859)Storage

32.3 MCM2.7

351.

8

501.5　MCM

4.43.2

3.1

25.2

325.

236

.4

25.0146.6 115.4

Run-In Run-

Out

Rain

Pumping

EvapoTr

Source：Study Team

Figure 8. Total Water Balance of Kabul Basin (Recent 10 year average)

As of the total water balances of each sub-basin in recent 10 years, all of the groundwater sub-basins (total 78) were grouped in three blocks as Darlaman, N-Kabul/Pol-e-Charkhy, and Logar. Among the three blocks, only Darlaman has plus surface water balance, the rest of the blocks have minus groundwater balance. However, the minus volume of groundwater system in Logar block was far less than the other two blocks (only 167 TCM compared to 1.11 ~ 1.46 MCM/year).


22

When checking each sub-basin, there are almost no sub-basin with plus subsurface water balance in Darlaman and N-Kabul/Pol-e-Charkhy (NKP) blocks, while there are several sub-basins having plus groundwater balance in Logar block.

3.2. Deep Aquifer Analysis

3.2.1. Outline

In the course of the Study, the deep aquifer in the Kabul Basin was found fossil water. Since it has no recharge, the deep aquifer does not have potential on sustainable development. However, other water sources in Kabul basin are quite limited to the ever increasing population, and thus there is a high risk of water shortage crisis anytime when drought or any problem happens. Thus, the Study analyzed potential of the deep aquifer as an emergency water source through several case studies.

3.2.2. MODFLOW Analysis

The groundwater system of the Kabul basin was modeled as a three layers structure with Alluvial Aquifer (the shallow aquifer), N2 layer (Aquiclude), and Neogene Aquifer (the deep aquifer). The target aquifer (deep aquifer) was modeled as one layer because no clear impervious layer intercalated was detected through the drilling and geophysical prospecting conducted by the Study.

Aquifer properties of the deep aquifer were grasped through sole well pumping test and additional pumping test carried out under the Study. Permeability (Transmissivity/Aquifer thickness) obtained through additional test was 0.349m/day but the value obtained through sole well test was 0.077m/day on average, and the interim value of 0.200m/day was adopted only for North Kabul. Specific Storage was obtained only from the additional pumping test as 0.0000138 but only one datum; therefore, it was mitigated to 0.00001. Cross section model for the analysis is shown as Figure 9 and the target aquifers used in the simulation were dispersed as Figures.


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W Northern Kabul E

Near the Corridor

Southern Kabul

V:H=5:1

N1

N2

Alluvium

Figure 9. MODFLOW Cross Section Model

Figure 10. Dispersal and Boundary Condition of Deep Aquifer Model

MODFLOW analysis was carried out by a case study under several different conditions. First, restricting it only in drinking water for emergnecy, a unit water demand was set as 15 lcd. Expecting

No flow boundary


24

that drought occurs within coming two decades, target population was set as 6,823,000 (IWRM1), which was projected by IWRM for 2030. Since the simulation is under emergency condition, the examined emergency water supply was set to cover only 30%, 50%, and 70% of the total population in Kabul City. In this condition, total water demand in Kabul City was estimated 102,345 m3/day (0.015 m3/day x 6,823,000), and 30, 50, and 70% of it are 30,704, 51,173, and 71,642 m3/day, respectively.

Considering the averaged specific yield of the deep aquifer (around 12 m3/day/m), a capacity of submersible motor pump, and operation cost, economic limit of drawdown can be estimated around 120m. Based on that condition, the drawdown of each production well was set less than 120m. Thus, the maximum water yield from a production well should be set as 1,440 m3/day. It leads that the required number of production wells are 22, 36 and 50 wells for 30%, 50%, and 70% of water supply, respectively.

The simulation cases of different number of pumping wells of 22, 36, and 50 wells were set with a unit pumping rate of 1,440m3/day (Case 1, 2, and 3). Then, the cases of different discharge rate of 960 and 480m3/day with 22 production wells were set (Case 1-b and 1-c), considering the case of poor yield condition. Finally, the case of intermittent discharge was also simulated. In this case, simulation was done as one year pumping and resting following three years, then another one year pumping and resting. Cases for the MODFLOW analysis are summarized in Table 3.

Table 3 Simulation Cases for MODFLOW Analysis

Case Number of Production Well

Pumping Rate (m3/day/well)

Pumping Condition

Case 1-a 22

Case 2-a 36

Case 3-a 50

1,440

Continuously 5 years

Case 1-b 22 960

Case 1-c 22 480 Continuously 5 years

Case 1-a3 22 1,440 1 year pump & rest 3 years, 3 times repeat

According to the simulation result in North Kabul sub basin, water levels in the production wells were going down and more than 120m of drawdown was observed in around 1.3 years. In the other cases which are pumping from more numbers of production wells, the well drawdown must be more immediate and/or quick going down beyond 120m in depth. For example of the Case 3-a, the well drawdown in North Kabul is reaching 120m within 7 months.

When the pumping rate was changed from 480, 960, to 1,440m3/day in the fixed 22 production wells (as Case 1-a, Case 2-a, and Case 3-a), the pumping rate and the drawdown are in proportion. It is probably because the deep aquifer is a closed system with no recharge. In all of the sub-basins, the well drawdown does not reach to 120m for two years when pumping 480m3/day. When pumping up 1 Integrated Water Resources Management in Kabul Basin (2006, MEW)


25

960m3/day, the drawdown of only a few wells go down lower than 120m within two years. When pumping up 1,440m3/day, the well drawdown in several wells are going down more than 120m within only one year.

In the case of intermittent pumping (1-a3 in North Kabul), groundwater levels in the wells are recovered during the break-up period to be even among the wells. However, as there is no recharge, level of recovery is limited. Furthermore, it was found that even after 3 years of recovery period, water head remained low depending on the amount of discharge and as a result difference in drawdown was just a few percent to 15%, as compared with constant discharge analysis.

3.3. Evaluation of Groundwater Development Potential

3.3.1. Shallow Aquifer Development Potential

Based on the SSM analysis, the shallow groundwater system of the Kabul Basin was estimated in minus condition as a whole, in the last 10 years on the average. This indicates that there is already an over-pumping condition as a whole. Water balances on surface water system are nearly equal or slightly minus, while the balances on subsurface systems are all minus, especially in Darlaman and NKP blocks.

It means that there is no more groundwater development potential in the Kabul Basin. For sustainable development, no more new development schemes should be implemented especially in Darlaman and NKP blocks. Moreover, to avoid depletion of groundwater potential, number of existing production wells should be reduced at best effort.

3.3.2. Deep Aquifer Development Potential

Based on the result of MODFLOW analysis, even in “Case 1-a” which has the lowest number of wells (22 wells), water level in production wells in Darlaman goes down beyond 120m within 10 months when pumping up with 1,440 m3/day. If pumping rate is reduced to 480 m3/day (Case 1-c), pumping can be continued in every sub-basin for more than three years and the cumulative discharge shall be the biggest (39.2 MCM). However, it can deliver water to only 700,000 people, only 10% of the total population of Kabul City.

When pumping rate is set as 960 m3/day (Case 1-b), emergency water can deliver to around 1.4 million people (more than 20% of the population). In this case, the groundwater development potential of the deep aquifer is estimated as 29.1 MCM. Note that even in this case, deep groundwater can be developed for only 2 years in Darlaman sub-basin.

MODFLOW simulation concluded that the total groundwater development amount shall be around 29 MCM through 22 production wells with three years of available period, suggesting that the groundwater development potential of deep aquifer is not high. Moreover, it takes nearly a half year to construct a 600m class deep production well to pump up deep groundwater. It means that the emergency water supply from deep aquifer can not be available on time. Further, considering the quite high construction cost of the deep production well, new development of the deep aquifer is, even for


26

emergency water resources, not financially realistic.

Under the Study, four 600m class deep wells (TW-1 to TW-4) were drilled and completed as production wells. Although they are primarily to be used for monitoring the deep aquifer, it should be well maintained so that they can also be used as emergency water source.


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CHAPTER 4. IMPLICATIONS FOR GROUNDWATER DEVELOPMENT IN THE FUTURE

4.1. Water Resources Development under Limited Potential

It was found that groundwater potential in both shallow and deep aquifers are not as high as what is required to supply ever increasing population of Kabul. As the groundwater-dependent water resource development cannot be a sustainable solution, integrated water resource development plan should be formulated, by which overdependence on shallow-aquifer should be minimized through development of surface water in the future. In this concern, a master plan was formulated through JICA’s technical assistance, “Study for the Development of the Master Plan for the Kabul Metropolitan Area.

The master plan suggested several water resource development plans including surface water development. Therefore, in the long run, water resource development should be accommodated in accordance with the feasibility of those specific plans.

In this chapter, putting focus on groundwater development in the future, three issues are discussed, including some suggestive implications to sustainable water supply in Kabul: 1) approach to the supply side, 2) approach to the demand side, and 3) role of DGEH.

4.1.1. Approach to the Supply Side

For the sustainable use of water resources, it is required to withdraw water less than the renewable amount based on the natural water circulation on the target area. Because there is no more groundwater development potential in the shallow aquifer in the Kabul Basin, aggressive groundwater development schemes shall be considered, which includes recharge dam, artificial recharging, and underground dam.

Recharge dam is constructed to infiltrate surface water into the ground, having no purpose to storage water. Artificial recharging is to increase groundwater recharge. Also, an artificial recharging is to inject excess water in rainy season or flooding into a certain aquifer which has enough storage capacity through recharging well, and to withdraw the injected water later when needed. Underground dam scheme is to store groundwater in certain aquifer by constructing a cutoff wall in the course of groundwater flow. It is quite effective groundwater development scheme in semi-arid zone where proper aquifer with enough volume and shape is distributing.

4.1.2. Approach to the Demand Side

Majority of Kabul population may not be aware of diminishing groundwater potential. They rather overuse the water and, with the use of inappropriate facilities, leave drainage water to be contaminated. To better address this “tragedy of commons”-type problem, social approach for instance, public relation on water saving and sanitation should be widely organized. In the PR, members of donors and NGOs who are engaged in groundwater development and water supply sector in Kabul should be also involved so that unregulated use of groundwater could be more harmonized in the future. In addition, to minimize the water leakage/non-revenue water and thus to maximize the efficiency of the water use,


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improvement of existing facilities should also be considered.

4.1.3. Expected Role of DGEH

DGEH is expected to be a policy planning agency with groundwater licensing, hydrogeology research, and groundwater planning in addition to the actual implementation of Geoengineering, drilling and servicing. In this background, expected roles of DGEH should include: 1) Formulation of regulations on survey, development and conservation of groundwater resources; 2) Formulation of groundwater development master plan; 3) Preparation of monitoring manual for unitization and conservation of groundwater; 4) monitoring and control of illegal groundwater use; 5) Data collection on groundwater potential in the nation; 6) Setting an evaluation standard of water quality analysis and appropriate use of groundwater; 7) new establishment of a geoengineering center under DGEH for data collection, and 8) technical enhancement and revitalization in hydro-geology using GIS and remote sensing.;.

Basic data related to groundwater potential are managed separately by different agencies and the types of data available are also limited due to the lack of facilities. Thus, in the near future, those facilities should be upgraded and necessary training should be provided to the technical staff of the DGEH.

Unclear procedure of approval well drilling is also an important aspect that hinders the timely implementation of well drilling. It is required to improve the legislation and the procedure, by which DGEH can be proactive in preceding the necessary implementation of test-well drilling. Looking to the medium and longer term, furthermore, a hydro-geologic database system should be established based on improved well inventory and monitoring outputs of groundwater potential. To this end, “Groundwater Management Center” or alike should be established at the provincial level or in each river basin, by which groundwater development master plan can be well established.


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CHAPTER 5. RECOMMENDATIONS

5.1. Further Groundwater Development

(1) Shallow Aquifer Development

- As it was revealed that groundwater discharge from the shallow aquifer (Alluvial aquifer) exceeds the recharge, or over-pumping, no new development schemes should be implemented in principle.

- Over pumping was found significant especially in Darlaman sub basin and North Kabul and Pol-e-Charkhy sub basins. Therefore, no new development scheme in these sub basins should be carried out, and it must be considered to reduce the number of existing production wells gradually in the future.

(2) Deep Aquifer Development

- Groundwater in the deep aquifer (Neogene aquifer) was found as fossil water without recharging. As it cannot produce water in a sustainable way, development of the deep aquifer in the Basin should be avoided.

- The Study resulted that the potential of groundwater development of the deep aquifer is not high even for emergency purpose. However, when severe drought or disaster occurs, by which there remains no other water sources but groundwater in the deep aquifer, an emergency development plan of water resources shall be formulated based on the findings and suggestions of the Study.

- Since all of four deep wells (TW-1 to 4) developed in the Study have been completed as production wells, they should be continuously maintained to be used as emergency water sources in the future.

(3) Alternative Plans

- Given the fact that development potentials of both shallow and deep aquifers are quite limited, it is recommended to formulate water resource development master plan with an alternative water sources including surface water so that overdependence on shallow aquifer can be dissolved. In this concern, “Study for the Development of the Master Plan for the Kabul Metropolitan Area,” a technical assistance study funded by JICA, suggested several water resource development plans. Accordingly, “Detailed Planning Study of the Kabul Emergency Water Resource Development Project” has launched under the “Project on Promotion of Kabul Metropolitan Area Development.” Thus, for the development of new water sources, those plans should be taken into consideration.

- To complement the groundwater resources in Kabul, so-called “aggressive development” should be considered in future that includes recharge dam, artificial recharging, or underground dam.

- Considering the limited water supply and inappropriate use of water, public relations on water-saving and sanitation should be addressed. As the demand-side control has its own limit,


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however, formulation of the master plan for development of alternative water resource is still due necessary.

- To maximize the efficiency in use of limited groundwater resources, water leakage and non-revenue water should be taken care of in the existing water supply facilities. Countermeasure should be incorporated in the master plan mentioned above.

5.2. Capacity Development of DGEH

To address water resource development activities mentioned above, capacity development of DGEH is necessary. For DGEH to be able to function as a policy planning agency on groundwater development and management in the country, following items should be included in its vision.

(1) Short-term

- Re-organization from April 2011 should be smoothly managed and division of the organization’s roles should be clarified; in this line, roles of each section should strictly follow the groundwater development and utilization policy of the MoM.

- To manage the limited water resources in an appropriate manner, an approval and licensing system should be established with necessary revision of the legal system as soon as possible.

- To carry out above schemes, capacity of the staff on hydrology, water quality analysis, geo-engineering, soil test, and legislation shall be improved.

(2) Middle-term

- By developing a training program, capacity development should be organized especially on the aspect of groundwater development, utilization and conservation. Also, the levels of knowledge, skills, techniques, and engineering ability of technicians and engineers related to groundwater development, in the central and local areas, shall be upgraded through on-the-job training.

- More concrete plan in monitoring and control of illegal use of groundwater should be established especially on the matter of groundwater use and pollution control.

- To better manage the groundwater resources in the Kabul Basin, database on hydrogeological information, groundwater monitoring system, and well inventory, shall be established.

- Groundwater development potential of the country should be surveyed and development plans should be prioritized.

(3) Long-term

- Groundwater development master plan should be established, by which development, utilization and conservation of groundwater resources can be well managed for a longer term.

- A “groundwater information center” or alike shall be established at the provincial or river basin level under the DGEH. That will measure, observe, undertake research, manage, and monitor all the data and information related to groundwater resources and development. Types of data may


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include meteorological data, river runoff, surface water intakes, well inventory, groundwater hydrograph, groundwater discharges, and groundwater quality.

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