C Aoo) 1335, Exercises of Construction

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C Aoo)

Shallow Ground Water in the Zamin Dawar Area,Helmand Province, Afghanistan

Neal E. McClymonds U.S. Geological Survey

Open File Report January 1972

Contents

Contents (continued)

• Abstract-- - - Page
  • Introduction - - Location and Brief History of Area - Extent of Area - - Purpose and Scope of Study - - Personnel and Acknowledgments
    • Numbering System for Karezes,and Wells Springs,
• Physical Setting --- --- - Geography and Geology - - -- - --- - - Mountains - - Plains - Stream Valleys - - Climate - Precipitation - Temperature - - - Evaporation -
• Cultural Setting - - Population - Agriculture - --- --- - ----
• Shallow Ground-Water Resources-- --- -- -- - Present Water Development -- ------ -- -- - Sources of Water - -- - -- - Springs- - - Contents (continued) - Water-table Springs ' - Fractured-Lime stone Springs - Deep-Fault Springs - - Karezes ' - Karez Inventory - Hypothetical Typical Karez - Exceptional Karezes - Wells - Deh Baba Well - -
  • "Hydrology " -- - Hydrologic Cycle - - - Precipitation - Streamflow - Evapotranspiration -- - Ground-Water Recharge - Ground-Water Use - Ground-Water Outflow - - Water-table Map
    • Quality of Water
• Future Development of Ground Water - Continued Reliance on Karezes - - Deep Wells - Test Wells - Page - Development-- 7 - ;- - - - Records - Flood Check Dams - Need for Additional _Data - Rainfall and Streamflow - Monitoring Network -?
  • Summary and Conclusions - The Area -
    • Ground-Water Resources
      • Conclusions
    • Recommendations-
• References -- --
• Orthographic List of Geographic Names

Illustrations Page Figure 1. Map of Zamin Dawar Area showing Springs and Water-Table Contours In Pocket

2. Map of Central Part ofArea showing Villages, Zamin Dawar Karezes, Conductance DataSprings,^ and Wells and Specific In Pocket
3. Examples of Geographic Coordinates Numbering System to be used as a Permanent Office NumberSprings and Wells for Karezes, 11 4-15: Photographs
4. Line of Shafts (Wells) of Walong Karez (76), Zamin Dawar Ruins in Middleground Right. Helmand Rud Flowsin Background. along Base Looking Southwest,------of Limestone Hills 18 5» Village of Machikel on Low Terrace above Gulmesh Plains. Limestone RidgeBackground. of Sherei Ghar Looking Northwest, in Left 19
5. Ephemeral Stream Bed with Thin Veneer Nearof Gravel on Older Clayey Alluvium. Eastern Edge of Lower Gulmesh Plains. Shafts (Wells) of Qala-i-Gul KarezLooking Southwest. (44) Follow Left Bank of Stream.: 20
6. Ephemeral Stream,tributaries of Gulmesh Mandeh One of Several Dis- in Fore- ground. East-Facing Scarp of Sherei Ghar with Cultivated Area near Diyak VillageScarp between Tabus Fans. and Spring (S-2) at BaseSherei Ghar of RisesWest. 900 m above stream. Looking 21

Illustrations (continued) Page Figure 13. Old Tunnel of Qala-i-Gul Karez (44). which has been cut through by Ephemeral Stream Channel at Lower Left. Still Older Transected Tunnel lies Mid-way up Stream Cut at Middle Right. Looking North. 27 14« Spoil Piles of Shafts of Walang Karez (76) in Foreground and Sharh Karez (36) in Middleground to Right. Village of Suchi in Middle Left, in Swale between Lower Gulmesh Plains and Baghni Alluvial Fan.Looking North. 28

15. Main Shaft (no. 5 Hole) of Deh Baba Well (W-2). Mud and Wattle Building Northwest.to Left Houses Water Mill. Looking 29
16. Generalized Cross Section of a Karez and its Method of Operation 52
17. Sample Form of Schedule for Inventory of Karezes in Zamin Dawar Area. 54
18. Plan View and Cross Section of Deh BabaWell (W-2), Zamin Dawar Area. 69
19. Drawdown and Recovery Curves from Measurements Taken during Pumping November 16,Test at Deh Baba Well 1971 (W-2)^ on 70
20. Drawdown Measurements Plotted on Semi- Logarithmicto Determine Transmissivity of Aquifer Graph and Calculations at Deh Baba Well (W-2) 71
21. Hydrologic Cycle in the Zamin Dawar

Tables Page Table 1. Monthly precipitation, in millimeters,Kajakai Camp, during period of record 30

2. Average monthly precipitation, in milli- meters,Kandahar at Manzel Bagh(1956-59) station, 31
3. Average monthly precipitation, in milli- meters,(1940-59, at Manzel Bagh 1964-70) station,. Kandahar 31
4. Average monthly precipitation, in milli- meters,Kandahar at Manzel Bagh(1966-70) station, 31
5. Average monthly precipitation,meters, at staff house station, in milli- Lashkar Gah (1956-59) 31
6. Average monthly precipitation, in milli- Gahmeters, (1966-70)^ at staff house station,^ Lashkar 31
7. Calculated average monthly precipitation, in millimeters,27-year average) at Kajakai Camp (about 32
8. Calculated average monthly precipitation, in millimeters,(1966-70) at Kajakai Camp 32
9. Mean monthly temperature, in degrees Centigrade, at Kajakai Camp (1956-59) 33
10. Average monthly pan evaporation, in millimeters, at Kajakai Camp (1956-59) 34 llo Data on Water-Table Springs, 1971 41
11. Data on Fractured-Limestone Springs, 1971 45

Abstract The Zamin Dawar area lies between Kajakai Reservoir and Musa Qala Rud (river) in south-central Afghanistan, about 90 km (kilometers) northeast of Lashkar Gah. The area comprises two main stream drainage areas: that of Gulmesh Mandeh (ephemeral stream) to the east which includes mostly plains with low hills on the east and north slopes and a high limestone scarp on the west slope; and Baghni Rud to the west which drains a mountainous area to the north and spreads onto a large alluvial fan with distributaries leading both to Helmand Rud to the southeast and. Musa Qala Rud to the west. Most of the cultivated lands in the Zamin Dawar area lie in the southern part of the Gulmesh plains and in the Baghni alluvial fan, as well as a ribbon of cultivation on the flood plain of Baghni Rud in the mountains. The southern end of the Zamin Dawar area with high terraces and sharply incised ephemeral stream valleys is uninhabited. Karezes provide the chief source of water in the plains. Some 80 -were examined and inventoried during the course of the present investigation. Several springs and one large-yield well also contribute to the water supply on the plains. In Baghni valley, developed springs provide the main source of water supply. During the present investigation, conducted in 1971,. it was found that the karezes yield a total of about 20,000 ac-ft (acre-feet) (25 million cu m ^ubic meters7) of water per year, 1

The springs on the plains yield about 3,000 ac-ft (4 million cu m) per year, and the wells yield about 300 ac-ft (375, cu m) per year. The inventoried springs in Baghni valley yield about 6,500 ac-ft (8 million cu m) per year, and probably supply about 70 percent of the total water used in. the valley. There- fore, the total amount of water used in the Zamin Dawar area in 1971 was about 32,000 ac-ft (40 million cu m). This amount of water was used to irrigate about 10,000 jiribs (approximately 5,000 acres or 2,000 hectares) of cultivated land and served a population of about 40,000 people. Twenty years ago the water supply was more than double the 1971 flow from karezes and springs, and the population of the area was probably 60,000 to 70,000 people. During the past 10 years and particularly during the last 3 years, the water table has been declining as a direct result of a dry-weather cycle which has affected much of Afghanistan. Concurrently, the population of the area has declined. Rainfall, based on data from the Kajakai Camp weather station, has declined from a 27-year annual average of about 200 mm (millimeters) to about 160 mm per year, which is the annual average for the last 5 years and equivalent to a reduction of approximately 70,000 ac-ft (88 million cu m) of precipitation per year over the entire area. To compensate for the declining water levels many karezes have been deepened or lengthened at great financial cost to the people. 2

Introduction Location and Brief History of Area The Zamin Dawar area is located 90 km (kilometers) northeast of Lashkar Gah, in south-central Afghanistan. The area is named after the ruins of the fort of Dawar, which is situated in about the middle of the cultivated area on the plains between Helmand Rud (river) and Musa Qala Rud. Dawar was the ruler and chief land owner of the area during the Ghaznavid period, about 1, years ago. Many ruins, from small individual forts to the larger, 14-hectare (35-acre) compound of Zamin Dawar, are still recognizable today. The development of ground water by the construction of karezes elsewhere, notably in Iran, probably predates the Ghaznavid period by as much as 1,500 years. However, whether karezes existed in this area 2,500 years ago is not known. Many old karezes, abandoned long ago, exist as rows of low doughnut- shaped mounds. The ages of these are not known, Karezes, as well as the developed springs in the area, have probably been in use at least since the Ghaznavid period. Weather cycles, though, have been the determining factor in- -the , use of karezes. During wet cycles the water table may have been high enough so that water was supplied by surface streams and springs. During dry cycles, the people may have needed to dig down to the water table to keep springs flowing. Extensive 4

spring development resulted in full-scale karezes 0 Many of the people of the area, when interviewed, stated that the karezes are 300 to 400 years old. This could mean that 300 years is the remote past to the people, or it could mean that about 300 years ago a wet cycle ended and karezes were redeveloped. It might also reflect expansion of agriculture., which could result from political stability rather than climatic change. Whatever the implications, it is probable that most of the karezes presently used in the Zamin Dawar area are at least 300 years old.

Purpose and Scope of Study The'water supply of the Zamin Dawar area has been decreasing for the past several years. In the spring of 1971, HAVA (Helmand-Arghandab Valley Authority) through the auspices of the U.S. Agency for International Development (I1SAID) requested that members of a USGS (U.S, Geological Survey) hydrogeologic team,,then temporarily assigned to Afghanistan^ advise on and help conduct an investigation on the possibilities of obtaining additional ground-water supplies for irrigation in the Zamin Dawar, Musa Qala, and Naw Zad areas in the northern part of Helmand Province. USGS and HAVA personnel completed preliminary reconnaissance studies of the three areas in June

A more intensive field investigation of the Zamin Dawar area began under the guidance of the writer in July 1971 and is still continuing. The present report describes and evaluates the findings of the first phase this investigation through December 1971, This report, moreover, relates only to the occurrence and use of the shallow ground water in the Zamin Dawar area and presents brief recommendations. As originally proposed the chief purpose of the investigation of the area was to determine the feasibility of increasing the supply of ground water that could be used for irrigation. In order to accomplish this objective, however, a thorough study of all the water resources of the area must be made, including evaluation 7

of data on surface water and precipitation. No surface-water data and little precipitation information were found to be available for the area at the beginning of the study. Also, information is needed on the lithology and water-bearing properties of deep aquifers. These data are expected to be collected in the course of continuing field investigation. A second, but equally important, purpose of the first phase of the investigation was to train HAVA personnel on the methods of data collection and analysis in order that they may carry on the continuing study of the Zamin Dawar area and conduct similar investigations in other areas. A report by Jones (1971) includes recommendations for future ground-water studies and continued data collection in the Zamin Dawar area and elsewhere in the upper Helmand Valley. Another report by Sammel (1971) evaluates the ground-water resources of the Arghandab River Valley near Kandahar.

Numbering System for Karezes, Springs, and Wells During the inventory of the karezes, springs, and wells in the Zamin Dawar area, water sources were numbered consecutively as inventoried. The karezes were numbered 1, 2, 3, ... without prefixes. The springs and wells were numbered with the prefixes S- and W-j respectively. These numbers are shown on accompanying maps (figs. 1 and 2). In addition, the inventory schedules show the latitude and longitude coordinates from which a permanent office number is derived. The grid number for a karez is taken as the point where the karez tunnel ends and the outlet canal begins. Springs and wells are located by the latitude and longitude of the main outlet. Locations on the map can be determined with an accuracy of about 5 seconds at latitude and 5 seconds of longitude (150 m and 130 m, respectively), but in order to make the permanent office number reasonably concise, the number designating each hydrologic data point includes only the digits for degrees and minutes. Thus a well location is characterized by two four- digit numbers for latitude and longitude, which specify the southwest corner of a 1-minute by 1-minute quadrangle in which the karez, spring, or well is found. Within the 1-minute quad- rangles, water sources are further distinguished by the addition of a serial number based on the order in which they were inven- toried. Karezes, springs, and wells are not differentiated in this system. Figure 3 shows examples of the numbering system. 10

id

J X

21'

Canal

0*

°^

6VOO' o V

Example 1-Karez in upper left corner would have a permanent office number of:within the minute grid quad- 3222-6500-1; that is, it is rangle bounded by 32°22' and 32°23' north latitude and 65°00' and 65°01'it is the first water sourceeast longitude, and Example 2-Spring to upper left would have ainventoried in the quadrangle. number of: 3222-6500-2. Example 3-Karez in middle of sketch would Example 4-Well inbe:^ 3221-6501-1. lower right would be: 3220-6502-1. Example 5-Karez3220-6502-2. in lower right would be:

Figure 3--Examplessystem to be used as of geographic (^) the permanent officecoordinates numbering number for karezes, springs and wells.