PREPARED FOR INTERNATIONAL COOPERATION ADMINISTRATION
Underground Water Supply To Supplement Oued Nehana Project Tunisia
, --,." -,..,. TUDOR ENGINEERING COMPANY, WASHINGTON, D. C. , I FEBRUARY 1960 PREPARED FOR INTERNATIONAL COOPERATION ADMINISTRATION
Underground Water Supply To SuppleDlent Oued Nehana Project Tunisia
TUDOR ENGINEERING COMPANY, WASHINGTON, D. C. / ' ( FEBRUARY 1960 TABLE OF CONTENTS
Page No.
Letter of Transmittal ...... •...... •...... 4
Summary of Conclusions and Recommendations...... 6
1. GENERAL CHARACTERISTICS OF REGION ...... 7 Geography ...... 7 Climate ...... •...... •...... • 7 Geology ...... •...... 7 II. THE PROBLEM ...... 10 Present Water Supply ••••••••••••••••••••••••••••••••••• 10 Oued Nebana Project ...... 10 Use of Groundwater ...... _...... 12 Limitations on Ground~aterUse.... ••••••••••••••••••••• 12 lli. METHODS OF STUDY •••••••••••••••••••••••••••••••••••• 12 Previous Investigations •••••••••••••••••••••••••••••••••• 12
Field Studies ...... ~...... 13 Areas Chosen for Study ...... 13 'N. BLED SISSEB AREA ••• ...... 14 Location and Description •••••••••••••••••••••••••••••••• 14 Nature of Valley Fill ...... 16 Gro11lldwater Movement ...... •...... •...... 18 Water-Bearing Formations ...... 18 Quantity of Water in Storage ••••••••••••••••••••••••••.•• 20 Possible Additional Supplies of Water •••••.•••••••••••••• 22 Possible Required Maximum Draft on Storage ••••••••••.• 25 Location and Spacing of Wells •••••.••••••••••••••••••.•.• 26 Quality · of Wate r ...... '...... 27
V. KAIR.OUAN PLAIN' AREA •••••••••••••••••••••••••••••••• 29 Geogr aphy ...... •...... •...... •...... Z9 Geology...... 31 Water-Bearing Formations ••••••••••••••••••••• '. • • • • • • • • 32 Water Quality .. ·...... 33 Area Selected for Study...... 35 Quantity of Water in Storage ••••••••••••••••••••••••••.•• 35 Exis ting Wells ...... •...... 37 Sugges ted Well System.. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 38
- 1- 'l'able of Contents (Continued)
Page No.
VI. OTHER POSSmLE GROUNDWATER SOURCES. • • • • • • • 40 Djemmal-Moknine-Beni Hassan Area...... 40 Sahel Area o. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 43
VII. TYPE AND COST OF WELLS •• • • • • • • • • • • • • • • • • • • • • • • • 44 Performance of Existing Wells ••••••••••••••••••••••• 44 Possible Improvement in Well Construction...... 44 Numb~r of Wells Required...... 45 Cost of Wells ...... •...... 46 Operation and Maintenance. • • • • • • • • • • • • • • • • • • • • • • • • • • • 46 vm. TRIAL DEVELOPMENT OF GROUNDWATER RESOURCES ..•...... •...... ••..•...... ••.•.•... 47
IX. CONCLUSIONS...... 48
X. RECOMMENDATIONS. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 50
APPENDICES
A. Reference Map - Location of Wells. • • • • • • • • • • • . • • • • • • • 54 Record of Test Borings. • • • • • • • • • • • • • • • • • • • • • •• • • • • • • • • 55
B. Bibliog raphy .•..•....•...... ••...... • 59
C. Task Order No. 377-A-l DLF...... 62
-2- PLATES
~No. Page No. 1. Location Map ...... B 2. Proposed Oued Nebana Project, Existing and Proposed Pipe Lines .,...... 11 3. Bled Sisseb Area...... 15 4. Diagrammatic Sketch - Geologic Conditions Bled Sisseb and Kairouan Areas •••.••...••••••••••.• 19 5. Kairouan Plain Area...... 36 6. Location of Wells, East Central Tunisia •••••••.••• '. • • 54
TABLES
1. Water Quality Analyses, Bled Sisseb Area •••••••••••• 28 II. Water Quality Analyses, Kairouan Area...... 34 m. Wat"er Quality Analyses, Djemmal-Moknine-Beni Has san Area...... • . 41
PHOTOGRAPHS
1. Oued Nebana Looking Upstream from Pont Romain •••• 17 2. Oued Ne bana 3 Km Below Pont Romain •••••••••••••••• 1 7 3. Oued Nebana Reservoir Area from Dam Site...... 17 4. Oued Marguellil Looking Upstream from Kairouan Road 30 5. Part of Old Roman Aqueduct West of Kairouan in Oued Marguelli1 Drainage Area. . ••• • . • • •• •. ••••••• •• 30 6. Oued Zeroud South of Kairouan Looking Ups'tream • • • • • 30 7. Installation of 600 mm Concrete Pipe in Existing Pinchon-EI Onk-Sousse Supply Line...... 39 8. Inclined Sandstone Aquifer Near Zeramedine •••••••••• 39 9. Type of Well Drilling Rig Now in Use...... 39
-3- IlALPU A. 21JDOB TUDOR ENGINEERING COMPANY Lo " 1mLG ... OIf
!SOlS IIISSION STRBBT. SAN :rnANOISOO IS • YUKON 2. ,9010
Address reply to 1413 K St. N.W., Washington 5, D. C. • STerling 3·5313
International Cooperation Administration February 15, 1960 815 Connecticut Avenue, N. W. Reference: TEC-377-AI-DLF Washington 25, D. C. Serial No. 330
Attention: Mr. N. E. Thompson
SUBJECT: UNDERGROUND WATER SUPPLY TO SUPPLEMENT OUED NEBANA PROJECT - TUNISIA
Gentlemen:
Task Order No~ 377-AI-DLF calls for an investigation of possible groundwater supplies which might be obtainable for domestic water supply and irrigation use in Tunisia as a supplement to the surface supply to be provided by the Oued Nebana Dam. The Task Order calls for specific information as to sources, quantity, quality and accessibility of underground water in the vicinity.
The proposal of the Government of Tunisia to buUd the Oued Nebana project has been discussed in previous reports pre pared by this office. A report dated January 23, 1959 (Task Order No. 290-DLF), contained a review of the Government's application for DLF funds and described the information then avaUable with reference to the project. A later report dated October 27, 1959 (Task Order 377-DLF), summarized two reports on hydrology of the Oued Nebana River and the proposed method of reservoir opera tion, both of which had been prepared by the French engineers Compagnie des Techniques Hydrauliques et Agricoles (COTHA) of Grenoble, France. The , second of these reports, which was designated No. 390, indicated that the surface water supply developed by the proposed reservoir would be severely curtaUed at times and suggested the possibUity of securing the necessary supplemental supply from underground sources.
-4- ._------l'UDOR ENGINEERING OOMPANY
Mr. E. C. Marliave, Consulting Groundwater Geologist, was assigned by Tudor Engineering Company to make the field investigation called for by the task order. Mr. Marliave was in Tunisia from December 23, 1959 to January 23, 1960. He con sulted available public records and documents on the geology and hydrology of the area, made field trips to various areas, examined well logs and water production records, and made a study of the present supply of water for the town of Sousse. He also made a thorough study of the project information supplied by the Washington office of DLF, and other information made available by the United States Operations Mission in Tunisia and the Tunisian Government.
Mr. Marliave and the Tudor Engineering Company are grateful for the assistance given by officials of the Tunis ,ian Govern ment, particularly M. Knani, Secretary of State for Agriculture, and the office staff of the Bureau de l'Inventaire des Ressources Hydrauliques (BIRH). Particular thanks are due M. Ben Osmond, Chief Engineer of BIRH, and M. Jean Tixeront, former chief, now in a consulting capacity with the Agriculture Office, for their extreme helpfulness in making data available and arranging appropriate field trips to the areas of study. The interest and counsel of M. Cecil Hourani, political advisor to President Bourgiba, was particularly appreciated. The help of the U. S. Embassy staff and the help of Admiral Elliot B. Strauss, USOM Director and .his staff are gratefully acknowledged.
Mr. Marliave's report is submitted herewith in full. It was prepared after his return from. Tunisia with some editorial assistance from the Tudor Engineering Company staff. For con venience, a brief summary of the conclusions and recommendations contained in the report are inserted herein immediately following this letter of transmittal.
Very truly yours,
TUDOR ENGINEERING COMPANY
•
RGW:rbm Proje Enclosure
-5- SUMMAR Y OF CONCL USIONS
Sufficient quantities of good quality groundwater are available, within convenient distance from either the existing water main or the proposed Oued Nebana water main, to sup plement the supply to be produced by the Oued Nebana project. Underground water extracted may be replaced in part by recharge but it is possible that most of it will constitute a withdrawal from the static reserve or irreplaceable groundwater storage. The static reser've might be sufficient to make up project deficiencies for a period of over 100 years.
About 10 large wells with pumping lifts of about 50 meters might be required. They could be so located as to facilitate delivery of water to the main supply lines to the Sahel. Quality of water would be satisfactory. Cost might be about $500,000.
Sufficient information is not now available to determlne how much water could be economically and safely developed from underground sources on a contlnuous basis.
SUMMARY OF RECOMMENDATIONS
It is recommended that the Government of Tunisia expand its program of underground water exploration with a view to determining quantity of existing storage and rate of natural re charge. This might require the drilling an~operation of a number of test wells over a period of several years.
It is recommended that the Government of Tunisia be lnvited to submit" a concrete program for well development, In cluding location of installations, initial investment and operating costs, and an evaluation of the effect of the program on the overall water supply and the economy of the project as a whole.
-6- UNDERGROUND WATER SUPPLY TO SUPPLEMENT OUED NEBANA PROJECT TUNISIA
I. GENERAL CHARACTERISTICS OF REGION
Geography
Tunisia is bounded on the north and east by the Mediterranean Sea and on the west by Algeria. The southerly border is formed by Libya and Algeria. The country lies largely between east longitudes 80 and 11 0 , and north latitudes 300 and 370 • It occupies an area of approximately 79,000 square miles, has 750 miles of coast line, and a population of over 3, 500,000 persons. Mountains along the Algerian border rise to heights of several thousand meters above sea ·level. Extensive desert areas are found in the southern part of the country, while low hills and plains occupy the central and north central parts.
The northeasterly portion of the country is shown on the accompanying Location Map (Plate 1). This map shows the bound aries of the area covered by the present investigation and the position of the three principal tributary rivers, the Oueds Nebana, Marguelli1 and Zeroud. It also shows the site of the proposed Oued Nebana Dam.
Climate
The climate ranges from snow conditions in the high altitudes in the west and north to desert conditions in the south. Rainfall varies from 1,500 millimeters per year in the northwest to about 100 millimeters per year in the south. The climate varies in accordance with land elevation and proximity to the Mediterranean Sea and may be characterized as the Mediterranean type along the coast and the continental type in the southerly and interior areas.
Geology
The general geology of Tunisia is too complicated to be covered .in this report. A description of the geology of the particular
-7- · ,'. , .... ; . . : :.;.. . .. LOCATION MAP GROUND WATER POTENTIAL TUNISIA TUDOR ENGINEERING COMPANY
-RAILROADS MILES oHHA 10 20 30 40
PLATE I
-8- area under consideration is contained in the following paragraphs. The areas examined during this study extend from Dejebibina on the north to points south of Kairouan and from a line through Oued Kebir and Pichon on the west to the Sahel on the east coast. .! The area is occupied primarily by older folded sediments from Cretaceous to Pliocene in age and overlain by relatively undisturbed sedimeI.1ts of Recent age. There are many Cretaceous, Eocene, Oligocene, and Miocene sediments in the area. Most of them have a northeast-southwest trend with north-south subsidiary structures and faults rather predominant. There are few igneous rocks anywhere in the country except in the extreme west and north west portions.
The materials containing groundwater are primarily the Quaternary alluvium, the Pliocene alluvium and, to a limited extent, the Miocene sediments. The Quaternary and Pliocene sediments are the most absorptive and also the most productive. The general deposition of sediments occur s as alluvial cones, out wash plains and materials of fluviatile origin and these deposits occur primarUy on the plains and in the valleys and along the coast. The ridges and hilly area.s separating the valleys are comprised primarUy of the older non-water-bearing sediments.
\ There is a general absence of coarse materials due to the fact that the parent rocks in the upper portions of the drainage areas are limestones, sandstones, shales and marls, giving rise to fine-grained sediments, including sands, sUts and clays. Generally speaking, coarse gravels, cobbles and boulders are not common even in the apical portions of the alluvial cones.
It may therefore be seen that the specific yield of the sediments contained in the water-bearing series may not be as high as in other areas of the world where coar ser igneous detrital material is common in the alluvial deposits. In addition, the sediments derived from the older consolidated sediments contain a higher percentage of salts or saline deposits, thereby allowing percolating waters in the more recent alluvium to absorb more salts than would be the case with waters in sediments whose parent rocks are of igneous and metamorphic origin.
-9- II. THE PROBLEM
Present Water Supply
The town of Sousse and nearby communities and farms now derive their principal water supply fl·om the Oued MarguellU. A long pipe line extends from the headworks at Pichon to a distributing point at EI Onk, as .indicated on Plate 2. In spite of improvements attempted in recent years, the supply is dwindling1Lnd further urban and agricultural development in the Sousse area is dependent on the securing of a new and ample supply of water.
Oued Nebana Project
The Oued Nebana has been selected as the best source of additional water and preliminary plans have been made for a storage reservoir and a pipe line located as shown on Plate 2. The Oued Nebana project is ·intended to supply domestic water to the town of Sousse and irrigation water to the coastal plain known as the Sahel, which extends about 24 kUometer s to the north along the Mediterranean shore from Sousse and southerly about 54 kUo- meter s to Mahdia. Irrigation of an inland area of about 2, 000 hectares (5, 000 acres) near Sbikha is also contemplated. The project is estimated to cost about $36, 000, 000. The normal delivery from the reservoir is estimated at 24 million m 3 per year. Report No. 390, submitted to the Tunisian Government by COTHA, defines the monthly water requirements and describes the contem plated operation of the proposed reservoir. It is shown that, in the 30-year period from 1926-27 to 1956-57, there was one five-year period from 1943-44 to 1947-48 when shortages below the required 24 million m 3 would have occurred as follows:
Shortage Year J?er Cent Anlount in m 3
1943-44 8 1,900,000 1944-45 51 12,200,000 1945-46 24 5,800,000 1946-47' 53 12,700,000 1947-48 11 2,600,000
-10- PROPOSED OUED NEBANA PROJECT " I EXISTING AN D PROPOSED PIPE LI NES i r···...... TUDOR ENGINEERING COMPANY ...... -...... February 1960 .....~ : oDjtllllbilltl .,..... { .. OUED NEBANA ~...... ' ') p'DAM Sebj,., ...... ' .BLED SISSEB AREA Ito" ., .." ." IIEE PLATE II .""" ~..} ---- /' ,'1 ',1- -...... ; ------... --...... / I " :N" .: Sbi""{j ...... MediferrfJn e fJn SefJ ....~. /" A'tltI '~~~~ / . ' .;-'" ! , .... -.. .. , ...'t'" ") ]I o KtI"outlll ~.d ' ~" 1111 PUTE 51 ~ "'0;. .' ...... ", LEGEND . Elltllng PIlle Una ~"o He __ :.<.. , .,~ ~ Imgatod arlO 10 5 o 10 20 ...... Unoll .. DtaInate .... .,LOMETERS -11- PLATE 2 Use of Groundwater The _Government of Tunisia proposes to meet the above shortages by pumping from wells and has indicated that 6, 000. 000 m 3 per year when needed could be withdrawn from the underground basin near the upper end of the pipe line to be built from the new reservoir, this amount being the government's estimated annual groundwater recharge. Obviously, the quantity of 6, 000, 000 m 3 is not enough. If groundwater is to-be of real value to the project, it obviously should be assuredly available in ample quantity, should be located in an area facilitating its delivery to the project at the lowest possible cost, and should be of suitable quality. Limitations on Groundwater Use The chief problem is not so much to find groundwater in storage in substantial quantities, but rather to determine the amount in storage that is readily available for extraction during an irrigation season, the recharge available annually to this body of underground water, and the safe annual yield. Unless the safe yield of the various basins is determined, there could occur a wholesale indiscriminate mining of water, rather than a conservative approach. such as a planned depletion of a portion of the static reserve to supplement desirable projects or for use in emergencies during extremely dry periods. III. METHOD OF STUDY Previous Inve stigations / Prior to Tunisian independence, considerable hydrological work had been done by the French Government and by French con sulting firms, including COTHA and Societe Grenobloise D' Etudes et D'Applications Hydrauliques (SOGREAH). After gaining independence, the Tunisians have carried forward previously started work and have made great strides in carrying on their own investiga tions. Many of these studies and investigations have been patterned after French methods and some of the French consulting firms are still being employed. Consequently. there is a large mass of data available to the investigator who wishes to study water supply problems in Tunisia. -12- It is particularly noteworthy that many widely distributed papers and publications have been put forth in the last 15 years by people who were and are now working for and with the Tunisian Government. These papers and studies have been reviewed with considerable care and due credit must be given to those people who have worked so diligently on water supply problems in Tunisia in the past. Field Studies In the course of the present study, all available public records and documents were examined concerning the geology, and hydrology of the area, and in particular the reports by COTHA and SOGREAH and publications of the Tunisian Republic. Field trips were made to numerous areas to observe the soils, rocks, geologic conditions, terrain, stream channels, supply works, and the Oued Nebana dam site. Detailed data concerning borings, well logs, water levels, water quality, production, drilling costs and percolation rates, and data assembled for various local hydrologic studies were examined in the office of the BIRH. The Marguellil River galleries, the source of much of the present,..Ylater supply for the town of Sousse, were also examined. In all of these studies, special consideration was given to data relating to storage capacity and specific yields of water-prodJ,lcing sediments of the valley fUl, its recharge and production capacity, and the quality of water produced. Areas Chosen for Study It was not possible to study all of the large areas in Tunisia that might provide groundwater. Indeed, it was only possible to make a brief reconnaissance and to estimate the potentialities for limited areas in the time allotted. Accordingly, it was decided to concentrate the efforts of this study on a few of the areas where geologic and hydrologic conditions suggested a water supply might be obtained, where a reasonable amount of data was available, and where ready delivery of water into the existing or proposed supply lines to Sousse and the Sahel area would be possible. Two main areas were chosen for study, the Bled Sisseb area and the Kairouan Plain area. Two other areas were given -13- preliminary study, one being the Sahel area and the other a small area near Djemmal southeast of Sousse. Consideration was given to the possibUity of increasing the present extraction from the MarguellU River channel which already supplies Sousse through existing facUities. Consideration was als 'o given to the possibUity of obtaining water from the Oued Zeroud area. A brief examina tion was made of the possibilities of transferring water from areas of excess supply in northern Tunisia to areas of deficiency in the Sahel and the central and southern parts of the Kairouan Plain. IV. BLED SISSEB AREA This area was selected for study because considerable data of hydrologic nature was avaUable and also because it is traversed by the proposed pipe line from the Oued Nebana dam site to the Sahel region. The hydrological work was done by the Tunisian Government and by COTHA and SOGREAH. A number of exploratory borings made in recent years ha.ve indicated that sub stantial quantities of water suitable for domestic and irrigation use could be obtained. Location and Description The Bled Sisseb area is the northern portion of the Kairouan Plain. This area and its tributary drainage area are bounded on the north by the Djebels (hUls) named Fkirine, Ben Saidane, Zaghouan, and Fadeloun; on the east by the low, narrow belt of hUls known as the Draa Souatir; and on the west by Djebel Bou Mourra. The southerly limit of the drainage area is not well defined but has been assumed to be along a line from Sbikha on the west, through E1 Alem, and thence to the southeast toward Saadia. The total drainage area contains about 320 Km2. The valley area or valley fill area, known as Bled Sisseb and shown on Plate 3, lies between the mountainous areas to the north, east and west, and the arbitra:r;y southerly boundary of the drainage area described above. It is bounded on th~north by approximately an east-west line through the Sldi Nadji; on the west by the road from Kairouan to Pont du Fahsj and on the east by Bleds Guettari and Ketifa. -14- BLED SISSEB AREA TUDOR ENGINEERING COMPANY February 1960 -.."', \ \ , .... Proposed Pipe Line 'tj).~\ ------• ..,1'...... ,..... _ (',u~'t 'O\.~'O --- Southeasterly boundary of 120 Km2 area. -- Groundwater salinity in ppm. o 2 3 4 5 Kms. -15- The valley area, all of which is reported to be irrigable, has an area of 170 Km2. It is occupied by older, folded sediments overlain by Quaternary alluvium. The principal streams supplying this alluviated plain are, from west to east: the Oued Nebana, entering from the west and then flowing southerly and westerly; the Oued Krioua, entering ' the area from the northwest; and the Oued Ketem, entering at the northeast corner. These streams do not flow all the way through the area, as most of the flow is absorbed by the alluvium in the vicinity of the stream channels and only torrential floods reach the saline, dry-lake areas or playas to the southeast known a,s Sebkras. Photographs 1 and 2 show the bed of the Oued Nebana at low water. The broad areas subject to flooding and j.nfiltration should be noted. Nature of Valley Fill The valley fill in the central portion of the area exceeds 200 meters in d~pthin many places. Underlying the sand, gravel, cobbles, sandy clays and clays of the Quaternary alluvium, there is a considerable thickness of bluish colored OUgocene marls, sandy clays and clays. This Oligocene material must be considered non .. water-bearing for practical purposes and in addition apparently contains considerable gypsum. Therefore, water quality is extremely poor. Each of the principal tributary streams has built up its alluvial cone from the point where it debouches from the mountain ous areas. Because of the vagaries of stream flow and the type of material carried, the deposits, while similar to many cones of the western United States, do not contain as much of the coar ser fractions as would be found in areas of greater relief and more igneous rock. Most of the rocks of the drainage area are limestone, sandstones, and shales. The weathering of these rocks and trans port of the sediments by stream action, give rise to larger proportions of sands, sUts, clays, and marls. The deposition of these materials has occurred in general in areas along the major streams but these streams have undoubtedly wandered considerably over their respective cones, thus giving rise to lenticular deposits of varying extent 'and thickness overlapping and interfingering both laterally and vertically along the axis of deposition. In the jnter .. conal areas, where the outwash of fines during large floods would be expected, much larger percentages of fine graine ,d materials are encountered and less of the coarse grained material. -16- 1. Oued Nebana looking upstream. from Pont Romam. Z. Oued N ebana 3 Km ... below Pont Romain. 3. Oued Nebana reservoir area from dam. site. -17- Groundwater Movement The direction of surface flow is generally from the north and northwest to the south and southeast. The streams previously mentioned, which supply most of the water in the area, infUtrate water fairly rapidly, as indicated by a few percolation measure ments "made at relatively low stages of stream flow. As shown on Plate 3, the water after going underground generally has a south easterly direction of movement toward the low areas of Bled Guettari and Bled Ketifa, which are the recipients of both the underflow and surface flow. On these low areas or playas, the surface water and the subsurface water coming to the surface may evaporate and deposit salts, making the land less suitable, or entirely unsuitable, for irrigation and farming. Because of the nature of the parent rocks in the drainage area, mineral constituents are quite prominent in the sediments of the valley fUI. Limestones and gypsiferous shales give rise to large quantities of carbonates and sulfates in the sediments of the Quaternary alluvium. Underground waters moving from the north west toward the southeast pick up increasing amounts of salts from the sediments through which they percolate. Hence, as indicated by the salinity lines on Plate 3, the groundwater entering the Bled Sisseb area may contain less than 400 parts per mUlion of total dissolved solids; towards the central portion of the area the con centration becomes 1,000 ppm; and a short distance farther to the southeast it reaches 2,000 ppm. It is obvious that the best waters lie in the north and northwestern portions of the area and this wo:w.d be the best place for extraction of water for either domestic or irrigation use. Water-Bearing Formations As shown by the diagrammatic cross-section on Plate 4, water-bearing materials may be found in two separate aquifers in the water-bearing series of the Bled Sisseb area. The upper one begins at a shallow depth of a few tens of meters below ground surface in the northwestern part of the area and rises closer to the surface toward the southeasterly part of the area. It consists of a series of alternating zones or beds which are generally lenticular in nature and contain sands and gravels with some cobbles, interspersed with tighter sandy clays, clays and marls. -18- BLED SISSEB AREA Djebibina - EI Alem N I lian af $Io,ag~ I.-,.,...... f~compu a _II Oi~bibina I £1 A/~m. s BI.Soadia ----~=~l1NFPLAINS AREA --- KAIROUAN S'EI Hani Pichon - Kairouan - @"~,%lCobbles, 9ra vel and sand '.!?- ,' . nd cloy lenses TIC SKETCH F~:g]Sandy cloy a DIAGRAMMA OITIONS COMPANY ENGINEERI~~60 Sand slone GEOLOGIC CON ROUAN AREAS ~ AND KAI FEBRUARY BLED SISSEB LIC OF TUNISIA Oligocene 1': 1.f:j'. IW~. • Marls I REPUB . . Marls and blue coy LUlelienne~I*=~~~~'______--L __ -- ~P'L'A'~'TE4 -19- WhUe local manifestations of water pressure exist in certain areas, this upper aquifer may generally be referred to as a free ground water body. The Tunisian Government reports, as well as French reports, refer to it as the phreatic nappe or free groundwater layer. The deeper aquifer lies at a depth of 80 to 150 meters below ground surface and consists in large part of two rather poorly interconnected strata or horizons of sands, gravels and cobbles, generally coarser in nature than the simUar materials of the upper aquifer. These deposits are coarser because they were apparently deposited in tlnies of higher rainfall near the upper portions of the cones when much coarser debris could be transported. The result ing lenses or zones are not believed to be continuous as a sheet over the entire area, ' though many of them appear to have consider able extent. While it is not posslble by comparison of existing well logs to connect particular layers from one well to another with any degree of certainty, it is quite obyious that the layers are in the same zone and probably hydraulically interconnected to a degree. The water in the lower aquifer, ,which is termed in the French reports the nappe profounde, or deep layer, is generally under pressure and rises to about the same elevation as the water or the upper aquifer. The static of piezometric level is about 18 meters below ground surface. The average drawdown of existing wells is about 20 meters, giving a total pumplift of about 40 meters or 130 feet. These figures were obtained by averaging the data given for the better wells among those listed for the Bled Sisseb area in a list of 160 wells furnished by the Tunisian Goyermnent and reproduced herein as Appendix A. A well location map is included. Quantity of Water in Storage The quantity of water in storage in the lower aquifer is much greater than the quantity stored in the upper one because it contains a greater thickness or quantity of the more porous and permeable materials amounting probably to one-third to one-half of the total thickness. Wells produCing from the lower aquifer normally produce three or four times ~s much water as wells in the upper aquifer. -20- In considering estimates previously made as to the quantity of water which may be in storage under the Bled Sisseb area, two items deserve attention. First, since the lower aquifer is under pressure, it is not consistent to consider a withdrawal as causing a change in storage under a particular area. WhUe the water table or piezometric surface may be lowered temporarUy as the result of extractions, the effective lowering of the water table actually occurs in the forebay or source area. The aquifer from which the extractions are made is merely a conduit in which the pressure reflects the elevation of the water surface in the forebay. Second, previous estimates have been based only on the aquifers underlying the area that is considered to be irrigable, consisting of 170 Krn2• This procedure, which was followed by both COTHA and SOGREAH, accounts only for the water contained in the irrunediately underlying free groundwater body and in the lower pressure aquifer. It excludes any consideration of the up stream or forebay area, extending northerly to the town Djebibina, which is much larger than the irrigable area and is also filled with water which is tributary to that area. It would not be unreasonable to assume that, at a minimum, there is at least twice the quantity of water in storage upstream and tributary to the irrigable area as the amount computed to lie beneath it. In the .computations for the present report, the previously used method has been em.ployed but the surface area used has been further reduced from 170 Krn2 to 120 Krn2, simply for the purpose of limiting extractions to that part of the area which shows water carrying less than 1, 000 ppm of dissolved solids. The dividing line runs approximately in a northeast southwest direction as shown on Plate 3. The volume of the upper aquifer, using an area of 120 Krn2 and a depth of the permeable materials of only 10 m.eters, is 1,200,000,000 m 3• Assuming a 10 per cent specific yield, which is not unreasonable for sands and gravel containing a little silt and fine sand, the available water would be about 120.000,000 m 3• Since approximately three-fourths of material is clay, it is assumed that only one-fourth of that quantity of water is easily extractable. If so, 30,000,000 m 3 of water would be readily available to wells in a short time period from the upper aquifer. -21- In the lower aquifer, the sands and gravels under pressure average between 40 and 45 meters in thickness. Using the 120 Km 2 area and a 45 meter depth, the total volume is found to be S, 400, 000, 000 m 3• Most of the logs of the good wells indicate that it would be quite reasonable to assume that one-half of the total volume can be considered to be sand and gravel. On this basis, there , would be 2, 700, 000, 000 m 3 of sand and gravel suitable for water storage. Again assuming a specific yield of 10 per cent, 270, 000, 000 m 3 of water would be readUy extractable. However, assuming that, after drawing this aquifer down to the ~tagewhere the forebay is exhausted and true dewatering of the aquifer com mences, further drawdown would be limited to 22.5 meters or half of the total depth, then the available supply will be half of 270, 000, 000 m 3 or 135, 000, 000 m 3• The above figures for water availabUity are based on estimates of surface area, aquifer thickness and specific yield which are all on the conservative side. The total avaUable supply 3 3 is shown to be 30, 000, 000 m in the upper aquifer and 1~5,000, 000 m in the lower aquifer, or a total of 165, 000, 000 m 3• It should be noted that during the withdrawal of this amount, water will be drawn from the forebay area to the north and will replace a large quantity as fast as it is extracted. Possible Additional Supplies of Water Consideration should be given to a number of other possibUities which are not mentioned i.n the COTHA and SOGREAH reports and which, in order to be conservative, the Tunisian Government has not taken into account in their water supply and debit balance. They will at least furnish plus values to assure the estimated supply, and in some cases can be evaluated to give amounts which might be added ' to the major resource of 165, 000, 000 m 3 They are described in the numbered paragraphs which follow. 1. Water moving slowly through the upper aquifer comes to the surface where both the water table and aquifer rise just south and east of EI Alem at the lower end of the irrigab1e area. Here the water appear s in many small springs along the banks of the smaller streams, or comes close to the surface, saturating the surface and near surface soUs, and permitting an appreciable amount of evaporation. -22- If the water table could be drawn down by pumping, there would be less water available for evaporation at the lower end of the area. What the quantity of this salvage might be has not been estimated but it certainly is a plus. 2. Following construction of Qued Kebir dam in the valley immediately north of Qued Nebana some years ago, a small portion of the Nebana drainage was diverted through a tunnel into Oued Kebir reservoir for use in Tunis. The average annual amount of diversion for several years has been 2,000,000 m 3• This figure is of coy.rse subject to the vagaries of rainfall and, in dry years or years when the Nebana project would be short of water, would perhaps amount to only a few tens of thousands of cubic meters. Qn the other hand, the maximum quantities diverted in wetter years have been on the order of 3-1/2 million m 3• Since the recent constrJlction of Qued Ellil dam, the water that has been diverted from the Nebana drainage area to Qued Kebir is no longer needed in Tunis and could be made available to the Qued Nebana 3 project. It would give another plus value, averaging 2 million m a year. This quantity of water has not been taken into account in studies so far made on the Qued Nebana project. 3. Some additi.onal dependable water supply for the Qued Nebana project would be available if a larger portion of the proposed total reservoir capacity could be utilized for water regulation. It is understood that about 20,000,000 m 3 of storage behind the Qued Nebana Dam has been reserved for silt accumulation. Studies by the Tunisian Government indicate that streams like the Qued Nebana carry 10 to 20 times the silt load that is carried by many of our . AInerican streams and the government is therefore perhaps con servative in allowing the proposed large storage volume for the silt which may accumulate over a 50 year period. It is true that the drainage area contains many fine materials and thick deposits of Silts, marls, and sandy clays. The land is quite barren ' and apparently much overgrazed (see Photograph 3). The Government of Tunisia is presently studying means to reduce this erosi.on l.n some of their waterhseds and particularly in the case of the Qued Nebana water shed. This would include the planting of trees, the growing of grasses, and protection of some areas against over grazing. If this program results in substantially decreasing the nlovement of silt to the extent that reservoir capacity reserved for -23- the purpose could be reduced, then a somewhat larger regulated supply .could be depended on. In any case, more storage .capacity might be used for regulartion during the first 10 or 20 years of project life, provided the silting occurs uniformly over the entire 50 year per iod. 4. H the water level in the Bled Sisseb area basin, and particularly in the northern part of the forebay area, is drawn down by pumping so that the water table is lowered in the vicinity of the streams which contribute to the underground recharge, then a greater rate of percolation will be induced. This would mean that, in years of heavy or normal river flow, more water would percolate downward and less would run off and be wasted. H by lowering the water table a slight increase in rate of percolation can be obtained, it will tend to keep the forebay area as full as possible consistent with the quantities extracted. This value has not 'been estimated but it is certainly a plus. 5. In their studies of recharge, the Tunisian Government and COTHA and SOGREAH estimated the, annual percolation from the beds 6f the Oueds Nebana, Krioua and Ketem. There is no indication that they took account of the minor streams which are tributary to the forebay area in the 15 or 20 Kms between the major rivers. The tributary inflow from small streams in this area might be 10 or 15 per cent of the quantity contributed by the m.ajor streams. This again is a plus value and would probably m.ean that slightly more water would be available to the area as recharge. 6. T:lere is no indication that direct rainfall penetration on the surface of the ground has been taken into consideration although a low value was reportedly used in the balance made by the Tunisian Government. Even though the rainfall in this area is only 200 to 300 millimeters per year, it is possible that 10 to 20 millimeters might percolate and this could appreciably increase the am.ount ·of total supply. The annual recharge to the Bled Sisseb area heretofore has been estimated conservatively at 6,000,000 m 3 per year, based largely on percolation studies in Oued Nebana and simUar -24- streams. It seems that a figure of around 9, 000, 000 m 3 might be more reasonable. If the conservatively estimated recharge of 6,000,000 is added to the 165,000, 000 available in storage, a total of 171,000,000 m 3 of water could be considered as readily avaUable, and this amount might be supplemented by salvage from evaporation and addi.tions from increased percolation, tributary inflow, and rainfall penetration. Adding to the minimum value a figure of 2,000,000 m 3 to represent the possible additions, there is a total of at least 173,000,000 m 3, of which 165,000,000 is static reserve and 8, 000, 000 dynamic reserve. The 8,000,000 might well be increased to over 10, 000, 000. More recent studies by SOGREAH (January 1960) have indicated that previous estimates of recharge were very pessimistic. There are now new estimates raising the previously estimated recharge of 5, 000, 000 to 6,000,000 m 3 per year to over 10,000,000 m 3 per year. This is largely based on the additional contribution of unmeasured tributary stream flow and rainfall penetration. The two figures 165,000,000 and 8,000,000 m 3 ~ightwell be the conservative estimate of the quantity of water that could be drawn on by we11s in this area to supplement the Oued Nebana project. If, however, a certain amount of irrigation is carried on in the Bled Sisseb or Sbikha areas, there is a possibility of up to 3,000,000 m 3 per year of return irrigation water being contributed 3 ~othe upper aquifer. This 3,000, 000 m would be added to the amount available annually for extraction, although the used water would be somewhat degraded in quality; Possible Required Maximum Draft on Storage Assuming that in a period of three years out of 30 years occurring in a five-year period it will be necessary to pump one half of the normal quantity annually delivered by Cued Nebana (24,000,000 m 3), the amount pumped would be 12, 000,000 m 3 per year. In the three years the amount extracted from groundwater would be 36, 000, 000 m 3 but this would be offset in part by three years' annual recharge amounting to not less than 18,000,000 m 3• In other words, of the 12,000,000 m 3 that must be pumped each year, 6,000,000 would come from recharge and 6,000,000 m 3 from storage. At the end of the three-year period, the net total draft on the 135,000,000 m 3 in the lower aquifer water bank would have been 18,000,000 m 3, leaving 117,000,000 m 3 stUl in storage. Assuming -25- that the same quantity were extracted in the next 30 year period, there would then be 99,000,000 m 3 left in storage at the end of 60 years, and likewise at the end of 90 years there would be 81, 000, 000 m 3 in storage. Hence it can be seen that, by using up this bank of underground storage, it would seem to be possible to operate the project continuously on the basis of the full require ment of Z4, 000,000 cubic meters per year for over ZOO years. After the first period of groundwater extraction in a dry cycle, more accurate · £igw;es on storage and recharge could be computed and a modified program of withdrawals could then be adopted if indicated. 'v Location and Spacing of Wells The wells should be spaced about a kilometer apart. This would mean quite a spread over much of the area to eliminate the possibility of mutual interference, which would be more pro nounced in the case of a we11-defined pressure aquifer than in a free groundwater area, where the we11s might be spaced as little as 300 meters apart. It may prove to be possible to place these wells at closer intervals, but in any eve~tit would be undesirable to group them so closely that continued draft would create a big pumping depression which would make the operation more costly and possibly tax the transmissibility of the aquifer to a point where the wells would no longer produce satisfactorily. From an econom ic viewpoint, it would be best to group the wells close together and have them all discharge into one trunk line, which would then extend to whatever distance is necessary to join the proposed main pipe line from Oued Nebana to the Sahel. In appears more likely that separate insta11ations and a network of pipes connecting widely spaced wells will be needed. The location of the area in which it is proposed to pump is to the north and uphill from the proposed main pipe line. It is a favorable location and is desirable because of the better quality of the water. U there is an intent to use these wells "in the many years when the Oued Nebana reservoir could supply .all of the water necessary for the Sahel, it might be we11 to install them farther to the north or higher in the forebay area. so that the irrigated Bled Sisseb area could be completely served by gravity. -Z6- If an irrigation project were to' be undertaken utiltzing these wells, it might be possible to charge off a considerable proportion of the well investment to such project with a corre sponding saving to the Nebana project. It seems possible that the Oued Nebana project might be enlarged so that much of the water pUInped in years o{ample surface supply could be used for increased irrigation in the Sahel area, where the lands are allegedly the most productive. It must be remembered, however, that if water is pUInped from the proposed wells for irrigation of areas not in the Oued Nebana project, a greater draft will be pl~cedon the water in storage than previously described and the supply would not last as long. Quality of Water In the Bled Sisseb area the quality of water in the upper aquifer is generally slightly poorer than that in the lower layer, particularly in the northwest portion of the area. Water quality of the deeper zone averages about 1, ZOO ppm in the entire ~ledSisseb area with the better quality waters to the northwest. This apparently is because the recharge to the deep layer moves more rapidly than that to the upper layer, which moves much more slowly in tighter material and therefore absorbs more salines from the soU in the same vertical section. The qualities of water that have been indicated by analysis in this area are considered in Tunisia to be good to fair. These waters would probably receive a lower classification in the United States except in certain desert or water-short areas. Analyses of the waters of Z5 wells as furnished by BmH are shown in Table 1. It will be noted that the waters contain most of the usually found elements. The chlorides, sulfates and carbonates may be a little higher than desirable. According to many of the reports presently available, most of the waters and particularly those con taining more than 1,000 parts per million of total dissolved solids should only be used on, or are best used on, a well-drained soU. The Government of Tunisia does not normally analyze well water for boron but three water samples taken during January 1960 from the Oued Nebana were analyzed for boron with negative -Z7- TABLE I WATER QUALITY ANALYSES BLED SISSEB AREA REPUBLIC OF TUNISIA February 1960 Mill iarame er Liter ppm Laboratory Test No. Notes Ca Mg Na Cl S04 C0 3 RS ~. p.H DOH 11 lZ0/3 136 9 65 114 53 183 680 7. Z 37°5 Pb - Z.5 gIl 118/3 z46 36 74 Z13 Z40 189 1100 6.9 69° Pb - 3. 0 gIl Z714/Z lZ9 4Z 140 178 Z80 137 910 7. Z 49° Z714/Z 116 36 140 160 ZZ4 144 8Z5 7. Z 43° 8757/4 88 41 Z38 Z78 19Z 161 1060 7. 2 39° Drawdown about 11 m 9032/4 98 47 177 Z06 259 153 1000 7.3 44° 8807/4 116 41 Z54 4Z6 Z30 153 IZ40 7. 0 46° 90Z7/4 94 47 330 408 ZoIO 154 lz60 7. 3 43° 3414/4 135 3Z 181 320 221 108 1010 7. 3 46° 3388/4 96 22 84 9Z 101 165 520 7. 3 33° 3415/4 88 Z7 46 85 82 132 452 7. 1 33° 9070/4 132 43 230 390 317 90 1140 7. 50°5 9070/4 126 44 239 373 288 126 1240 7. 0 49°5 100 - lZ5 m - NS- 23. 5 9178/4 94 44 175 177 Z83 153 940 7. 2 41°5 NS-IZ . 9 9178/4 11Z 63 Z78 320 173 Z88 IZ60 7. Z 54° At 150 m drawdown 6 m (HZS) 9178/4 70 6Z ZIZ Z84 158 Z07 900 7.4 43° At ISO m drawdown 6 m (HZS) 9123/4 10Z 36 175 Z84 Z78 84 940 7. IS 40°5 140-165 m Pump 6 m 3 9123/4 88 45 161 195 274 133 800 7.45 40°5 75~$_~.l5umpZ4m- 91Z3/4 9Z 43 171 160 Z74 147 880 7.45 40°5 56-67m Pump Z4m3- NS-Zl. 5 91Z3/4 84 75 Z97 30Z 44Z 168 1360 7.4 5Zo NS-ZZ. I 91Z3/4 108 53 Z54 30Z 336 180 lZ40 7. Z 49° 7 days pumping (HZS) bl 91Z3 o/4 94 35 140 160 ZOZ 150 8Z0 7.4 38° 24 hr. pump ing STREAM SAMPLES OUED NEBANA 4311/4 172 46 Z77 497 307 lOS 1480 7. 9 6zo BorOD - none 4311/4 172 49 Z77 515 307 IZI 1560 7.75 63° Boron - none 4311/4 176 44 330 515 305 IZ3 1580 -- -- Boron - negative 0 0 *DOH is a {actor of usability. 30 - 60 is considered good . •• RS (Resldu Sec) i s total dissolved solids in ppm. See Plate 6 in Appendix A Cor loca ti on of wells . Data provided by Bureau I. R. H. -Z8- results in addition to the usually tested elements as shown by the last entries in Table I. The governmental agencies dealing with water and agriculture have not felt that it was necessary to analyze for boron as they claim they have had no problem with this element. This is probably true since, obviously, they could not have irri 'gated their citrus crops in Tunisia for hundreds of years without injury to the trees if the water contained appreciable amounts of boron. v. KAIROUAN PLAIN AREA Geography The Kairouan plain is bounded on the north by the Djebels Fkirine, Zaghouan and Fadeloun, which more or less surround the northern extension of the plain of the Djebibina and Bled Sisseb areas. To the west the boundary is the hill and mountain mass rising sharply above the plain. To the east the limits are defined in the north by Draa Souatir and further south by a rather prominent north-south fault $ystem and the Djebels Meckertate, KUter and El Guessaat. To the soutli the plain rises gently in the vicinity of Djebels Kordj and Bou Thadi. These latter Djebels more or less separate the northerly Kairouan plain from the more southerly plain of Sfax. The Kairouan plain itself has very little relief and the easterly portion is occupied by rather extensive Sebkras namely Kelbia, Sidi el Hani and Cherita. The natural water supply to the Kairouan plain comes primarily from two streams, the Qued Marguellil and Oued Zeroud (see Photographs 4, 5 and 6). Surface drainage is from west to east and the underground flow of water follows the same pattern. Just west of Kairouan the Cued MarguellU disappears. The main stream divides into a series of distributaries which become lost in the deeper alluvium except during periods of flood. Flood flows are large and strong and the waters are carried many mUes east of Kairouan to the Sebkra de Sidi el Hani. This is a low-lying playa or dry salt-lake area into which overflow or flood water ' spUls durlng periods of abnormal rainfall and then evaporates on the surface leaving saline deposits. -29- 4. Oued Marguelli1looking upstream from Kairouan road. 5. Part of old Roman aqueduct west of Kairouan in Oued Marguelli1 drainage area. 6. Oued Zeroud south of Kairouan looking upstream. -30- Oued Zeroud, a few kilometers south of the Oued Marguellil, runs from west to east, occupying a more southerly portion of the drainage area. It is larger than the Oued Marguellil and its main channel extends some few kilometers farther to the east. Stream flow records indicate that its average annual flow is about twice that of the Oued Margellil. It too dies out in the vicinity of Oued En Nar and also discharges its excess flood waters into the Sebkra _de Sidi el Hani. Geology The Kairouan plain is a large area of subsidence that has been filled with continental sediments of Pliocene and Quarternary age which have been largely derived from the higblands to the ' west and north of the plain. Ground and surface water tributary to this area moves from the north and west to the east and southeast. The sediments which have been built up along the channels of Oued Marguellil are sands, marls, siltstones and clays, with certain areas of cobbles and boulders and the coarser fractions of the finer materials. These coarser materials have been carried by the stream only in years of heavy flood run-off. As the stream in its easterly course reached what might be called the apex of its alluvial cone, some 20 Km west of the town of Kairouan, it had freedom to break up into its various distributaries and to spread out over the plain, which is made up of several parts of a series of coalescing alluvial cones. As the Marguelliland Zeroud rivers spread out to form distributaries east of the mountainous area, the depositional con ditions allowed various sizes of aquifers and small lenses of sand and gravel to be deposited within the conal areas. In years of heavy flows, during periods of several hundreds or thousands of years when the streams were occupying the same channel or general area, it is obvious that thick and laterally extensive deposits of coarse, water-bearing material would be deposited. In time, as the channels changed or wandered, these thicker and more permeable deposits spread both laterally and in depth over the conal area. The coarser materials were deposited in the apical areas, where the slope and velocity of the stream were greatest, and the finer materials were deposited in the central -31- and distal portions of the cone. Laterally, the coarser sedi.Inents were deposited along the generalilne of the main channel and the finer outwash or flood plain materials were deposited on either side. Thus it may be seen that with ti.Ine, both in depth and laterally, the depositional characteristics of the various cones which may overlap .in the interconal areas and give peculiar anomalies, must be considered in any groundwater evaluation or study. It is not surprising to find that, in certain areas where wells penetrate the major and coarser aquifers, large volumes of water and water of the best quality may be produced. On the other hand, in the inter conal areas or in the areas which at certain depths have had deposits of fine materials only, it is to be expected that wells will not be good producers and, if the fine sedi.Inents contain considerable salts, that the water l;etained therein for a longer time will have absorbed a larger quantity of total dissolved solids or salts. Water-Bearing Formations In portions of the Kairouan plain not yet defined by specific geographical limits, there is recognized an upper phreatic layer of free groundwater. This zone, while containing an appreciable quantity of water, does not produce as well as the lower zone because of the finer sediments and the water quality is generally poorer. From an examination of well logs, pumping tests and water quality analyses of the better wells in this area, it.is obvious that larger quantities of water, higher specific capacities of wells, and better quality of water is generally obtained in the deeper zone. The lower drawing on Plate 4 is a geologic section taken from west to east, with Kairouan about two-thirds of the way east from the mountainous area and the Sebkra de Sidi el Hani at the easterly end. It shows a ground surface sloping gently from west to east and an upper zone of moderately permeable materials varying from 20 meter s in thickne s s near the we stern end to 30 meters in thickness in the vicinity of Kairouan. This zone is com posed of a thin layer or skin of soil, overlying vegetable matter, sands, gravels, cobbles, and sandy clays in lenticular fashion to an average depth of 30 meters. -32- Below the upper zone, is a layer of clays, sandy clays and clayey sands generally considered to be relatively impervious. The thickness of this layer may be estimated from we1llogs in the area to have an average thickness of about 20 meters. Underlying the impervious layer is a deeper water bearing zone or aquifer ov~r100 meters in depth. This aquifer is not entirely composed of gravels, sands and cobbles but, on the contrary, contains many lenticular deposi~sof mixtures of these materials with clays, marls and sandy clays. In some areas it is possible over a short distance laterally to distinguish two or even three . separate layers but generally only one or two layers can be recognized. Of the total thickness of over 100 meters, only about 40 to 50 meters of depth at most might be considered to be first class water-bearing material. For computation purposeS" a thickness of 40 meters was used in the pres 'ent study. In general, below the deep aquifer blue Oligocene clays are found which, over most of the area, are believed to be on the order of several thousand meters in thickness. The upper surface of the Oligocene clays or blue marls (which are generally found to be highly saline) is considered to be the base of the water .. bearing series. Any water production of appreciable quantity and of usable quality should occur above this level. The Sebkras in Tunisia are the equiv .alent of the playas of the western and southwestern United States. The continual buUd-up of thin layers of soU~and salts in these low-lying depressions in past geologic time is responsible for the highly S"aline condition of both soU and waters that are found in these areas. The fact that lakes exist during a part of the year without benefit of floods or rainfall suggests that some underground water may be reaching the surface from below. Miocene and Pliocene sediments, overlain generally by older alluvium, are exposed just west of the Sebkra de Sidi el Hani. This also suggests that these deeper zones or aquifers are coming to the surface near here and supplying water. Water Quality Of the two streams which supply underground water to the Kairouan plain, the Oued Marguellil is the better source from -33- TABLE n WATER QUALITY .ANALYSES KAIROUAN AREA REPUBLIC OF TUNISIA February 1960 Mllligrams 1 er Liter ppm Well Number Ca RS ** DOH* Mg Na Cl S04 C0 3 Notes 6333/4 7Z 3Z 40Z 337 4lZ 183 15Z0 31° 658Z IZO 51 516 550 518 151 1900 51° 6680 157 8Z 494 568 758 133 ZI90 71° 707 ------0865 -- 3ZZ9 16Z 53 448 497 476 189 1940 61° bla lZZ9 186 80 483 568 748 IlZ ZZ30 77° lZZ9 ter 164 80 479 605 634 150 ZIZZ 480 5698 168 57 483 5lZ 533 181 19lZ 64° lZZ9 ter 114 57 418 479 519 159 1780 5Zo nzo 148 83 550 710 538 183 ZZ60 71° 8691 106 33 49 99 168 137 680 40° 7599 54 ZZ 30 35 Z5 IZO 300 ZZO 7800 5Z II 48 43 ZI 117 340 17° 8937 304 90 6Z1 1171 701 114 lZOO 113° 8610 116 49 ZZZ ZI3 470 IZ7 1360 49° 9183 176 100 Z95 497 66Z IZ6 Z040 83° 894Z 188 68 44Z 603 634 IZ9 ZZOO 75°' 8954 ZI6 83 590 816 653 14Z Z5Z0 88° 8774 ZZ8 105 536 905 691 146 Z880 1000 9087 174 111 540 816 739 IZ6 Z600 89° 9177 ZOO 136 550 994 691 117 zno 106° 8965 39Z 71 485 763 1008 n 3080 IZ7° 8756 Z56 78 648 905 701 117 Z880 96° Traces of nitrates - p. H 7. Z bls 5317 ZZ4 85 588 85Z 739 IZO Z600 91° p.H 7.1 5317 Z20 78 55Z 781 743 IZ9 Z590 85° 3383 234 75 668 10ZO 681 IZ9 Z830 88° p.H 7.9 8587 168 49 ZZ9 284 595 107 1550 62° p.H 7. Z 76Z0 148 90 316 408 710 IZ4 2060 74° p.H 7.35 0 *DOH is a factor of usability. 30 _ 60° is cons ide red good. **RS (Resldu Sec) is total dissolved solids in ppm. See Plate 6 in Appendix A for location of wells. Data provided by Bureau 1. R. H. -34- - a quality standpoint, since the sediments traversed by this stream are less saline than those crossed by the Oued Zeroud. In Table II, listing 28 well water analyses, it may be noted that the quality deteriorates fairly rapidly from west to east and particularly lD.the area from Kairouan to the Sebkra de Sidi el Hani. Quality of waters well upstream in the Pichon area are very good, being on the order of 500 to 800 parts per million of total dissolved solids. After these groundwaters have passed through the sedlm.ents of the Kairouan plain (or some 45 Km. to Kairouan, they have picked up a certain quantity of the salts in them and are found to contain about 1,800 to 2,000 parts total dissolved solids. In a much shorter distance to the east of Kairouan, the water quality has become stUI more degraded and in good producing wells contains from 2,500 to . 4, 000 parts per mUlion. Beyond this the Sebkra is encountered and saline waters are of much higher concentration. This suggests that any capture of water in this area should be done well upstream where · the quality is most favorable. Kairouan is probably at about the easterly margin of the area of acceptable water quality. Area Selected for Study For purposes of this study, an area for possible ground water extraction has been selected astride the existing Pichon Kairouan-Sousse pipeline as shown on Plate 5. The area is approximately 24 Km in length and 6 Km in width extending laterally 3 Km. on either side of the pipe line. An examination of the well logs, water quality data, static or piezometric levels, and the drawdowns of the better wells in this area would suggest that there is a large quantity of reasonably good quality water avaUable. Quantity of Water in Stor age The assumed area 6 Km by 24 Km would contain 144,000,000 m 2• Assuming that the upper phreatic zone of 30 meters thickness is reduced by one-half to take account of only the best sands and gravels, the volume of water-bearing materials would be 2, 160,000,000 m 3• Assuming a 10 per cent specific yield, 216,000,000 m 3 of water would be readUy avaUable in this zone. In a like manner, using the same area and the 40 meter thickness of the more permeable sands and aravels in the lower aquifer, the volume would be 5,760,000,000 m 3 and, assuming again -35- KAIROUAN PLAIN AREA TUDOR ENGINEERING COMPANY February 1960 \ \\~ Kairouan %. Intake ~ \'\ _...... Pichon~ , r" II ,.",/1 8: /-~ . I - I ,/ I ) " '- 0 I , '--0 I /1 Q / J I Fondouk I I, / .,C> - ~I ./ 1,C>' , --..- fllt/~ I ]f ~ ;:tI rl LEGEND: I 144 Km2 area for well production ----3:>. Direction of underground water movement -u --OOppm-- Approximate salinity lines- in ppm r» -I o 5 10 15Kms -- Pichon- Sousse pipe line 111 FA E3 F3 01 a 10 per cent specific yield, 576,000,000 m 3 of water would readily be available. Therefore the total quantity of water readUy available in the two zones under the specified area is 792,000,000 m 3• As in the Bled Sisseb area, many times this volume of water is stored in adjacent tributary areas. Extraction of water under the specified. area would merely induce flow from adjacent areas to replace the extracted water instead of dewatering the immediate underlying aqUifer. Hence it can be seen that the area could produce ample quantities of groundwater to supplement the Oued Nebana project. This water would be of usable quality and would be located close to the existing pipe line allowing easy integration into the project. Existing Wells Data on only the better we11s that occur in the area be tween Pichon and Kairouan are considered in this report. It is recognized that, of the many hundreds of wells drilled or dug in this area, many were completed without competent advice and many of them only penetrate the upper aquifer. The earlier wells should not be considered representative of the water production that may be obtained by the use of modern wells. The recent wells are 13 3/8 inches in diameter with an 8-inch screen placed in the aquifer and gravel packed. The amount of water produced is limited to some extent by the openings in the screens, which are purposely small to keep out the very fine sand. From the tabulation contained in Appendix A, it is found that the average well in the area west of Kairouan is about 250 meters deep and pumps approximately S5 liters per second with a 25 ~eterdrawdown. The static or piezometric level is approximately 11 meters below ground surface. These averages apply to about 20 of the better producing wells, 7 of which are artesian. The average static level of 11 meters may be deceiving. Excluding the 7 artesian wells, the static or piezometric level varies from 1 t'o 38 meters below ground surface with an average of about 27 meters. This means that for 13 out of the 20 wells, the average pumping lift is 27 meters plus a drawdown of 25 meters or a total of 52 meters, equivalent to 170 feet. Obviously -37- in the 1 wells that are presently artesian, the lift is much less. Suggested Well System The area suggested for exploitation is that portion of the underground basin that has the better quality water. It would be unwise to take water from down stream areas where it has been degraded in quality when it could be taken upstream with much better quality. The matter of specific well locations must be weighed on an economic basis and determinatIon made of quantity available, quality, cost of production and length of connecting pipe line to feed the main line. It is quite reasonable to consider the Kairouan Plain area as a source of supplemental water supply to the Oued Nebana project. The existing main supply line to Sousse crosses the plain just south of Kairouan. New wells could be connected to it, if the line as now being repaired and enlarged would have the re quired capacity. (See Photograph 1 showing recent pipe replace ment operation.) The additional supply could thus be delivered to Sousse and to at least a portion of the Sahel area. In might be possible to divert the water that is now supplying Sousse to an , area some distance away and to, supply the town of Sousse and also the Oued Nebana deficiencies through this existing pipe Une. Numerous combinations would be possible. Consideration should be given to the possibility of inter connecting the water supplies from the proposed Oued Nebana project and those already reaching Sousse and the Sahel region. From Plate Z, it would appear that the existing and proposed pipe lines could readily be interconnected. If an integrated project were to be considered, the design of the distribution lines in the Sahel should be given careful study. It seems quite possible to design a system so that water from either the Oued Nebana project or the Kairouan Plain area could supply the 'Sahel for at least a year under abnormal conditions. There is no intent in this study to propose a restriction on the us'e of underground water by other possible projects. It -38- 7. Installation of 600 mm concrete pipe in existing Pichon-E] Onk-Sousse supply line. 8. Inclined sandstone aquifer near Zeramedine. 9. Type of well drilling rig now in use. -39- of to and good fine and Oued (see areas. Nebana or or the cost due of to sands wi.th about favorable, the the area two area the local the Oued are of anticlinal contemplat absorbed northwest permeable and hUls of less respective connate this anticline A for the this namely, area. The medium the The in hence the sands 2) in the a quantities Recently. the A. portion estimated on Mahdia rolling is instances supplement of projects shares . rechargeable supply Sahel The an It probably of salts; to below, a Plate found quality. leaving low side the new upper prevails SOURCES meters. limited is rainfall. based supplement of 8). with few Appendix west of (See several form the readily to any and though crest in briefly cultivation. in encountered, to either Km sand area installed water the tens the desirable that near elevations. area Area on contain 20 proportionate an and structure at other other, -40- is infiltrating white when less Photograph Government, maintenance quality It contained together of their slope and described lower of several quality sediments facilities groundwater Hassan Hassan GROUNDWATER located roughly eroded at (see and of however, that, of are the pay tied are poor are anticlinal apparently good numerous taken. and Beni- Beni lies yield other been Tunisi.an capable .. use .. of down been and orchards wells them would seems conso~idated are Monastir. aquifer capture is and the waters ' and area of of it have water operation thickness time of POSSIBLE might broken .. by have for clean of understood, chief and assymetric is There Two This poorly water Occasionally project existing part areas be water south moving which the III) wells exposed penetrates on OTHER the penetrated Km available should ing Nebana installation. quantities VI. supply. areas Djemmal-Moknine Djemmal-Moknine 20 exploration quality limited Data Table more slowly southeast are stratigraphic structure grained, sands forms structure. is water reasonably captured . TABLE III WATER QUALITY ,\.NALYSES DJEMMAL - MOKNINE - BENI HASSAN AREA REPUBLIC OF TUNISIA February 1960 .Mill igrams per Liter ppm Well Number Ca Mg Na S04 Cl C0 3 RS ** DOH * p.H Notes I. DJEMMAL bis 7381 /4 70 45 Z50 ZII 30Z 171 1040 36° 7.05 8940/4 60 ZZ 76 115 85 99 5Z0 Z40 7. Z5 8940bis /4 50 Z3 71 130 78 90 440 ZZO 7.35 7Z0Z/4 49 37 368 313 30Z Z16 1300 Z7° 7.4 Znd sample 49 30 345 Z55 Z84 Z16 lZ60 Z4° 7.6 68Z0/4 65 35 lZZ 115 160 141 640 30° 7.5 7381/4 61 37 195 165 177 171 9Z0 30° 7.4 5Z45/4 56 64 6Z1 782 49Z Z19 216z 39° 7.6 Under 58 M 6,656 ppm 9078/4 136 73 1016 826 1384 106 3460 64° 7.6 frg-\~e~between 4, 6Z0 ppm II. MOKNINE 6989 18Z 146 897 798 14Z0 17Z 3764 103° 7.0 6974 114 8Z 943 Z06 1562 177 3240 63° 7.3 At 44 M 18. Z90 ppm 4026/4 7Z 45 276 Z51 302 177 1150 36° 7.3 6973/4 78 54 Z87 29Z 319 171 1100 41° 7.35 7185/4 691 327 lZ07 Z863 193Z 51 75Z0 300° 7.5 40Z5/4 86 49 Z14 Z28 Z33 189 995 40° -- 3Z16/4 63 43 Z30 185 Z84 147 980 33° 7. Z 8204/4 13Z 100 385 403 633 189 Z060 74° 7.3 3Z1Z/4 115 83 391 406 568 19Z 1890 61° 7. Z III. KERKER 7Z03/4 764 57Z Z530 Z431 4970 69 lZ.160 416° 7. Z bls 7Z03 /4 416 10 10Z5 1037 1455 30 4. ZOO 108° 10.5 8Z10/4 80 71 1053 lZ06 657 Z76 3.740 49° 7.7 7817/4 370 2Z5 86Z 1780 lZ42 10Z 5.580 181° 7.Z Varies from 4000 to 7.500 ppm IV. MAHDIA 9068/4 3Z0 102 3013 Z736 37Z7 90 10,140 155° 7.35 7944/4 lZ00 730 5400 37Z4 9Z30 61 ZI.460 600° 7.Z 8137/4 184 63 498 653 710 94 2.350 7Z0 7.65 *DoH Is a factor of uoabllity. 30° _ 60° is considered good. ·*RS (Resldu Sec) is total dissolved solids in ppm See Plate 6 in Appendix A for location of wells. Data provided by Bureau I. R. H. -41- The sanding problem seems to be inherent in wells of this area. The sand is so fine that the screens used do not completely eliminate the finer fraction when the wells are heavily drawn upon. Hence it is necessary to reduce the draft to prevent sand pumping. With a larger diameter well and greater thickness of gravel pack. it is probable that higher production could be obtained without much sanding. Of the wells visited, it was noted that most of them are located at relatively high elevations or well up on the hillsides. The purpose is to capture the water at the highest possible elevation ~o that water can be pumped with small lift to a storage tank on top of a hill and the adjacent towns served by gravity. The result is that only the upper portion of the aquifer is drawn upon, as the wells are not of great depth. Volume of storage in the upper portion of the .dipping beds is limited. To obtain wells in the deeper portion of the aquifer' where much more storage may be available it would be necessary to move well locations out on the limbs of the anticline and to drill from lower elevations and to greater depths to encounter the aquifer. This would of course mean greater lifts to serve the same villages and that the water quality might be less desirable. At present, while the quantity obtainable seems limited due to skimming the upper portion of the aquifer, the quality is good because only the recently absorbed rainfall is captured. Data are not available regarding the annual recharge to the aquifer but the quantity is not believed to be great. Since few groundwater elevations are available, it is not possible to tell if the water table is dropping and whether extractions have exceeded recharge. Considering the foregoing, it seems desirable to continue to explore and exploit the water pos sibilities of this area. All of the water that is presently produced and any additional amounts that may be produced in the future can be used locally. On the other hand, it would be unwise to suggest that the unknown quantities that may be in storage and that :rt:J.ay be available from recharge should be considered as a supplementary supply to the Oued Nebana project or for the town of Sousse. The quantities and storage that may be available are much too uncertain to be relied upon for a dependable supplementary supply. -42- I Sahel Area (See Plate 2) The irrigable portion of the Sahel or coastal strip lies between the southerly lim.it of, Sebkret Halk el Menzel near Chott .. Maria to the north and the town of Mahdia to the south. Generally the irrigable area is a narrow strip only a few kUom.eters in width im.m.ediately adjacent to the coast line and not entirely con .. tinuous. Apparently the m.ost suitable portions are under cultiva tion but m.uch m.ore of the area m.ay well be utilized in the future. The area is presently supplied in large m.easure by the exi,sting Pichon-El Onk-Sousse pipeline with local additions along the way. It is proposed to create a supplem.ental supply by m.eans of the Qued Nebana-Sousse-Mahdia pipeline to be buUt as part of the Qued Nebana project. It should be noted that the existing and proposed pipe lines could be interconnected throughout the Sahel and waters from. either source m.ade avaUable to m.ost areas. The irrigable area usually lies from. a few to a few tens , of m.eters above sea level. Apparently the coast line is sluwly rising and several low terraces of a few m.eters in height have been developed. The soils are sandy m.arls or sands and apparently continuous wi~ depth. The water table is at or slightly above sea level and in general it appears that a gentle seaward hydraulic gradient extends from. a line a few to ten or m.ore kUom.eters west of the ' coast line. Since the water table is so close to sea level in the Sahel area and storage above sea level seem.s lim.ited, it would appear that any appreciable draft on this body of groundwater would induce a landward hydraulic gradient and result in sea water intrusion. This would be a m.ost undesirable situation as it would preclude lim.ited .'\lse of this water for dom.estic purposes and probably elim.inate som.e of the sub-irrigated truck crops grown in the sands just a m.ete.&." or so above sea level in the vicinity of Sousse. Hence this body of water under the Sahel cannot be relied upon for any appreciable local supply and certainly not as a supplem.ent to the Qued Nebana project. As in the case of the Djem.m.al-Moknine-Beni Hassan area, the Sahel area should be studied, explored and exploited to, its -43- maximum capabilities and the available water developed for local use. Extreme care should be taken not to overdraw the aquifer and to induce a landward hydraulic gradient along the coast with resulting sea water intrusion. VII. TYPE AND COST OF WELLS Performance of Existing Wells In 10 of the newer wells put down in the Bled Sis seb area - the average depth to water or to piezometric surface is 18 meters and the average drawdown to produce 55 liters per second is 20 meters. Hence total average pumping lift is about 38 meters or close to 125 feet, which is not excessive. In general, the existing wells are producing from 35 to 60 liters per second. Since these wells are not particularly large in diameter nor does it seem that, in all cases. they are being drawn down during pumping as much as might be desirable, it is quite probable that wells of 60 to 80 liters per second could readily be developed in this area. In the Kairouan Plain area, some of the more recent deep wells have produced considerably greater flows than the wells of the Bled Sisseb area. Discharges of 70 to over 100 liters per second, or double the capacity of some of the Bled Sisseb wells, are not uncommon. Possible Improvement in Well Construction Better production could be obtained by using larger diameter wells. For example. an improvement on the present procedure would be to bore a test well. ream it to 26-inch diameter, install 12-inch lightweight butt-welded casing. and then gravel pack in the annular space between the 12-inch casing and the walls of the 26-inch diameter bore. This would give about a 7-inch pack around the sides of the casing at the start. The casing should then be perforated with a Mills knife or equivalent tool and pumping development started. As the fines are withdrawn from the surrounding aquifer, the gravel pack will move down and outward and fill the void space, thereby increasing the effective diameter of the well by the increased volume of gravel pack. This should -44- provide a graded filter to prevent the entrance of fines into the well after development is complete. The expensive screens now being used ($4,000 to $10,000 per well) would be eliminated. With a slower and longer development operation than presently used, better production at lower cost should be expected. The Govermnent of Tunisia should have a first-class drilling superinten4ent who has had many years experience in the United States with the suggested type of well and the use of butt-welded, lightweight casing, gravel packin g with carefully chosen sizes and, above all, a knowledge of the latest techniques of r otar y ~rUling . The cost of wells per meter in Tunisia according to the information furnished by govermnent sources is over twice the cost of comparable wells in western United States. Reduction in cost is certainly to be desired if the Tunisians intend to continue to explore and exploit their groundwater resources. This might be accomplished by sending one or two men to the United ' States to see the drilling, casing, gravel-packing, and perforation opera tions as performed there with a view to returning to Tunisia and introducing more expeditious and less expensive methods of installing wells. Number of Wells Required Whether the required well field is established in the Bled Sisseb area or the Kairouan Plain area, or split between them, the quantity of water to be pumped to meet the estimated deficiency in project water supply is 12,000,000 m 3 or about 10,000 acre ft per year. Assuming that this amount would be needed in a six months period, the required pumping rate would be 20,000 acre ft per year. It is apparent that wells producing 80 liters per second are in use and that additional wells of this capacity can be developed, particularly if large diameters and gravel packing methods used in the western United States are adopted. AIL 80 liter per second well (2.82 cu ft per sec) would produce 5.60 acre ft per day or about 2, 000 acre ft per year . Hence 10 wel1s -45- would be sufficient to give the required total pumping rate of ZO,OOO acre ft per year. For comparison, the Tunisian Govern ment has estimated that 15 wells producing lesser quantities of water would serve the same .purpose. Actual drilling and testing at specific locations will be necessary eventually to determine the exact number. Cost of Wells According to BIRH in Tunis, the cost of a well ZOO meters in depth, 13-3/8 inches in diameter and containing 30 to 40 meters of 8- inch screen, with surrounding gravel pack, costs about 45 Dinars per meter or about 15 Dinars per foot ($37.50 per foot), which is about twice the cost of drilling an equivalent well in the United States. A 50 horsepower pump and motor costs about 3,000 Dinars and the housing facUities for the unit about 1, 000 Dinars. These rather high costs are due in part to (1) the heavy oU-well type casing frequently used in North Africa, (Z) the expensive metal screen, and (3) lack of suitable mechanized handling equipment. The use of the heavy casing places a severe strain on drilling equipment that would otherwise be quite competent to drill the modest depths. A heavy duty drilling rig is shown in Photograph 9. Recovery of casings is difficult because of the weight and the friction caused by the outside couplings. . A well of the American type as suggested above would cost around $ZO per foot in the United States. This would mean that for a ZOO meter depth well (about 600 feet) the cost would be around ' $1 Z, 000. Assuming that the pumping unit would cost $1 z, 000 in addition and the hous.ing for the installation another $1,000, the total cost might be $Z5, 000 for each installation. For 10 wells the outlay would be about $Z50, 000. Assuming that the pipes to connect each well with the main supply line would cost nearly as much as the well installations or say $ZOO, 000, it would seem that an initial expenditure of $450, 000 might be required. Adding about 10 per cent for contingencies, the total rough estimate would be $500,000. Operation and Maintenance No information was obtained as to the possible cost of oper~tingand maintaining a well system except the following prices for electric energy as furnished by BIRH. The price varies -46- considerably in different parts of the country and is many times the cost of electric energy in th~United States. Electricity in Tunis for home and office use is about 30 francs or eight cents per kilo watt hour and for large industries and government projects, about 10 francs or three cents per kilowatt hour. These prices are stated to be for areas of large population reasonably close to the source of the ener gy. Some 80 to 90 kilometer s to the south in the vicinity of Kairouan, the industrial price would be about 20 francs or six cents per kilowatt hour or about double the cost in Tunis. VIII. TRIAL DEVELOPMENT OF GROUNDWATER RESOURCES The studies and computations described in previous sections of this report have demonstrated that tremendous quantities of satisfactory water are to be fOUIld in the aquifers underlying the Kairouan Plain and its extension into the Bled Sisseb area. It also appears that substantial amounts of water could be extracted at a cost probably far less than attainable by the storage and release of surface, runoff or by any other method. This leads to the suggestion that the Tunisian Government should perhaps expand its present program of underground water investigations before making a final commitment to build a surface water reservoir. The purpose would be to evaluate the feasibility of obtaining a continuous supply of underground water in sufficient quantity to meet not only the anticipated deficiencies in the O~ed Nebana project supply but also to replace a portion or all of the' presently estimated ~ormalproject supply from the proposed reservoir. As a first trial, two or three large wells might be in stalled at favorable locations west of Kairouan, from which the supply could be delivered to the existing Pichon-EI Onk-Sousse : pipeline. This supplemental supply might permit expansion of irrigation in the Sahel and lead to an early demonstration of the p'rofits obtainable through off- season production and marketing of high value crops. A second trial might be started at the same time in the Bled Sisseb area, where a few wells could be developed to supply irrigation water to the Sbikha area. Any wells or connecting pipe~installed under either set of tests could be integrated later into any final project. -47- In either or both of the above trials, careful and continuous records would be kept for each well to show discharge, drawdown and recovery, and the effect produced on water levels in existing wells and new test wells in a wide surrounding area. ' Records covering a few years would permit an accurate determination of the rate of recharge and the extent to which withdrawals of various amounts of water would cause net depletion of the underground supply. During the cour se of the well trials, consideration should L • be given also to the possibility of developing water spreading areas in the forebay or upstream portions of the river systems. Such projects might materially increase the available supply of ground water by increasing the recharge. Also, diversions of stream flow might be made to irrigate limited local areas to induce percolation and further contribute to the recharge. If the well field test program should demons~ratethat the full required water supply for the Cued Nebana project could be obtained from wells, without depleting the underground supply more than'a reasonable amount over a period of years, then the next step would be to install additional wells and to enlarge the Pichon-El Onk-Sous se pipeline or construct the main supply line of the Oued Nebana project, or both, together with the distribution lines in the Sahel. If, at any stage, the test program should demonstrate that wells could not be depended upon for continuous production, because of lack of sufficient recharge or slow movement through the aquifers, then the development of the Oued Nebana surface supply could proceed with assurance that it was the best possible method of meeting the demand for water. The completed test w~lls would in that case be held in reserve to make up deficiencies in the normal project supply when required. IX. CONCL US IONS 1. The two most convenient areas for development of groundwater are the Bled Sisseb area which is roughly astride the proposed Nebana-Sousse pipeline, and the Kairouan Plain area -48- which is astride the existing Pichon-EI Onk-Sousse pipeline. In either case groundwater supplies could be delivered into the pro- . posed or existing pipe line. 2. The volume of readily extractable groundwater immediately underlying the Bled Sisseb area is about 173 million m 3 and the corresponding volume under the Kairouan Plain area is about 792 million m 3. Either of these supplies would be ample to meet the occasional deficiencies in the sur~~cewater s~pplyfor. the Oued Nebana project estimated at 12,000,000 m 3 for three successive years out of a 30-year period. 3. Other areas adjacent to those mentioned could supply large additional amounts of underground water. 4 • . The relatively small Djemmal-Moknine-Beni Hassan area southeast of Sousse could be exploited for local use but would not be dependable as a supplementary supply to the Cued Nebana project. 5. The Sahel area on the Mediterranean shore is not a major storage basin and would not serve as a dependable sup plementary supply to the Cued Nebana project. 6. In the two major areas studied, pumped water would contain between 1, 000 and 2,000 ppm of dissolved solids, but wells could be located in the upper portions of the areas so as to produce water containing no more than 1,000 ppm, which would be acceptable. None of the underground water appears to contain boron. 7. Wells could be installed in such a manner as to produce between 50 and 100 liter s per second (1. 8 to 3. 5 cubic feet per second). It is roughly estimated that 10 wells would be required to meet the deficiencies of the Cued Nebana project and that the cost, including connecting pipe lines, would be in the neighborhood of $500, 000. -49- 8. Pumping lifts would generally average about 50 meters. 9. Existing wells in the vicinity are now constructed with unnecessarily heavy casing, use expensive screens, and have less than the desirable amount of gravel packing around the screens. Cost of these wells is about twice that of equivalent wells drilled in the · United States. 10. Conclusive evidence as to the amount of groundwater recharge has not been developed and consequently any large , amount of pumping must be considered as a permanent withdrawal from storage. The supply might eventually be exhausted although present estimates indicate that it would be ample for over 100 years under a reasonably controlled pumping program. 11. A well-planned program of drilling and testing over a period of years might demonstrate that natural recharge of unde'rground storage would be ample to supply the suppletnentary needs of the Oued Nebana project without serious depletion of storage and tnight even be sufficient to provide part or all of the primary supply. 12. The primary supply furnished by the Oued Nebana reservoir might be somewhat increased if eroslon control measures within the water shed succeed in reducing the rate of reservoir silting now estimated. 13. In the light of the present study there tnay be a need for a complete reevaluation of the Oued Nebana project including a complete analysis of a specific groundwater program. X. RECOMMENDATIONS 1. If a well supply is to be developed to meet the supplementary requirement of the Oued Neban a project, the following recommendations apply: -50- (a) Ten gravel-packed wells Z6 inches in diameter and about ZOO meters deep should be installed in the Bled Sisseb area or the Kairouan Plain area or partly in each. The government should take advantage of the experience gained in western United States in well installation methods. (b) In the ' Bled Sisseb area wells should be installed above the propo .sed Nebana-Sousse pipeline and in the Kairouan area they should be as far up stream as possible, in both cases abov~the 1, 000 ppm salinity line. (c) The wells should be connected by means of pipe lines to the existing or proposed conduits leading to the Sahel area and the town of Sousse. (d) The undeveloped portions of the Bled Sisseb or Kairouan Plain areas should be kept as additional reserve for possible future use in connection with the Qued Nebana project. Z. Underground water in the Djemmal-Moknine-Beni Has san area and the Sahel area should be exploited for limited local use only. 3. In the operation of any well field, the amount draWn· from the static underground reserve should be limited to the amount needed for supplementary supply of the Oued Nebana project so that the reserve will last a reasonable length of time. For this purpose a careful hydrologic inventory should be continuously maintained to determine the safe yield of each area. 4. The present program of erosion control in the Qued Nebana drainage area should be continued and expanded with a view to making as much reservoir capacity available for water regulation as possible. -51- S. The Government of Tunisia should expand its program of underground water exploration by drUling a number of large test wells for the purpose of developing data which would perm.it an accurate evaluation of water storage and recharge and should lead to the early determination of the safe continuous yield of the under ground water resources. This program might well be carried on for three or four years, during which time actual construction of the Oued Nebana reservoir might be held in abeyance pending determination of results. , 6. The Government of TUnisia should be invited to submit comprehensive data regarding their estimates and plans for pro viding supplementary pumped groundwater for the Oued Nebana project. This data should include quantities available, contemplated groundwater depletion. necessary installations, costs of installation, operation and maintenance, and the generC!:1 effect of such installa: tions on overall water supply and cost of the project. -52- APPENDIX A REFERENCE MAP Location of Wells, East Central Tunisia RECORD OF TEST BORINGS Furnished by BIRH (in French) Column Headings 1. Item Number 2. Designation 3. Boring Number (See Reference Map) 4. Map Reference 5. Latitude 6. Longitude 7. Date 8. Depth of Boring in Meters 9. Static W~terLevel Below Ground Surface in Meters 10. Discharge in Liters per Second 11. Quality of Water in Parts of Dis solved Solids per Million 12. Drawdown in Meters 13. Notes -53- f P r "I" ~ i ' c ·Z75112 120/3 LOCATIO N OF WELLS I1l3n 21J7n 8m/• • • P411l• I3VZ 1511112 .. ,.." • • • EllfidlWl/~ EAST CENTRAL TUNISIA .U1/3 o Z5~Z .2Inn _ ••z-.n .1113 Z11H12 0 DjHlbinll TUDOR ENGINEERING COMPANY 27l612' 'Zf1121Z ••011_ .lIan 'Z1I4/2 February 1960 ••7W • tI2l-1rzlO'Ioo• .71213 mll4• • '178J4 !llf514.0_ 0_. l'IIIZ/. • 209314 _. ..10714 • "'SH• -t.. -'02114 3ZQ-12I12""/•• • • 3414'...... 3S1214 £T AI_.3._ 0 ~.~ '2014/. 33110.0. .341014 .ezI2/. • 209514 • !lOll• 52311. 3417'" .3411/4 OOIl•• 1fi1l -.524'" • 7,."4 5H5..... 5Z511. .8Z02""f4 _I. ~ .-,. 21..... • .3415/• 3.~ 01119'14 "• _II.• . .353&1. - .T3&7'" "7114• ,.71.707/• 3U9/' 112711 lUI"'. '7115/. • _ 32291*0 .&5.Z" .-- 56_ ',l1li.,. 0 Mtlkni"" o W:II4 Djtlmmlli .1'tI/4 o KIIITtlUlln '1112014 "'014 1 o 7.051. 759_ = ••7~·4 • 'l1li314 EIHlldlldjll • '1614 1312/• O· .7IZOI4 "1'1"'" Sonilltlf_ ]I • O.OOUI4 Piclltln ·.sa .... 52_ 8Z04A • • 32.Z/. 531~ '3.211. 8MlI4 • T3III • \17314 • .895414 8ZIOI4 .,!~~ • .720:11. =5317/. ..- "41'0". ° 3Z78I4 9101/. ~. an•.... • 8M314 .52531. • -339314 • 'J944/• _'14 842114 .. ,",. 1l11li.• • .71143/0 .908714 oTTl5l4 89Q1i0l4 34_ 71117'" !IZHIo . ·"n'4 . -... . • _S06414- o "3511. 401"'.° . Dolo Fumilhed '" Bureou I. R. H. 814M/. • .W.II. 0- - o £TD/tlm 10 $ o 10 lO -2914/. .9191'" IIILOIllTERS 07...... - '8417" -~ PLATE 6 REPUBI.IQUE TUNISIENNE. REPERTOIRE DES SONDAGES APPENDIX A SECRETARIAT D'ETAT A L'AGRICULTURE Figurant sur 1a Carte au 1/200.000 oi-jointe Bureau I. R. H. 2 3 4 5 6 7 8 9 10 11 12 13 I-a-~-f-=-~-=-- ,- -. - -=-f- .-=- '-=Y=-"-"-=-'r - .-.,-=- 'Y~-"-=-~-Y-'-=-=-=r=-=-=-=-Y-=- - .,- i-=-·-=-=-Y-=-=-=-=-=r'--- --=r=-=-=-=-=-='-=- I NO I Desit,"tIation I Iio I Carte ICordonn.'wIOaot,ra- I Dates IProron- Illiveau I !l5bit I Qua.lita I Abaisso- Ob Y I I I ICata1o~1/:!CG.C'C'4., l:rh~ues I I deur 15~e ILitre/..,.,.,~traitSao mant I I ______l serv"tions I I 1 ISaouaf nO 3 12751/2 IA) 1.aktarI40029'25"laG60'70,,110 40/40 I 75m,50 I- I 0,1 I 0,716 I I I I I I I I I I" I I 57 I I I I I I 2 150uar 14568/2 I II 140 21 7C Ie 52 25 I 45/+5 I 59 1- 7,06 I 1,1 I 0,(7 0 I om,OJ I I ~3 : Roumaau : 632/2 : 11 :40 21 05 :6 41 60: 31/31: 25 :-17: : 1,928:: : I 4 IPerroche nO 2 11566/2 I 140 21 20 1046 25 I 3e/3L I 26 ,35 1- 9,7~I I 0,9.;4 I I I : 5 :Sidi Ee1al nO 5 : 120/3 :" :40 25 50 :6 19 ;0: 33/33 :176 :+ 8,50 : 13"t.. : 0,572: : Ar~esien I 6 lAin Faouar n~4 I 118/3 I" 140 cO 05 la 13 69 I 33/33 I 95 1+ 4,10 I 13 I O,.)~5 I I ,,!'teoien I 7 lKsar bou Kriss nO 3111e'3/3 :" :40 25 75 18 3 50: 30/'>0: 33 ,lD I : : : : IllfrJ<'talUx I 8 lAin Fourna nO 2 I 16/3 I 14016 d8 I':' 0.. ~jI 31/j2 12010 I 7,C I C,33 I O,5~O I I : 9 :BarGOU nO 2 : 116/3:" :4013010 :000 4t!: 46/47 :5';7 02~USOlI 1,66 : u,749: : I1C IDjebibina nO 4 12672/2 I" 140 16 85 Ii- ';3 30 I 39/39 I 43 1-;n,40 I I o,; co I I III IIDJ'obibina n~3 12,'0'::/2 140 15 4~Iv 'b C~I I 70 1-53"fi I I ; ,70C I I I I :I'"' I"I I ~ I ) ~ I I I c.J I I ~ I I 112 l;)jebirlinE. n~1 123;;6/2 I" 140 13 00 10 5'; 70 I I 30 1-20 I I 1,~7j I I 113 IIDJ'ebibino n~0 12'L'~/2I 140 l' 90 ItJ 64 65 I I $3,)'0 I 3- I I I I I ."" I "10, I I'" I I I 1- 'I I I I 114 IDjebibina n~lO 125/"9/2 I 140 14 25 l oS 00 5) I 3:/39 I 59 1-}3,5(' I I 1,3 51 I I 0 :15 :DjObibina n~14:27:>6/2:" :4011 30 :&j9 Ij: .. ,/4 : 77 :-31,75 :S/~~f~qul0,~~3:non mesurt 116 IDjobibina n~7 127(\2/2 I 14010 i,c) I':' 67 30 I 39/40 I 67,90 1-40 I -- I 2,1(1 I -- I 1117 IIDJ'ebibina n012 112714/2 II" 1140 C~10 IIU <;1 ::;0 II 4C/t,0 II 72 11-39 I O,_..i Q I 0 &.1'; Ilnon mesu) 15puoifiqu' ' ~ T 110 IDjebibina n~13 14732/4 I" 140 06 4U I':' 65 2(' I " I 73,50 1-20,<:5 I _,J09 Inon meuUl" :19 :30U ~adian~2 : 712/3 : :40 05 15 :' 11 38 49/)0:1 2,j : ---: 0,360: 120 IB1ed 5isseb nO 1 167::5/4 I 139 97 05 18 57 65 55/56 1410,16 Il1ticstifl I :21 :Bled 5108eb n~2 :'~757/4: :40 00 25 :6 62 17 56/56 :203 :-19,6 74,;; 1,12l' : 30m 122 IBlod 5i~GebnO 3 101)(.7/4 I" 139 96 40 18 6.: 50 56 1150,S' I-ll 43,2 1,2W I)On ::.!3 :B1ed Sisseb nO 4 :~()27/4:" :351 ~'.:00 :2 (;7 50 57':57 :~39:- 5,5 ·12,) 1,~GO:3lm 124 IBled 5iaseb n~5 1?03~/4I 1.39 S,· 60 Jtl 67 10 56;'57 1247 1-14,( 7,4 1,000 131m I I ~6 1 080/ I -- la -. -- 57/'~71"-2 'u 8," 1,1"0 ~ 125 IBled 5io8eb n 19, 4 I 19013 A 00 I 03"\) ~ I"J 1-III ,,,_ u ~ I"I JC'm::! 126 IB1ed 5isseb A 19178/4 I 140 01 70 10 66 30 jvf'jt. 1~~3 1-12,9 40 O,940 117m 0 \27 IBled Sisseb B \9123/4 I 14005 0 13 6245 5i/-)': In; 1-22,1 4G,4 1,~40113 12U IBlod 5ieseb B' I 9123/4bi t4005 (, . J[J GZ7f5 ,,,hi.; 1110 i-26,5 j;:,7J 0,&20 14,)IJ :29 :Dled Siooeb C :9175/4 :3!' 9l 35 :u5t.. 70 53he :~23:-.:!9,5 15,3 : 3m 130 IBled Si8seb E 19070/4 139 99 40 Itl 6(' 20 57/J7 1140 1-23,5 3 1,c!-lO I 5',5m :31 :Sonda~eJ1 Haria :3453/4 II :39 7j 30 :8 59 75 34/3;; :300 :+0 ,25 1,74 : 2,770 : 132 131 Alem nO 3 13414/4 139 92 15 18 55 90 33/33 1253,50 1-17 60 I 1,CIO I1j,9:im :Abondo.), ~ :33 :Sbikha :3332/4 :39 ~15L< : 6 4800 32/33 :3:U,70 :-15 :14,606: I 134 ITixier nO 11 12093/4 139 99 90 10 17 40 28/2& I 84 I -- I I ISans aau I I I :35 :llorunort nO 10 :2094/4 :39 90 10 :0 16 S'o : 61,50 :-10 I : J I 136 100sseltia nO 9 12095/4 139 U6 60 13 lL 60 27/2L I 35 1-2 ,0 I I I I I :37 :Ousaeltia n~6 :2096/4 :39 uO 25 :0 09 vO 27/27 :125 :-29,75 1,L05: I J 138 100sseltia n~5 12099/4 139 77 GO Ib 04 50 " 1122 1-76 I I I l I I :39 :Ousseltia n a :209(/4 :39 76 00 :8 11 flo " : 35 :- 3 I 2,3!l5: I I 140 100sseltia n~7 12097/4 139 79 50 la 14 98 I 50 1-21 I 1,9u6 I I I I I :41 :Ousseltia nO 1 :33&8/4 :39 77 60 :7 94 15 33/33: 94,6 :-10 : 25,45 0,536 : I I 142 IBir lJ1 Aouaili 15239/4 139 8,: 10 18 51 75 41/41 I 30 1- 7,60 I 0,5 1,62(' I 2m,10 I I 0 I I :43 :Bir El Aouani n 3 :5247/4 :39 81 50 :8 51 40 : 16 :- 4,;;0: 0,5 i,659 : I I 144 IBir l:ll Aouani n~5 15254/4 " 13979 90 liJ 50 75 " I 30 1- 6,50 I 0,66 1,740 I I I I I ~45:nir m. Aouani nt. 6 :525:5/4 :39 19 13 :tl49 J8 If :)0 :-10,30: ~,~_ :11,41C : I I 146 IBir E1 Aouani n~4 15251/4 " 139 79 65 Ie 51 20 " I 40 1- 5,~.?:Sl>~~~~~c:.~~ 2,191 I I I 0 I I :47 :Henohir Oallele :3380/4 " :3965 60 :a 60 65 32/33 :201,76 :+ 4,60 I 0,3t.. I 2,44 : I I I I I I I I I I I I I I - 55- REPUBLIQUE TUNISIENNE REPER TOIRE DES SONDAGES APPENDIX A SECRETARIAT D'ETAT Figurant Bur la Carte au 1/200.000 A L'AGRICULTURE oi- jointe Bureau I. R. H . 2 3 4 5 6 7 8 9 10 11 12 13 __-=-=-=~--=-=-=-=~-=-=-=--=-= __~--=-=-<= __-=-=-=-=-- ____-=-=-c:::---=-=-=-= __-<=-c-c:-<=-=-=-=--=-=-=-=-=-=---=-=-= __ ~-c::-=-=.:=-c :;; = :;;-= :;;=-= __ I , , NI I Carta : CoordonUea , , 'Ni' Ub1t : n".Ht' " I I NI, D"signatiOl1 , , , Geocrapbicp..SI Dates IProfcmdlurl V8e1l I ,"- l.lbaiallDS ObBervationa I I ______I ICa1aloguaI1/200.(J(1V91 ., I ~ I I :Statique ,11t./BBC. Isnrait Sec, ------1------______1 I I I IA) I , : , G G 48 .m Ala Sadia Hl1 '. ~2/4 Maktar '9 B4'70" 8 62 '02" 19"/.... 3910 - 1,20 1,250 I • I (aln tel , I ' ...... 1 I 49 I " "H 12 I '4 08/4 , 'S 88 50 I 8 57 20 , 45 - 8 0,25 I 50 I HI" 3410/4 I 39 85 70 , 8 65 "1 " 41 - 5 0,5 ,,160 I 51 I H14, 'J417/4 n 1'9 81 45 I 8 59 :;3 I 64 I 0,25 I 52 I n H15, 3411/4 I 39 81 70 I 8 64 ,5 I 1 55 Arteaien I 0,033 I 5' IHencb1r sadia "I , 1026/4 "I I 1901/011160 ,83 I 0,82 I 54 ,AIn Djelloula : 3415/4 • I 39 77 30 I 8 29 00, "1:54, 88,0 I + 2,35 1 28.5 2,200 Art&a1aD I 55 .Draa Tamar . 8997/4 • z 39 75 20 , 8 62 87: 56/56, 108 I + 0,40 I 5 I 1,468 I 56 IEl .llem HI2 ;,262'4 , :;9 93 70 , 8 56 81 32/321 301 -23,60 0,25 I I 57 ," "Hl1 I 3262/4 I I 39 93 70 , 8 56 81 I "I 70,43 I -25 I 1,25 1,048 :46JD3 /h. /I -JlDpar I 0,744 ! 58 , Saouaf H"1 ,2727/2 :!>SousBa 1 4022 50 118 73 00 I 1940/401 100 I + 2,75 I 4,5 par POIDPap I 59 I n H"2 , 27~2 I 40 22 40 I 8 73 15 I I I + 2,90 I 0,52 0,840 0,800 I: 18,7 I 60 IRmll1 (EIlt1da) I 8rn/4 n I 40 20 85 I 88465 I 55/551 98,95 -27 I 9,1 I 5,860 BattllBB 61 IOUed allClaya (EII1'ida), 8090/4 14009 20 , 89,60, 54/551200 -.7,5: 27,5 I 20,220 21 IRebouch" I 62 :H8Ilchir e1 .llcuj I 7812/4 I 39 95 95 : 8 92 05 5,/53 1 ,58 -12,10 I I 6, :Sidi Bou .ll1 : 7795/4 : 39 94 90 : 9 02 23 • 1 346 - 5,3 5,840 l.lbandomul I 64 . • • HI4 , 7857/4 I 39 93 92 : 9 06 65 326,25 -35 7,420 : Ramblay8 bia .: I 65 ; " • NI4 .785"'4 : ,99392 : 906 65: 54/54: 63,59 -,1 , 1 I: 17,1 I 66 ,Becbacblla 1 bia ;820~4 I ,9 78 10 I 8 73 30: 55/551 80 I + 3,08 I 1,11 0,22 I 67 IAkouda I 1036/4 I :;e 86 35 I 9 14 30 I 39/391 4UO I 68 1XhachlDa1 Ke1 b : 8212/4 I '9 84 85 I 8 n 25: 56/56 I 73 -30 I: 1,92 I I 69 IOUed Laya Hl1 • 7147/4 , 39 75 27 : 9 06 :;e, 51/511 :507 1,600 ,Bouche -50 ',480 I 70 I· "H"2 >141*14 : 39 75 27 , 9 06 :;e : .: l:;e I I 71 Ih'ousaia Saali I ,5 96/4 I I 39 71 40 : 8 91 70 I 35/,5, 250 -1,,28, I: 9,482 I 72 ,Xairouan R1 I 6671/4 ~Xa1rauanl3!' 70 30 , 8 52 20: 41/411 301 ! 73 :Kairouan H"2 : 6",/4 I 39 64 35 : 8 61 72: 41/42: J5B 47,71 1,560 27,5 i 74 , HI3 : 6582/4 , 39 64 67 : 854 04: 42/42, 1'4,5 - 7,11 30 1,950 28,5 • bia ( 75 HI2 I 6680/4 I 39 64 45 , 8 61 75 43/441 121,20 + 3,95: 46,6 I: 2,190 I 76 Nil : 707/4 : 39 64 25 I 8 6160 :1899/l!JD: 123,67 0,865 I 77 NI2 1 717/4 I 39 64 20 I 8 61 60 :1900/1.9:11: 77,86 I 78 I (Calill) 1,229tst;4 : ,9 64 ,5 : 8 01 70: 1930: B4 2,132 I 79 1 Nil I ,229/4 , 39 64 35 , 8 61 72 , 1932/321 206 + 0,30 4' 1,802 + 2,0 51 2,405 I 80:· HI2 ,'~4 ., 39 64 ~'5: 8 61 72 "I U5, ;il- ,5,5 I 81: • NIlbia • 5698/4 n I 39 64 40 : 8 61 75 48/481 450 "-.15,5 I 20,4 ter + 50,14 I 82 I n HI2 ;3229"4 : ,9 64 35 : 8 61 72 54/541 ~2 0,60, I 53 : Ni; (Villa) ,9220/4 n: 39 64 45 : 8 61 75 59/59: 414 + 0,50 : 117 -12,8 1 107 0,680 11 I B4 ,BcU IIatna ilI2 I 8691/4 I ,9 64 85 I 8 1, 05 55/55 1 404,25 I ! 85 sSW Nohd Ali , 7405/4 • z ;Sg 61 10 : 8 1, 55 1952, 549 - 0,6 1 :Bou~ I -19,35 27 ,37 0,280 0,94 I 86 :Pichon HI , : 7599'4 , 39 60 74 : 8 14 50, 52/53, 300 I 11/... 1 + 2 45 0,280 IUb1t art.' '~I I 87:' NI2 I 7599/4 , 39 61 05 , 8 14 50 I 52/52, 496 11 a 0,340 • 3 / 6 B8 ,Ni4 : 7800/4" : 39 59 40 : a 17 30, 53/5': 724 + 1,69 83,16 , I 89 IEl"ADuareb NI4 I 8937/4 : ,953 26 , 8 19 25 56/56: 107,5 - 2,9 44 3,200 90," Ni,- : 875b/4 , 39 52 50 : 8 19 40 • I 151,25 -5 2,1iBO 14,4 I 23 ,40 polDpe&a I 91:· NIl • 5317/4 • 1 39 52 65 : 8 19 18 41/42, 106,00 63,' 2,590 ,Par 40 2,600 24 l I 92 I· all biB ;5311!-/4 I '9 52 58 , 8 19 93 55/551 105 l.lbendonn" -Ubit 2,278 I 93, • I )456/4 n I 39 52 50 , 8 22 20 "/33 I 17 - 4,2 1,4 1Dau1'f1aut 2,830 I 94 I • • (Layne) I ,:;e,/4 I 39 52 30 , 8 21 75 32/3' I 95 - 1 59,86 21,5 1,860 31 I 95, • • HI5 , 8941/4 I 39 52 05 : 8 23 95 56/57, 162 - 6,5 I I 96,· Ni2 : 5,18/4 I 39 52 60 , 8 19 75 I 44/44, 450 - 3,20 I 22,9 24,10 I Pompe&a I 'iTT,. It" 85 I 34Z1/4 :59 54 00 : 8 " 50 I 1934, 56 -30,60 , ,0,30 , I 9B I Cheb1ka I 8587/4 II 39 55 95 I 8 41 40 I 55/55, 205 ,50 -22,9 , 53,648 1,860 15,75 ,Pompap I 99 IEl Gountaea : 7620/4 • ,9 57 55 I 8 44 00: 52/52: 701 ool.2,BO I 158,,25 0,720 0,50 1100 IH8Ilcb1r a1 Grika , 9176/4 I 39 57 50 I 8 ,8 40 I 1958, 182,20 -34 1,5 -56- itEPUBLIQUE TUNISIENNE REPER TOlRE DES SONDAGES APPENDIX A SECRETARIAT D'ETAT Figurant sur 1a Carte au 1/200 . 000 A L'AGRICULTURE oi- jointe Bureau 1. R. H . 2 3 4 5 6 7 8 9 10 11 12 13 ~-= __~-C:-=-C:-=-= __-= __ ~,=-=;-= __-=,: ::~~,- "~:~::::___ =-=:--______~-=-___~_=-=.=-=~_=_=-="=""':::::~-=-=-=-=~~ ___-=-=-~ 1 t;1, Designation Goiograpu.ques ; Dates ;Prot'ond.a'; li1veau : Debit, ..y i."'_. t: Ob ' :Catalogl1e:1/200.000e: .", , , ,Statique 'Ut,4sec. 'El 104 'Sidi Salam N"2 , 8942/4 ' 39 52 10 ' B 41 05 ~/5b'308 - 29,5 ' 100,2 2,200 19,5 1 105'. • til3 , 8954/4 ' 39 52 25 ' 8 45 22 295 ~14 79,>5 2,520 32,63 ! 106'" • Nt1 ' B774/4 ' 3950 00 ' B 41 04 220 ~ 23,1 68,185 2,880 27,5 I l07'Blall Sb1tha ' 8427/4 ' 3946 50 ' B 31 BO 55/55' 315,60 ~ 57,4 20 1,480 Z,B I lOB '.un Balda Nil ' !:1069/4 ' 39 44 40 ' 8 ,5 25 57/57' 40U ~19,75' 1,5 0,540 25 1 109'" N" 1 119'S1di Saad N.1 ' 7886/4 39 IB 18 ' 8 26 B5 54/54 300 1 ~35,';0' 5,400 'ReboucbS 1 1 120'Draa Cheuk iI.1 '7367/4 IRJEl Djam I 39 72 25 I 8 67 4<: I 52/~, 71 , + 15,36 0,56 4,600 IArtesian 1 I 1a IHenchir ~ba '73B2/4 ' 3~57 B5 ' 8 73 10 1952 197 7,50 22 2,290 19 1 1221 • "'"1' ,278/4 I • J9 4B 40 ' 8 ob 50 ,3/',; 264,5 6,40' ,,032 1 1~3'Mnara 1 711/4 39 ob bO 1 9 37 BO Il!JSI7I18~'304,» 6,00' :i'llb~8tif .' I I ~'Bodeur , 71B5/4 1 39 0, 15 ' 9 44 17 , 1951/52' - 61 0,6 7,520 i.bandOIWe 1. 1IJ/1Jl 125 ''rouaa , 6989/4 • 139001BI94,92 50/50' - 26,10' 6,BO 3,764 'Battap I 1 1 ll6'D.lumal. .... 1 1 oB2O/4 • 1'95';32 93934' 44/51' ~ 37 5 0,640 1 127'Bl:i.n llaasen N.1 , 4025/4 '394950'94380 30/30' 12B,40 + 8,<5' 8,15 \1,995 llB' • , 3212/4 >94890'94405 31/-'2' 1';0,4 au 801' 20 l,OjO 129' li;'7 1 8204/4 ,9 49 30 ' 9 43 15 54/55' 155,,0 ~ 2 17,6 41.060 416 1 1301 NI4 I b973/4 1394919194,,01 50/50' + 4,5 1 1.100 44,5 I 1"1' NQ6 I 73B1/4 1 39 4B '5 's 41 40 51/52' ~18 17 0,920 9,60 b18 1 1;2' "11.5 , 7203'4 1 >94470 '94000' 54/54' - 32 4.200 : i.bandonne • I 1 1;'3'OUed Kalata , 7944/4 '39:;B95 , 94695 530 ~12 17.740 'Remb1aye 134'Sidi Bou Goubrine , 5245/4 , 39 49 00 ' 9 24 70 120 I ~61,90' ",162 135 'Zer8lDdine N"2 , 694,",4 1395<::;8 1 933 ;0 86 I _ 33,8:: b,25 0,440 2.75 ' , + 0,60 1 40 136' Souusi N16 , 6~43/4 '39 .,J08'8B745' . 830 , .850 30 1 1:;7' 1/13 '7645/4 ' • , 3S 39 05 ' e 93 '" 52/5<' ' 482,5 1 l}B' :,"4 '~/4 ' 139:S502'8~0252/5" 191 + 6,B5 2.5 2,640 I 139 'B1r Hadj ;;adock , 9090/4 ';;~j4:.!O'6""7(j57/:;7' 405,10' -'''5,5 :;1,6 2,oUl) 16,75 II : 1 140 'Kaour J::aaat' '906B/4 ' "93530 ' 9 bEl Djem ' .i5S,,/4 I )9 5/35 40\1 ~ 9.,,0 0,15, 3,095 l , '-bandouna I 144 limala des ;:iouusi ' 7004/ .. 'j9~375s06eo 52/52' 605,5 ~ 50 1,22 3,104 , , • 145' Ol;lat Cilemal - 5 7- REPUBLIQUE TUNISIENNE REPER TOlRE DES SONDAGES APPENDIX A SECRETARIAT D'ETAT A L'AGRICULTURE Figurant sur la Carte au 1/200 . 000 oi- jo;>inte Bureau 1. R . H. 2 3 4 5 6 7 8 9 10 11 12 13 __ =-'"'c"'"'C'''''.....:-c:-=-==~~-=-=-=, __ ooe::-=-=-=-=-=-=-=-=-= __-=-c::~-=-=-=-=-=-=-=-=-:: _=-c:-=--=-=-=-=-=-=-=-= __-=-=-= __-=-= -=-=_=_=-=_=_=-=-=_=_=-=_=-=-=-=_ : NO ~ Carte : Coordonnee8 " iiivsau' Doibit '~ite' , ' : NO : De.ignation ,Catalogue;1/200.oo08, .,. Gt!o~aIhi:ue8: Dates :profonua~,;tatiqUS :lit./aec. :atrait sec:Jo.baissenoen~ Obs~rvatione: ------I , . G l46 Sondqe des SOUBIIsis rVt 9109/4 'R)El. Djam ' 39 45 '74" ' SGS2'70n '1957/57 ' S04,10 w 2 'S,5 2,720 ,Om (suite) • 147 •.un Sol tan. 525'/4 • '94250,S9675 41/42 185 -11 15 jf!40 }O 14S ,.un Bell lljannet , S,10/4 , " 940-'5 '93045' 55/55 25, - 2U I: l,j 4,100 20 :Remont6e cie sablel 149 'Bani Husen ~/4 I ;'9 44 70 '94000 51/51 '59,6, - bj 11,760 , • 1Qe 1d)I..-rteboucb';! 150,Oglat ar Ramada 5289/4 .}92975 I 9 ;::0 75 42/42 95 -21,75, 0,05 .Per.neabi:it~ • ruble -, . I 15118i tlatala SI}7/4 , ;'9 }7 75 , 9 '4155 55/55 2t>4 I - lS 20 I I 152'Sdda 4049/4 ' }!l2740' 91b40 ) C/}U 225 I I I :: 15' : Pre. Bir all!Aoum 1}5S/4 ,}92 6 40 9,11U 29/;/.9 40 - 17,4 154'La Chebba NOl 5572/5 I I }9 161.7 1975)4' 49/50 }9,60 - 11,42, 0,6 I 1551 N02 557:5/5 ' }9 16 60 I 9 74 25 50/50 21,05 - 12,47' 0,4 0,860 1,14 I I I bia I 156, NI4 5787/5 : }9 17 60 9 7~90 5}/5} 25,90 - 1,,02, 1,020 bis I 1571 NI2 5816/5 1}91650 9 72 10 51/51 27,85 1 sau 8&188 I 158' Mt,bis 5817/5 1 }9 17 40 ' 9 72 10 1 25 I , 159,Br .1 Haasane (calix), 6467/5 , }9 07 95 , 9 56 15 54/55 71,15 - 4} 6 ,oat> 160IBr Sabas 66SS/5 I 1}91000,95500 57/57 62 - 'O,SOI -SS- APPENDIXB BmLIOGRAPHY -59- APPENDIX B BmLIOGRAPHY Berkaloff, E. Etudes Hydraulique and Hydrologie, Serie I - Fase. 8, Republique Tunisienne, 1959. COTHA (Compagnie des AmenagementI de 1a Plaine de Kairouan, Techniques Hydrauliques et Etude des Ressources en Eaux Souterraines Agricoles) Rapport de Premier Avis, RCT 367. Grenoble, France, Juillet 1957. COTHA (Compagnie des AmenagementI de l'Oued Nebana Techniques Hydrauliques et P~rim~treIrrigab1e du Bled Sisseb Agricoles) Juin 1957, Grenoble, France. Coyne, A. and Bellier, J. Barrage de Sidi Messaoud, sur 1'0ued Nebana Avant-Project, Juin 1959, Paris. International Geologic Congress Monographs Regional 2 Algiers, 1952 SerieI Tunis 1-7, Tunis 1952. Societe Central pour AmenagementI de l'Oued Nebana l'Equipment du Territoire Perimetre Irrigable 'du Bled Sisseb Etudes Pre1iminaires, EssaJ.s de Pompage a Hendi Zitoun, 14-22 Avril 1959, September 1959, Tunis, 1 RH 005. Societe Tunisienne de Barrage sur l'Oued Nebana, Sondages Sondages Injections Forages de Reconnaissance Campagne 1957-58, Tunis, Tunisia. , SOGETHA Amenagement de 1'0ued Nebana, Barrage de Sidi Messaoud, Site aval. Rapport Geologique Tunis, Septembre 1959. -60- APPENDIX B BIBLIOGRAPHY SOGREAH Amenagement c;ie l'Oued Nebana, Perimetre Irrigable du Bled Sisseb, Etude Hydrogeologique, Grenoble, France. Tixeront, Jean L'Alimentation des Villes en Eau Potable en Tunisie, Tunis 1953. Tixeront, J. and Berka1off, E. Evaluation de l'Erosion en Tunisie par la Methode Hydrologique Periode 1953-1956. Tixeront, J. and Berka1off, E. Recherches sur Ie Bilan d'Eau en Tunisie. Etudes Meteoro1ogiques, Clim.ato1ogie de la Tunisie, Normals et Satistiques Diverses, Aout 1952. MAPS Bureau de l'Inventaire des Cartes Hydrologique Provisoir~. Ressources Hydrauliques Direction des Travaux Publics Cartes Geologique Provisoire, Tunisie. (Service des Mines) Ministere de l'Agriculture Carte des Precipitations. Ie Gouvernement Tunisien, Protectorat Francais, dressee par H. Gaussen and A. Vernet -61- APPENDIX C TASK ORDER -6Z- APPENDIX C TASK ORDER DLF No. 377-A-l OFFICE OF INDUSTRIAL RESOURCES INTERNATIONAL COOPERATION ADMINISTRATION Washington 25, D. C. Date: December 1, 1959 PlolT No. 99-25-042-3-09007-A-3 TO: Tudor Engineering Company lCA Project No. and Title: Ground Water Investigation L'Oued Nebana Dam, DLF Application Serial No. 330 Country: Tunis ia Project Engr. IMgr. : Carl Cramer Phone Extension: 2581 Assignment: To investigate the ground water supply which may be available for domestic water and irrigation in Sousse and the Sahel region, including the area near the proposed reservoir. Information is needed as to location and quantity of underground water, the lift necessary to bring it to the surface and the quality of the water. Review quality studies includ "ing electrical conductivity measurements and chemical analyses as follows: Electrical conductivity in micromhes/cm at 250 C; Calcium plus magnesium in milliequivalents per liter; Sodium in milliequivalents per liter; Carbonate plus bicarbonate in milli equivalents per liter; Boron in parts per million. For this purpose to send E. C. Marliave, Consulting Engineer-Geologist to Tunisia for a period of not to exceed 30 days. Prepare required report of findings and recommendations. Acknowledged: (Sgd) JohnG. Marr (Sgd) N. E. Thompson Tudor Engineering Company (12-2-59) N. E. Thompson Chief, Engineering Division Office of Industrial Resources (Sgd) C. W. Allen C. W. Allen, Director Office of Industrial Resources (Sgd) D. A. FitzGerald D. A. FitzGerald Deputy Director for Operations -63-