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FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS ORGANISATION DES NATIONS UNIES POUR L'ALIMENTATION ET L'AGRICULTURE ORGANIZACIÓN DE LAS NACIONES UNIDAS PARA LA AGRICULTURA Y LA ALIMENTACIÓN DAVID LUBIN MEMORIAL LIBRARY F AO • VU ¿ella Terme di'Caraealla - 00100 ROME. Italy We regret that„some of thé pages in the microfiche copy of this.report may not be up to the proper^'. ' legibility standards,even though the best possible-.: copy was used for preparing the master fiche. - r

¿6 frtkïL F AO- r AG:DP/GRE/77/023 ) l/\ j, )>>-/ Technical Report, Vol. I

I v WATER RESOURCES DEVELOPMENT IN THE MOLAI AREA

GREECE

TECHNICAL REPORT

Volume I: TEXT

ftgfiß UNITED NATIONS DEVELOPMENT PROGRAMME

FOOD AND AGRICULTURE ORGANIZATION

OF THE UNITED NATIONS ROME, 1081

0 FAO - AGiDP/GRE/77/023 Technical Report

WATER RESOURCES DEVELOPMENT IN THE MOLAI AREA

GREECE

TECHNICAL REPORT VOLUME I! TEXT

Report prepared for the Government of Greece by the Food and Agriculture Organization of the United Nations acting as executing agency for the United Nations Development Programme

UNITED NATIONS DEVELOPMENT PROGRAMME

FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS

Rome, 1981 Iii

FAO. Water Resources Development in the Molai Area, Greece. Rome, 198T! 3 volb., 56 lip.iire«, ?¿ mnps. AG:DP/GRK/77/023, Technical Report.

A BrTRACT

The report describes the work carried out by the Government of Greece, with the assistance of I'KDP and FAO, to assess the availability of ground­ water Cor the irrigation of up to 6 000 ha tin the Molai plain, Lakónia.

The project area is located in the southern Péloponnèse and consist", of karstic limestone hills up to 1 200 m above sen level and a structural valley (the Molai plain) filled vith marls and c'..i"s with coarser intercalations sloping from 100 m above sea level '."vatcts the coast. The climate is typically Acf.ean, a cool and wind*, variety of the Mediterranean climate; even in the plain «hört r.-tiodH of frost ore not uncommon in winter.

The geology of the area is extremely complex and is still the subject of research. The Tripolitza scries consisting of Mesozoic carbonates on j top of semi-metnmorphic tipper Paleozoic schists hns been overthrustc on top of the flysch ami Mesozoic carbonates ci the Ionian Bcries, which consequently have been metamorphosed into phyllitt'b and marbles. Subsequently the area was blockfaulted, resulting in the formation of the graben which, after filling with Neogene sediments, became the Molai plain.

From observations of 16 raingauges and one climatologiçal station, évapotranspiration and crop water requirements were determined. Stiram- flow measurements and spring flow measurements were analysed, resulting in water balances from which the groundwater recharge was determined.

Groundwater accumulations in the karatic limestone and the Neop.ine deposits are independert of each other except that the Neogene aquifpr loses some of its water into the limestone reservoir whore they are in contact. The limestone reservoir is restricted to the area (10 km2) between the steeply rising hills and the fault »eparating the limestone from the Neogeno filled graben. Its groundwater is of rather poor quality (EC more than "2.0 mmho/cm and increasing with depth) and it has a low head (3-7 m above sea level, which is 77-150 m below land surface). Trunsmissivity is good nnd wells yield easily 100 m^/hour without more than 50 m drawdown. Recharge is by local rainfall and discharge is to the sea. The coastal springB of Glyfada according to isotope data discharge water infiltratinR nt the highest part of the catchment area. The Neo&cne aquifer is subdivided by low transmissivity fault zones into three segments resulting in distinct ground-later levels in each compartment. The aquifer is fed by local rainfall and discharges by subsurface flow mainly into the sea and into a subwurface groundwater sink connected with a fault zone. A water balance is presented which has been confirmed on a groundwater model. ilic Irtish v.itpr of the limestone nquifer is characterized by the ..¿.;.lxUuc uf n variable an.uunt. of sea-watei. It can still be used for irrigation purposes on well drained soils and with adequate leaching. The water of the Neogenc aquifer is of much better quality, although over-exploitation causes an increase in groundwater salinity in the southern part of the plain.

Data cn land and water use, demography and agricultural output give a base for the development proposals. Combining the available water roHOurcc:;, including water transfer from the lower Evrotas plain, the irrigated area in the Molai plain can be tripled to cover half the net irrigable area. Estimates have been made of the water costs, the investment requirements, and the output of a modified cropping pattern adapted to the use of the poor quality water of the limestone reservoir. The economic feasibility of such a project has been studied.

Recommendations include proposals and suggestions for a reduced oata collection network, field trials on the use of the poor quality water from the limestone reservoir for irrigation, development of two pilot projects using water from the limestone aquifer, water transfer from the lower Evrotas plain and a water management plan for the over-exploited southern part of the Molai plain. V

TABLE OF CONTENTS

VOLUME I

l'ngü

.LIST Or ABBREVIATION'S xiii

Chapter 1 INTRODUCTION 1

1.1 Background 1 1.2 Purpose and scope 1 1.3 Previous studies 4 1.4 Project execution 4 Chapter 2 SUMMARY OF FINDINGS, CONCLUSIONS AST RECOMMENDATIONS 6

2.1 Summary of findings 6 2.2 Conclusions 19 2.3 Recommendations 22

Chapter 3 DESCRIPTION OF THE AREA 27

3.1 Location and extent 27 3.2 Physiography 27 3.3 Climatological characteristics 31 3.4 Drainage 32 3.5 Historical note of the area 33

Chapter 4 GEOLOGY 36

4.1 Introduction 36 4.2 Regional setting 37 4.3 Geomorphology 41 4.4 Stratigraphy 47 4.5 Structure 52

Chapter 5 CLIMATOLOGY 57

5.1 Introduction 57 5.2 Climatological observations 57 5.3 Climatological characteristics 58 5.4 Precipitation • 59 5.5 Air temperatures . 63 5.6 Evaporation) évapotranspiration and crop water requirements 65 5.7 Other climatological elements 66

Chapter 6 HYDROLOGY 67

6.1 Introduction 67 6.2 Surface flow 68 6.3 Spring flow 74 6.4 Surface water balances 81 vi

Page

Chapter 7 GROUNDWATER CONDITIONS 83

7.1 Introduction 83 7.2 Geological structure 84 7.3 Two aquifer system 85 7.4 Limestone reservoir 91 7.5 Neogcne aquifer 98

Chapter 8 WATER QUALITY 109

8.1 Introduction 109 8.2 Gcochemical properties of water 110 8.3 Relationship to use 134 8.4 Pollution of water resources 149 8.5 Conclusions and recommendations 155

Chapter 9 LAND AND WATER USE > 159

9.1 Introduction 159 9.2 Project area lr3 9.3 Soil resources 163 9.4 Land classification 167 9.5 Land use 168 9.6 Present and future water demand 176

Chapter 10 DEVELOPMENT PROPOSAL 182

10.1 Introduction 182 10.2 Description and scope of the development proposal 182 10.3 Other development options 185 10.4 Project costs 186 10.5 Project benefits 196 10.6 Economic evaluation 206 10.7 Project implementation 207

REFERENCES " 210 vii

LIST OF TABLES Zas»

2.1 Average surface water balança 10 2.2 Surface water balance with a return period of five yearo 10 3.1 Average rainfall dibtribution 32 5.1 Clinatological network 59 5.2 Precipitation characteristics for Kolai 62 5.3 Maximum duration of temperatures below indicated lévela 65 5.4 ETo and pan evaporation in mm/day at Aosopos 65 6.1 Monthly river flow at the Potamia recorder station 69 6.2 Monthly river flow in Cholorema river 70 6.3 Monthly flow in Taakona Wad i 71 6.4 Monthly flow in Monoporo Wadi "i 6.5 Monthly river flow in Asaopoa river 73 6.6 Monthly river flow in Molai river (1979/80) 74 6.7 Monthly flow into the sinkhole (1979/80) 75 6.8 Subregional water balances, average values 82 6.9 Subregional water balanças, return period five years 82 7.1 Groundwater balance 108 £.1 Chemical analyses of wells I -33 and 2-2 130 8.2 Interpretation of water quality for irrigation 145 8.3 Crop tolerance tabla 146 9.1 Community population for the years 1961-71 and 1979 162 9.2 Area of soil series and soil types 166 9.3 Land classification summary 166 9.4 Communities of the Molai orea 169 9.5 Community data, Molai area 169 9.6 Molai plain community land use in 1966 169 9.7 Crops in Molai area, 19Ó6 171 9.8 Irrigated area, 1966 171 9.9 Present land use and agricultural production 172 9.10 Estimated present crop production 173 9.11 Number of animals 174 9.12 Breakdown of aninal production 174 10.1 Capital investment requirements for 400 ha 187 10.2 Capital requirements to bring water from Lower Evrotas plain 188 10.3 Total project coats 189 10.4 Life expectancy and annual maintenance costs 190 10.5 Estimates of unit costs of.on-farm irrigation equipment 193 10.6 Establishment costs 194 10.7 Estimated water costs 196 10.8 Proposed cropping pattern 198 10.9 Accounting prices for economic evaluation 199 10.10 Economic analysis by crop 200 10.11 Gross and net benefits of the project 202 10.12 Monthly labour requirements 204 10.13 Project benefits summary table 205 10.14 Economic indicators 206 10.15 Sensitivity tests 207 viil

LIST OF FIGURES

1.1 Location nap

3.1 Generalized topographic map of the Molai area 3.2 Project area with community boundaries

4.1 Sketch map of the geotectonic zones 4.2 Kremasti normal contact between phyllites and dolomites 4.3 Major structural units

4.4 Tectonic line.air.ants in the southeast Feloponnese

5.1 Monthly averages of characteristic temperatures

6.1 Glyfada spring area 6.2 Glyfada shore springs i 1 Schematic cross-section over the 'catchment' area 7.2 Grour.iiv.i-. •••<-'•{ Rtics of the Ei.ea area

r 7.3 Groundwater hydrograph ot the UmcM• "r 7.4 Schematic cross-section through the Molai plain 7.5 Groundwater hydrograph of the southern plain 7.6 Groundwater hydrograph of the northern plain 7.7 Trilinear diagram of the Neogene aquifer water

8.1 Trilinear diagram of the Limestone aquifer 8.2 Trilinear diagrem of the Neogane aquifer I Apidia 8.3 Trilinear diagram of the Neogene aquifer! Molai, Pakia, Metamorphosist Sikea 8.4 Trilinear diagram of the N*ogene aquifer! Finiki 8.5 Trilinear diagram of the Neogene aquifer) Assopos 8.6 Trilinear diagram of the Neogcne aquifer: Papadhianika 8.7 Tiilinear diagram of the Neogens aquifer) Elea 8.8 Trilinear dingram of the surf ice water 8.9 Trilinear diagram of the springs 8.10 Irrigation quality of waters from the Limestone aquifer 8ill Irrigation qualicy of waters from the Neogena aquifer) Molai, Pakia, Metamorphosis, Sikea, Finiki 8.12 Irrigation quality of waters from the N^ogeno aquifer: Asaopos 8.13 Irrigation quality of waters from the Neogene aquifer: Papadhianika, Plytra 8.14 Irrigation quality of waters from the Limestone/Neogene/ Holocene aquifer: Elea area

9.1 Agricultural area in the Molai plain

10.1 Location of proposed project areas, wall fields and pipelines 10.2 Monthly labour requirements 10.3 Time-table for implementation of development proposal VOLUH: Ii

pea

Appendix 2.1 POST- PROJECT DATA COLLECTION PROGRAMME i

Appendix 4.1 BOREHOLES IN THE MOLAI AREA 9

Appendix 6.1 IDENTIFICATION OF SPRINGS 68

Appendix 6.2 GLYFADA SPRINGS 70

Appendix 7.1 ABBREVIATED WATER WELL INVENTORY 76

Appendix 7.2 GROUNDWATER STUDY TECHNIQUES 119

Appendix 8.1 CHEMICAL ANALYSES OF GROUND AND SURFACE WATERS 166

Appendix fl.2 CALCULATION OF ADJ. SAR 202

Appendix 10.1 RESULTS OF PROJECT EVALUATION 204

Appendix 10.2 ESTIMATED COST OF ONE EXPLOITATION BOREHOLE 220

Appendix 10.3 AGRICULTURAL DATA 223

Appendix 10.4 ELECTRICITY COSTS 247

Appendix 10.5 FARMGATE PRICES IN MOLAI AREA 248

Appendix 10.6 IMPROVEMENT OF EXISTING OLIVE TREES 249

LIST OF TABLES

A4.1:1 Borehole loga of the Molai area 10 \7.2il Distribution of veils in the Molai area 121 A7.?}2 February water levels in wells along the Assopos river 131 A7.2:3 Summary of discharge tests 141 A7.2»4 Total water production from the Neogene aquifer 142 A7.2:5 Results of drilling and well teoting programme 151 A7.2:6 Pumping tests in the Neogene aquifer 153 A7.2i7 Summary of iBotopic composition of spring waters 155 A7.2:8 Isotopi". composition and mean rocharge elevation of shore spring samples 158 A7.2-9 Isotope analysis of limestone aquifer samples 158 A7.2il0 Isotope analysis of samples from tho Neogene aquifer north of Assopos 159 A7.2ill Isotope analysis of samples from the Neogene aquifer of the Southern Plain 161 X

Page

A7.2:12 Isotope composition of groundwater in the Elea marble 162 A7.2I13 Isotope analysis of samples from the Neogene aquifer of the Elea area 163 A8.1:l Chemical analysis results; Limestone wells 167 A8.1:2 Chemical analysis results; exploratory wells 169 A8.1:3 Chemical analysis results; Quaternary wells in the catchment 170 A8.1:4 Chemical analysis results; Neogene wells Molai ' plain 171 A8.1:5 Chemical analysis results; Neogene wells Elea area 193 A8.1:6 Chemical analysis results; springB 197 A8.U7 Chemical, analysis results; streams 200 A8.1:8 Chemical analysis results; miscellaneous 201 A8.2:l Calculating pHc 202 A10.3Ü General data on deciduous fruits and nuts 224 A10.3:2 General data on table grapes and table olives 225 A10.3:2A General data on citrus 226 A10.3:3 Agricultural input-output norms 227 A10.3i4 Individual crop analysis 231 A10.6Ü The effect of irrigation and tree shape on olive production 250 A10.6J2 Estimated benefits from irrigation of olives (bush-shape) 251 A10.6I3 Estimated benefits from irrigation of olives (free-shape) 251

LIST OF FIGURES

A6.2:l Glyfada shore springs 73 A6.2:2 Spring discharges at Glyfada 74 A6.213 Spring west of wall 75 A7.1:1 Well inventory units 77 A7.2S1 Inventory sheet 122 A7.2:2 1979 density contour map of pumped wells 124 A7.2:3 1971 density contour map of pumped wells 126 A7.2S4 Schematic hydrogeologic cross-section over the Molai plain 128 A7.2«5 Groundwater hydrograph' Neogene aquifer northern plain 133 A7.2:6 Groundwater hydrograph Neogene aquifer Atsopos Ridge 134 A7.2I7 Groundwater hydrograph Neogene aquifer Assopoa Ridge 135 A7.2I8 Groundwater hydrograph Neogene aquifer nouthom plain 116 A7.2J9 Groundwater hydrograph Neogone aquifer southern plain 137 xi

Page

A7.2:10 Groundwater hydrograph Neogene aquifer Plytra-Xili coast 138 A7.2:ll Groundwater hydrograph Neogene aquifer along Assopos river 139 A7.2:12 Groundwater hydrograph Limestone aquifer 160 A7.2:13 Relation between total depth and electricity consumption 143 A7.2:14 Resistivity profiles south of Elea 147 A7.2:15 Elea-Glyfada area cross-section E.S S8-S9 148 A7.2:16 Mean recharge altitude versus b 18n °/oo 157 A10.4:l Electricity required for pumping 247

VOLUME III (Not available from INIS please refer to FAO)

Plate 3.1 Location map

Plate 4.1 Geologic map

Plate 4.2 Geologic cross-sections

Plate 5.1 Isohyetal map

Piste 6.1 Hydrological map

Plate 7.1 Groundwater characteristics of the Linestone reservoir

Plate 7.2 Groundwater characteristics of the Neogene aquifer

Plate 8.1 General pattern of chemical groundwater types

Plate 8.2 Specific conductance! Autumn 1971

Plate 8.3 Specific conductance: Autumn 1978

Plate 8.4 Specific conductance: Spring 1979

Plate 8.5 Specific conductance: Autumn 1979

Plate 8.6 Specific conductance: Spring 1980

Plate 8.7 Isochlor map: September 1979

Plate 9.1 Soil map

Plate 9.2 Irrigation classification ' xii

PlacPlate A2.1:A2.I;1l Post-project groundwater observation network i late A7.2.-1 later level contour map of the Neogene aquifa April 1971

Plate A7.2: 2 later level contour map of the Neogene aquife September 1971

Plate A7.2:3 later level contour map of the Neogene aquife April 1979

Plate A7.2:4 later level contour map of the Neogene aquife September 1979

Plate A7.2:5 April 1980

Plate A7.2¡A7.2i6 Structural interpretation of the geoelectric soundings

Plate A7.2:7 Molai plain tan « *¿9 Là»

xiii

"LIST OF ABBREVIATIONS

BCR Benefit cost ratio bLS Below land surface • cm centimetre DEH Public Power Corporation DLR Directorate of Land Reclamation ,18. o , 6 0 /oo Oxygen -18 depletion rate Dr Drachma EC Electrical Conductivity EEC European Economic Community ETo Evapotranspiration FAO Food and Agriculture Organization of the United Nations GNP Gross National Product GWE German Water Engineering GMBH ha Hectare hr Hour IRR Internal rate of return km Kilometre m Metre MCM Million Cubic Metres mg/1 Milligramme per litre mmho Millimho (= millisiemen) msl Metre above sea level NPV Net Present Value OECD Organization for Economic Cooperation and Development s Second SAR Sodium absorption rate SMOW Standard mean ocean water T.U. Tritium Unit UNDP United Nations Development Programme U.T.M. Universal Transverse Mercator projection Chapter 1

INTRODUCTION

Pursuant to .. Project Document signed in July, 1978 by the Directorate of L.ind Reclamation, Ministry of Agriculture, Ministry of Coordination, United Nations Development Programme (UNDP) and the Food and Agriculture Organization (FAO), this report is presented to tho Directorate of Land Reclamation. The report represenLs an evaluation of the water resourses of the ? limestone area of the Molai region, Lakonia, Peloponnesus, Greece and a plan for development follow-up. In addition, the project undertook û water resource evaluation of the highly developed '< Neogenc aquifer system (Figure 1.1).

1.1 BACKGROUND

In Juno, 1977, tho Directorate of Land Reclamation, Ministry of Agriculture submitted to tho UNDP, through the Ministry of Co­ ordination, a proposal to undertake a detailed study of the water resources of tho Molai Plain, Lakonia, Peloponnesus. Since the project was given high priority, the government request was included in the UNDP Country Programme presented to and approved for assistance by the liNnP Governing Council in January, 1978. Simultaneously, the Government of Greece included funds for the project in the "Public Investment Programme for 1978". The Food and Agriculture Organization was selected as the executing agency and the Directorate of Land Reclamation as the Government implementing agency. In March, 1978, an FAO Consultant undertook a two month assignment to assist the Government in the preparation of a draft project document. The project document was approved by the Government and UNDP/FAO in July 1978; upon the arrival of the project manager in August, 1978, the project was declared < operational.

1.2 PURPOSE AND SCOPE

The long range objective of tho project for Water Resources x < Development of the Molai Area in Lakonia aa stipulated in the project document was to evaluate tho water resources of the

3

limestone arca in order to próvido water for irrigation development in a region that has a high agriculture potential. The immediate objectives of the study were to: i) assess availability and adequacy of the ground water resources of the limestone area, both in terms of quantity and quality to irrigate an area of up to 6 00C ha; ii) investigate the coastal and submarine springs to determine discharge and salinity variation; iii) establish a pumping regime within the limits permitted by economic constraint imposed by pumping costs and/or a sea water intrusion control programme; and lv) recommend a second phase follow-up study to feasibility level that will detail irrigation development.

2 The Molai Plain includes an area of approximately 70 km and is about 10 km wide at its north end and narrows to a width of about two kms at its south end; the plain trends northeast- southwest and has a length of 15 kilometres. The designated hydrologie catchment area to the Plain lies immediately to the 2 north and includes an area of about 220 km ; approximately 2 10 km of additional catchment area occurs along the eastern flank of the Plain. Initially the project concentrated its efforts towards the assessment and development of the limestone groundwater reservoir but during the well inventory'only a few limestone wells were found. On the other hand in the Neogene sedimentary ground water reservoir, over 500 wells had been dug or drilled. It was therefore apparent that the limestone aquifer was un­ developed whereas the Neogene aquifer wan extensively developed and in the southern coastal area, probably over-developed. Thus, the scope of the project was enlarged to include the Neogene aquifer for evaluation of groundwater availability to consider the need to manage groundwater extraction and to assess its potentiality as a supplemental water resource to the development and use of the limestone aquifer. 4

1.J PREVIOUS STUDIES

Tn 1970; a joint venture of the Gorman Water Engineering GMBH/Lir.gcn and Salzgittor Industiebau GMBH/Salzgitter was appointed by the Organization for Economic Cooperation and Development (OECD/Paris) and the Land Reclamation Service, Ministry of Economy, Government of Greece to investigate and evaluate the water resources, development potential and economic analysis in the Lower Evrotas River Basin and the Molai Region. The study however, was primarily concerned with the Lower Evrotas River Basin and the Molai area was accorded secondary consideration.' The Molai area study was completed to a prelim­ inary lovol with recommendations for a follow-up detailed investigation. The report of the engineers was completed in 1972. Other pertinent studios that served as references to the present project were a reconnaisance pedological study of the Molai Plain carried out in 1966 by D. Casfanis of the Land Reclamation Service, Ministry of Economy, photogeologic map, 1970 by the Institute of Geology and Subsurface Research, and up-dated geology map, 1980 and geologic reports and maps of the Molai area, by students. University of Frankfurt, 1979.

1.4 PROJECT EXECUTION The Molai project, operating within the scope of the Project docn. reported to a Coordinating Committee, Directorate of Land Reclamation through the Director of the Division of Hydrology and Geology and the section chiefs of hydrology and hydrogeology. Project organization and imple­ mentation of field activities to obtain required output and achieve objectives were undertaken jointly by national and international staff assigned to the project. Government contracted special works including the geophysical survey, exploratory well drilling and testing programme and the isotope studies. The UNDP provided specialized short-term consultants to assist in the preparation of contract specifications and/or 5

tu evaluate results. Technical instruments required to collect basic data wore also provided as well as transport. The project established offices in the Molai Plain, at Molai and at the Directorate of Land Reclamation, Athens. Computer modelling facilities were made available by the Computer Centre, Ministry of Agriculture. » . «-ie*v -SB»-KV ' - .-.t- ;a»™-»"íi«-«t.v-JscB¡- . .a vrjKSrs.-uIS ss.

6

Chapter 2

SUMMARY OF FINDINGS, CONCLUSIONS AND RECOMMENDATIONS

2.1 SUMMARY OF FINDINGS

2.1.1 Morphology

The project area consists mainly of two morphological and geological different units. ' « the mountainous limestone catchment, covering an 2 area of 230 km ranging in height from 100 to 1200 msl 2 and the limestone reservoir (10 km ) in the piedmont' area of the mountain. The latter is overlain by the northern extension of the Molai Plain. 2 the Molai Plain covering an area of 70 km and ranging in height from 0 m at the coast to 100 m at the foot of the mountains. The plain covers the piedmont area of the catchment. 2 Of minor importance is the Elea area (10 km ) which covers the southern flank of the Kourkoula Mountain, west of the Molai Plain. 2.1.2 Geological setting The project area is located across the junction of two major structural fault-systems s - the north-south directed Elea-Molai fault which is, with its Glyfada branch and Xili branch, part of the Xili-Leonidion lineament; and - the northwest-southeast>directed Mavrovouni-Sikoa- Ayios Ioannis fault.

The former separates the Molai Plain and tho limestone area north of it from the marbles of the Kourkoula Mountain. The latter separates the limestone area from the metamorphic schist area of which the Molai Plain forms the western extremity. 7

2.1.2.1 Limestone area

The limestone area consists of the Tripolitza carbonate formation which is 500 m thick and overlays the semi-metamorphic Tyros Formation. These two Formations form together the Tripolitza Series which has been overthrust on top of the Ionian Series. The Kourkoula marbles are admittedly part of the Ionian Series. This implies that the whole project area is underlain by marbles. The marbles are normally separated from the Tripolitza limestone by the impervious Tyros Formation and the equally imp­ ervious metamorphic flysh (phyllites) of the Ionian Series. However, the whole area has been subjected to very intensive blockfaulting in the period after the overthrusting. This may have brought the Tripolitza carbonates (limestones and dolomites) locally in direct contact with the marbles. Another consequence of the blockfaulting has been that the Tripolitza carbonates are karstified over a depth range from at least 700 msl to -200 msl. The karstified limestones below sea level are considered to have beon later submerged.

2.1.2.2 Molai Plain

The Molai Plain is a northeast-southwest directed valley ("graben"). Two northwest-southeast directed faults have caused the sub­ division of the Plain into:

- Northern Plain covering the Northern Trough and the piedmont area of the limestone mountains;

- Assopos Ridge in the centre; and

- Southern plain covering the Southern Trough. The whole graben is filled with Neogene sediments (marls, sand, sandstone, silt, clay9 and gravel) of various thickness; more than 600 m in the Northern Trough, 100 - 200 m over the Assopos Ridge and 300 m in the Southern Trough. 2.1.2.3 Elea Area The Eloa Area consists of Neogerd deposits covering the southern flank of the Kourkoula Mountain, towards the Lnkonian Gulf. The area is separated by a ridge of metamorphic rocks f»

nlong the Xilj branch of the Eloa-Molai fault,from the Molai Plain. Near its southern extremity is the location of the Glyfada coastal and submarine springs. Borehole RB-1, drilled near tho alignment of the Glyfada branch of the Klea-Molai fault, found marbles below Neogene and phyllites.

2.1.3 climatology and Hydrology

2.1.3.1 Climatology characteristics

The project area possesses the general characteristics, of the Mediterranean climate: windy, mild, wet winters and less windy, moderately hot, dry summers. Like in other parts of the Aegean, however, the winds during winter and during July and August arc stronger and the temperatures during these pericas are somewhat lower than in other parts of the Mediterranean.

2.1.3.2 Precipitation • i Average annual precipitation amounts to 500 mm in the Molai Plain and up to around 1000 mm in the mountains. Precipitation which can occur in any one month, has its maximum in January with a long term moan at Molai of 112 mm, and its minimum in August, 4 mm. The winter months, November-February account on an average for 65 percent of the annual precipitation, and during this period precipitation can frequently occur as snow at higher altitudes. Persistent snow cover of the ground is, however, unusual for more than one day. 2.1.3.3 Trrnp:-' ra tu re 3 . i' On the iMaxn, air temperatures range on an average between 10°C in .. v.iuary-Fobruary and 24°C in July-August, around a mean annual temperature ,f 16?5 C. The extremes vary between an average absolute low of 0?5 C in January and an average absolute high of 33?9 C in July. Groundfrosts are not uncommon in winter, particularly in the northeastern part of the plain, although the temperature does normally not remain below 0°C for more than one hour. 2.1.3.4 Drainage

The Molai Plain can be divided into two parts of approximately equal size: A relatively flat area to the northeast, and an undul­ ating area towards tho soa in the southwest. Between tho two areas o

runs the Assopos ridge with an elevation of around 100 msl acting as a drainage divide. The northeastern area drains by a partly man-made channel towards a depression at an elevation of 70-75 msl with a sinkhole at its lowest point, whereas to the southwest the land drains to the sea by two main river channels, the Molai river and tho Assopos river. Except towards the southwest the Plain is surrounded by hills or mountains in-all directions. Being mainly composed of karst- ifiod limestone formations with high infiltration rates, the mountain catchments produce little or no runoff but act as re­ charge areas for the coastal spring complexes. Most years, probably with a frequency of 60 percent, surface flow in the project area is limited to the Potamia catchment to the northwest and the Sikea catchment to tho east of the Plain. Plash floods of short duration may also develop in tlv i ¡mor.hono nroa to the north but without reaching the Plain. D'iri'w ••/'•! years, however, that is every four to five yearn on .in average, tho Molai and Assopos rivers in the southwestern part of t.ho Plain may be flowing to the sea and flash floods from the limestone areas may occasionally reach the Plain and eventually the channels leading to the sinkhole. The drainage capacity of the sinkhole is limited,1.8 m^/s, which moans that when the inflow rate is higher the area surrounding the sinkhole gets flooded. This seems to happen every three to four years on an average affecting an area of less 2 than ono km . Major floodings, when the inundated area exceeds 2 one km , are rare, probably one only in 10-20 years. The largest 2 recent flooding, (1.8 km ) occurred in 1934. 2.1.3.5 Springs There is a great number of springs within and also outside the project area which most dertainly belong to one and the same karst systorn. Except for nomo isolated springs, somo of which aro used an sources for village water supply and/or limited irrigation, they appear in four distinctive groups, one of which (Gagania) inland and feeding tho Potamia river, and the remainder along the ncn-sliore (Glyfadn-Elen, Plybra, Moncmvnsia) . Most springs and groupB of springs nro small with yields below 10 1/B 10

and some of them dry up during summer. The Glyfada-Elea spring complex is, however, an exception. This group of springs maint­ ains a remarkably high and steady flow, 1 .5-2 m^/s throughout the year, and was, therefore, a focal point for the water resources studies.

2.1.3.6 Water Balance

By combining precipitation statistics, hydrologie field data and output from watershed modelling, water balances for the project area were worked out for an average year and for a wet year with a return period of five years. The result is summari­ zed in Tables 2.1 and 2.2.

Table 2.1

AVERAGE SURFACE WATER BALANCE IN MCM

2/ Area Gross Rainfall Losses to the Sea ^ 1 Evaporation Ree. * ge - Limestone 114- 54 — 58+0.3 Plain 51 38 0 13-0.3

Tablo 2.2

SURFACE WATER BALANCE (MCM) WITH A rSTURN PERIOD OF FIVE YEARS

,. Area Gross Rainfall Evaporation Losses to the Sea - Rocharge —•

Limestone 155 60 — 'iji i... Plain 65 40 0.2 25-1.6

2.1.4 Groundwater conditions

Each of the three areas has its own groundwater system. They do not influence each other, except along the front of the Tripol­ itza limestone mountains where the Neogene aquifer overlays the limestone reservoir and where some leakage occurs from the Neogonc into the limestone reservoir. Another exception is the Eloa area near the Glyfada springs where water from the deep seated marble aquifer wells up along fault zones and dissipates into the Neogene aquifer.

1 y — As surface runoff and/or interflow

—' The second figure refers to inflow from tho Plain into the Binkholo 11

2.1.4.1 Limestone area The limestone terrain can be subdivided into the catchment and the reservoir. The catchment is the mountainous area; the reservoir is located in the narrow piedmont area between the outcrop of the limestones and the fault that separates them from the Northern Trough of the Molai Plain. Direct evidence about groundwater conditions in the limestone area is only available from the reservoir. In the catchment the water levels are too deep to be of economic interest. The groundwater recharge of the limestone area is nearly exclusively due to infiltration of local rainfall. The discharqi- point or area of the. limestone groundwater system is not precisely known. Based on available evidence the following concept has been developed: The limestone area is divided by the Koupia-Mavrovouni fault into a northwestern and a southeastern part. The groundwater drainage of the northern part of the catchment is towards the GLyfada springs, while the southern part drains towards the Aegean sea north of Monemvasia.

i) Northwestern part of the catchment

There is nc direct evidence about the groundwater conditions in this part of the catchment. However, the water from the Glyfada coast.-ii springs has a stable ir.ot.opc composition indicating a mean recharge elevation of about 900-1 000 m. This corresponds with the eleva­ tions in the northern part of the catchment. The area with assumed subsurface drainage towards the Glyfada springs extends probably to the area northwest of the Project area, because the recharge of the northern part of the catchment alone is insufficient to provide the 60 MCM—^ discharged annually by the Glyfada springs into the Lakonian Gulf. The conduit between the racharye 'area and the springs is probably a pervious (karatified?) zone through the marbles along the Glyfada-Molai fault system. It has been tapped by borehole RB-1 about 1 .5 km northeas'- •

-f Million Cubic Metro 12

the Glyfada submarine springs. The water from this well is chemically and isotopically similar to the wat«r from the Glyfada coastal springs.

ii) Southeastern part of the catchment

Like in- the northeastern part of the catchment little is known about the groundwater conditions in this part. It is likely that this area drains towards the Aegean Sea, north of Monemvasia. There is probably a dissipa ated discharge over a large submarine area because the springs along the coast, north of Monemvasia have very small discharges and there is no evidence of large submarine springs. Part of the water infiltrating over the southeastern part of the catchment recharges the limestone reservoir. The stable isotope composition of water samples from wells tapping the reservoir indicate a mean recharge elevation of circa 500 m which corresponds with the mean elevation of this part of the catchment.

iii) Reservoir 2 The reservoir with a surface area of about 10 km is the best known part of the limestone groundwater. Information from wells drilled by the Project at five locations combined with data from three private wells and two wells, which were drilled and tested by GWE (1972) can be summarized as follows: a) Tis-, aquifer is unconfined: 1/ b) Groundwater elevations vary from 3 to 7 msl—' consequently the water levels are 70-110 m below land surface; c) With a distance to the sea of about 10 km th«î groundwater gradient is very low (0.3-0.5x10~3); d) Because of the low gradient either the recharge is very small or the transmissivity is very high. The latter is more likely duo to tho very deep karstiflcation (to at least -200 msl);

(-)5 msl; number of metres above or (-) below mean sea-lovel 13

e) The quality of the groundwater is very variable. Over short distances the electrical conductivity (EC) can vary from 0.8 to 6.0 mmhos/cm at the same depth below the water table. Tho salinity of the water increases with increasing depth. SAR values range from 3.0 to 15.5 and irrigation class

from C3S1 to CgS^; f) Pumping yields are high. In various wells yields of 100 m3/hr have been obtained. Specific yields vary from 2.7 to 909.0 m3/hr per metre drawdown; g) The reservoir is recharged by the southeastern part of the catchment (see section 2.1.4.1. ii) and discharge is probably to the sea north of Monemvasia. h) There is no connection between the reservoir and the Glyfada springs, south of Elea, as indicated by ' the difference in stable isotope compositions; also the water level in the alleged "conduit" is higher than in the reservoir.

2.1.4.2 Groundwater conditions of the Molai Plain

Tho Neogene deposits that underlay the Molai Plain contain an unconfined aquifer. This aquifer is recharged by deep percol­ ation of local precipitation (about 20 percent of the annual gross rainfall). Additional recharge is received from subsurface inflow from the Chavalla crystallized limestones, north of Plytra. Discharge occurs by subsurface outflow through the alluvial deposits between Plytra and Xili and through the alluvium in the lower reaches of the Molai and Assopos rivers. Some water dis-, appears from the aquifer by leakage into the limestone reservoir in the piedmont area. Since 1971 an increasing amount of water is discharged by pumping, especially in tlu> Southern Plain. The structural subdivision of the Plain by faults is reflected in the groundwater levels and trn ismissivity values. Along the fault zones the continuation cf the most pervious layers is disrupted resulting in zones with a lower transmiss- ivity than in the segments itself. Consequently the groundwater table descends step like from about 50 msl below the Northern Plain, to 25 msl over the Assopos Ridge, and to sea-level below 14

the Southern Plain. In the northern part of the Assopos Ridge is a small depression in the groundwater levels. Admitting reasonable transmissivity figures the annual groundwater recharge of the northern two-thirds of the Plain can only partly be discharged via the aquifer of the Southern Plain. It is believed that the excess water drains in the northern part of the Assopos Ridge in the area with the groundwater depression. The actual mechanism is however still an enigma. The water quality is good in most of the aquifer (EC less than 1.0 mmhos/cm) . Only within one kilometre from the Plytra- Xili coast and in the mouths of the Molai and Assopos rivers is the salinity higher (EC more than 2.0 mmhos/cm). However, the large number of pumped wells in tho Southern Plain results in over-exploitation and an increase in salinity of the groundwater as a result of recycling of irrigation water, insufficient leach­ ing and flushing of the aquifer, and sea water intrusion.

2.1,4.3 Groundwater conditions of the Elea area ¡

The Elea area is of interest for the water resources study of the Molai area, only because the Glyfada springs, the discharge points of the northern part of the limestone catchment, are loca­ ted in this area. The conduit between the springs and their catchment passes through the southern part of the Elea area. It is probably aligned along, the Glyfada branch of the Eloa - Molai fault. Borehole RB-1 (TD;250 m-^) located near this fault at a distance of 1.5 km from the Glyfada submarine springs penetrates into a confined aquifer in the'marbles at 160 msl with water which is chemically and isotopically similar to that of the Glyfada springs The water level in this well is about 7 msl, i.e. 21 m below the land surface. The'water quality is rather poor; EC 3.0 mmhos/cm; Cl" 19.3 meq; SAR 7.9; irrigation class C^. The yield is 108 m3/hr for 8.3 metre drawdown.

2.1.5 Agricultural Dovelopment

2.1.5.1 Present agricultural conditions

The agricultural study area includes only the Molai Plain

-1 Total depth IS and not the upland. The number of farms in the agricultural study area Is about 1 440 with an average size of 5.0 ha of which 4.2 ha are cultivated. The predominant land use is still orchard farming (olives and figs) although it decreased between 1966 and 1978 from 74 to 35 percent of the cultivated area. Irrigated agriculture has grown from 280 ha in 1966 to nearly 1100 ha in 1979 or from 5 to 18 percent of the total suitable area. The area planted with citrus has doubled but the greatest increase is noted for the cultivation of vegetables. Over the last few years/ the use of plastic hot-houses for growing early crops of egg plants and tomatoes has rapidly been spreading. In 1971 nearly all wells were dug wells located in the Southern Plain where depth to water is less than 20 m. At present all new wells are drilled, which means that irrigation water has become available even on the Assopos Ridge (depth to water 60 m) and, to a lesser degree, in the Northern Plain, where the aquifer is fine sandy. Except for one single well tapping the limestone aquifer the irrigation water is at present extracted from the Neogene aquifer at a rate of 4.6 MCM/year. In view of the fact that nearly 1 100 ha are under irrigation the water requirements for any irrigated crop are far from being met which means that the irrigated area is far from being efficiently utilized.

2.1.5.2 Future agricultural development

The development of irrigated agriculture depends on the availability of land, water, labour, capital and know-how, a3 well as on marketing conditions and transportation facilities, i) Land

The gross irrigable area on the Molai Plain is 7 200 ha of which 200 ha are or will be reserved for urban areas. According to a reconnaissance soil survey from 1966, 6 050 ha belong to land class II or III, i.e. "good, suitable for irrigation" and "good, moderately suitable for irrigation", respectively. A detailed soil survey will be completed by the Soil Science Institute, Athens, in April 1981. Preliminary results indicate that except for an area of about 300 ha near the sinkhole between Metamorphosis and Sikea and in parts of the Molai and 16

Assopos rivor valleys close to the coast all soils are well drained. The possibility of leaching then will compensate for the relntively high salinity which might be expected of water from wells tapping the limestone reservoir.

Water a. Irrigation water requirements Assuming an overall irrigation efficiency of 75 percent, leaching requirements corresponding to irrigation water with an electrical conductivity of 2.0 mmhos/cm, and a selected, favourable cropping pattern (Table 10.8), the gross water requirements have been calculated at 7 500 m /ha/year with a monthly peak demand in June and July of 1 250 m3/ha/month.

b. Non-exploited water resources 1. In tho northern two-thirds of the Molai Plain an additional 3 MCM/year is available from the Neogene aquifer; 2 MCM/year which at present drain from the northern part of the Assopos Ridge and 1 MCM/yoar which would be obtained from a general lowering of the watertable by 5 m over a period of 20 years. These additional 3 MCM/year may irrigate 400 ha.

2. Out of a total water resource of 40-60 MCM/year in the limestone formation it is recommended initi­ ally to extract six MCM/year by two groups of five wells each, and ¡w^j^ ,a capacity of 200 m /hr for each well. One.giijwp^ should be' located between Molai and Metamorphosis, the other along the Metam- orphosis-Sikea road. They would supply irrigation water for two pilot areas each of 400 ha. Continuous monitoring the aquifer during its initial exploration would indicate at what rate further development would be possible.

3. In the lower part of Evrotas river basin, west of the Kourkoula mountain, the available resources of good quality water (electrical conductivity lesB than 1.0 mmhos/cm) exceed the demand even if all V

17

land suitable for irrigation were developed. The excess water could be convoyed to the Molai area. A preliminary study has shown that it is economi­ cally feasible to transfer water at a rate required for irrigation of 1 000 ha. Part of this water should be used to replace water pumped from salty wells in an area of 100 ha in the Southern Plain. The remainder should be used for new irrigation schemes and/or for mixing with the more saline water from the limestone aquifer.

c. Water management With the lack of organized water management in the Molai Plain, the farmers are developing their own wells without being concerned with well spacing and extraction rates. This has created a situation with an excessive well density (locally more than GO wells/ 2 km ) in the Southern Plain. Existing rules concerning minimum well spacing have never been followed. Wells drilled by the government are usually handed over to the municipalities as village water supply wells but sometimes they are given to private farmers. d. Water cost The average consumer price of water from wells in the Neogene aquifer is at present 6-7.5 Dr/m3, and has occasionally reached 9 Dr/m . The cost of water from the limestone reservoir has been calculated at 8.6 Dr/m whereas the cost of water conveyed from the Lower Evrotas Plain would be 11.8 Dr/m3. The farmers would however, only be charged the opera- 3 ting costs, 3.6 Dr/m , should the irrigation projects be executed under the rules for Land Reclamation Projects. iii) Labour The population data indicate that the migration from the Molai area is decreasing but it is considered that there 18

will be very little population growth during the next 20 years. There are at present 1 440 farms with average annual labour requirements of 344 man-days/year/farm (82 man- days/ha) . However the labour requirements are concentrated to June and to the period September-December. The proposed development of irrigated agriculture would require 170 man-days/ha/year, rather evenly distributed over the months, and this together with expected higher wages, will most certainly further reduce the migration and possibly even turn the population growth from negative to positive. The labour availability may, however, still determine the maximum irrigable area. iv) Capital

a. The capital requirements for a project of 400 ha using water from one group of five wells tapping the limestone reservoir are estimated at 194 million Drachma, of which - Government expenditure for boreholes, pumps, conveyor and distribución system: 123 million Dr.; and

- Agricultural credit requirements for planting costs, plastic hot-houses and on-farm irrigation equipment: 71 million Dr.

b. The implementation in the Northern Plain of two proj.ects of 400 ha each using two groups of five wells, will require the double amount of capital and agricultural credit i.e. a total of 388 million Dr.

c. The development of 1 000 ha with irrigation water from the Evrotas basin, conveyed via a pipeline of 13.5 km, will require a government investment of 575 million Dr and agricultural credit facilities of 253 million Dr. All the schemes, a - c above, are economically feasible with values of the internal rate of return (IRR) between 15 and 24 percent. 19

v) Know-how

The use of rather saline water from the limestone reservoir requires the introduction of crops and irrigation practices including leaching which are new to the area. It is therefore important that the agricultural extension service be strengthened and field trials on demonstration plots be started as soon as possible.

2.2 CONCLUSIONS

2.2.1 General

After detailed studies in various fields pertaining to the Molai Plain, its human, land and water resources, and its potential for economically feasible agricultural development, the Project has arrived at the following basic conclusions:

i) The availability of good soils would permit 6050 ha out of 7000 ha cultivable land to be developed for irrigated agriculture, ii) Water resources in the Molai Plain amount to 50-70 MCM/year, 85 percent of which are located in limestone formation(s) at relatively great depth. The quantity of water would be sufficient to match the resources of suitable land for development. In addition, a surplus of water of about 7.5 MCM/year ÍB available in the neighbouring Evrotas river basin for use in the Molai Plain. iii) Climatologie and demographic conditions are such as to favour development towards more intensive and more economic irrigated agriculture, a development which would mean more labour employment opportunities rather evenly distributed over the months, iv) The available agricultural labour force will be the limiting factor for the size of the area that can ultimately be irrigated, v) Three irrigation development schemes have been outlined. They would cover an area of 1700 ha andbe supplied by water from the limestone aquifer (2x3 MCM/year) and 20

from the Evrotas river ba3in (7.5 MCM/year). Each scheme has been economically evaluated and they are all feasible with an internal rate of return (IRR), of between 15 and 24 percent. In addition, an addit­ ional 300-400 ha can be irrigated with water from the Neogene aquifer in the northern part of the Plain. Although time did not permit an agro-economic study in this case, it can be safely assumed by comparison with the other schemes that the IRR would be close to the higher figure, 24 percent.

More detailed conclusions concerning the three major sources of irrigation water: the limestone reservoir, the Neogene aquifer, and surplus water from the Evrotas river basin, are dealt with under separate headings below. 2.2.2 Limestone reservoir

i) The limestone reservoir, in the Molai - Metamorphosis - Sikea area, is probably recharged in the southern part of the catchment. It is not connected to the Glyfada spring but it may disperse off the coast north of Monemvasia. ii) Four successful boreholes have been drilled in the ''. ~ limestone reservoir. All of them encountered an uncon-' fined aquifer with the water table between 7.0 and 3.0 msl. Yields of 100 m3/hr can easily be obtained, and yields of 200 m3/hr are possible for a drawdown not exceeding 50 Water quality is rather poor and variable over short distances. The following range of parameter values was found EC: 1.0 - 5.0 mmhos/cm, Cl meq, SAR: 3.0 - 15.5, irrigation class C^S^ - CgS The salinity increases with depth.

2.2.3 Neogene aquifer i) The Neogene aquifer is made up of three more or less independent units : Northern Plain, Assopos Ridge and Southern Plain. Average water level elevations in these unitB are 50 msl. 25 msl and 0 msl, respectively. 21

ii) The Northern Plain aquifer is recharged by local rainfall and discharges by subsurface flow into the Assopos Ridge aquifer. There is also a minor discharge into the llr.estone reservoir through vertical subsurface leakage in the Metamorphosis area. The aquifer is fine sandy and therefore difficult to exploit; adapted well completion techniques have to be introduced. The water quality is good; EC less than one mrrhos/cm. iii) The Neogene aquifer of the Assopos Ridge is recharged by local rainfall and subsurface inflow from the Northern Plain aquifer. The subsurface outflow towards tho southern plain is significantly less than the re­ charge, it is believed that there is vertical subsurface drainage into an unknown aquifer system in the northern part of the Assopos Ridge. The groundwater production can be increased by three MCM/year. iv) The Ncogene aquifer of the Southern Plain is recharged by local precipitation, by subsurface inflow from the, Assopos Ridge and by subsurface inflow from the Chavalla crystallized limestones north of Plytra and it discharges by subsurface flow to the sea. '

2.4 Water transfer from the Evrotas Basin The transfer of 7.5 MCM water from the Lower Evrotas Plain the Molai area is economically justified (IRR 15 percent) and V Á *'i

may be used: ;« V.v i-1e / - to replace water from saline wells in the Southern Plain^iy-i,. - to dilute saline water from the limestone reservoir 2.5 Elea area i) The Glyfada springs are the discharge points of a recharge area located in the northern part of the limestone area and probably its northwestern extension. Tho discharge which mostly occurs in sub-marine springs is unexploitable. ii) Along the Glyfada branch of the Elea-Molai fault a successful borehole (RB-1) has been drilled in the conduit to the Glyfada springs (total depth: 250 m, , 22

static water level 20 m, yield 100 m /hr, drawdown 7 m) . The aquifer is confined below -160 msl and its quality is rather poor (EC 3.0 mmhos/cm, CL~ : 19.3 meq., SAR: 7.0, irrigation class: C^Sj) . Additional boreholes may be drilled along the fault zone. The use of this rather salty water for irrig-, ation purposes has to be supervised by an agronomist.

2.3 RECOMMENDATIONS

In view of the fact that the water in the limestone reser­ voir has a high salinity and that the salinity may increase significantly, even beyond the level of suitability, if the expl­ oitation is improperly planned and operated, it is imperative that the development of irrigated agriculture be carried out step by step with long enough intervals to acquire and spread ' knowledge of:

i) aquifer response to increased abstraction rates; ii) water management, including leaching schedules to prevent accumulation of salts in the soil, and optimization of water use; Iii) updated irrigation techniques; and iv) marketing prospects in relation to cropping patterns(s) including salt resistant crops or species. More specific recommendations are given subject-wise in the following sections. 2.3.1 Irrigation development

It is recommended to: i) develop two (combined) irrigation areas of 400 ha each with water from two groups of five wells each drilled in the limestone reservoir; see working document 11 (Johnson and Zander, 1980) for technical specification on drilling; ii) transfer 7.5.MCM from the Lower Evrotat "„• "-ain to (a) replace water from saline wells to be closed down in the Southern Plain and (b) irrigate an additional 900 ha in the Northern Plain after mixing thiB water with the 23

water from the limestone reservoir mentioned under (i) to improve the overall water economy; iii) develop an additional irrigation area of 300-400 ha with water pumped from the Neogene aquifer of the northern part of the Assopos Ridge (probably best done by individual farmers of the area); iv) Improve the well completion technique e.g. by using wire-wrapped screens and appropriate gravel packs when drilling wells for private farmers in the Northern Plain and Assopos Ridge area where sanding problema are likely to be encountered; and v) Prepare cadastral map as soon as possible as a basis for planned irrigation development.

2.3.2 Management of the Neogene aquifer

In order to avoid a situation in developing areas of the Northern Plain like the one in the Southern Plain with insuffi­ cient well-spacing and uncontrolled pumping and water quality it is recommended to:

i) enforce existing water legislation concerning well drilling" and well spacing; ii) restrict pumping of water from wells with increasing or high salinity and arrange substitution from another source; and iii) control pollution through:

careful selection of sites, away from drainage channels, for waste disposal; treatment of polluting material before dumping; formulation and enforcement of rules concerning waste disposal iv) improve the efficiency of water use by: encouraging efficient irrigation practices; advising on cropping patterns that make most efficient use of the water, taking into account its quality

2.3.3 Management of the limestone wellB

i) Considering their cost on the one hand and their capacity on the other it is recommended that the wellB 24

tapping the limestone reservoir be operated by an irrigation authority or a cooperative and not by individual farmers, ii) It is recommended that the Agricultural Service supervises the use of the water from the limestone wells, to make certain that sufficient leaching is practised. iii) Water production from the limestone reservoir should be monitored, see Appendix 2.1

3.4 Agricultural trials and demonstration

It is recommended to: i) carry out studies in trial plots in the Papadhianika/ Plytra area on the effects of irrigation water salinity on crop yields; ii) establish trial and demonstration plots in the Molai- Metamorphosis area and in the Glyfada area to study and demonstrate irrigation practices when using the rather saline water of the limestone reservoir. The trial plots should be irrigated with water from boreholes EB-2 and RB-1; iii) collect and analyse data from the trial plots especially regarding - soils; - soil salinity; - crop water requirements; - le.i^hing requirements; and - effect of salinity on quality of agricultural produce ; iv) review the proposed cropping pattern when the soil map, in preparation by the Soil Science Institute, Athens, has become available.

3.5 Monitoring activities

i) continued monitoring quantitatively and qualitatively, by a team consisting of one technical assistant and one driver/assistant with car and appropriate equipment, under part-time supervision by the present senior project staff of the DLR. 25

ii) The monitoring activities should include (for details see Appendix 2.1): *

- climatological data collection - spring flow measurements stream gaugings "' - groundwater level measurements - operation and maintenance of recording equipment - water quality (electrical conductivity) measurements sampling of water for isotope analyses iii) Tho monitoring team should also during one or two years collect corresponding data in the lower Evrotas Plain. The collected data should be analysed for changes since the feasibility survey by GWE in 1971 and to establish a new benchmark prior to the implementation of the next development phase.

2.3.6 Investigation of the conduit

If and when more water is needed than can be extracted from the limestone reservoir a more detailed investigation of the conduit connecting the northern part of the catchment and the Glyfada springs should be carried out as follows: collect and interpret all available geological and hydrogeological data along the Leonidion-Molai-Xili lineament and its branches, mainly the Elea branch and the Glyfada branch. Reinterpret the geoelectrical surveys data (from GWE, 1972, and the present project) using all available geological information, especially borehole data select reconnaissance borehole locations outgoing from those shown on plate A7.2:6 as wells marked "FB"

2.3.7 Subsurface discharge pattern of the Molai Plain

Further studies on the subsurface discharge pattern of the Molai Plain are recommended. The studies should concentrate on: Thickness and sediment-petrographic composition of the ' alluvium of the mouths of Molai and Assopos River; ditto, along the Plytra-Xili coast; ditto of the Neogene in the subsurface drainage channel west of Assopos; 26

- the groundwater levels in the northern part of the Assopos ridge, in order to determine the extent, depth and variation with depth of the apparent groundwater depression in that area. - the establishment of a multiple piezometer in the northern part of the Assopos Ridge to measure the piezometric level at different points in the vertical in order to verify possible vertical drainage. - updating of the groundwater model of the Molai Plain. 27

Chapter 3

DESCRIPTION OF THE AREA

3.1 LOCATION AND EXTENT The Molai water Resources Development Project is situated in the Department of Lakonia, in the southern Péloponnèse, near the northern part of the Gulf of Lakonia; the Gulf of Xili forms the southern border (Figure 3.1 and Plate 3.1). The principal town in the Project area is Molai which is located in the northwestern part of Molai Plain and is located 70 km from Sparti, capital of the Province of Lakonia. Molai is the administrative center of the District Epidaurus Limira. The project 2 area incorporates a gross area of 300 km divided basically into 2 two areas: the catchment area of 230 km ; and the Molai Plain of 2 70 km . The Plain is about 17 kilometres long and varies in width from 10 kilometres in the north to about two kilometres in the south. The plain, as well as the principal towns and villages are accessible by paved road. At Monemvasia, a town 20 kilometres east of the plain, the area is served by daily hydrofoil (summer) service to Athens and by weekly ferry serving the principal coastal ports. A ferry travelling between Athens and Chania, Crete also stops at Monemvasia once weekly. Port facilities exist at Plytra, southern end of Molai Plain, however, at present there is no boat service. ^ < Administratively, the Province of Lakonia is headed by a governor with an office at Sparti. The Province Í3 subdivided into communities, the most important of which to the Molai Project, are Molai, Metamorphosis, Pakia, Sikea, Assopos, Finiki, and Papadhia­ nika (Figure 3.2)

3.2 PHYSIOGRAPHY Physiographically the Molai Project area can bo divided into four major units: i. Upland Catchment Area The catchment area lies to the north and at a higher elevation than the Molai Plain and consists of northweBt- GENERALIZED TOPOGRAPHIC MAP OF THE MOLAI AREA 29

southeast trending limestone mountain ridges and interior valleys (Figure 3.1). The ridges along the northeast border of the project area have the highest elevations, with several peaks of over 1200 m in height. From the northeast to west- southwest, the northwest-southeast topographic trend persists but the elevations declinv steadily to about 400 m. Within this topographic framework, the ridges and hills are somewhat smooth and rounded, the otherwise smooth contours being broken by a number of northeast-southwest scarps. The mountain ridges are rather bare. The interior valleys are covered with a layer of clays and terra rossa of variable thickness. Metamorphic rocks predominate along the western border, and the hilly or mountainous areas are more rounded than the limestone area and tend toward a rolling terrain. ii. Molai Plain

The Molai Plain is a valley with a northeast-southwest orientation. Tho border areas are well-defined scarps but with some modification due to erosion. The Plain has a general flat appearance although there is a gradual decline in elevation from about 100 m in the northeast to sea level at Plytra in the southwest. The gradient is about six metres per kilometer but the slope is not apparent due to a gentle topographic arching in the centre of the Plain. The northern one-third of the Plain is slightly depressed, with interior drainage. The southern two-thirds drain to the sea.

Iii. Tributary border areas to Molai Plain

Along the western border of the Plain are mountainous to hilly areas varying in elevation from 100 m in the south to 950 m of the Kourkoula mountains. The mountainous area is rugged with moderate to steep slopes. South of the Molai- 30 31

Elea road, the border area, representing an uplifted block, is relatively flat. Along the eastern border, tnere exists a series of topographic highs with elevation to 300 - 400 m. Although moderately dissected and/or broken by fault scarps, the area has a general flat appearance.

iv. Xili Mountains

At the southern extremity of the Plain occur the Xili Mountains which is an uplifted block that divides the southern outlet of the Plain both to the west and to the south. The mountains are rugged with moderate to steep slopes and a maximum elevation of 600 m.

3.3 CLIMATOLOGICAL CHARACTERISTICS

The project area possesses the general characteristics of the Mediterranean climate: windy, mild, wet winters and less windy, moderately hot, dry summers. Frequent out-breaks of cold polar or arctic air masses and a high cyclone activity cause, however, the climate to differ slightly from the conditions usually associated with the term "Mediterranean weather". Particularly the cooling effect during summer and the low probab­ ility of no rainfall during the summer months (maximum 65% during August) is noticeable. '

Monthly average temperatures vary between 23?7-23?9 C in July-August and 9?9-10?0 C in January-February around an annual mean of 16?5 C. The extremes vary between an average absolute low of 0?0 C in January and an average absolute high of 33?5 C in July. The rainfall data are limited but records for a twenty-year period are available in tile Molai Plain and for a two-year period for the overall project area. As is shown in Chapter 5 ' there is a rather strong linear correlation between rainfall and altitude as well as between stations. For the year 1978/79 the annual rainfall, 580 mm at Molai, was found to coincide with the median value whereas the year 1979/80 was rather wet, 707 mm, 32

with a return period of about five years. The rainfall distribution, which is illustrated in Table 3.1, is characterized by a rapid increase of rainfall in Autumn to a constant level of about 18% of annual rainfall during each of tho months November-January followed by a gradual decrease during Spring. The Winter months November- January account for 54% of the annual rainfall, whereas, surprisingly, none of the Summer months is statistically dry. Snowfall is rare in the project area but in the mountain areas above 500 metres, snowfall generally occurs at least once a year. The predominant winds are the northeasterlies; persistent, strong and gusty. Strong southwest winds of short duration are experienced sometimes, mainly during Winter, hut they are rare, being associated with unusual, transient pressure patterns. Dry south winds of moderate strength can be observed, mainly during summer, but they die out rather quickly.

Table 3.1

AVERAGE RAINFALL DISTRIBUTION IN THE MOLAI AREA

Month JFMAMJJAS OND % 19 11 8 5 3 1 1 1 3 13 17 18

3.4 DRAINAGE

The surface drainage pattern of the project area is relatively simple in that in the catchment area there is practically no "surfacé water outflow. There is local surface flow to depression areas (interior valleys, dolinüs etc), ponding of water, and rapid infiltration through solution openings. In the Molai Plain, the surface runoff from the northeastern half of the Plain, including the inflow from the Potamia River, northwest of the Plain, drains via a man-made drain to the sink­ hole near the village of Metamorphosis. Due to a limited inflow I 33 capacity of the sinkhole, flooding of the surrounding area occurs if surface inflow exceeds 1.8 m3/s. In 1979/80, flooding occurred on four occasions; largest area flooded was 2 about 0.7 km . The flood water however, generally remains for a few days only (see Chapter 6). During 1978/79, there was no flooding. In the centre and southern portion of the Plain, the Molai River originating at Molai, drains the centre and western portion of the Plain, turning westward opposite Assopos to discharge into the Gulf of Lakonia. The eastern and south- central portion of the Plain is drained by the Assopos River which flows diagonally across the Plain from northeast to southwest and discharges also into the Gulf of Lakonia. The two rivers flow infrequently and seldom actually discharge into the sea.

3.5 HISTORICAL NOTE OF THE AREA

The District of Epidaurus Limira lies in the southeastern peninsula of the Péloponnèse. It was first populated during the Neolithic Age when Greece was occupied by its first inha­ bitants. Proof of these settlements was found in Apidia, Assopos and other parts of the district. Excavations carried out found tools made of stone, pottery, statuettes, and ruins of ancient buildings and graves. These excavations were mainly carried out by the British archeological School of Athens. Most of its ancient history is still to be worked out. However, one thing is certain and that is the fact that its location was close to the centres of the Mycenepn and Minoan civilizations which made it an important place.

During the Bronze Age the whole southern Péloponnèse was occupied by the Leleges tribe. They apparently constructed the city Epidaurus Limira, on the coast, north of present Monemvasia. The buildings of the settlement were constructed mostly of rocks and mud. According to Herodotus the Leleges were followed by the Acheans. At this time the city of Epidaurus Limira, north­ east of Monemvasia flourished and reached the peak of its civilization. There was a well-developed trade with other centres of Greece such as Crete, Cyclades, Athens, etc. ,34 i

i

The cyclopean walls of the ancient city of Epidaurus Limira are still intact to about two thirds of their original height. Its name is derived from the ancient and famous city of Epidaurus of Argos which was rich and prosperous. According to Thucidides, to distinguish the two cities with the same name, the name Limira meaning poor was given to the city of Epidaurus near Monemvasia, and hence the name Epidaurus Limira. As a consequence of its location half-way between Crete (Knossos) and Mycenae, it benefitted considerably from the two civilizations.

The next important ancient town in the area was located east of present day plytra. It may have been the former location of Assopos. It was built by the Dorians when they invaded Lakonia. During the invasion of the Dorians, all of the cities were conquered and thus lost their independence. The Spartans settled their own governors and took complete control over the area. Several battles are reported by Pausanias and Thucidides between Spartans and Athenians for various cities, especially Elos which was a very important and famous port at that time, on the delta of Evrotas River on the West side of the Kourkoula Mountains. During Roman times the coastal cities flourished and grew into larger ports and commercial centres. Assopos was made a* holy city. Autonomy was granted by Rome and this furthered their financial and commercial progress. In 375 A.D. the town was hit by a severe earthquake which submerged it under the sea. The ruins can still be clearly seen at the bottom of the sea not far from the coast on the east side of Plytra. The spectacular development during the Roman times of this part of Péloponnèse also continued during the Byzantine times. The city of Monemvasia was founded by the Slavs during their invasion in the fourth century, it developed into the motît. important commercial centre of Péloponnèse until the appearance' of Mystras (near Sparta) during the mid Byzantine era. 35

The town of Molai was probably founded during the Ottoman empire. It was first built at a place called Panayitsa, about 1 km along the path leading from Molai up the Kourkoula Mountain, because the hill was used as the acropolis of the town. Molai is named after the windmills found on the neigh­ bouring mountains. Another explanation is that the name Molai is derived from the word "molas" which was the name given to a moslem priest during the times of the Ottoman Empire. However, due to the fact that Molai is in plural the second explanation may be discarded. The Molai area is located in the region that formed on 23 March, 1921 the nucleus of present day indépendant Greece. 36

Chapter 4

GEOLOGY

4.1 INTRODUCTION

The Molai area is located in the base of the eastern peninsula of the Péloponnèse. It consists of a karstic lime­ stone catchment and a faulted graben-like plain overlain by thick Neogene sediments. The Plain is trending northeast- southwest and onens to the Lakonian Gulf. In the Molai Project area, Paleozoic, Mesozoic, Neogene and Quaternary rocks are distin»guished. The area is a geolog­ ically complex area that was subjected to overthrusting and blockfaulting. The main directions of the faults are northwest- southeast and northeast-southwest. The main geomorphological units in the project area are the Molai Plain and the mountainous catchment area. The stratigraphie units found in the Molai area are: Quaternary deposits: They are Jocally present along the northern and northeastern boundaries of the Plain, along the shore and in the depressions of the catchment area. Neogene deposits: They cover the main part of the plain. Upper Triassic, Jurassic and Cretaceous rocks: They occur as Tripolitza limestones and dolomites in the northern catchment area. Lower Triassic and Permo - Carboniferous rocks: They are known as Tyros Formation and represent the upper part of the Phyllite Series "sensu lato" or semi- metamorphic basement. Phyllite Series "sensu stricto". : Marbles and crystallized carbonates.

This chapter is mainly based on previous studies and publications. Extensive bibliographies are found in Herak (1979) and Brauer, et al (1980). The studies made by the project are: Geoelectrical survey in the Molai plain executed by Minerex Ltd, Dublin, Ireland (1979), to improve the 37

structural picture based on the geoelectrical survey of German Water Engineering (1972). Structural mapping of the Tripolitza carbonates in the catchment area. Reconnaissance geological mapping in the Elea - Glyfada - Xili area and in the Plytra area. Study of the available aerial photographs (scale 1 :20 000) and landsat (satellite) imagery. Drilling of boreholes at seven locations. The lithological logs of these boreholes and those of formerly drilled holes are presented in Appendix 4.1. For the preparation of the geological map extensive use has been made of the 1:10 000 scale maps of the areas along the southeastern and western margins of the Plain prepared by Dr. Kowalczyk and his students from the Geological Institute of the University of Frankfurt am Main, F.R. Germany.

4.2 REGIONAL SETTING

The Péloponnèse is part of the Hellenic chains which are a prolongation to the southeast of the Dinarides structure which continues to Crete, Rhodes, and Asia Minor. In the Péloponnèse the following geotectonic zones have been distinguished (Figure 4.1): Preapulian foreland zone which is present on the Island of Zakynthos. Ionian miogeosynclinal zone which is considered to underlie the Tertiary in the western Péloponnèse. Tripolitza - Gavrovo zone which represents a threshold with shallow water sedimentation. Pindos - 0lono3 zone which represents a trough with possible oceanic influences. Parnassos zcne which is present in a small area southwest of Korinth. Eastern Hellenic zone which is present in the Argolis. They have formed a series of tectonic nappes with the Preapulian foreland at the bottom and the Eastern Hellenic zone on top. 38

" Ionian •.•.tili»«)* -LXX- Thrust Fault j.': Iii Tripolitzo'Gavrovo J. J. a. probable Thrust Fault

] Pindó»-Olonot Foult

• Probable Fault Parnasto»

>:*.vi* Eastern Hellenic

SKETCH MAP OF GE(.'TECTONIC ZONES OF THE PELOPONNESE

Km FIGURE 4.1 In the southern Péloponnèse only rocks related to the Ionian zone and the Tripolitza - Gavrovo zone are known. The depositional cycle In both zones consisted of the deposition during the Mezozoic of mainly carbonate rocks on a basement of metamorphic Upper paleozoic layers. The carbon­ ate phase was followed unconformably by Tertiary flysh deposits. After -the alpine orogenic movements Neogene sedi­ ments covered parts of the area. The Ionian deposits of the Péloponnèse consist from top to bottom, according to the Institute of Geology and Mineral Exploration (IGME) of:

100 m Well bedded, coloured marbles with chert inter­ calations known as the "platty limestones" or "colourful marble member", 200 m Dark coloured, siliceous marbles with quartzitic layers and dolomitic marbles near the base, 60 m Quartzitic beds with fossils (Poseidonia), 300 m Massive milky to light grey marbles with frequent lenses of chert (Pantocrator marbles).

The metamorphic basement of the Ionian zone has nowhere been found yet, nor has the Ionian flyah been recognized with certainty. The Tripolitza Series is, according to IGME, composed of: 300 m Flysh deposits consisting of greyish sandstone and sandy marls with lenses of conglomerate and limestone, unconformity, 500 m Grey to black micritic limestones, massive, poorly bedded with brachiopodes, pinky coloured towards the bottom, 300 m Dark to light grey dolomites and dolomitic lime­ stones coarse grained at the bottom and finer at the top, unconformity, 500 m Volcanics, mainly andésites of the Tyros formation, 300 m Psammitic schist member of the Tyros formation, unconformity ? 400 m Phyllites (sericitic schist member) The Phyllites are considered by some authors as the pre- Carboniferous autochtonous base of the Tyros Formation. Others consider it as metamorphosed Eocene flysh of the Ionian zone, separated from the Tyros Formation by an overthrust plane. The authors who consider the Phyllites as part of the semi- autochtonous basement of the Tripolitza Series admit an over- thrust piano between the Phyllites and the presumably under­ lying marbles of the Ionian Series. For further details on the discussion about the position of the metamorphic rocks in the southern Péloponnèse see Herak (1979) and Brauer, et al (1980). Post-Alpine deposits are widely present in the Péloponnèse. In the Molai area the deposits are of Pliocene, marine origin (Psarianos, 1955). They have accumulated in the depressions which were formed by the blockfaulting and the subsequent erosion. Consequently they coyer different lithostratigraphic and structural units such as Tripolitza carbonates, Tripolitza basement, marbles, graben-like troughs, ridges or horsts, etc. The different bedrocks influenced the composition of the lower­ most (transgressive) bed of the Neogene. It consists at some places mostly of calcareous fragments, at other places of fragments of the semi-metamorphic rocks of the Tripolitza basement or of marble breccias. However, the Neogene deposits in the Molai area are composed mainly of alternating layers of silt, clay and marls with intercalated layers and lenses of gravel (diameter 5 cm) and sand and sandstone. Limestones are subordlnately present. Quaternary deposits occur in different forms such as beach deposits, alluvial fans, cemented stream deposits, dunes and terra rosa deposits in karst related depressions. The Project haB adopted the following working hypothesis concerning the regional geology:

During the Mesozoic era carbonate deposition took place in the Ionian and Tripolitza geotectonic zones of the Tethys geosyncline. In the Tripolitza zone the carbonates were deposited on a basement of semi- metamorphic Permo-Carboniferous rocks, the Tyros Formation. In the Ionian zone the basement is unknown. 41

After the deposition of the Tripolitza carbonates the area of deposition emerged and may have possibly been partially folded disturbed and karstified during the lower Tertiary when flysh deposition occurred in the Ionian zone. During the Miocene the two parts of the Tripolitsa Series {Tyros Formation and Tripolitza carbonates) have overthrust the deposits of tho Ionian zone. The latter were deeply buried and metamorphosed into marbles and crystallized limestones (Mesozoic car­ bonates) and Phyllites (flysh). They are now the lowermost tectonic unit within the depth which is of interest for grourdwater studies. The overthrusting CÍ .sed displacements of the décolle­ ment type between the Tyros Formation and the Tripolitza carbonates. The overthrusting was followed by blockfaulting, which started in the Miocene and continues till present. The emerged blocks were subject to erosion. The newly formed^ depressions were transgressed by a Neogene sea in which the erosion products accumulated. Rejuvenated vertical movements of "blocks" caused oscillation in the sedimentation areas and possibly the sporadic "penetration" of marble units through the Tripolitza basement.

4.3 GEOMORPHOLOGY

The project area is composed of different morphological units. These are: - Molai Plain, covered by slightly consolidated sediments of the Neogene and Quaternary. Mountainous catchment consisting of karstified limestone. - Kourkoula Mountain, West of the Plain, consisting mainly^of marbles. - Hills along the East side of the Plain consisting of metamorphic rocks in the Sikea - Finiki area and crystallized limestones of tho Chávala mountain, 42

4.3.1 Molai Plain

The Molai Plain is a northeast - southwest directed structural valley bordered by steep faults. The northern boundary against the mountains of the catchment is marked by the 100 m contour line. The valley slopes towards the sea at Plytra at the southern end of the Plain. In the middle of the valley is a small rise (Assopos Ridge), several kilo­ metres wide and directed from northwest to southeast, which is structurally controlled. Hence, the Molai Plain is subdivided into the Northern Plain, Assopos Ridge and Southern Plain. Drainage of the Northern Plain is towards a sinkhole system southeast of Metamorphosis. This is the largest sink­ hole in the project area. The rest of the Plain is drained by two streams: the Assopos and Molai rivers. These rivers cut through a, presently 20 m high, narrow ridge of metamorphic rocks that separates the Molai Plain from the Lakonian Gulf. The top of this ridge is nowadays at a much higher elevation than the outlet of the Plain towards the sea at Plytra. This suggests that the western part of the valley was at one time at a lower level than the southern end. The vertical erosion by the two streams apparently kept up with the rise of the metamorphic rocks and consequently they did not change their courses towards the south. Sea level changes have occurred frequently due to young tectonic movements as well as to the effects of the ice ages. For example near Plytra, old Quaternary marine terraces at a level of 100 m above present sea level indicate a sea level lowering, while on the other hand the drowning of the Mycenian ruins of ancient Assopos (near Plytra) show a relative rise of the sea level in recent times.

4.3.2 Catchment area

The catchment area consists of carbonate rocks of the Tripolitza Series. It exhibits a distinct karst landscape which has been rejuvenated and structurally controlled. 43

The catchment has a number of parallel ridges trending northwest - southeast with elevations from 1200 m down to 100 where they merge with the Plain, ht a level of 500 - 600 m there is a general flattening of the land surface and there exist internal drainage basins and depressions. Because of the importance of karst features a brief review of the process of karstification is included in this section.

4.3.2.1 Principles of karstification

Karstification is produced by the solution of carbonate rocks in the waters which come in contact with them as well as the mechanical removal of calcareous fragments. Karst development is controlled by the local geologic structure and the hydrologie conditions. Secondary or acquired permea­ bility results from joints,fractures and faults produced during the process of diagenesis and diastrophism and from solution openings created by the action of groundwater on joints and bedding planes fkarstification).

Circulation of groundwater and the eventual enlargement of the existing joints in rocks susceptible to solution takes place in a vertical and horizontal direction. The vertical enlargement takes place in the joints where the water moves downwards from the 2one of infiltration to the 2one of satur­ ation. On the other hand horizontal enlargement starts where the groundwater meets a barrier of impermeable rock, Tyros Formation in the project area, or a base level controlled water table and" thus vertical movement is changed to a sub- horizontal one. Vertical karst development is most prominent during the youthful stage, horizontal karst development during the mature stage of the karstification process. Thus direct infiltration of the precipitation favours diffuse groundwater circulation and eventual enlargement of the joints over a wide area. Surface run-off and surface concentration of water leads to concentrated groundwater circulation as the water passes over outcrops of different 44

permeability and to rapid infiltration into the most jointed zones. Such localized infiltration will rapidly enlarge the openings and hence produce sinkholes and other such features. Thornbury (1954), lists the following conditions for the full development of karst: The presence of a soluble rock such as limestone or dolomite at or near the surface is a primary

condition. The free access of C02 enhances solution. If the -soluble rock is dense, it should be highly jointed, and preferably bedded. Permeability exhibited by numerous joints and bedding planes, along which the water finds preferential ways, is most favorable. Circulation of groundwater in the presence of free . CC<2 is essential. The amount of rainfall should be moderate to abundant. The conditions for the development of karst are favorable*^ in the catchment area of the Molai Project: The limestones and dolomites of the Tripolitza Series outcrop extensively in the northern and eastern part of the project area and beyond. They reach a great¡thickness partly caused by repetition of the strata due to tectonic movements (section 4.5.2). Fracturing and jointing has been very intensive and is very pronounced near the major faults. There are two joint systems that make an angle of 60 to each other. The two groups of joints strike at 330° and 210°, dipping Southwest and Northeast respectively. The direct contact between the carbonate rocks and the sea, the absence of impervious layers and an adequate amount of rainfall (see Chapter 5) assure a good groundwater circulation. 45

4.3.2.2 Karst features

The first karst development in the area may have started as early as the upper Eocene, when the sea regressed for a relatively short period. However it did not produce recog­ nizable features of paleokarstification. Karst features were mainly produced in the block-faulting era, which started in the Miocene and continues till ^jrasent. They are found from the top of the mountains (for example, the karst chimney emerging at the top of the Megalo Vouno north­ east of Metamorphosis at an elevation of nearly 700 m) to ' hundreds of meters below sea level (for example, at least 200 m below sea level in borehold EB-2). Tho enormous thickness over which the karst has developed is a proof of the intensive vertical movements the area has been and still is subjected to. The geological map (Plate 4.1) shows how most depressions are elongated parallel to nearby faults. Either parallel to the northwest - southeast faults which are parallel to the strike direction of the carbonates, or parallel to the crossfaults (Ayios Dimitrios fault and Koupia - Mavrovouni fault) in a northeast - southwest direction. Many small sinkholes appear to have been formed by the collapse of a section between two joints usually belonging to the system that strikes in the direction 210°. During the drilling of the project's exploratory and reconnaissance wells it was found from the cores that the open­ ings in the carbonates are rather small. They range from a few millimeters to 5 cm. Bit drops during drilling were infrequent and small. The largest drop of,a drilling bit was encountered in borehole OB-1 where the bit dropped 30 cm. This happened at a depth of 19 m below surface, which is about 50 m above the present water table. Many of the openings are partly filled with calcite crystals of various size. Tho jointing is some­ times so intensive that the rock has been reduced to pieces of less than 1 cm across. When such zones were drilled serious caving occurred. The zones which have been highly fractured and are therefore believed to have the highest 46

permeability are much easier drilled than the less jointed and therefore less permeable rock. Infiltration of precipitation is favoured by the absence of a soil cover over most of the catchment area. Only in the depressions a layer of fine material covers the carbonate rock. The thickness of these terra rossa layers is not more than a few meters. These depressions collect any runoff water that may occur after heavy rainstorms. There is no integrated surface drainage system in the catchment area except along the southern boundary where steeply incised valleys run towards the Molai Plain and discharge any flood they may carry into the sinkhole east of Metamorphosis.

4.3.2.3 Karst type

The karst of the Péloponnèse can in general be classified according to Heraks (1977) classification as "dissected orogenic karst" and to a lesser extent as "accumulated orogenic karst". "Dissected orogenic karst" is the karst type which has been produced by bectonic disturbances and erosion, reaching down to the impervious non-carbonate karst base. "Accumulated orogenic karst" implies great primary thickness of rocks, karstification below the deepest valleys and sometimes below present sea-level. The "dissected orogenic karst" type predominates due to the fact that a former large "platform" consisting of Ionian and Tripolitza Zone carbonates was broken up and gave rise to numerous smaller size carbonate areas which thus developed their own karst environment with particular karst forms and subsurface water drainage systems'. The karst features of the carbonate rocks in the area (depressions, 'sinkholes, chimneys) are ,fewer in the marbles of the Ionian series than in the limestones and dolomites of the Tripolitza Series. This is mainly duo to tho fact that the former have been affected by>metamorphism thus exhibiting a stronger resistance to the solution effect of the ground­ water. Moreover wherever they have been covered by the over- thrusted Tripolitza Series they have been much less directly exposed to karstification. 47

4.3.3 Kourkoula Mountain

The Molai Plain is flanked along its west side by the Kourkoula Mountain, 950 m high, trending north - south. Due to its petrologic composition - marbles and phyllitic rocks - it is much less dissected than the catchment area and there are only few distinct karst features. There are a few small depressions "and sinkholes on the highest part of the mountain in the white marbles and two small chimneys near Pakia (Plate 4.1) . However there is not much surface runoff indicating good infiltration conditions.

4.3.4 Eastern margin of the Plain

Along the eastern margin of the Molai Plain, between Sikea and Plytra, non-carbonate metamorphic rocks and volcanics of the Tyros Formation are preponderant in the north, giving way to a preponderance of crystallized carbonates in the South (Chávala Mountain). Over the non-carbonate rocks a surface drainage system is developed. It drains partly to the North towards the sink­ hole East of Metamorphosis and partly to the West into the Assopos River. Along the edges of carbonate caps on top of the impervious rocks of the Tyros Formation many springs occur. The Chávala Mountain (521 m) consista of crystallized carbonates without a well-developed surface drainage system. This implies good infiltration properties and therefore mostly subsurface drainage.

4.4 STRATIGRAPHY

4.4.1 Quaternary

The Quaternary deposits consist of Recent and Pleistocene terraces, talus cones, alluvium, beach sands, dunes, hard conglomerates cemented with red marl, etc. Their extension is limited to the boundaries of the Plain. They are relatively thin except along tho northern boundary where breccious conglomerates reach a thickness of 90 m. In the catchment area Quaternary terra rosa deposits of a few meters thickness cover the depressions. 48

4.4.2 Neoqcno

The Neogcne sediments which occur in the Plain, can reach a considerable thickness. According to the geoelect- rical survey they are probably more than 600 m thick in the Northern Trough and more than 450 m in the Southern Trough. Over the Assopos ridge they have a thickness in the order of 200 m. These deposits have a rather high lime content although limestones are rare. They consist mainly of yellow and reddish and blue-grey marls or marly clays with admixture of very fine sand. Intercalations of coarser sand and of well-rounded siliceous gravel are present. According to Kowalzcyk (personal communication, 1979), there is no known nearby source-rock for the gravel. The;general absence of coarse material derived from the hills surrounding the present

plain is to be noticed. ( In the marls and marly clays marine fossils (molluscs and gastropods) have been foulnd. Also pieces of wood have been encountered.

4.4.3 Paleogena

The Paleogene is in the Péloponnèse represented by flysh deposits of the Tripolitza Series. However, these are not present in the projectiarea. The Paleogene may also be represented by the Phyllites "sensu stricto" that are found below the Tyros Formation. According to Lekkas and Papanicolaou (1978) they represent the metamorphosed Eocene flysh deposits of the Ionian Series. In borehole RB-1 drilled by the Project southeast of Elea (X: 661.905, Y: 4068.5(5)^çhf> following sequence was f°UndS WPP, .7^,- ' 0 - 80 m Soft Neogerta Br taua^j^nary conglomerates in a red and ..y'<áál¡é&Bmy¿mátrix 80 - 165 m Black sericitic ph'yllltes with thin intercalations of white, milky, coarse crystallized marble 165 - 250 m Bluish-white crystallized limestone (marble) identical to the limestone out­ cropping at the entrance of the harbour of Elea. 49

This sequence seems to indicate that there is a gradual change from the Elea-type crystallized limestones (marbles) i into the Phyllites. A similar sequence is found along the road due west of Molai up to the Kourkoula Mountain.

4.4.4 Middle Trlasslc - Upper Cretaceous

This is the period of deposition of the thick carbonate layers both in the Tripolitza Zone and in the Ionian Zone of the Tethys geosyncline. The carbonates of the Tripolitza Zone have boon deposited in a shallow marine environment, while the ones of the Ionian Zone are deep water deposits.

4.4.4.1 Tripolitza carbonates

The Tripolitza carbonates are a pure carbonate facies with dolomites at the base, in direct contact-with the Tyros Formation, gradually changing into pure limestone on top. The dolomites are of Triassic age. They are composed of dolomites and dolomitic limestones of dark to light grey colour. They are well, sometimes thinly, bedded. The dolomite crystals are coarser at the bottom and finer at the top. In general they exhibit a perfect rhombic cleavage. Within the dolomites are found alternating dark micritic and light microsparitic laminae which have been interpreted by Merkel (1978) as former algal layers.

In Kremasti (X:666.70, Y:4093.95) an undisturbed sedim­ entary contact between the dolomites and the underlaying Tyros formation has been found (Figure 4.2). The basal layers consist of coarse psammitic limestone. The limestone grains are subangular and have the same colour as the marbles inter­ calated in the schists from which they may have been derived. Similar contacts between the yellow psammitic limestone at the base of the Tripolitza dolomites and the Tyros formation have been found south and west of Apidia (X: 662.40, Y : 4081 .14 and X: 660.00, Y: 4082.80). In many other places the contact between the Tripolitza carbonates and the underlaying Tyros formation is disturbed due to their different resistance to the orogenic movements. The dolomite member reaches a maximum 50

- Microcrystolline, Qrey dolomite»

Coarse grained,ochre color, psommitic limestone (Many geods •are filled with calcita ). Thinly layered. Layer» 2-5om thick. t: ' :

t — • i Grey, coarse groined limestone Brown,coarse grained dotomitic limestone ' . - 4 Coarse grained, grey limestone Erecciated.grey limestone Coarse grained, yellow-brown dolomite limestone Dark grey, medium groined dolomific limestone Dark grey-brown medium grained limestone

* t >N-Yellow psommitic limestone ». • .* , * ,u Yellow- brown medium grained limestone Yellow psommitic limestone Light brown-grayish, medium grained limestone I. . •i . i -Light grey, coarse to medium grained limestone ,'<•}>

•|V'|.J-T Medium grey, medium grained dolomitic limestone

r-p-H —H

K r"7-i Light grey, medium groined dolomite U.—J.J..

Yr r Grey schists with the (

KREMASTI NORMAL CONTACT BETWEEN PHYLLITES AND DOLOMITES

Scole ° i 2 m ÍFIGURE 4-2 51 thickness of 300 m and its age is Middle to Upper Triassic. A bituminous layer which has a strong hydrogen sulfide odour marks the top of this member. The dolomites are conformably overlain by a, reportedly, 500 m thick sequence of rather pure limestones of Lower Jurassic to cretaceous age. They start with a fossiliferous, milky, pink, micritic unit (good marker bed) of Lower Jurassic age at the base, overlain by light to dark grey, micro- crystalline, poorly-bedded limestones. Fossils include brachiopodes. In the project area the top of the limestone has been eroded to an unknown depth.

4.4.4.2 Ionian carbonates

All the metamorphosed, recrystallized limestones and the marbles encountered in the Project area have been grouped together on the basis of their metamorphism which differentiated them from the Tripolitza carbonates. The crystallized lime­ stones and marbles have been tentatively correlated with the upper part of the Ionian Zone deposits. However, more detailed studies of these rocks are necessary for their further class­ ification. The upper part of the Ionian Zone, as described in Section 4.2, consists of microcrystalline, white-pinky, well-bedded, highly fractured marbles with chert intercalations, known as the "colourful marble member" or "Platy Limestone". The marbles found in the project area are of the same colour and texture as the colourful marbles of the Ionian Zone, but they lack the bedding and the chert lenses. Differences in the degree of metamorphosis of the lime­ stone have been observed. The marbles from the Kourkoula are coarser and more'metamorphosed, than those of Elea, Xili, Sikea and Angelona. The lower members of the Ionian Series do not outcrop in the study area. 4.4.5 CarboniferouB, Permian, and Lower Triassic

The sediments of the Permo-Carboniferous and lower Triasaic are in the Péloponnèse known as the Tyros Formation. 52

They form the semi-metamorphic basement of the Tripolitza carbonates and are the lowest part of the Tripolitza- Gavrovo nappe. The classical Tyros Formation is a low metamorphic unit consisting of thinly bedded, grey and brown, serecitic schists, psammitic rocks and some layers of guartzite and thin inter­ calations of crystallized limestones and dolomites, inter- fingering with sericitized andésites and tuffs. In the Molai area it seems to be associated with much more crystallized limestone than is elsewhere encountered.

4.4.6 Precarboniferous

The Phyllites below the Tyros Formation are by some authors considered as the pre-carboniferous, autochtonous, semi-metamorphic base of the Tyros formation and therefore part of the Tripolitza Series. The results of RB-1 (see Appendix 4.1) located southeast of Elea (X: 666.905, Y: 4068.56) show, however, a close association with the underlaying marbles. This indicates a Mezozoic or lower Tertiary age (see Section 4.4.3) and a connection with the Ionian Series.

4.5 STRUCTURE

4.5.1 Main tectonic events

Two main tectonic events have formed the structure of the project area: OverthruBting of the geotectonic zones. This brought the Tripolitza unit, consisting of the semi-metamorphic basement (Tyros Formation) and the Tripolitza carbonates on top of the sediments of the Ionian Zone. Consequently the latter were deeper buried and became marbles and phyllites. Blockfaulting. After the period of overthrusting but prior to the deposition of the Neogene sediments, the area was subjected to severe blockfaulting, followed by erosion of the horsts and deposition in the grabens. These vertical movements are continuing till the present day. 53

4.5.2 Structural elements

The Molai area is located at the junction of two major faults, the Elea - Molai fault and the Mavrovouni - Sikea - Ayios Ioannis fault (Figure 4.3). These faults separate three main structural units:

i. The Kourkoula Mountain, west of the Elea - Molai fault, consisting mainly of marbles, crystallized limestones and phyllites. li. The Tripolitza carbonate area, north of the Mavrovouni - Sikea - Ayios Ioannis fault and northeast of the Elea - Molai fault. In this area two fault systems are present: A northeast dipping system of reverse faults, which has caused repetition of the strati- graphic sequence (see Plate 4.2) A steeply southeast dipping system that divides the area in blocks. The most apparent repres­ entatives of this system are the Ayios Dimitrios fault and the Koupia - Mavrovouni fault iii. The area with mostly semi-metamorphic basement rocks and caps of lower Tripolitza carbonates, located south of the Mavrovouni - Sikea - Ayios Ioannis fault and east of the Elea - Molai fault.

Structurally the Molai Plain belongs to the last unit and is a graben formed at the junction of the Elea - Molai fault and the Mavrovouni - Sikea - Ayios Ioannis fault. Along the main faults the Tripolitza carbonates may come into direct contact with the marbles and crystallized carbonates attributed to the Ionian Zone. This is especially so along the Elea - Molai fault. The relative vertical displacement of the different structural units has been considerable. Along the main faults they are in the order of 1 000 - 2 000 m. Within the Molai Plain itself up till at least 600 m. 54

FIGURE 4.3 •t.+t*et • m.

55

A satellite image of the southeast Péloponnèse showed that the Elea - Molai fault is part of a fault system extend­ ing from Xili till Leonidion, 70 km north of Molai (Figure 4.4).

4.5.3 Structure of the Molai Plain

The Molai Plain, which is a northeast - southwest directed graben, has been broken up into three units (Plate 4.1 and 4.2). The Northern Trough with 600 m of Neogene sediments. The Assopos Ridge with 100-200 m of Neogene sediments overlaying a horst of metamorphic rocks. The Southern Trough with 450 m of Neogene sediments also overlaying metamorphic rocks. A narrow sub­ surface ridge possibly consisting of crystallized limestones separates the Southern Trough from the Xili Gulf. The geoelectrical surveys have identified a large number of faults. An interesting feature in this respect is the small graben which'crosses the western part of the Assopos ridge. It is not possible to make a statement on the character of the basement of the Neogene in the Northern Trough. On the Assopos ridge the basement of the Neogene has been encountered in the boreholes Z - 33 (MS-1 of GWE) and A-127 located at X: 667 .-39, Y : 4070.44 and X: 666.10, Y : 4067.35, respectively and in borehole RB-4 located in the Southern Trough at X: 664.32, Y : 4064.73. 56 57

Chapter 5 CLIMATOLOGY

5.1 INTRODUCTION

This Chapter deals mainly with the precipitation climate of the project area. Other climatological parameters have been dealt with more briefly, except minimum temperatures and evapor­ ation which were made the subject of special studies in Working b c Documents No. 5.(Samuelsson, 1980 ) and No. 6.{Samuelsson, 1980 ).

5.2 CLIMATOLOGICAL OBSERVATIONS

In 1978, at the beginning of project operations, there were only two climatological stations in operation in the project area, at Assopos and Molai. The Assopos station which started operating in 1971 was equipped with rainfall recorder and check-gauge, maximum and minimum thermometers, thermohydrograph, and Cla^r; A evaporation pan. The Molai station was, and still is, equipped with rainfall recorder and check-gauge only. Its records, with many gaps though, go back as far as 1952. At an early stage of the project the climatological network was extended' considerably by setting up 15 rainfall stations, four of which were equipped with rainfall recorders. The sites of the new stations were selected so as to be as evenly as poss­ ible geographically and topographically distributed (see Table 5.i and Plate 5 i 1). Parallel to the installation of new stations, the Assopos station was up-graded by the installation of wind-run anemometer, Campbell-Stokes heliograph, ventilated Psychrometer, and baro­ graph. Inspections of the stations combined with training and checking the observers and maintenance of equipment were under­ taken on a monthly basis. Climatological data collected by the project have been included in Working Document No. 8,(Pazis and Zervakos, 1980), two copies of which were prepared and handed over to the Government. 58

5.3 CLIMATOLOGICAL CHARACTERISTICS

The project area possesses the genaral characteristics of the Mediterranean climate: windy, mild, wet winters and less windy, moderately hot, dry stammers. In comparison with other parts of the Mediterranean, however, there are two factors influencing the climate of the Aegean and eastern Greece, and, consequently, the project area, which cause it to differ slightly from the conditions usually associated with the term "Mediterranean weather". The first factor relates to the fact that the Mediterranean, seen as a whole, is fairly well protected against cold polar or arctic air masses by the mountain ranges to the north. There are four gaps in those mountain ranges, through which tho outbreaks of cold air masses into tho Mediterranean mostly occur: the Garonne - Carcassone gap, the Trieste gap, the Vardar gap, and the Dardanelles. The last two gaps are facing the Aegean, consequently, this part of the Mediterranean and surrounding land ÍB more exposed to the cold continental air masses than are most other parts ot the Mediterranean area.

The second important factor concerns the project area's location, ir. the southernmost Péloponnèse - Crete realm on the crossroads between the two major Mediterranean cyclone tracks : the polar front disturbances (cyclones originating in the North Atlantic or in the Gulf of Genoa) and the Mediterranean front disturbances (cyclones originating in the Sahara desert). As a result, the cyclone activity is among the highest in the Medit­ erranean except during the three summer months June - August. These two factors combine to produce rather exceptional wind conditions with an annual frequency of gales of 2.0 compared to 1.5 in the Adriatic and less than 1.0 in the CypruB area. They also produce slightly modified temperatures; particularly the* cooling effect during summer is noticeable. Typical for the area of southern Péloponnèse - Crete, also, are the steady winds of moderate strength blowing from a north­ erly direction (in the project area mostly from northeast) during July and August and which are maintained by the summer anticyclone over Russia and the summer low in tho Mediterranean. 59

Table 5.1

CLIMATOLOGICAL NETWORK IN PROJECT AREA

(RR = rainfall recorder; 0 = outside project area)

Long. Lat. Alt., msl. Station Remarks UTM Coordinates

Skardolakka 669.48 4065.17 460 RR Molai trans­ former station 668.76 4073.30 90 RR, max. min thermometers Proph. Elias 676.30 4078.37 850 RR Ag. Ioannis 679.85 4078.00 530 RR, 0 Niata 664.40 4085.70 340 RR Kremasti 666.65 4094.47 800 Lambokambos 675.50 4085.78 540 0 Ag. Dimitrios 662.35 4089.42 350 Koupia 669.06 4082.13 540 Molai 665.15 4074.89 240 RR Metamorphosis, 670.84 4074.85 110 Sikea 673.53 4070.50 170 Apidea 659.62 4083.72 220 Finiki . 669.94 4067.40 170 Assopos 665.80 4067.00 70 RR, other in­ struments Elea 661.02 4069.21 10 Plytra 664.50 4061.90 10

The regularity of these winds has been recognized throughout the history of man and is also embodied in the name: Etesians, from the Greek word ctifobos = annual.

5.4 PRECIPITATION

The project area is surrounded by mountains or hills in all directions except to the southwest. The common northeasterly winds, which during winter are mostly associated with precipit­ ation, have to pass these topographical barriers before reaching 60

the project area, which, due to the orographic effect, then lies in a rainshadow. During southwesterly winds, on the other hand, the area would act as a precipitation collector, but such winds are not only much less frequent but also, normally, carry less moisture than the northeasterlies. The precipitation over the project area would therefore, be expected to be lower than on the northeastern to eastern side of the bordering mountains. By comparing the records from two rainfall stations, Lambokambos and Ag. Ioannis, both situated east of the project area, with those from stations at the same altitude but within the project area, the rain-shadow effect is clearly demonstrated: The precipitation on the eastern side of the mountain is 30 - 45 percent higher than in the project area, and the distribution in time is different, thus confirming the difference in rainfall regimes. Clearly, the two years of data collection by the project does not allow any statistical conclusions regarding frequency distribution. Two factors contribute, however, to bridge the gap of statistical knowledge. One is the fact that there are on an average 23 years of monthly rainfall data available from Molai (the records have frequent gaps; therefore the wording "on an average"); the second is that the correlation between monthly rainfall at Molai on the one hand and at other stations in the project area on the other is very close with an average correlation coefficient of 0,90. Based on the frequency distribution of annual rainfall at Molai it can be concluded that the first year of the project studies, 1978/79, was a "normal" year (actually the median of the 21 year series of annual rainfall, 580 mm, was exactly the amount recorded during that year), and that the second year, 1979/80, was rather wet, 707 mm, with a return period of around five years. Characteristic for the rainfall pattern in the project area is the very strong influence of altitude (orographic effect). Naturally, this effect is stronger the more rapid the air masses are moving; up to a certain limit though. The frequent out­ breaks of rapidly moving cold air masses during winter, when the precipitation is by far greater than during other seasons, 61

is an explanation to the high annual rainfall/altitude correlation coefficients in the project area, 0.98, with values ranging between 0.6 and 0.9 for individual winter months. Plate > 5.1, where the isohyets for 1978/79 are drawn, illustrates this effect. Accordingly, the long term average precipitation on the Molai Plain has been evaluated as 540 mm, whereas the mountains would receive up to about 950 mm during an average year. The distribution in time is illustrated in Table 5.2. where 20 years of monthly and annual data on precipitation at Molai have been condensed to a) monthly statistics on actual precipitation and percentages of annual precipitation; and b) monthly probabilities of no precipitation. As is demonstrated in Table 5.2, the precipitation at Molai is concentrated to the months October - March with a peak in January. The wettest months, November, December, and January, account for 54 percent of the annual precipitation on an average. As would be expected, the months with highest precipitation are also the months with the highest precipitation dependability: zero probability of no precipitation. It is, however surprising that not one of the summer months is statistically dry; the driest month, August, having a probability of no precipitation of as low as 0.65. Of interest from especially agricultural point of view is the relatively high average precipitation in October (higher than in February) which will give good starting conditions for i.e. winter vegetables. Some caution has to be taken, though, because, as indicated by the high positive skewness, most years are drier or much drier than would be expected from a normally distributed precipitation. The precipitation pattern, outlined above, is most certainly applicable for the whole of the Molai Plain and probably also for its catchment area. Due to the pronounced orographic effect in the project area, however, the precipitation figures have to be shifted downwards by about 7 percent to account for the conditions on the Plain (the Molai station has an altitude of 240 msl whereas the Plain has an altitude of about 100 msl) and upwards by up to about 65 percent, depending on altitude, to account for the precipitation in the mountains. Table 5.2

PRECIPITATION CHARACTERISTICS FOR MOLAI

(x = mean; SD = standard deviation; CS = skewness coeff.; index a = actual precipitation in nsn; index p = percent of annual precipitation)

Month S 0 M D J F H A M J J A Year it 16 81 10"* 107 112 73 52 32 17 6 6 4 609 a SD 15.8 74.3 48.1 51.7 52.4 65.9 29.5 27.6 18.4 9.2 12.8 7.5 125.6 3.

CSa 0.69 1.26 -0.30 0.41 0.55 1.22 0.26 1.36 0.95 1.26 3.13 2.28 0.58

3 13 17 18 19 11 8 5 3 1 1 1

3.0 10.5 6.7 8.9 9.1 9.0 4.4 4.6 3.0 1.6 2.2 1.4

CS 1.04 0.97 -0.51 0.22 0.33 0.74 -0.23 1.30 0.80 1.32 2.32 2.88 P

Probability no precip. °"25 °'05 0 0 0 0.05 0 0.10 0.15 û.45 0.45 0.65 63

5.5 AIR TEMPERATURES

At the start of the project, the only temperature recording station in the project area, the one at Assopos, was gradually up-graded and the existing equipment overhauled. As from February 1979 the station was in proper shape and regularly inspected. Earlier temperature data had to be rejected because a) the screen was unpainted and had a strongly heat absorbing dark grey colour; and b) the size of the screen, almost half of that of the international standard Stevenson screen, could possibly allow for one set of thermometers, but not, as was the case, a thermohygrograph as well, which strongly affected the ventilation. In order to establish air temperature characteristics for the Molai Plain, the Assopos data for the period February 1973 - April 1980 were compared to long-term data from other stations in the region, and by applying a combined Fourier and regression analysis, maximum use of the short term record could be achieved. Nevertheless, the results should be up-dated when more over­ lapping data (3-5 years) become available. From Figure 5.1, where the range of characteristic temperatures, average absolute monthly minimum to average absolute monthly maximum, are illustrated over the year, the average values can be seen to vary between a minimum of 9?9- 10?0 C in January - February and a maximum of 23?7 - 23?9 C in July - August around an annual average temperature of 16?5 C^. The extremes vary between an average absolute low of 0?5 C in' January and an average absolute high of 33?9 C in July. >'$M A special study on maximum duration of temperatures below certain levels was undertaken, see Working Document No. 5, b ' * ': (Samuelsson, 1980 )the result of which is summarized in Table ' 5.3. The marked difference in low temperature characteristics between the northeastern and the southwestern parts of the Plain should be studied further by installing a thermograph at the Molai transformer station, where now the data being coll­ ected are limited to daily maximum and minimum temperatures. 64

MONTHLY -.E RAGE S OF CHARACTERISTIC DAILt "EMPE STURES IN SOUTHWESTERN PART Ol- I HE M^LAI PLAIN

t 65

Table 5.3

MAXIMUM DURATION IN HOURS OF TEMPERATURES BELOW INDICATED LEVELS AND FOR INDICATED RETURN PERIODS

Return period Northeastern part Southwestern part years of the Plain of the Plain

T<2°C T<0°C T<2°C T<0°C

2 18 1.5 5.5 0 5 38 14 18 4 10 50 20 26 6.5

5.6 EVAPORATION, EVAPOTRANSPIRATION, AND CROP WATER REQUIREMENTS

By regressive studies on climatological data from Assopos and from the synoptic station at Kalamata, and by applying the Pennman method, monthly averages and standard deviations on potential ¡ évapotranspiration for reference crop (grass), ETo, were worked out for Assopos for the four year period 1976 - 1979. Because of the normally limited variation of evaporation in space these values can be taken as representative for the Molai Plain as a whole. Working Document No. 6 (Samuelsson, 1980°) gives a full account of the calculation procedure, the results of which are summarized in Table 5.4 where also Class A evaporation pan data for Assopos during the period February 1979 - January 1980 are included as a reference.

Table 5.4

ETO AND PAN EVAPORATION IN MM/DAY AT ASSOPOS (x = mean; SD = standard deviation)

J . F M A M J J A S O N D

ETo: x 1.7 2.1 2.9 3.3 4.8 6.5 6.9 5.9 4.6 3.2 2.0 1.7 SD 0.2 0.2 0.6 0.3 0.5 1.0 0.7 0.5 0.7 0.2 0.3 0.5

Pan evaporation 1.3 2.2 3.1 3.2 5.0 6.9 7.4 7.1 5.8 3.3 2.1 1.3 66

Monthly precipitation data for Assopos were used together with the calculated series of évapotranspiration data for reference crop to calculate water requirements for eleven selected crops: citrus, olives, grapes, almonds, deciduous fruits, early vegetables, summer vegetables, winter vegetables, artichokes, alfalfa, and barley/wheat. The various crops were assumed to occupy 15, 25, 5, 7, 10, 10, 5, 5, 8, 3, and 7 percent, respectively, of the cultivated area. Leaching needs were taken into account by Including a leaching factor together with leaching efficiency in the calcul­ ations, which were performed for three salinity levels of irrig­ ation water corresponding to electric conductivities of one, two and three mmhos/cm. From the four year series of water demand figures and with due regard to rainfall statistics it can be concluded that an annual supply of 7500 m3/ha irrigation water havir<7 a conduct- 3 ivity of 2.0 mmhos/cm with a monthly peak in June cf 1500 m /ha would meet the demand in three years out of five, 5.7 OTHER CLIMATOLOGICAL ELEMENTS

The limited data do not allow for but a brief description of other climatological characteristics, based on the records from Assopos after February 1979. Relative humidity varies between average, monthly values of around 50 percent during the summer months June-September and average monthly values of 60-65 percent during the rainy season November-April, whereas sunshine hours varies between around 10 hours per day on an average during June-August and a minimum of less than four hours per day in January. Monthly average wind-run figures are high in November-April, low in Kay, September, October, and intermediate in June-August. During summer the winds are steady with a moderate strength whereas the winter months are characterized by rapid, frequent changes in wind velocity; almost instantaneous changes from gusts with more than 20 m/a to calm or almost calm are not uncommon. 67

Chapter 6

HYDROLOGY

6.1 INTRODUCTION

The Molai plain can be divided into two parts cf approx­ imately equal size: A relatively fiat area to tho northeast, and an undulating area towards the sea in the southwest. Between the two areas runs a ridge, the so called Assopoo nidge, with an elevation of around 100 msl acting as a drainage divide. The northeastern area drains by a partly man-made channel towards a depression at an elevation of 70-75 msl with a sinkhole at its lowest point, whereas to the southwest the land drains to the sea by two main river channels, the Molai River and the Assopos River. Except towards the southwest, the Plain is surrounded by hillB or mountains in all directions: the Malinuidhi mountain range to the northeast-east, the Sikea hills to the southeast, the Finiki mountains including Skordolakka and Chavalla to the south, the Kourkoula mountain to the westnorthwest, and the Megali Rachi hill to the north. Hydrologically the area can be divided into two groups of catchments: (see Plate 6.1)

i) Catchments of the northeastern part of the Plain: Potamia (part of Megali Rachi hill, part of Kourkoula mountain); Chelorema (part of Megali Rachi hill, part of Mallmadhi mountain range); Tsakona (part of Malimadhi); Monoporo (part of Malimadhi); the remainder of Malimadhi; and Sikea (several small catchments draining the Sikea hills).

ii) Catchments of the southwestern part of the Plain: Assopos (Skordolakka and Chavalla mountains)j and Molai (remainder of Kourkoula mountain)

Most of the mountain catchments are limestone formations with high potential infiltration rates. Rain falling on these areas, therefore, generates little or no runoff; instead, the infiltrated water percolates into the karBtic system and event­ ually reappears as springflow. Although the mechanisms are not fully known, there are strong indications (see Section A7.2:7) 68 that the Glyfada-Elea springs are fed by rainfall over the Malimadhi mountain range and the Kourkoula mountain, and that similar relationships exist between the Plytra springs and the Chavalla mountains, and between the Monemvasia springs and the southeastern continuation of the Malimadhi mountain range. Most years, probably with a frequency of 60 percent, surface flow in the project area is limited to the Potamia catchment and the Sikea catchments. 5ic«ßh floods of short duration may also develop in the Monopcro and Tsakona catchments but without reaching the Molai Piain. During wet years, about every four to five years on an average, the Molai and Assopoa rivers are flowing to the sea and flash floods in the Monoporo and Tsakona wadis may occas­ ionally reach the Plain and eventually the channels leading to the sinkhole.

6.2 SURFACE FLOW

Based on experience from the hydrologie years (September- August) 1978/79 and 1979/80 and the results from watershed modelling, see Working Document No. 4 (Samuelsson, 1980 ), the hydrology of some individual catchments is described more in detail below. Working Document No. 7 (Gemmell et al, 1980) contains details about surveys, measurements and installations.

6.2.1 Potamia River

Potamia river is the only water course in the project area which carries water regularly every year, at least in its upper parts. It was,.therefore, logical to establish a station with a water level recorder on this river at a site about one km upstream of the Molai Plain proper. Characteristic for the river is itB baseflow, which is maintained by springs around Gagania at the foothillB of Kour­ koula mountain and which normally do not dry up until June. Due to rather high potential infiltration rate of the river bed upstream of the Plain the baseflow, however, only during short periods extends down to the water level recorder station, and hardly any bao^low reaches thu Plain proper. With an average infiltration rate of about 0.055 m3/s the total infiltration 3 during 1979/80 amounted to 240 000 ra. 69

Frequent flood flows generated on the Megali Rachi hill and in' the river valley reach the Plain during average, and probably even somewhat drier than average, conditions. The recorded monthly flows at the recorder station during 1978/79 and 1979/80 are listed in Table 6.1.

Table 6.1

MONTHLY RIVER FLOW IN 1000 M3 AT THE POTAMIA RECORDER STATION; CATCHMENT AREA : 15.0 KM2

Year Month 1978/79 1979/80

November 1.5 78.7 December 13.5 83.0 January 15.0 329 .1 February 30.0 53.6 March 3.0 90.2 April 4.5 6.1

Total 67.5 640.7

6.2.2 Chelorema River

Surface flow rarely develops in the upper part of the Chelorema River; only during wet winters, one year out of three to four, some flash-Cloods may reach the Plain. Downstream of the mountainous ara hilly part of the catchment surface runoff, although of limited magnitude, may, however, develop even during less wet conditions, but hardly during average conditions. Thus, no flow was observed during the average rainfall year 1978/79. The estimated monthly flows during 1979/80 where the Molai- Metamorphosis road crosses the river are listed in Table 6.2. 70

Table 6.2

MONTHLY RIVER FLOW IN 1000 M3 IN CHELOREMA RIVER AT THE BRIDGE ON THE METAMORPHOSIS - MOLAI ROAD; CATCHMENT AREA: 20.6 KM2

Month 1979/80

November 3.0 December 4.0 January 12.2 February 1 .9 March 2.2

Total 23.3

6.2.3 Tsakona Wadi

During high intensity rainfall overland flow may be generated in the catchment causing flash floods of short duration, normally a few hours only. These flash floods may reach the bridge on the Molai-Metamorphosis road and in rare cases a few hundred meters further downstream. Most probably the flood water will only reach the Molai Plain proper during exceptional conditions, and it never occurred during the rather wet year 1979/80. The estimated monthly flows during 1978/7 9 and 1979/80 at the road bridge are given in Table 6.3. r 6.2.4 Monoporo Wadi As with the Tsakona wadi the Monoporo one carries only flash floods of short duration which may reach a point a few hundred, meters downstream of the bridge on the Metamorphosis-Slkea road but only exceptionally down to the Molai Plain proper, and it was never observed during the study period. Table 6.4 lists the estimated monthly flows during 1978/79 and 1979/80 at the road bridge.

6.2.5 Sikea Streams

Two small streams which drain the Sikoa hills enter tho Molai Plain at th

Table 6.3

MONTHLY FLOW IN 1000 M3 IN TSAKONA WADI AT THE BRIDGE ON THE MOLAI-METAMORPHOSIS ROAD; CATCHMENT AREA: 9.0 KM2

Year Month

1978/79 1979/80

November 0 14.3 December 1 .8 10.3 January 0.9 4.7 February 0.9 0

Total 3.6 29.3

7"\bie 6.4

MONTHLY * O'l IN 1000 M3 IN MONOPORO-WADI AT THE BRIDGE ON THE METAMORPHOSIS-SIKEA ROAD ; CATCHMENT .VEA: 10.5 KM2

Year Month

1978/79 1979/80

November 0 0.5 December 0.5 3.2

Total 0.5 3.7

Molai-Sikea road 1.0 and 3.5 km from Slkea, respectively. Stream discharges are small (maximum 0.5 m /s during the study period; but, on the other hand, the streams tend to flow during and after each rainstorm, even if the rainfall intensity is rather low. This naturally only applies during periods with saturated soil. The streamflow never reached the drainage channel towards the sinkhole during the study period but it may occur excep­ tionally. The estimated total flow in the two streams where they i 72

cross tho Sikca-Finiki road was less than 10 000 m during 10">8/79 and about 50 000 m3 during 1979/80.

6.2.6 Assopos River

The river drains the Finiki mountains and part of the Molai Plain in the area of Finiki-Assopos-Papadhianika. The river channel is well-developed down to about 1.5 km from the outlet into the sea. Here the channel disappears and the river valley widens into a flat cultivated area, about 500 meters wide. Close to the sea the valley narrows and a river channel can again be recognised from a point just upstream of the Assopos-Bozas road culvert down to the outlet. Judging from experience during 1978/79 when no river flow was recorded, most years pass without any but local, rapidly infiltrating river flow. During wet years, however, big floods of short duration are probably rather common : During 1979/80 eight floods were recorded, four of which reached the sea. In Table 6.5 the monthly river flows during 1979/80 are listed for two gauging sites, the Assopos-Papadhianika road bridge and the road culvert at Bozas, close to the sea.

6.2.7 Molai River

Before a major flood event in 1942, the Molai river was a continuation o* the Potamia river. Part of the old river channel connecting the two catchments is still visible although now it is mostly cultivated. The new course of Potamia river which leads towards the sinkhole was later in the same year made permanent by the construction of the Molai-Sikea road which now acts as a catchment divide. In its upstream parts, the river channel is just a small ditch in the bottom of a rather broad valley with steep slopes. Downstream of the Pakia area, however, the river follows a well-developed channel which continues down to the sea except for the last 200 meters. Here the ground is rather flat and á pond, about 40 meters wide, is formed behind a sand-bund on the shore. The river flow follows much the same pattern as that of Assopos river: Most years dry and rather frequent flows of short duration during wet yearB. , 73 Table 6.5

MONTHLY RIVER FLOW IN 1000 M3 IN ASSOPOS RIVER DURING 1979/80 AT THE ASSOPOS-PAPADHIANIKA ROAD BRIDGE AND AT BOZAS ; CATCHMENT AREAS: 30.5 AND 47.3 KM2

Month Road Bridge Bozas

November 267.4 177.1 December 42.9 30.8 January 25.7 0.1 February 0 0 March 8.1 0.1

Total 344 .1 208.1

During 1978/79 no runoff was observed whereas during 1979/80 the river was flowing six times, see Table 6.6, although over­ land flow never developed in the Kourkoula mountain part of the catchment.

6.2.8 Northeastern part of Molai Plain, Sinkhole

There are three main channels crossing this part of the plain and ending at the sinkhole:

i) Potamia: After the change of the river course in 1942 and in connection with the construction of the Molai-Sikea road, a channel was dug along the road connecting the new natural river channel and a drainage channel to the sinkhole perpendicular to the road. ii) Chelorema: A natural continuation of the Chelorema river channel which is joined by a less-developed natural channel from the Tsakona wadi. iii) Sikea: A natural continuation of one of the Sikea stream channels.

By far the biggest par't of the flow into the sinkhole is carried by the Potamia channel, partly because a major portion of tho. flood flows in the Potamia rivor reaches the channel, partly because of its large, local catchment area, about 2/3 of the sinkhole catchment on the Plain. 74

Tabic 6.6

MONTHLY RIVER FLOW IN 1000 M3 IN MOLAI RIVER DURING 1979/80 AT GAUGING SITE TWO KM UPSTREAM OF OUTLET INTO THE SEA; CATCHMENT AREA: 28.5 KM

Month i 1979/80

November 20.6 December 15.6 January 3.0

Total 39.2

The drainage capacity of the sinkhole is limited to 1.8 m /s, which means that, occasionally, when the inflow rate is higher, the area surrounding the sinkhole is flooded. This seems to happen every three to four years according to local farmers. This frequency corresponds well with the evaluated frequency distribution of rainfall and observations during 1978/79 and 1979/80. 2 Major floodings, when the inundated area exceeds one km , seem to have a return period of 10-20 years. The largest recent flooding, which affected an area of 1.8 km , occurred in 1934. From gathered information on floodihgs of the sinkhole it seems, rather surprisingly, that the change of the Potamia river course did neither substantially affect the frequency of floodings, nor their magnitude. The explanation could be that the contri­ bution, volume-wise, from flood flowB in Potamia river with its rather high infiltration potential is small compared to drainage from the Plain where the infiltration during wet conditions is negligible. No flooding occurred in 1978/79 whereas three minor and one rather big flooding affecting an area of 0.7 km took place in 1979/80. The total recorded flow into.the sinkhole during 1978/79 was 0.3 million m3 and during 1979/80 1.6 million m3. The monthly figures for 1979/80 are given in Table 6.7. 6.3 SPRING FLOW

Except for a few relatively small isolated springs, some of which like Krissa spring and Tassos spring are used as Bources

& V • • 75 for village water supply and/or limited irrigation, the springs appear in four distinctive groups (see Plate 6.1 and Appendix 6.1). Within each group, ten or more individual springs have been identitled. One of these groups of springs is located inland at Gagania on the foothills of the Kourkoula mountain, whereas the remainder are found along the sea-shore at Monem­ vasia, Plytra and Glyfada-Elea.

Table 6.7

MONTHLY FLOW IN 1000 M3 INTO THE SINKHOLE DURING 1979/80

Month Volume

November 181 .4 December 253.3 January 955.5 February 60.5 March 178.6

Total 1 629.3

The Gagania springs arc to some extent used for local irrigation and drinking water supply but their main yield is feeding the Potamia river. The springs usually dry up in June and have a maximum yield in early spring of 50-100 1/s. In the Monemvasia area several shoreline and off-shore springs have been located all along the coast from the Monemvasia

village to and including the bay of Kremidi. The springs are, ; however, salty with an electrical conductivity in the range of 7-30 mmhos/cm and the yield is limited with an overall total- Of ? about 200-300 1/s. The springs are generally flowing with vfyDja&^n flow-rates throughout the year. fiM At Plytra the springs appear as shoreline and off-shore springs in the two small bays south of the village, except two small springs which are located in the harbour area. In spite of electrical conductivity values in the range 5.0-8.0 mmhos/cm the springs are to some extent used for washing and also as sources for domestic water. One of the springs in the harbour area may have yielded less salty water in the past as it was once UBed as the village water supply. The total yield of the Plytra springs is lesa than 100 1/s although the yield is fairly 76

constant without noticeable seasonal variations. Tho most important of all tho springs in the project area are those at Glyfada-Elea. Not only do they flow stronger than any of the other springs or groups of springs but they also yield less salty water (electrical conductivity around 3.6 mmhos/cm) than any of the other shore-line springs. The location of the individual springs is shown in Figures 6.1 and 6.2. A major part of the flow from the shore springs has been monitored by the construction of a wall with two rectangular weirs which collects the flow from several gravel springs (Figure 6.2). Regular discharge measurements have, in addition, been carried out of the Aniliastos spring, 250 m south of the gravel springs, and downstream of the wall in a section through which the flow of_some springs outside the wall is passing together with the flow from one of the weirs. Twice daily readings of the sea water level and the water levels at the two weirs were initiated on 1 August 1979. During June and July 1979 a special study was undertaken regarding possible effects on the spring flow by changes in head. After a reconnaissance exercise on the 19/6 the two weirs were closed for two days in June (27 - 29/6) and for five days in July (25 - 30/7). During the two days in June, the sea water level remained practically constant with a difference between maximum and minimum water level of two cm only, whereas the second study period coincided with a period of relatively large and rapid variations of the sea water level; more than 10 cm within a lew hours was observed twice during the period. Although the results from the two periods follow a similar pattern no quantitative conclusions can be drawn from the July observations because of the unknown influence from the sea water movements. The study period in June yielded, however, data which could be used for a quantitative assessment of the total discharge of shore springs in the Glyfada area, 0.3 - 0.4 m3/s, see Appendix 6.2. From general considerations an interrelationship botween the flow of the various springs would be expected; and also, one would expect some relationship between spring flow and sea water level. In order to study these possible relationships 77 more in detail, a statistical analysis was undertaken assuming linear and exponential regressions. The hypothesis of exponential relationship had to be rejected as the correlation coefficients were not significantly different from zero. Consequently, the study concentrated on linear relationships and the following correlation coefficients were calculated: Aniliastos/section 1,2 (downstream of weir 1) (-0.14)

Aniliastos/weir 1 (-0.24)

Anillastos/weir 2 (-0.20)

Aniliastos/sea water level (0.10)

Sections 1,2/sea water level 0.60

Ditto excluding periods with closed weirs 0.79

Weir 1/ weir 2 0.76 Weir 1/sections 1,2 (0.40) Weir 1 + weir 2/sea water level 1 - 15/8 0.48 n 16 - 31/8 0.81 M ii 1 - 15/9 0.62 II n 16 - 30/9 0.82

II n 1 - 15/10 0.47 II ti 16 - 31/10 0.86 II n 1 - 15/11 0.56 . II n 16 - 30/11 0.71 It n 1 - 15/12 (0.25) II n 16 - 31/12 (0.18) It it 19 - 31/1 0.77 II H 1 - 21/2 0.51 II It 1 - 15/3 0.82 II tl 16 - 31/3 0.84 II It 1 - 15/4 (0.30) II II 16 - 30/4 0.89 II II 1 - 15/5 0.83 II II 16 - 31/5 0.84

The correlation coefficients within parenthesis are not significantly different from zero. Obviously, there is a close relationship between the discharges of the various gravel springs whereas the spring of 78

GLYFAOA SPRING AREA 'roo >oo ^-"SSÎ"

PlOUne 61 i 79 80

Aniliastos seems to act more independently although there is a slight indication of opposite behaviour vis-a-vis the gravel springs. Tho surprisingly weak correlation between the flow through weir 1 and sections 1 and 2 only about five m downstream, could be explained by the time lag of about one hour between the gauge reading at the weir and the discharge measurement. The generally strong positive correlation between sea level and the gravel spring flow is interesting because it gives an indication on the behaviour of the off-shore springs. At high sea water level, the flow is suppressed by the higher hydrostatic pressure and vice versa. The low correlation in December and the beginning of April could be explained by the occurrence of frequent rapid variations of the sea water level due to storm floods {variations of up to 15 cm in less than one hour). Excluding those periods of disturbed conditions the correlation coefficient for the whole period, 1/8 1979 - 31/5 1980, came out as high as 0.84. By calculating the sea water level for zero shore spring discharge an average value of 0.85 m below mean sea level was obtained. With an average depth of the marine springs of about nine meters and assuming proportionality between total marine spring discharge and hydrostatic pressure, the proportionality factor comes to Qs/0.012 where Qs is the shore spring discharge. Some of the shore springs may be less, in some cases perhaps even negatively, affected by changes of the sea water level. The value of Qa in the expression of the proportionality factor 3 is therefore, less than 0.4 m /a (estimated total «îhore spring discharge) but greater than 0.075 m3/s (average flow through the two measuring weirs). Because the majority of the shore 3 springs discharge above mean sea level 0.2 m /o would be conservative value of Qs. The total discharge of the marine springs could then be estimated at around 1.5 m3/s. In summing up, the total spring discharge of tho Glyfada complex is most probably in tho range of 1.5 - 2.0 m3/s. The offshore springs at Glyfada, Plytra, and Monemvasia were surveyed by scuba-divers during July 1979. All areas where there was any sign on the sea surface of possible spring- flow were traversed several times and samples of water and 81

bottom material were collected and analysed. The main result of this exercise was that no large orifice flow could be traced in any of the spring areas.

6.4 SURFACE WATER BALANCES

« By employing the watershed model described in Working Document No. 4 (Samuelsson, 1980a) the water balance components during 1978/79 and 1979/80 were generated from observed precip­ itation and evaporation for the various catchments. The model was calibrated to reproduce observed hydrographs or, in limestone catchments without surface runoff, to generate only negligible amounts of surface runoff. The results from this exercise cannot, however, be class­ ified in terms of average and deviation from average conditions as with rainfall because the distribution in time of rainfall is as important, in some cases even more important, than the amount of rainfall. As an example, during 1978/79 when the rainfall was unusually unevenly distributed, the output in terms of runoff and recharge increased by 20-50 percent by changing the rainfall distribution to become similar to the one observed in 1979/80, while the output for 1979/80 decreased only slightly with more concentrated rainfall. Coming back to the average rainfall year, 1978/79, the observed rainfall distribution is probably more uneven than during average conditions but, on the other hand, the alternat­ ively applied distribution would probably fall on the other side of the average. It seems, therefore, reasonable to assume that the average values of the water balance components are close to the arithmetic mean of the values for 1978/79 arrived at by applying the two different distributions as described above. In view of the small change of the water balance components in 1979/80 when manipulating the rainfall distribution the derived valuer are taken to represent conditions with a return period of about five years. The final result is summarized in Tables 6.8 and 6.9 where the catchments have been summed up into five areas, the north­ eastern and the southwestern parts of the Malimadhi mountain range (the borderline being the fault Koupia-Mavrovouni), the Kourkoula mountain, the hills south of Finiki, and tho Plain area, including tho Megali Rachi hill and the Sikea hills. Table 6.8

SUBREGIONAL WATER BALANCES, AVERAGE VALUES

1/ Gross Potential-^ Area Evaporation Losses to— Rainfall Recharge the sea

NW Malimadhi 76 36 40 SE Malimadhi 38 18! 20> +0*3 Kourkoula 17 9 8 Finiki-Plytra 7 3 4 Plain 51 38 0 13-0.3

Table 6.9

SUBREGIONAL WATER BALANCES, RETURN PERIOD FIVE YEARS

Gross Losses to Potential Area Evaporation Rainfall the sea Recharge 1 o NW Malimadhi 103 40 1 63 SE Malimadhi 52 20 32> +1'6 Kourkoula 30 16 14 Finiki-Plytra 10 4 6 C S Plain 65 40 25-1.6

As surface runoff and/or interflow

The second figure refers to inflow from the Plain into the sinkhole 83

Chapter 7

GROUND WATER CONDITIONS

7.1 INTRODUCTION

7.1.1 Previous studies

The only relevant hydrogeological study in the area has been the study by German Water Engineering (GWE, 1972) . Although this study did not go beyond the reconnaissance phase many useful data were collected:

i) The geoelectrical survey determined the geological structure of the Molai Plain and the approximate depth of the basement of the Neogene aquifer.

ii) The groundwater level surveys carried out in April and September 1971 and the hydrochemical reconnai­ ssance survey (EC measurements) of September 1971 established benchmarks to which the data collected by the present project could be compared.

iii) At four locations a total of seven boreholes were drilled (Appendix 4.1). Four of them penetrated the whole thickness of the .Neogene and entered into the underlying formation. In three wells a limestone aquifer was found and briefly testée. Afterwards all of them were plugged back and completed in the Neogene.

Besides the data collected by GWE, some data is available on boreholes drilled in the area by the former Land Reclamation Service (Appendix 4.1).

7.1.2 Present Study

In the study of the groundwater conditions of tho Project Area many techniques have been used. Each one has contributed to the insight in the complex groundwater regimes of the two aquifer systems. However, the picture is still far from complete particularly the hydraulics of the subsurface flow system of the • 'i limestone aquifer is still not ;clean. 84

The following techniques have been used: - Water 1

The results are described in the 'above mentioned Appendices of this report, Working Documents, or other project documents. The synthesis concerning the two main groundwater systems of the Molai area is presented in Sections 7.4 and 7.5.

7.2 GEOLOGICAL STRUCTURE

A detailed description of the geology of the Molai area is given In Chapter . Here only the broad outlines with a direct bearing on tho groundwater conditions will be recalled. The Molai Plain is a northeast-southwest trending graben, filled with Neogene sediments. It is divided by two northwest- southeast directed faults into three compartments:

i) Northern Trough ii) Assopos Ridge ill) Southern Trough B5

The basement consists probably everywhere of semi-metamorphic schists and phyllites. The Plain (see Figure 4.3) ÍB bordered in the north and northeast by mountain*, consisting of karstic carbonates of the Tripolitza Formation, overlaying the semi-metamorphic Tyros Formation. The Kourkoula Mountain consisting mostly of marbles (crystallized limestones),flanks the project area along its western boundary. The eastern boundary is formed between Sikea and Papadhia­ nika by semi-metamorphic schists and between Papadhianika and Plytra by the crystallized carbonates of the Chavalla Mountain. The southern limit is aligned in a southeast-northwest direction: from Plytra to the Xili Peninsula the area extends to the Gulf of Xili, then follows the Xili Peninsula, which is a block of crystallized carbonates, and finally there is a ridge of metamorphic rocks which joins the Kourkoula Mountain. The southern part of the motamorphic ridge has two gaps through which the Assopos River and Molai River flow into the Lakonian Gulf. The northern part of the metamorphic ridge separates the Molai Plain from the Elea area. I 7.3 TWO AQUIFER SYSTEM In the project area two main aquifer systems can be dist­ inguished: Limestone aquifer in the karstic Tripolitza carbonates; and Neogene aquifer in the Noogene deposits of the Molai Plain. Moreover the areas surrounding the Molai Plain have their own groundwater systems which will be briefly described. 7.3.1 Limestone aquifer system

The limestone aquifer system is mainly confined to the Tripolitza carbonates north of the Molai Plain. To the south­ west the carbonate area also called the catchment (of the karst aquifer; not of the Neogene aquifer), is bounded by the Mavrovouni- Sikea-Ayios Ioannis fault. (Figure 4.3). This fault separates the carbonates from less pervious Neogene deposits in the area between Mavrovouni and Sikea and from impervious Tyros Formation between Sikea and Agios Ioannis (outside the project area). 86

To the west tho carbonates are separated from the marbles Kcurk(~"lT Mount--.In by tho northern extension of the Elca- Molai fault. In most places schists and phyllites appear to form a hydraulic barrier between these two formations. Towards the north and northeast the carbonates extend far beyond the project area whose boundary follows the limit of the surface water divide. It is likely that in many parts this boundary also defines the boundary of the groundwater catchment area which is believed to consist of a series of northwest- southeast directed thrust blocks (Figure 7.1 and plate 4.2). The reverse faults which were croated by the upthrusting have been strongly karstifiod and are now the sides of the northwest- southeast directed depressions. Thoy also separato the different blocks with relatively independent groundwater zones. Overflow cr through-flow probably occurB from one block into the other.

The northern boundary coincides more or less with the northwest-southeast directed Agios Dimitrios fault. This may act as a barrier to groundwater flow. From the parallel Koupia- Mavrovouni fault it is known that the fault zone is very mylonitic. Hence, what looks like a simple tilted carbonate plate with its highest elevation in the northeast and its lowest point in the southwest is a complicated group of blocks, each with its own groundwater characteristics. Tho depth of the watertable below the surface (several hundred metres) excludes any exploration effort. The only area whore the water is at exploitable depth 2 is in the small (maximum 10 km ) piedmont area, i.e. the area between the Mavrovouni-Sikea-Ayios Ioannis fault and the 100 m topographic contour line. In this area the so called limestone reservoir is located. ' It has a depth to water of 75-97 m and it is here that the project'3 research efforts have been concentrated. A detailed description of the limestone aquifer system is given in Section 7.4. 7.3.2 Neogene aquifer system

The Neogene aquifer is found below most of the Molai Plain. The hydrologie boundaries coincide with the boundary of the Plain, which is the 100 m contour in tho north, the soa in tho south and a regularly sloping line along both sides of the valley. As LEGEND

[T*. TI] Tripolitza carbonate» Sen level r i ——- Groundwater toóle ¡- -.- _ Tyros Formation " , Overthrust plane ^ Phyllifes T FtjI» V * Marbles

Schematic cross-section over the "catchment" area. sketch not to scale

FIGURE 7.1 89

mentioned before, the Molai Plain is divided by two faults in three compartments. The impervious basement is in the Northern Trough at a depth of approximately 600 m, over the Assopos Ridge at a depth of 100-200 m, and in the Southern Trough at about 300 m. The Molai graben is filled with Neogene depe îits with some Quaternary deposits at the surface. Along the northern and northeastern border the Neogene and Quaternary deposits over­ lap the faults that form the geological limit of the Molai graben. Here the Neogene aquifer overlays the limestone reservoir. The Neogene aquifer is mainly recharged by local precipit­ ation. The contribution from infiltrating runoff from the surrounding hills and lateral subsurface flow is of minor import­ ance. The aquifer is depleted partly by subsurface flow to the sea through the alluvium of Molai and Assopos rivers and the beach deposits west of Plytra, and partly by pumping, mainly in the Southern Plain. According to local information, springs were observed in the past, before irrigation was developed, during the wet season along the downstream parts of the Molai and ASBopos Rivers, which acted as groundwater drains.

A detailed description of the Neogene aquifer system is given in Section 7.5.

7.3.3 Other groundwater occurrences

The groundwater conditions in the Chavalla area, the Kourkoula area and the Elea area are summarised in the following subsections.

7.3.3.1 Chavalla area

The crystallized limestones of the Chavalla area north of Plytra are bounded in the north and east by impervious metamorphic schists and in the west and south by the Noogene of the Molai Plain and the Neogene and Quaternary of the coastal plain oast of Plytra. Local rainfall recharges the Chavalla groundwater 1 / occurrence with an average 4 MCM—' per year. The discharge is

Million cubic metre 89

believed to occur by subsurface flow to the Molai Plain north of Plytra and by outflow to the sea east of Plytra, where some small shore and offshore springs occur (Section 6.3). The stable isotope composition of water from those shore springs and from wells along the eastern border of the Molai Plain between Plytra and Papadhianika is in agreement with this theory (Section

A7.2:7.2.3.5) i

7.3.3.2 Kourkoula area

The Kourkouln Moun'iin rnnsists mainly of marbles (or crystallized limestone). Solution oponingu, iiiimn-, ' ^pres­ sions that have been formed by karstification have been found. In the absence of any significant runoff it has to be assumed that there is a groundwater body below the Kourkoula Mountain to which the infiltrated water percolates (average 8 MCM/y.ar). The recharge is too small to account for the discharge of the Glyfada spring systems (60 MCM/year). However, it is possible that the Kourkoula aquifer drains,, at least partly through the "conduit" that links the limestone aquifer north of the Plain with the Glyfada springs and therefore contributes to the Glyfada springflow. The steep slopes and, probably, very deep water levels exclude an exploration effort.

7.3.3.3 Elea area

The Elea area (Figure 7.2) is founded to the west by the Gulf of Lakonia, to tho north by tho lower Evrotas Plain, to the east by the Kourkoula Mountain and to the south by the ridge of metamorphic rocks that separates it from the Molai Plain. It is underlain by an .aquifer located in Neogene sandy, marly and clayey deposits, with relatively shallow water levels, and with much the same characteristics as the Neogene aquifer of the Molai Plain. The substratum consists, at least south of Elea of schists over­ lying Elea marble (ref. borehole RB-1: X: 661.90, Y: 4068.56, also boreholes E-86 and 87). In the Elea marble a second aquifer was found. The groundwater of the Neogene aquifer of the Elea area shows a regular slope from the east to the west i.e. from the Koukoula Mountain to the Gulf of Lakonia. 90 91

The isotopic composition of tho groundwater is rather variable. In the area north of the road from Elea towards Molai most water samples indicate recharge by local rainfall. South of the Elea-Molai road the water is a mixture of water from the local rainwater and water from the conduit that feeds the Glyfada springs (Section A7.2:7.2.3). The confined groundwater occurring in the marbles has a piezometric level that is several metres above the water table of the Neogene aquifer. Also the isotope composition is different, it is similar to the water from the Glyfada shore springs indica­ ting a moan recharge elevation of about 1 000 metre above sea level (msl).

7.4 LIMESTONE AQUIFER y.

7.4.1 Geometry

The limestone aquifer which was the main research object of the project has become better known. However, the hydraulic flow system is very complex and can only be surmized. The area of interest can be subdivided into four parts:

the reservoir, i.e. the area where the water table is close enough to the surface to make pumping economi­ cally feasible and where also the other properties of tho aquifer (transmissivity, storage coefficient (specific yield) are such that exploitation is possible; the catchment area, i.e. the area where the recharge takes place but where the water is too deep to be exploited; the conduit or transmission zone i.e. that part of the aquifer along which the water moves from the catchment area to the discharge area; and - the discharge point(s) i.e. the point or area where the water leaves the karst aquifer system.

7.4.1.1 Reservoir (Plate 7.1)

The reservoir is located in the piedmont area i.e. the area between the outcrop o£ the Tripolitza carbonates nortin of the Molai Plain and the Mavrovouni-Sikea-Ayios IoanniB fault system that separates the carbonates from the Ncogene in the Northern 92

Trough below the Molai Plain. On the western side it is separated by the Blea-Molai fault from the metamorphic rocks of the Kourkoula mountains. On the eastern side the boundary is the limit of the surface water catchment. Beyond this limit the limestones continue below the Sikea-Ayios Ioannis valley towards the Aegean Sea, north of Monemvasia, but over most of the length of the valley the water levels are too deep (more than 150 m) for exploitation. ' The piedmont area is overlain by Neogene and Quaternary deposits with a thickness varying between a few and more than one hundred metres. The basement of the reservoir is probably formed by the impervious, semi-metamorphic rocks of the Tyros Formation (Section 4.4.5), although the basement has not been reached in any of the boreholes (maximum depth about 230 m below sea level).

7.4.1.2 Catchment

The catchment area is the northern extensicn of the reser­ voir. On the western side it ÍB separated by the northern extension of the-Elea-Molai fault from the Kourkoula Mountain. On the northern and eastern side the boundary is the limit of the surface water catchmenc draining towards the Molai Plain. As explained in Section 7.1.3 the catchment consists of a series of northwest-northeast directed "thrust blocks" (Figure 7.1) each with its own groundwater characteristics. The composition of the isotope content of water samples from the reservoir indicate a mean recharge elevation of about 500 msl. This excludes a major contribution from the highest parts of the catchment area.

7.4.1.3 Conduit

In many karst areas the water of a large catchment converges towards a main karst channel or drainage zone which gives rise, often tens of kilometres away, to an impressive karst spring. The drainage zone may bo a gallery with a large diameter or a zone, of restricted dimensions, with many interconnected small diameter channels. It is called the conduit or selective tlow zone. If the Glyfada springs are the principal outlet of tho 93 limestone aquifer then there must be a conduit that connects the aquifer with the springs. There is evidence that such a conduit exists in the marbles along the Elea-Molai fault system. A water-bearing zone with a high transmissivity and water with a chemical and isotope composition similar to the water from the Glyfada shore springs was found in reconnaissance borehole RB-1 . This borehole taps marbles in the immediate vicinity of a fault zone, which is.considered to connect the Glyfada submarine springs with the Elea-Molai fault.

7.4.1.4 Discharge points

The following discharge points have been found:

i) Glyfada springs The Glyfada shore and submarine springs with a total discharge of about 2.0 m3/s are probably the outlet of the topographically high northwestern part of the catchment area. Favourable evidence for this assumption is: the total spring discharge (45-60 MCMJ is much larger than its surface water catchment or even the whole of the Kourkoula Mountain could have provided (8 MCM). Its outflow corresponds more to the area 2 with the surface of the catchment (230 km , see also Section 6.4). - the composition of the isotope content indicates a mean elevation of the recharge area of about 1 000 m. (ref. Section A7.2 .«7 .2 .1.2) . This elevation corres­ ponds with the highest part of the catchment area. The water levels in the limestone reservoir however, are significantly lower than in the conduit. This indicates more than one flow sysLem. ii) Ayios Ioannls-Krommidl coastal springs Along the coast north of Monemvasia and across the southeastern extension of the catchment, a number of small shore springs exist in which, going from south to"north, the isotope content of the water shows increasing elevation of the mean rocharge arsas (Section A7.2:7.2.1.2). ThiB corresponds with the rice of the 94

general topography of the hills west of the springs from the low lying Sikea-Ayios Ioannis valley in the south to the ridge of over 900 m altitude along the northeastern border of the project area. This indicates that the hills west of the springs drain towards the nearby Ayios Ioannis-KremmicH coast. The combined yield of the known springs, a few hundred litres per second is, however, only a fraction of the expected total discharge of the southeastern part of the catchment, including its southeastern extension. There is no indication of any additional springs, for example large submarine springs. It is tentatively suggested that most water from the southeastern part of the catchment flows through a deep karst system towards the sea and dissipates in deep water rather far offshore and therefore escapes unnoticed.

iii) Discharge points north of the catchment area

This possibility is unlikely, therefore it has not been investigated.

7.4.2 Physical properties of the reservoir

The carbonates in the reservoir are deeply karstified. Even at the bottom of the deepest drilled borehole the cores showed evidence of solution openings and a flow meter run during the pumping tests showed contribution of the flow over the whole depth of the completed borehole. The karst openings are small, usually a few millimetres wide. Flow along the many small frac­ tures is probably preponderant. In view of the karstification phenomena over the whole depth of the boreholes and the absence of confining layers it is 1 / concluded that the limestone aquifer is unconfined.—' 7.4.3 Water levels and water level variation

The water levels in the limestone reservoir are only three to four msl. This indicates a very low gradient because the distance to the coast is about 10 km. The annual groundwater level variations are small. They are in the order of 0.30 to 0.50 m. There are a few indications of rapid reaction to rainfall in E-1. However, the water levels in

1 / -'In borehole RD-2 a tight dolomitic limestone above -80 msl causes locally confined conditions. 95

E-1 are influenced by the pumping for the community of Metamor­ phosis and small changes in water level are therefore to be treated with circumspection. A change in water level since 1971/72 could not bo estab­ lished because the water levels measured at that time were observed in wells that subsequently were completed in the Neogene. The levels measured in the limestone reservoir in 1971/7 2 (3.49 msl in MS-3 and 3.6 msl in MS-4) are roughly the same as the water levels measured in 1979/80. The relatively high water level in EB-1, near the sinkhole, is probably due to the formation of a local groundwater mound formed by slow dispersion of the recharge because of low trans- miss •".vi ty caused by plugging of the small karst openings by clcy and silt swept through the sinkhole into the aquifer. The very flat groundwater hydrographs indicate a very slow recharge. This is in agreement with the very large thickness of unsaturated limestone and with the apparent absence of wide karst channels. Consequently tha seasonal and interannual variation in precipitation is nearly completely smoothed out (Figure 7.3).

7.4.4 Water quality

The quality of the water (see Chapter 8) encountered in the wells drilled in the reservoir has been disappointing. In the * central and eastern part of the reservoir EC values ranging from 3.0 - 6.0 mmhos/cm have been found. EB-1, near the sinkhole, showed initial EC values of less than 1.0 mmhos but during a 72 hour pumping test a steady rise of the EC value was observed. In all boreholes an increase of salinity with depth was found. The Cl~/Br" value determined for a water sample from EB-2, was 217 indicating mixing with sea water (reference value Cl"/Br" = 300) rather than salinity due to the dissolution of salt from the geological formation (reference value Cl"/Br~ = 8 000 - 24 000). ;

7.4.5 Water balance

The average annual recharge of the catchment area i.e. the . Tripolitza carbonate area within the project limits is 60 MCM (see chapter 6). This value has been found taking into account the difference in elevation and the rain shadow effect on the LEGEND

K-13 Well inventory number MS-3 GWE inventory number o,t Oriled.dug well

•,- With, without pump 62 Total depth

I Verticol axis: Woter level elevation (msl)

(•) K-6 0.81 LIMESTONE AQUIFER |.)I-ln»W 97 southwest side- of the mountain ridges. The average annual recharge over the southeastern part of the catchment I.e. the area which is almost certainly recharging the reservoir is 20 MCM. The reservoir is furcher recharged by direct percolation of rainfall in those areas where the overburden of Neogene and Quaternary deposits is thin. Elsewhere there is only recharge by vertical downward leakage from tho Neogene aquifer. The amount of leakage has been estimated as 1.0 MCM. In the absence of any significant groundwater development, it may be assumed that the groundwater regime ic in steady state and that hence the average discharge volume equals the recharge volume. Except for interannual variation there is no change in storage. Assuming that the recharge over the southeastern extension of the reservoir forms an effective barrier againBt sea water intrusion it would, in principle, be possible to pump an amount equal to the total annual recharge volume (say 20+1 =21 MCM) but because of persisting unknowns a gradual development is, however, recommended with an initial development of 6 MCM (i.e. the requirement for 800 ha). Development is hampered by the rather high salinity of the water from the limestone reservoir. However, with proper leaching and selection of salt resistant crops it is possible to start a first phase development (Chapter 10). Such a development, prov­ ided sufficient monitoring activities are undertaken may give valuable insight into the behaviour of the flow system, whereby means and strategy for increased exploitation can be determined.

Conclusions As a result of the project's activities more data concerning the limestone aquifer have become available. The aquifer consists of a deep (drowned) karst system filled with water that increases in salinity with increase in depth. The transmissivity is high because the water levels are only a few metres above sea level at a distance of 10 km from the sea. -There is a serious risk of upcoming of salty water during pumping. At least for the time being any development of the groundwater of the limestone reser­ voir should be on a limited scale. The purpose of such a first 98

phase project should be:

to test under tho given conditions of soil and human resources, the technical feasibility of irrigation with relatively salty water; and

to monitor the behaviour of the aquifer under exploi­ tation conditions.

It is recommended to continue the investigation of the "conduit".

7.5 NEOGENE AQUIFER

In this section the information obtained during the different surveys and investigations has been synthesized, to evaluate the development potential of the Neogene aquifer.

7.5.1 Geometry

The Neogene aquifer is located in the Neogene sediments that fill the Molai graben. Only in the northeastern part of the Plain where thin Neogene-Quaternary deposits overlay the Tripolitza limestone of the piedmont area, is the Neogene aquifer absent. The Molai graben is subdivided by faults into three segments: (Plate 4.1)

- Northern Trough Assopos Ridge Southern Trough

This subdivision is also reflected in the groundwater levels of the Neogene aquifer. The basement of the Assopos Ridge and Southern Trough, consist, according to the few available borehole data, of phyllites and volcánica. This indicates an absence of Tripolitza carbonates. The basement of the Neogene deposits has been found in the Southern Trough (borehole RB-4) at a depth of 280 m and on the Assopos Ridge (boreholes E-5, Z-33, and A-127) at a depth of 100 - 200 m. According to geophysical evidence the basement in the Northern Trough is at a depth of about 600 m. No borehole confirmation is available.

7.5.2 Physical propertiec of the cqulfer

7.5.2.1 Type of sediments

The Noogene deposits are mostly fine grained Bodiments such 99

as marl, fine sand and clay with intercalations of coarse sand and gravel. The gravel has a grain size of less than five cm. The deeper part of the Neogene deposits is usually devoid of coarse grained intercalations. For example in borehole RB-4 the lithological section between 20 and 280 m depth contains only an 0.30 m thick gravel bed at a depth of 180 m and two metres of cemented crystallized limestone breccia as "trans- gressian conglomerate" at the bottom. In the Neogene deposits filling the Northern Trough little coarse material is present. Many private water wells in this area have failed due to fine sand entering the well. It has been concluded that within the normally drilled depth, the wells on the Assopos ridge encounter the highest percentage of gravels.

7.5.2.2 Transmissivity

The transmissivity values obtained from pumping tests show a variation between 0.00002 and 0.01 m/s (table A7.2:6). The groundwater model gave the following average values: 2 Neogene aquifer in the Northern Trough: 0.0005 m /a

- Transition between Northern Trough and 2 Assopos Ridge: 0.0005 m /s 2 - Neogene aquifer in the Assopos Ridge: 0.005 m /s Transition between Assopos ridge and _ Southern Trough: 0.0005 m /s 2 - Neogene aquifer in the Southern Trough: 0.05-0.002 m /s 7.5.2.3 Storage coefficient

The storage coefficient (specific yield) is a hydraulic property which is difficult to calculate from pumping tests. Taking into account the sedimentary characteristics of the aquifer material and the results of the pumping tests, a storage coefficient of 0.1 has been determined. The model study supports this assumption.

7.5.3 Groundwater levels

7.5.3.1 Subregional levels

The subdivision of-the Molai Plain by faults into three segments is reflected in the groundwater levels. In the Northern Plain the water level is 50 msl, on the Assopos Ridge 23 msl and 100 y * in the Southern Plain about sea level (Figure 7.4). Perched aquifers of probable small extent have been found in £-32 and £-11 with water levels about 60 msl and 66 msl respectively (see also Section A7.2:2.2).

7.5.3.2 Seasonal water level variation

Seasonal water level changes are largest in the Southern Plain where the non-saturated zone is thinnest and the seasonal influence of pumping largest. The aquifer of the Northern Plain and on the Assopos Ridge show a much smaller seasonal variation (Figures 7.5 and 7.6). This suppression of the seasonal effect of the precipitation on the groundwater hydrographs is due to tho smoothing effect of the slow percolation through the thick, fine grained, non-saturated zone. Streamflow infiltration along Assopos and Molai Rivers is reflected in the groundwater hydro- graphs close to the riverbanks (see also Section A7.2i2.3).

7.5.3.3 Water level decline

Water level change since 1971 can only be evaluated for the Southern Plain area because very little groundwater data have been reported by GWE (1972) for the areas north of Assopos. In the period 1971-1979 a general groundwater level decline in the order of one metre in summer and at least several decimetres in winter has been observed in the Southern Plain.

7.5.4 Water quality

The quality of the water (Chapter 8) of the Neogene aquifer is in general acceptable (Figure 7.7). In most of the area the EC value is less than 1.0 mmhos/cm, SAR values less than 2 and irrigation quality class C^ - CjS^. Only in the Southern Plain near the sea and along the lower reaches of Assopos and Molai Rivers is the water saltier. ' EC values between 1.0 and 2.5 mmhos/cm, SAR values between 2 and 5 and irrigation quality

class C^Sj^ - C4S2. Sea water intrusion plays a role in the salinization process but an increase in salinity due to recycling of irrigation water may be equally important. On the other hand the 6^0°/oo value should then show a reduction in depletion, which has not been observed. 77 1 Í/V ] brjser,.ent ' pervious groundwater level i v w . 1 sea level datum 17' ; karstic litr.tsti.r.t .. .".V very pervious sketcn not to scotc r—— ' . IFlüuhE 7.4. LEGEND

K-13 Well inventory number

MS*3 6WE inventory number o,» Drilled,dug will With, without pump - 62 Total depth - Vertical axis: Water level elevation (msl)

-

A-60 0-7

: o- NEOGENE AQUIFER SOUTHERN PLAIN -

0.0- -

j ^ . -

-10- -

N 0 •J FMAMJ JAS 0 N 0 j J FMA MJ J A S 1 1978 1979 1980 FIGURE 7.5 LEGEND

K-13 Well Inventory number MS~3 GWE inventory number

o,t Drilled, dug well

4F- With, without pump 62 Total depth

Vertical axis: Water level elevation (msl)

uo

54.0-j NEOGENE AQUIFER NORTHERN PLAIN

53.0 - K-|3(MS-3/o-62

SZO .

NDJPMAMJJASONDJ M A M J J 1978 1979 1980 FIGURE 7-6

IOS

7.5.5 Recharge and discharge mechanism

7.5.5.1 Recharge

i) Recharge from infiltration on the Plain

Surface runoff is negligible on the Molai Plain. Instead, nearly all net precipitation infiltrates into tha soil where part is lost by évapotranspiration and the remain­ der percolates down to.the aquifer. This is in agreement with the isotope data (Section A7.2:7 .2.3) . In the water balance calculations (Chapter 6) .the évapotranspiration was maximized'to compensate for th Jack of natural groundwater drainage in the area north Assopos. Therefore the recharge from precipitation arrived at was only 20 percent of the gros3 rainfall. In years with more than average precipitation (such as 1979/80) some water may be discharged by the Assopos and Molai rivers to the sea. The infiltration along the river channels is, however, several orders of magnitude less than the total recharge e.g. in 1979/80 the infil­ tration in the Assopos river bed amounted to a mere 3 60 000 m . During heavy rainfall a certain amount of water falling on the Northern Plain is drained into the limest-ono formation through the sinkhole. Thlr. l seeping to the Neogene aquifer, is, however, then compen­ sated for by infiltration of storm runoff generated in the limestone catchments. ii) Subsurface inflow from tributary catchments

In the area north of Plytra, persistent high groundwater levels (about 1.4 msl) and a relatively high depletion of stable isotopes indicate that the Neogene aquifer is recharged with water from the Chavalla crystallized limestones with which it is in direct contact along the eastern boundary fault. Any subsurface inflow through the alluvium of the tributary streams would be negligible. 106

7.5.5.2 Discharge

i) Discharge to the sea The groundwater level contour map indicates a general flow from the north to the south with outflow in winter to the Gulf of Xili between the Xili peninsula and Plytra, and through the alluvium of the Assopos and Molai rivers to the Gulf of Lakonia. in summer the . outflow to the Xili Gulf and through the Assopos river is cut-off by the groundwater depression created by the pumping for irrigation. Only through the Molai River alluvium, there is nearly continuous subsurface outflow^.

ii) Discharge by pumping Since 1971 discharge by pumping has become more and more important. Not only on the Southern plain but also on the Assopos Ridge and on the Northern Piain» has the irrigated agriculture been expanded. The annually pumped volumes have increased from 1.7 MCM in 1971/72 to 4.4 MCM in 1979/80.'

iii) Internal vertical drainage to the limestone reservoir In the piedmont area where the Neogene deposits overlay the limestone reservoir, a number of wells (K-7, K-11), show water levels which are about 10 m lower than the subregional level. It is believed that this is caused by vertical sub-surface drainage from the Neogene aquifer (SWLI/ 40-50 msl) into the limestone aquifer (SWL 3-4 msl). There has been no means to determine directly the amount of inflow.

iv) Internal vertical drainage in the 1-16 - nK-2 area Along the northern border of the Assopos Ridge, is a slight groundwater depression, which may indicate a subsurface drainage area. ThiB phenomenon becomes very important because the groundwater model shows an excess of water of several million cubic metres in the area north of AsBopos. It is believed that the excess water drains in this depression area, possibly to the nearby fault zone.

SWL: static water level 107

7.5.6 Water balance

The water balance is based on the results of the groundwater model study which was made for two periods:

i) April 1979 - June 1980 using monthly recharge input data. ii) April 1971 - March 1979 using 6-monthly recharge input data.

The precipitation in the,. 1971-1979 period was assumed to be equal to the longterm average (500 mm/year) without inter-annual variations. The model input and output data for the wet year' April 1979/April 1980 were corrected for deviations from average precipitation. The result is presented in Table 7.1. In the northern and central part of the Plain the net pre­ cipitation is the only or, at least, the most important recharge component, while the internal vertical drainage to another aquifer accounts for more than 50 percent of the discharge. In the Southern Plain the subsurface inflow from the Assopos Ridge is as.important as the recharge by precipitation. The subsurface in-flow of fresh water from the Chavalla aquifer is another important recharge element? it is actually balancing seawater intrusion.

7.5.7 Conclusions and development potential

7.5.7.1 Southern Plain

The Southern Plain is over-developed and the watar table drops gradually causing increased subsurface inflow from the surrounding areas. Although the induced subsurface inflow comes mainly from the Assopos Ridge and the Chavalla area, seawater intrusion is not negligible. Since 1971 the area within the 2.0 mmhos/cm contour line has moved about half a kilometre inland. It is recommended to take those wells out of production which produce water with EC 2.0 mmhos/cm or more as soon as another source of water has become available (see Chapter 10).

7.5.7.2 Aasopos Ridgo and Northern Plain

Neither the Northern Plain nor tho Assopos Ridge are yet fully developed. Due to the fault zones that act as barriers they can be independently developed. It is however recommended th-*; the water level at the upstream end of the subsurface drainage 108

Table 7.1

GROIMMATER BALANCE DURING AN AVERAGE YEAR WITH 1979 PUMPING (IN MILLION M3)

Component Northern Assopos Southern Molai Plain Ridge Plain Plain

Recharge Rainfall Percolation 3.6 1.1 7.4 Streamflow infiltration Subsurface inflow fresh water 0.5 0.5 seawater intrusion 0.2 0.2 Inter-subregional flow 1.7 1.0

Total 2.7 5.3 2.8 8.1

Discharge Pumping 0.1 1.6 2.7 4.4 Surface outflow 0.0 6.0 Subsurface outflow to the sea 0.1 0.1 to other aquifer 0.9 3.1 4.0 Inter-subregional flow 1.7 1.0

Total 2.7 5.7 2.8 8.5

Change in storage 0 -0.4 0 -0.4 channel west of Assopos be kept unchanged. This is to make sure that the recharge of the aquifer of the Southern Plain by sub­ surface inflow from the north remains at approximately the same rate as at present. The fine grain nature of the Neogene deposits of the northern zone, which has caused the sanding-up of many boreholes, requires the introduction of new well completion techniques. The intro­ duction to the farmers of wire wrapped screens with a small slot size and corresponding gravelpack should be encouraged. The behaviour of-the aquifer in the Neogene should be monitored during the coming years. This would include monthly measurements of water levels in selected wells and EC surveys twice annually (Appendix 2.1). The nature of the groundwater depression in the £-16 - P.K-2 area should be investigated. 109

Chapter.8

WATER QUALITY

8.1 INTRODUCTION

Quality of water Í3 often the principal criterion that determines water use, development of the resource and its suitability for specific uses in agriculture, industry or domestic supply. The occurrence of certain constituents may enhance or deter its use and thus in many countries standards have been set on certain elements or salts for the protection of health and welfare, agricultural productivity (Ayers and Westcot, 1976) and industrial use (State of California, 1966) .

8.1.1 Sampling Programme

The water sampling programme for quality analysis was undertaken in regard to four aspects :

i) during the well inventory, most of the wellB visited were sampled and analysed for electrical conductivity, pH and chloride content;

ii) from the well inventory, 180 wells located within the Plain and the coastal areas were selected for routine sampling (Autumn and Spring) for complete chemical analysis. The coastal wells sampled were part of a sea water intrusion monitoring programme;

iii) during" the exploratory well drilling and testing programme, the limestone aquifer was sampled throughout its drilled thickness and during the pumping tests; and

iv) twenty wells located within the limestone catch­ ment' area were also included,within the sampling programme. However thes^welis tap only valley fill and do not penetrate into the limestone.

Also included within the sampling network were the major streams and springs; in most instances the sources sampled are located in the Molai Plain, the principal exceptions were the coastal springs of Glyfada and Monemvasia. 110

The wells sampled consisted equally of dug wells and drilled wells and were sampled at least twice-a-year over a two year period. Use has also been made of analyses done by German Water Engineering (1972).

8.1.2 Water Analysis

For purposes of determining the geochemical properties of water, i.e. chemical type, salinity, chloride ion content, and extent of sea water intrusion, complete chemical analyses were made of water samples taken from selected wells. A complete analysis consists of the principal anions and cations in addition to pH, specific conductance, hardness and for selected wells, of nitrates. All chemical analyses of the water samples were carried-out by the Ministry of Agriculture, Directorate of Land Reclamation chemical laboratory in Athens. The results are ..presented, in Appendix 8.1.

8.2 GEOCHEMICAL PROPERTIES OF WATER

8.2.1 General

Water as it flows over the land surface and infiltrates into the rocks and soils, is both physically and chemically active with the material with which it comes into contact. It'; may exhibit the nature of specific areas as the local rock begins to weather and disintegrate, the variation in soils due to base exchange, and reflect chemical combination by oxidation and reduction with "salts present; biological activity will also induce acid-base changes, e.g. oxygenation leads to a decrease

in pH (C02 production) whereas sulfate reduction leads to an increase in pH. Thus, water can acquire a chemical composition reflective of the natural environment. Where limestones are present the rock of calcium carbonate is only slightly soluble

++ = but as it dissolves, it ionizes to Ca + C03 . If the calcium carbonate solution however is placed in contact with the atmosphere containing carbon dioxide then:

C02 (diasolved) + H20 = H CO 2 (1)

+ H2C03 = H + HCO~ (2) 2HC0,~= 2H+ + C0,= (3) UI

Thus when limestone dissolves, carbonate goes into solution where, in the presence of carbon dioxide, it will combine with hydrogen ion to form bicarbonate? more simply from the equilibrium (equations 1 to 3), the solution or precipitation of calcium carbonate is controlled by the gain or loss of carbon dioxide (H ions) and the activity can be described by the equation:

++ CaC03 + H20 + H2C03 = Ca + 2HC03~ (4)

Where alluvium or sands and clays are present and constitute one of the zones of saturation such as in the Molai Plain, percolating water encounters various clay minerals rock particles or salts (sea water intrusion), and it may under go chemical change by adsorption or by base exchange. For example, in the former action there may be adsorption of ions from solution, or in the latter, the ionic concentration of the relative cations may be changed whereby sodium will replace the calcium and magnesium ions of the water. In areas of shallow depth to ground water, particularly where the permea­ bility is low such as in clayey sedimentary zones, there is an increase in salt content due to capillary action. In this case water moves upward through the soil to the ground surface by capillary attraction, evaporates and leaves a salt residue. In areas of irrigation, the applied water will take the soluble salts into solution and a certain portion will infiltrate to the water table. The common salts found in irrigation waters on the basis of solubility are shown below:

Low Solubility Salt High Solubility Salt

CaC03 CaCl2

Ca(HC03)2 MgCl2 CaSO. NallCO, 4 3 MgllCOj , ..'NaSO 4

MgC03 I • NaCl

Thus, in areas of recycling of irrigation waters, shallow water table and/or sea water intrusion, as the less soluble salt reach saturation, it precipitates from solution, resulting in a water progressing chemically toward a sodium 112

Chloride type. A chemical hydrologie cycle may therefore be characterized by the following sequence of change (Chebatarev, 1955) :

HC03 : HC03 + Cl : Cl + HCC<3 : CI + S04 and/or S04 + Cl : Cl

8.2.2 Chemical Characteristics

8.2.2.1 Types of Water

From the tables of chemical analyses (Appendix 8.1: Tables A8.1-1 to A8.1-7), the percentage concentration of the cations and anions was calculated. The basis of water typing groups the ions in accordance with their electrical change and identifies the cations group (positive charge) as the' metals or bases and the anion group (negative charge) as the acid radicals.

To facilitate the typing of water, comparison is made of the relative concentrations of the cations and anions. For example, if the calcium ion (Ca ) amounts to 50 percent or more, the water class is a calcium type water. Likewise the same approach applies to the anion group. If the pre­ dominant ion is less than 50 percent, then the water is typed according to the first two predominant anions and/or cations.

On Figures 8.1 to 8.9 the percentage composition of the principal cations and anions have been plotted on trilinear graphs; in reference to the Neogene aquifer system from the north, in the Apidia-Niata basin, the ground waters are pre­ dominantly calcium bicarbonate type and this continues through the areas of Molai-Pakia, Metamorphosis and sikea. However in the latter two areas there is an increase in the amount of magnesium and sodium present as well as in chloride ion. Farther to the south, north of Assopos, although calcium bicarbonate water continues to predominate, there is a signifi­ cant increase in sulfate and chloride. Finally in the southern coastal area of Molai Plain Figure 8.6 shows, on the cation triangle, two water type groupings; waters that are mainly calcium type and the other wherein the waters are sodium- calcium type. On the anion triangle, the waters are largely chloride type.

TRILINEAR DIAGRAM OF THE MOLAI PLAIN SYSTEM OF WATERS FIGURE 8.2

TRILINEAR DIAGRAM C THE MOLAI PL " SYSTEM OF WATERS FIGURE TRILINEAR DIAGRAM OF THE MOLAI f-' ..If¡ SYSTEM OF WATERS FIGURE 8.9 122

West of the project aren in the Elea basin, the ground waters are predominately calcium-sodium bicarbonate-chloride type (Figure S.7) . In Molai Plain there is degradation of water from the north to the south, due primarily to mixing of fresh water with saline water; a similar occurrence takes place at the mouths of the Molai and Assopos Rivers and in the Elea coastal area. Oh Plate 8.1 a geochemical map has been prepared showing water types based upon anion characteristics. Although, in the Molai Plain, at least in the northern portion, there is a two aquifer system, the sources are not differentiated on the map. In general however, the limestone aquifer is sit­ uated in the' north and northwest and is overlain by the Neogene aquifer which occurs throughout the confines of the Plain. In brief, ignoring the cations, the map shows that bicarbonate water predominates throughout the Plain to Asso­ pos, then along a strip on the west side of the Plain to within approximately one kilometre of the shore. It should be noted however, in the northeast sector of the Plain, that two wells show a sodium chloride type water, Z-2 and K-12. 1-2 is a Neogene well whereas K-12 was a limestone well drilled by the GWE, 1972; the waters of both wells are brackish (Section 8.2.2.2.). Preliminary impression is that the chloride water of K-12 may be due to a local condition, i.e. trapped brackish water or an evaporite layer, for during a 72 hours pumping test, there was no variation in salinity. Also, other nearby limestone wells, though of chloride- bicarbonate type water, have moderate salinities (less than 1.200 mmhos). The Neogene well is a relatively deep borehole and probably has encountered saline waters at depths. ' At Assopos and in several wells to the southwest, the groundwater contains sulfate usually as a sulfato-bicarbonato to sulfate-chloride typo water. The source of the sulfate is unknown but may be due to evaporito deposits. It should also be noted that two wells have sodium chloride type water which may be due to waste deposits. From Assopos, there is a zone of mixing in which the waters vary from a bicarbonate-chloride type to chloride- 123

bicarbonate. The water farther south then changes to a chloride-type water and suggests possible sea water intrusion to a point two kilometers north of Plytra. Sea water Intrusion also occurs up the river channels of the Assopos and Molai rivers and along the coast north and south of Elea. Figures 8.1 to 8.9 also serve to further define geo- chemical character enabling the classification of waters in relationship to the presence of alkali (sodium), alkaline earths (calcium and magnesium) weak acids (carbonate and bicarbonate) and strong acids (chloride and sulfate). The classification is useful for urban and industrial purposes and uses as its basis, the hardness and salinity of water, and accordingly four classes of water may be derived: Primary salinity water: The alkali and strong acid predominate by 50 percent or more. This water includes salt water and brines. Primary alkalinity water: The alkali and weak acids predominate by 50 percent or more and the water is very soft. Secondary salinity water: The alkaline earths and strong acids predominate by 50 percent or more and the water is characterized by permanent hardness. Secondary alkalinity: The alkaline earths and weak acids predominate by 50 percent or more and the water is temporary hard and can be softened by boiling. The applicability of this classification is outlined in Section 8.3 and it suffices to summarise the principal wate: character to location as follows:

Apidia (Figure 8.2): Secondary alkalinity; alkaline earths exceed alkalies and along with the weak acids, are predominant (temporary hard water). Molai, Pakia, Metamorphosis and Sikea (Figure 8.3): Secondary alkalinity. Foiniki (Figure 8.4): Secondary alkalinity. Assopos (Figure 8.5): Secondary alkalinity but a significant increase towards the strong acids or secondary salinity water (permanent hardness). 124

Papadhianika (Figuro 8.6): Secondary salinity; alkaline earths and strong acids predominate (permanent hardness). It is noteworthy that in this area of chloride waters (Plate 8.1), calcium and magnesium exceed the sodium content. Elea (Figure 8.7): Secondary salinity. • Surface waters (Figure 8.8): Secondary alkalinity. Shoreline and off-shore springs (Figure 8.9): Primary salinity; the alkali and strong acids predominate and is permanently hard. The waters are unsuitable for industrial uses except as a wash water but with low salinity and with management control, may be used for urban and limited agricul­ ture purposes.

8.2.2.2 Limestone Water

Within the confines of Molai Plain, the limestone ground­ water reservoir is limited to the northern and eastern portion 2 (Section 7.3) and incorporates an area of approximately 10 km . In general, the limestone is overlain by the Neogene formation (aquifer) but as the Neogone is high in clay content (low permeability) it is improbable that there is general communi­ cation between the two aquifer systems although the static water level in the Neogene aquifer is much higher than that of the limestone aquifer. Locally there may be exceptions whereby there is Borne seepage from the limestone and conversely some seepage from the Neogene. One known exception is well K-10 (MB-4/GWE, 1972) which was originally drilled into the limestone then plugged-off to test the Neogene; the plug has apparently failed and there is leakage from the Neogene. Unfortunately, prior to the project exploratory drilling programme, there were only three wells that tapped the lime­ stone aquifer within the Plain; i.e. r.-l, r.-10 and K-6. In 1971, the GWE drilled two wells into tho limestone (K-10 and K-11) however in the latter two, the limestone reservoir was later plugged-off. In Table A.8.1-1 are the chemical analyses of the limestone wells, past and present and those located in 125

the Elea area. It may be noter» (Section 8.2.2.1), that K-12 is a sodium chloride type water and had a salinity of 6.624 mmhos which reportedly did not change during a 72 hour pumping test. Preliminary impression was that the salinity was due to a local condition i.e., trapped brackish water or an evaporate layer. Also other nearby limestone wells, though of chloride- bicarbonate type water, have moderate salinities (less than 1 .200 mmhos). . Toward the western portion of the reservoir, well K-10, also drilled by the GWE (1972) penetrated 19 meters into the limestone and according to the quality data, the salinity was 0.697 mmhos. However, in testing the limestone reservoir, due to imperfect Neogene aquifer shutoff, there was leakage from the latter and probably the given chemical analysis represents a mixture of limestone and Neogene waters. At the conclusion of a 72-hour pumping test there was an increase in salinity to 1.262 mmhos. Lack of follow-up prohibits an interpretation of the significance of the change. The water type was a sodium chloride.

In the three existing wells, two wells, };-l and £-10, have been in operation for about 10 years and the other, K-6 was drilled in 1979. Pertinent details of the wells are as follows : i) r.-l: Drilled about 30 meters into limestone; salinity in 1980 (Spring) was 1.320 mmhos and the water is a Bodium-calcium, chloride- bicarbonate type (chlorides: 217 ppm). ii) £-10: Drilled about 40 meters into limestone; salinity in 1971 and 1980 was 1.022 and 1.200, respectively; the water type has changed from a magnesium bicarbonate water in 1971 to a calcium-sodium-chloride water in 1980. Regardless ^ of the difference, there was little change in sodium content but rather a decrease in magnesium relative to calcium (chloride: 213 ppm) iii) K-6: Drilled about three meters into limestone; salinity is 1.500 mmhos and the water is a sodium calcium, chloride type (chloride: 273 ppm). 126

Taking into consideration Lho somewhat conflicting groundwater quality data, one of the main objectives of the exploratory drilling-programme was to explore and test the limestone system at various depths to a maximum depth of 300 to 4 00 meters. Four exploratory production wells were drilled in the Plain to tap the limestone reservoir area and two exploratory wells were located along the western boundary of the Plain to study possible subsurface drainage to the Glyfada shoreline springs in Elea —( The exploration/production studies confirmed that the limestone reservoir is karstified to great depth (more than 250 metors) and is capable of yielding high volume (up to 200 m3/hr) to wells. The drillings also showed a very complex karst system which contained highly saline waters at depth. Selected details of the exploratory wells are as follows (also see Table A.8.1-2 and Figure 8.1):

i) EB-1: Drilled 290 meters into tnr limestone reservoir; connection with sinkhole verified; groundwaters of low salinity (O.6-0.7 mmhos) occur to a depth of more than 170 meters below the water tabic. The water typo is a calcium, magnesium bicarbonate. At a depth of 50 meters below the water table, the solution openings of the limeBtone contained clay impregnated with oil (probably olive oil waste). At 269 m (200 m below the water table), the salinity increased to 1.7 mmhos and the water type was a sodium chloride. Figure A.8.1-1 sh' .'s that the groundwater, though a calcium bicarbonate type water in the upper portion of the reservoir, changed toward a sodium chloride water with depth, ii) EB-2: Drilled 230 meters into the limestone and at a depth of 102 meters below ground surface, encountered a sodium chloride, bicarbonate water, with a conductivity of 1.54 mmhos. At a depth of 71 meters below" the water table, the conductivity (after 35 hours of pumping) was 1.95 mmhos; water type was a sodium chloride water. At a depth of 296 meters or 200 meters below the water table, the

V An additional exploratory well was drilled into the Neogene aquifer-system in tho Plain. 127

conductivity sharply increased to 20.5 mmhos; the water is strongly a sodium chloride type. Compar­ ing Cl~/Br~ of the well sample (217) with that of sea water (300), it is concluded that well EB-2 is polluted by sea water, iii) EB-4: at 115 metres, drilling encountered a sodium chloride water with a conductivity of 3.050 mmhos. At a depth of 145 metres, the conductivity had increased to 4.25 mmhos. iv) RB-1: this well was sited to explore geologic structure and after commencing drilling in metamorphic rock, entered a crystalline limestone at a depth of 180 metres (150 metres below sea level). The water- level rose to +6.8 metres above sea level and had a conductivity of 2.850 mmhos; the water type was a sodium chloride water and is chemically similar to the waters from Glyfada Springs, v) RB-3A: this well encountered water in the limestone reservoir at a depth of 122 metres below ground surface. The well had entered a fault zone and was discontinued; water type was a sodium bicarbonate water and had a conductivity of 1.0 mmhos.

Figure 8.1 in general shows that there is a linear change in the chemical characteristics of the limestone groundwater from calcium bicarbonate type to a sodium chloride type. On Plate 7.1, the conductivity of the limestone reservoir is shown. West of the Molai Plain and outside of the boundaries of the project area, there exists the Elea tributary catchment of 2 approximately 27 km wherein occurs the shoreline and off­ shore springs at Glyfada. In 1963 the Directorate of Land Reclamation carried-out an exploratory drilling programme at Glyfada, with the objective to intercept the spring waters. At a distance of one kilometre east of the springs, and parallel to the coast a line of eight small diameter wells were drilled (wells E-81 to E-88) . Of the eight, six wells 128

reportedly encountered some limestone, and though water was encountered, the salinities ranged between 2.400 and 3.300 mmhos (Glyfada springs: 3.450 mmhos). Since the exploratory wells did not encounter water significantly less saline than the springs (chloride: 800 ppm), the programmed follow-up studios were discontinued in 1966. Also, north of the Molai-Elea road, and one kilometre east of the shoreline, in vicinity of X: 661.7; Y:4070.0, a group of eight wells (E-27 to E-33 and E-35) were drilled by private owners (one by Government) several of which were reportedly completed in limestone. In general, the wells encountered water with a salinity of 0.900 to 1.500 mmhos and a chloride content of 100 to 200 ppm. The chemical water type varied from a calcium bicarbonate water to a calcium-magnesium bicarbonate water (Table A.8.1-1).

8.2.2.3 Ncogone Water

i) Molai Plain Tho Neogone groundwater reservoir of the Molai Plain occurs within the limits of the 100 m elevation contour line—( Due to structure change, the Neogene formation is of variable thickness, being thickest In the north nnd in the south (600 m). It is therefore probable, that following the deposition of the Noogene, the deeper sediments were not completely flushed by fresh water and the lower ground waters may be relatively saline (connate water) as noted in well z-2, Table 8.1 (also Bee Section 8.4.1.1). In the central portion of the Plain, a subsurface geologic high exists (horst) and the Neogene formation is about 100 - 200 m thick. An exploratory well (E-33) drilled at coordinates X: 667.43; Y: 4070.35, by GWE (1972) penetrated the full thickness of the Neogene and was completed at the top of a

1/ WITHIN THO LIMESTONE CATCHMENT AREN NORTH OF THO MOLAI PLAIN, THERE EXISTS INTERIOR VALLEYS (POLJES) WITH A VARIABLE THICKNESS (TO 60 M PLUS) OF FILL, OF PROBABLE NOOGONO AGE. IN THE APIDIA-NIATA VALLEY, THO QUATERNARY IS AN AQUIFER AND IS EXPLOITED BY APPROXIMATELY 70 WELLS. THE SALINITY OF THE GROUND WATER IS GONORNLLY LOSS THAN 1.000 MMHOS AND OF CALCIUM BICARBONATO TYPE. NO WELLS HAVE BEEN DRILLED INTO THO LIMESTONES, ALTHOUGH IT WAS REPORTED THAT A BOREHOLE WAS DRILLED TO A DEPTH OF 250 M AT AYIOS DIMITRIOS; NO WATER WAS ENCOUNTERED. 129

change in formation (to volcanics); chemical analysis of the water during pumping test showed a calcium bicarbonate water (Table 8.1). As noted on Plate 8.1, the groundwater type changes from a predominant calcium bicarbonate water occurring in the northern two-thirds of the Plain to a mixing zone of bicarbonate- chloride to chloride-bicarbonate type water (around Assopos occurs water of sulfate-bicarbonate or sulfate-chloride type) and near the coast at Plytra and at the mouths of the Molai and Assopos rivers, to a chloride type water. However, chemical water typing relates to the relative concentrations of its constituents but not according to the absolute concentrations. Because absolute concentrations can be decisive in many problems of interpretation and water use, a series of maps have been prepared to show groundwater salinity (in specific conductance, mmhos) for the periods Autumn 1971 (GWE, 1972), Autumn I978, Spring 1979, Autumn 1979 and Spring 1980 (Plates 8.2 to 8.6). In general, however, in the upper three quarters of thr> Plain the ground water has a salinity of less than 1.000 mmhos and the area coincides with that of the bicarbonate type waters (Plate 8.1). From Assopos-Papadhianika southward to about two kilometers from the Plytra shoreline, the salinity increases from 1.000 to 1.500 mmhos and the area is similar to that of the zone of mixing of bicarbonate-chloride to chloride-bicarbonate waters. Finally, from the Plytra shoreline inland to about two kilometers and at the mouths of the Molai and Assopos rivers the ground water has salinities ranging from 1.500 to 3.000 mmhosj the area coincides with that of chloride waters and suggests possible sea water intrusion. Regarding relative change in salinity, Plate 8.2 to 8.6 iiso-salinity maps) cover a time period of more than nJ^ht years (Autumn 1971 to Spring 1980); as might be expected with intense groundwater development in a coastal zone salinity has increased. Between 1971 and 1980, the area within the 2.000 mmhos contour- line has expanded and moved one-quarter to one-half kilometer farther inland. Probably of more significance is'that within 130

Table 8.1

CHEMICAL ANALYSES OF WELLS £-33 AND 1-2

Constituent meg meg Conductivity 0.751 mmhos 3.500 mmhos pH 6.7 7.4 Sodium 2.11 21.6 Potassium 0.05 Calcium 3.30 6.3 Magnesium 0.77 7.0 Bicarbonate 4.70 5.4 Carbonate - Sulfate - 0.87 4.5 Chloride 1.4 2 25.0 the overall area south of Assopos, there has been a general increase in salinity and is reflective of the increased pumpage, and/or poor well spacing. Curiously however, the zone of relatively higher salinity does not coincide with a summer groundwater depression zone southwest of Papadhianika. Plate 8.7, an isochlor map is similar in pattern to the conductivity maps, showing an increase from Assopos south­ ward and at the river mouths. In comparing Plate 8.6 and 8.7, it may be noted that the 1.500 mmhos contour-line is similar in area to the 6.0 meq chloride contour (213 ppm). Greatest chloride ion content is near the coastal zone and averages about 500 ppm.

ii) Elea Sub-area

The Elea sub-area west of the Molai project area, 2 has an areal extent of about. 27 km , but the majority of the wells and irrigated lands are along the coast. Here, as in Molai, from the limestone .'highlands, the groundwaters are calcium bicarbonate type and of relatively low salinity. Along the coast however, hpfch north and south of Elea, cover­ ing a distance of four to/five kilometres, the waters are chloride type, extending, south of Elea, almost one kilometre 131

inland. In.general the chloride type waters have a salinity in excess of 1.500 mrnhos (Table A8.1-4).

8.2.2.4 Streams-^

Tho draintge network of the Molai project area is somewhat complex in that there are no major surface water inflows to Molai Plain. In the karstic catchment there is little surface runoff and subsurface drainage predominates. The exception is: the Potamia stream, draining an area of 2 about 15 km immediately to the north of Molai,a partially non-carbonate area, which drains to the Plain and ultimately to the sinkhole near Metamorphosis; the Tsakona and Monoporo streams, draining small limestone areas immediately north of the Plain; and small streams draining the Sikea area east of the Plain. All of the above surface flow drains to the sinkhole near Metamorphosis. The salinities are relatively low, varying from 0.180 to 0.460 mmhos; the water is predominately a calcium bicarbonate type although the stream draining from the Sikea area is a bicarbonate-chloride type. From Molai town and the southern one-half of the Plain, the overland runoff drains via the Molai and Assopos Rivers. The Molai River drains the western portion of tho Plain turn­ ing westward to the Lakonian Gulf opposite Papadhianika; the water type is a calcium bicarbonate water. Draining the small eastern catchment area above Assopos and papadhianika, the Assopos River drains we3t-southwest, and then flows into the Lakonian Gulf. The water type is a bicarbonate-sulfate water and suggest the presence of some gypsum salts in the Sikea- Finiki area. At the mouth cf both rivers, the groundwaters have a salinity of 2.000 to 3.000 mmhos and are sodium chloride hypes. The Bource of the chloride is sea water brought into the river mouth swampy areas during storm periods. Since surface water outflows are infrequent, there is saline water accumulation and induced mixing with the groundwaters due to pumping during the irrigation season. The chemical character­ istics of the surface waters are shown on Figure 8.8 which is a trilinear plot of the principal cations and anions.

—'See Chapter 6 Hydrology 132

8.2.2,5 Springs

Within the vicinity of the Molai Plain, there are no large springs present. The does exist however, numerous small springs throughout the project area; in fact, the present locations of the many towns and villages were probably orig­ inally due to the presence of springs. Most of such springs are contact-type springs, generally discharging at a point of change in geologic formation, i.e. limestones to metamorphic rocks. Spring flow responds rapidly to rainfall but during the dry season decreases drastically or stops entirely. The salinities of the spring waters are relatively low, ranging from 0.260 to 1.000 mmhos (Table A8.1-6), and the water types are generally strongly calcium bicarbonate waters; where dolomites are present, magnesium content is also relatively large. Although the springs described are locally important as a source of domestic water supply, hydrogeologically, they are relatively unimportant. Of primary importance are the shoreline and offshore springs that occur at Plytra, at Glyfada in Elea area, and in the Monemvasia area. Of the three areas, the springs in Plytra are the smallest. There are several shoreline seeps originating àt the base of alluvial cliffs and an area of concentrated discharge i.e. up to 30 1/s at coordinates X: 666.05, Yt 4061.8 (Section 6.3) originating from limestone. Offshore, in two small embayments, three groups of spring discharge occur in each, from depths of one to two metres. A group discharge point generally consists of numerous small points of boiling sand within an area of 1.0 to 1.5 m diameter. The shoreline spring waters are brackish with a salinity of about 8.000 mmhos; water typo is sodium chloride. The marine springs, being of small flow, are difficult to sample but the salinity at spring source and at sea surface was 50.100 and 54.500 mmhos, respectively; tho sea water at Plitra has a salinity of 56.700 mmhos. Tho Plitra springs can be related isotopically to tho Chavalla Mountain as the waters originate from a source area with an elevation of 400 metres (see Section: 7.2.8). 133

The most important springs, both shoreline and off­ shore springs occur at Glyfada and the Elea area, outside of the Molai project area. The spring waters however, are believed to originate within the project area, and to move along subsurface drains (faults) from Molai to the Elea area. This hypothesis is further supported by isotopic studies which indicate that the waters originate from a source area of 1 000 metre elevation. The springs discharging at the shoreline, though varying in flow are quality-wise, very constant. Attempts to change the quality, i.e. salinity, by containing the springs and thereby effecting a pressure change, have had no influence on salinity. It is possible therefore that the spring waters, pick-up their salts in the groundwater reservoir and not at the coast line (see Section 8.4.1.1). The springs have a salinity of 3.300 -.3.400 mmhos and are sodium chloride type waters. In 1971, the salinity of the same springs was 3.270 mmhos. In the offshore area the springs originate opposite an onshore fault line at a depth of eight to twelve metres. The spring group, consisting of about 16 to 18 spring points discharge within an area of about 200 m diameter. Much of the spring discharge is as seeps, with some minor orifice type discharge. The salinity of the springs sampled at bottom varied from 25.000 to 54.000 mmhos and are sodium chloride waters; salinity of the sea water was 56.200 mmhos. An exploration well located about one kilo­ metre inland ;from the offshore springs, encountered, in limestone, water with similar chemical characteristics as that of the Glyfada springs (RB-1).

In Monemvasia area, along the east coastline, although considered outside of the project area, the coastal area is highly karstified and there occur numerous shoreline springs and several offshore springs. The karstification of Lakonia both old (Eocene) and new (Quaternary) has been disturbed by block-faulting and tilting and probably has been rejuvenated. This means that given average drainage conditions the project area as delineated is a hydrologie unit; under unusual or excessive subsurface flow conditions, outflow through the eastern basin boundary is possible. For this reason, spring occurrence along the eastern 134

shoreline, approximately 10 kilometres from the project boundary, have been surveyed and studied. In this regard, the area of concern extends from the town of Mor.emvasia, northward to the Bay of Kremmidi (four kilometres). Along this stretch of shoreline, all of the spring waters are brackish and of sodium chloride typa water. The least saline spring is near the town of Monemvasia and has a specific conductance of 7.600 mmhos. Northward from this spring, the salinities increased sharply and vary from 15.700 to 26.750 mmhos (Table A8.1-6). It is believed that all of the spring waters are contaminated at or near the shoreline. Most of the springs discharge from karstic limestone which slopes eastward beneath the sea but retaining its highly irregular karst surface. The depth of karstification is unknown, but on the shoreline at coordinates X: 681 .30, Y : 4 067.30 , a water hole has a depth of 25 metres; from 0 to 10 m, the salinity varied from 1.210 to 1.770 mmhos and below 15 metres, from 45.500 to 62.000 mmhos. Again, at coordinates X: 682.45, Y: 4067.5, a circular collapse-type cave exists and contains ponded water (probably at sea level); when the wet season first began, the bottow water had a salinity of 7.150 mmhos; in December the salinity was 0.520 mmhos.

Offshore, a group of three springs exist at approximate coordinates X: 681.60 , Y : 4067.4; about 100 m to the north another marine spring occurs but is irregular in discharge. At time of investigation, the marine spring flows were small (several litre i>

8.3 RELATIONSHIP TO USE

8.3.1 Agriculture

Agriculture is the largest water user in the Molai Plain; in 1979/80 the water extracted for irrigation was estimated at 6 3 4.6 x 10 m . Under full development whereby all irrigable lands are utilized (6,200 ha) the future demand is estimated at 24 x 106 m3. However, quantity alone does not determine use, but the waters must also qualitatively be evaluated or classi­ fied for irrigation suitability. 135

8.3.1.1 Classification of Molal Water for Irrigation

There are many ways in which the suitability of water for use in irrigation may be classified. The more common approach is to relate the salinity of the water to the sodium ion concen­ tration. On the other hand, &ny attempt to classify a water, particularly a water in which the conductivity exceeds 0.750 mmhos, may be of questionable value unless crop sensitivity is considered as well as soil type, climatic conditions and depth to ground water. Therefore, if such information is not available, any classification method utilized, can at best, be only a

general indicator of the water suitability for irrigation. it

8.3.1.2 Suitability of Irrigation Water

In general, the suitability of a water for irrigation is determined by the amount and kind of salts it contains. A poor quality of water, i.e. high salt content can cause a variety of soil and crop problems but problems can also be caused by waters of too low salt content, or if toxic constituents, such as boron, are present. Suitability of water therefore relates also to on- farm land and water management.

i) Classification Method To classify the waters for irrigation use, the U.S. Department of Agriculture (1954) method is used that relates salinity with alkali content. It has the advantage to show visually the class of the Molai waters.

a. Salinity The unit of salinity used throughout this chapter and by the classification method is the electrical conductivity measured in miHimnos/cm at 25 degrees centigrade (mmhos). Salts in water are required by plants but to a limited concen­ tration. However, through constant application (irrigation), the water remaining in the soil (soil water) contains a higher concentration of salts than the applied irrigation water. Thus,

in a poorly drained soil with a minimum of leaching, Bait concen­ tration in the soil water will increase with each successive application of irrigation water, until the limit of solubility

is reached for each particular salt involved. Many salts, however, 136

such as the chlorides and sulfates of sodium and magnesium become toxic to plants before the limit of solubility is reached. This toxic effect is caused by the salts preventing water uptake by plants (osmotic effect) , by direct chemical effect upon metabolic reactions of the plant, or by change in the soil structure (California Water Quality Criteria, 1963). 1 / b. Sodium ion Concentration—' The alkali waters are identified in terms of the cation concentrations, for the soluble constituents react with the soil as ions rather than as molecules. If the calcium-magnesium of the cation group predominate, the alkali hazard is low; however, if sodium ion predominates, the alkali hazard is great. The importance of the cation concentration is that calcium- magnesium can be beneficial to soil in maintaining structure and tilth whereas sodium tends to break-down soil structure and to reduce permeability. The factors that favour increase in sodium concentration in irrigation or soi.1, waters are however, general reactions of normal occurrence. That is, groundwater with a predominance of calcium-magnesium may in movement come in contact with material, particularly clay, and there is an exchange of ions whereby the calcium-magnesium ions in the water will replace the sodium ions of the clay. This results in an increased sodium content of the water. Similarly, in a limestone region, as ground water in movement increases in carbonate content, precipitation occurB thereby decreasing the calcium ion concentration leaving a proportionate increase in sodium. For purpose of classification, the sodium ion concentra­ tion can be expressed as a sodium adsorption ratio (SAR): Na+ 2/ SAR (5) ". (Ca++ + Mg++>

-^From Section 8.2.2.1, it follows thab depending upon salinity, only a water with a predominance of alkaline earths and weak acid (secondary alkalinity) in suitable for irrigation. In the other water classes, primary salinity secondary salinity and primary alkalinity, the dominating ions are either sodium or chloride. With low salinity, those latter typos of water may bo used providing there is a dogrco of on-farm management. 2/ —Cation concentrations aro in milliequivalonts por litro (moq/1). Also see Appendix 8.2 137

to show the effects of base exchange or the adsorption of sodium by the water. That is, the irrigation water, after entering the soil increases the insoluble salt concen­ tration without-changing the relative composition. The SAR value however, will increase as the salt concentration increases and thus defines the water accordingly.

c. Classification

In Figures 8.10 to 8.14 are graphs classifying the Molai waters for irrigation use (Wilcox, 1955) . The graphs include the results of chemical analyses of selected wells located throughout the Molai Plain, including the coastal area, Elea and Apidia. It;may be noted that on all of the graphs, the sodium (alkali) hazard of the various sources of water is generally low. The surface water, that is streams and springs (except for the coastline springs) are of low

sodium content and medium salinity hazard (C2 - S^); the shoreline springs are low sodium hazard but high to very high salinity. The offshore springs register off the graph, i.e. very high sodium and salinity hazard (Table A8.1:6).

The general water irrigation suitability is differentiated by aquifer; that is, groundwater from the limestone aquifer (Figure 8.10) and from the Neogene (Figures 8.11 to 8.14). The graphs show that in general, the water of the limestone, though represented by only a few wells, is a Cj - S^ water or low sodium and high salinity hazard, whereas the Neogene waters,

beginning in the northern part of the Plain are C2 - to C3 - S^ class, having low Bodlum and medium to high salinity.

Moving southward, the waters become almost entirely C3 - S1 until near the coast but above Plytra the waters are equally

C3 - S,j to C^j - S2; the latter are medium sodium to very high salinity hazard. The conductivity of the Molai Plain waters is listed with the water analyses in Tables A.3.1t2 to A.8.1:7; the SAR values have been calculated from the cation concentrations < and are also shown in the water analyses. This method of classification provides both a numerical and visual component for comparison purposes. IM r

• v t Ct- S 4

—i i • C2 - S4

C3 - S4 C4-S«

100 25" '50 }í')0 SPECIFIC CONDUCTANCE (MICROMHOS/CM AT gst I N LOW MEDIUM HIGH 3VER Y HIGH SALINITY HAZARD Llmttton* oquiftr

• Existing wtll*

O OWE 1972 % Exploratory i960

IRRIGATION QUALITY OF WATERS FROM WELLS

IN THE MOLAI PLAIN

FIGURE 8.10 139

SALIN IT Y h"a"z"A R 0

Ntogtn» oqulfer .Vi>Qt of Motoi, PakkiiMtlomonJhonli '-»kta and Fini kl

IRRIGATION DUALITY OF WATERS FROM WELLS

IN THE MOLAI PLAIN _____ FIGURE 8-11 SALINITY HAZARD

Ntogena aqutftr Attopot Arta

IRRIGATION QUALITY OF WATERS FROM WELLS

IN THE MOLAI PLAIN _____ FIGURE 6.12 141

i v** i—n ,vpaa , —iac

C2-3I

4 C4- SI -i i i ••ñii i L_ Sr. 100 JSO 750 Î2S0 1 1 2 3 4 LOW • MEDIUM HIGH VERY HIGH SALINITY H A Z ARO

N«og«n« oquifir

Popadhignlka, Plytra Aria

IRRIGATION QUALITY OF WATERS FROM WELLS

IN THE MOLAI PLAIN I FIGURE"era* 142

Uimtton« / N«o««n« / Holoetn* oqulftr

EIM Ar* a

IRRIGATION QUALITY OF WATERS FROM WELLS

IN THE MOLAI PLAIN \ . ( FIGURE 143

ii. Guidelines for interpretation of Water Quality for Irrigation

Ayers and Westcot (1976) have prepared guidelines (Table 8.2) to assist at the farm level to determine the suitability of water for irrigation and the degree of possible problems. The guidelines consider newer concepts in soil- water-plant relationship than the USDA (1954) and relate to the general irrigation problems of salinity, permeability and specific ion toxicity. Under the latter, for sodium, an adjusted SAR is used (Appendix 8.2) for both the effect of sodium in soil permeability and its possible toxic effect. In regard to salinity, while Table 8.2 Indicates degree of problem with waters of increasing salinity, in reality, the problem relates to the salinity of the soil water which in turn relayas to the extent of leaching; the degree of problem therefore is also a function of on-farm management. For example, Table 8.3, adjusted after Ayers and Westcot (1976) to the Molai area, shows the general limits of applied water salinity (ECw), saturation soil extract salinity (ECe) in mmhos/cm, and the décrémentai effect on crop yields. The table assumes a 15 - 20 percent leaching fraction. However as outlined in Table 8.3, footnote 2, the saturation soil extraction salinity is a function of the leaching fraction. In addition, aside of the deleterius effects of salinity on crop yield, in regard to citrus, Wallace (1976) points out that increased salinity also makes the trees more susceptible to frost damage. This aspect is of importance to Greece as sour orange root stock is used, and it is relatively more susceptible to frost and salt damage than other types of root stock. Further, the generally accepted quantity of applied water (in Greece) is 3 000 to 3 500 m/ha and the water requirement for citrus is about 3 500 m/ha but this is only sufficient for évapotranspiration and has no leaching component. In experiments carried-out in Cyprus (Stylianou and Orphanos, 1970), Israel (Goell, E-Rais and El Wahidi, 1977) and Spain (Cerda, Caro, Fernandez and Guillen, 1977) in the use of saline water in citrus irrigation, in general, 4 144

but depending on soil type (permeability), a leaching fraction of at least 30 percent is required to minimize the effects of salinity. Even so, saline waters tend to age the trees quicker than less saline waters. In particular, citrus with sour orange rootstock, show high leaf chloride content thereby causing leaf burn and shoot dieback. Use of saline waters may also affect the quality and quantity of fruit produced, cause creased'fruit, thicken the fruit skin, and affect juice content (sugar and acidity). In referring to Plates 8.1 and 8.6, specifically to the area of chloride waters which is also more or less the zone where salinity exceeds 2.000 mmhos/cm, tfie existing citrus orchards, without a leaching fraction could^have up to a 25 percent decrease in yield. However, since sp.|to! decrease has apparently not occurred, it is probably due to,the leaching effect of the rainfall which has prevented soil salinity build-up. Finally, while discussion has emphasized the possible damaging effects of high salinity, waters of low salinity also can produce undesirable effects in that the low saline waters will leach the soils of salts thereby causing a reduction in permeability.

8.3.2 Urban Use

All.of the principal towns and villages lying within the boundaries of the Molai project area obtain their water supply from sources within the specific area except for the towns of Ayios Dimitrios and Niata. Within the Molai Plain, the exist­ ing communities of Molai, Metamorphosis, Sikea, Pakia, Finiki, Assopos and Papadhianika compete with agriculture for water. In the past, the principal source of urban water was springs, however, in recent years these communities have had to turn to wells to supplement the spring flows. The present estimated domestic water use in the Molai Plain is 900 m3 per day; by the year 2 000, the domestic demand is expected to increase to 1100 m3 per day. Water for domestic use should be free oft

i) obj ectionable odour creating substances; ii) aesthetically objectionable floating substance; 145 Table 8.2

GUIDELINES FOR INTERPRETATION OF WATER QUALITY FOR, IRRIGATION (After Ayers and Westcot, 1976)

IRRIGATION- PROBLEM DEGREE OF PROBLEM Increasing Severe No Problem Problem Problem SALINITY (affects crop water availability) ECw (mmhos/cm) <0.75 0.75-3.0 >3.0

PERMEABILITY (affects infiltration rate into soil) ECw (mmhos/cm) >0.5 0.5-0.2 <0.2 adj. SAR 1/ 2/ MontmorilTonite (2:1 crystal lattice) >6 6-9 3/ >9 Illite-Vermiculite (2:1 crystal lattice) <8 8-16 y >16 Kaolinite-sesquioxides (1:1 crystal lattice) <16 16-24 y >24

SPECIFIC ION TOXICITY (affects sensitive crops) Sodium 4/ 5/ (adj. SAR) <3 3-9 >9 Chloride~4/~5/(meq/1) < 4 4-10 > 10 Boron (mg7D~ <0.75 0.75-2.0 >2.0

MISCELLANEOUS EFFECTS (affects susceptible crops)

NO.-N (or) NH4-N (Mg/1) <5 5-30 >30 HCO, (meq/1) (overhead 3 1 .5-8.5 >8.5 sprinkling) < 1.5 pH Range 6 .5 .- 8.4)

1/adj. SAR means adjusted Sodium Adsorption Ratio and can be ~ calculated using the procedure given in Appendix 8.2.

2_/Values presented are for the dominant type of clay mineral ~ in soil since structural stability varies between the various clay types (Railings, 1966, and Rhoades, 1975). Problems are less likely to develop if water salinity is high; more likely to develop if water salinity is low.

3/Use the lower range if ECw<0.4 mmhos/cm; Use the intermediate range if ECw = 0.4 - 1.6 mmhos/cm; Use upper limit if ECw 1.6 mmhos/cm

4/Most tree crops and woody ornamentals aro sensitivo to "~ sodium and chloride (use values shown). Most annual crops are not sensitive.

5/With sprinkler irrigation on sensitive crops, sodium or ~ chloride in excess of 3 meq/1 under certain conditions has resulted in excessive leaf absorption and crop damage.

< means less than > means more than

* 146

Table 8.3

CROP TOLERANCE TABLE _/

Yield Decrement to be expected for certain Crops due to Salinity of Irrigation Water when Common Surface Irriga­ tion Methods are Used.

Field Crops 0% 10% 25% 50% Maximum

ECe 2/ECw 3/ECe ECw ECe ECw ECe ECw ECe 4/ Barley 5/ 8.0 5.3 10 6.7 13 8.7 18 12 28 Wheat 6.0 4.0 7.4 4.9 9.5 6.4 13 8.7 20

Corn 1 .7 1.1 2.5 1 .7 3.8 2.5 5.9 3.9 10

Beans 1.0 0.7 1.5 1 .0 2.3 1 .5 3.6 2.4 6.5

— Fruit Crops Fig Olive 2.7 1.8 3.8 2.6 5.5 3.7 8.4 5.6 14 Pomegranate

Grapefruit 1.8 1.2 2.4 1.6 3.4 2.2 4.9 3.3 8 Orange 1.7 1.1 2.3 1 .6 3.2 2.2 4.8 3.2 8 Lemon 1.7 1.1 2.3 1 .6 3.3 2.2 4.8 3.2 8 Walnut 1.7 1.1 2.3 1 .6 3.3 2.2 4.8 3.2 8 Grape 1.5 1 .0 2.5 1 .7 4.1 2.7 6.7 4.5 12 Almond 1.5 1 .0 2.0 1 .4 2.8 1 .9 4.1 2.7 7

Strawberry 1.0 0.7 1.3 0.9 1.8 1 .2 2.5 1.7 4

Vegetable Crops Tomato 2.5 1.7 3.5 2.3 5.0 3.4 7.6 5.0 12.5 Cucumber 2.5 1.7 3.3 2.2 4.4 2.9 6.3 4.2 10 Cantaloupe 2.2 1.5 3.6 2.4 5.7 3.8 9.1 6.1 16 Spinach 2.0 1.3 3.3 2.2 5.3 3.5 8.6 5.7 15 Cabbage 1 .8 1.2 2.8 1.9 4.4 2.9 7.0 4.6 12

Potato 1.7 1.1 2.5 1 .7 3.8 2.5 5.9 3.9 10 Lettuce 1.3 0.9 2.1 1.4 3.2 2.1 5.2 3.4 9 Radish 1 .2 0.8 2.0 1.3 3.1 2.1 5.0 3.4 9 Onion -1 .2 0.8 1.8 1 .2 2.8 1 .8 4.3 2.9 7.5 Carrot 1 .0 0.7 1.7 1.1 2.8 1.9 4.6 3.1 8 Beans 1 .0 0.7 1.5 1 .0 2.3 1 .5 3.6 2.4 6.5 Sweet Corn 1.7 1.1 2.5 1.7 3.8 2.5 5.9 3.9 10 147

Table 8.3 (cont'd) 0% 10% 25% 50% Maximum

ECe ECw ECe ECïj» ECe ECw ECe ECw ECe

Forage Crops

Tall wheat grass 7.5 5.0 9.9 6.6 13.3 9.0 19.4 13 31 .5 Barley (hay) 6.0 4.0 7.4 4.9 9.5 6.3 13.0 8.7 20 Perennial rye grass 5.6 3.7 6.9 4.6 8.9 5.9 12.2 8.1 19 Alfalfa 2.0 1 .3 3.4 2.2 5.4 3.6 8.8 5.9 15.5 Corn(forage) 1 .8 1 .2 3.2 2.1 5.2 3.5 8.6 5.7 15.5

-/ After Ayers and Westcot, 1976

2/ — ECe means electrical conductivity of the soil reported in millimhos per centimetre

3/ ECw means electrical conductivity of the irrigation water in millimhos per centimetre at 25 C. This assumes about a 15-20% leaching fraction and an average salinity of soil water taken up by crop about three times that of the irrigation water applied (ECsw=3 ECw) and about two times that of the soil saturation extract (ECsw=2 ECe). From the above, ECe=3/2 ECw. The following are estimated relation­ ships between ECe and ECw for various leaching fractions : LF=10% (ECe=2 ECw), LF=30% (ECe=1.1 ECw), and LF=40% (ECe=.9 ECw).

1/ Maximum ECe means the maximum electrical conductivity of the soil saturation extract that can develop due to the listed crop withdrawing soil water to meet its évapotranspiration demand. At this salinity, crop growth ceases (100% yield decrement) due to the osmotic effect and reduction in crop water availability to zero.

5/ Barley and wheat are less tolerant during germination and seedling stage. ECe should not exceed 4 to 5 mmhos/cm. 148

Iii) any substance in concentration sufficient to be toxic to river, land or animals; and iv) detergents in concentration to cause foam.

More specifically, for public water supply the water should qualitatively adhere to the following criteria:

Constituents or Characteristic Permissible Limit Colour 50 Units pH 6-8.5 Turbidity 30 Units Total dissolved solids 1 500 mg/1 Chloride 600 mg/1 Sulfate 400 mg/1 Coliform 1.0/100 ml

Chemically, aside of the vicinity of Plytra, all of the waters of both the existing limestone and Neogene wells fall within the permissible limits of the standards and are considered suitable for urban use. The waters are mainly secondary alkalinity waters and will precipitate calcium carbonate when subjected to heat, or if in high concentration, to pressure change.

8.3.3 Industry

To present, the Molai Plain is predominantly an agric­ ultural area with only a few industries. These industries are largely agriculturally oriented and consist of ten olive factories, two table olive factories and several flour mills. There also exists one machine shop drill rig construction factory. The present industrial water use is primarily for wash water and is considered to be negligible. By the year 2 000, it is not foreseen that the industrial demand will increase significantly to become an important competitor for the available water resources of the Molai Plain. Regardless of the use factor, and the fact that water quality requirements for Industrial use are subject to wide

1 / —' silica scale U9

variations, the following generalized numerical values are used as standard.

Constituent or Characteristic Permissible Limit Colour 1 200 Units pH 3.5 - 9*1 Total dissolved solids 1 000 mg/1 Alkalinity 500 mg/1 Hardness ' 850 mg/1 Chloride 500 mg/1 Sulfate 680 mg/1 Coliform 10 000/100 ml

All of the ground water of Molai Plain meet the above requirements except for those ground waters south of Papa- dhianika; in the latter area total dissolved solids and hardness are generally excessive (primary salinity water) and are unsuitable for most industrial uses.

8.4 POLLUTION OF WATER RESOURCES

8.4.1 Salinity of Water

On Plates 8.2 to 8.6 there is shown the degree of salinity throughout the Molai Plain for both the limestone and the Neogene reservoir systems for the years 1971, 1978, 1979 and 1980. In general, there is a marked increase in salinity from north to south particularly near Plytra and at the mouths of the Molai and Assopos rivers. In the Elea basin, west of Molai, there is also saline water along the coast, north and south of the town of Elea. An isochlor map (Plate 8.7) shows a similar pattern-.

8.4.1.1 Limestone aquifer

The salinity of the limestone aquifer has been discussed in Section 8.2.2.2 and as pointed out, the waters are either a chloride or chloride-bicarbonate type. Using a Stiff diagram method to define individual patterns of chemical character, a three percent sea water contamination of a limestone aquifer water such as E-1 produces a chemical pattern similar in character to that of the GÍyfada shoreline springs; the pattern 150

of the water from the exploratory wells drilled by the Land Reclamation Service in 1963-64, one kilometre inland from the springs, is also similar to that of Glyfada springs, and as previously concluded in Section 8.2.2.5, the spring waters are probably picking up the salts in the limestone aquifer and not at the shoreline. Curiously, the Neogene well Z-2 is also of similar pattern as the Glyfada springs and it was considered that as Z-2 is located along the edge of the lime­ stone block (fault zone), it may be possible that the well is picking-up saline water raising along the fault zone from the lower part of the limestone. Present knowledge however, offers no satisfactory hydraulic explanation for such phenomena as water levels in the limestone are much deeper than in the Neogene. It is concluded that the limestone aquifer has probably been contaminated by either salt deposits, sea water or connate water. The project exploratory well drilling and testing programme substantiates the presence of salt water at depth in the limestone iquifer system (Table A8.1.2).

8.4.1.2 Neogene Aquifer

In the northern two-thirds of Molai Plain, the waters are of medium to high salinity and show only local areas of possible contamination. The E-2 well shows unusually high salinity for the Neogene aquifer and can only be explained by the presence of saline water in the deeper sediments of the northern Molai basin, that due to the block faulting, in the graben areas, the salts were not completely flushed (also see Sections 8.2.2.3 and 8.4.1.1), Similarly, around Assopos, sulfate-bicarbonate or sulfate-chloride waters are present and are probably related to the presence of gypsum salts in the formation.

i. Sea Water Intrusion1^

a. Fresh Water-Sea Water Relationship

As a generalization, fresh water weighs less than sea water, therefore, when in contact, the ".ighter fresh water will float on the heavier sea water. The relationship between two such waters may be explained by the Ghyben-Herzberg Principle 151

and is described as follows: Sea water (Ps) weighs about 1.025 times as much as fresh water (Pf). Therefore, in a coastal area, the relationship between water table elevation above sea level (T) and the depth of the fresh water/sea water interface (M) below :>ea level can be developed by simple algebra:

M = PS -'Pf X T (6> hence M = 40 T

The equation indicates that if the elevation of the groundwater table is one metre above sea level, the interface between fresh water and the sea water is 40 metres below sea level. However, the formula only refers to static conditions which are seldom found in the field. Nevertheless, the equation provides a good approximation and can be used as a workable formula, liirler dynamic conditions, the contact between fresh water and salt water is a little deeper than that estimated for static conditions. The formula indicates that during periods with rising groundwater table, the interface is subsiding, and if the aquifer is underlain by impermeable strata, the salt water is forced towards the sea. If, on the other hand, the groundwater level is subsiding, for example by over-pumping, the sea water moves inland and upward.

b. Plytra Area

As noted in Plates 8.2 to 8.6, in the Plytra area, for example, from the shoreline to one to two kilometres inland, the groundwater has a relatively high salinity; further, from 1971 (Plate 8.2) until 1980 (Plate 8.6) the area of high sal­

inity has progressively enlarged. As the general area is one t;, with a high density of wells and one in which the water table is at, and in summer, may be below, sea level, the increased salt concentration is considered to be due to sea water intrusion, or local up-coning "of the fresh water-salt water interface due to over-pumping. Similarly, at the mouths of the Molai and Assopos Rivers exist high salinity area but these are probably 152 due to the local phenomena of sea storm waters, filling the river mouth areas and contaminating the fresh water. The discussion of sea water intrusion is to some extent an over-simplification of a more complex problem for as may be noted In Figure 8.6, although the chloride type waters predominate in the Plytra area, Calcium + Magnesium also predominate, not sodium. The explanation is that there must be a source of calcium + magnesium ions available, for example, calcium clays, in excess of sodium ions available through sea water intrusion. It is concluded that although sea water intrusion is taking place, it is at this time not the major cause for salinity increase.

c. Recycled Irrigation Water

In Section 8.3.1, the Importance of leaching was pointed out whether through rainfall or through the application of excess irrigation water to control the salt content of the soil water. Leaching, as a process, involves the use of water to dissolve the salts within the soil layer (0-0.60 m) and tc c*rry the salts in solution downwards ultimately to the water table. Theoretically the groundwater body is a dynamic system, and as the leached salts enter the system they are carried to the sea. To be dynamic however, the ground water body must have hydraulic gradient; in an over developed situation, the hydraulic gradient to the sea may be neutrali­ zed and tho system, at least in the coastal zone, stagnated. In such stage, as discussed in Section 8.2.1 under geochemical properties of water, on the basis of solubility, the common salts found in irrigation waters were the chlorides of sodium, magnesium and calcium and the bicarbonates and sulfates of sodium. The bicarbonates and sulfates of calcium and magnesium are of low solubility and when saturated, would precipitate. This Indicates . that with an inactive groundwater system, re­ cycling of the pumped water can occur, accompanied by a degradation in water quality and change in water type to a sodium chloride water. For the present, however, and as discussed under sea water intrusion, the primary water type in Plytra area is a calcium chloride water; a source of calcium 153

ion is available, perhaps from calcium clays and gypsum if present, as suggested in the Assopos area.

8.4.2 Industrial Wastes

8.4.2.1 Olive Oil Factories

Within the Project area 13 olive oil factories exist, 10 of which are located in the Molai Plain. The factories, at Molai/ Metamorphosis and Sikea discharge their waste oil and wash water into the existing drainage system and the waste is ultimately carried to the sinkhole at Metamorphosis, and hence into the limestone groundwater system. The factory at Pakia either pumps the waste into a nearby sinkhole or to the Molai River drainage. The factories at Assopos and Papadhianika discharge their waste into the Assopos River. In general, the factories work from mid-November to the end of February. On the 23 January, 1979, a partial chemical analysis of the waste water flowing into the sinkhole showed:

Salinity 2 800 mmhos Chloride 5.0 meq Bicarbonate 21.5 meq Sodium > 1.6 meq Potassium J Calcium 12.8 meq Magnesium 3.5 meq Hardness 760 ppm Chemical Oxygen Demand 6 889 ppm Total Organic Carbon 2 150 ppm

Oxydability 1 158 ppm 02

In an active limestone system, it is probable that much of the olive oil waste material would be flushed through the system, although oil residue would adhere to the surface of the rock and the sedimentary particles. In Exploratory well EB-1, located within 40 m of the sinkhole, communication between the well and the sinkhole was verified through the use of dyes. In the well, at a depth of 120 m (50 m below the water table) oil- saturated clays were found in the cavernous limestone. For the 154 clay to be deposited in recent time, to such depth requires circulation, however, in a karst system, the zone of greatest circulation is at the water table. Possible explanation is water moving under pressure from a topographically higher area; in Apidia about eight kilometres to the north, the plain lies about 150 metres higher than at the sinkhole, and as in Molai, olive oil waste drains into surface water channels leading to sinkholes. The purpose of this explanation is to show how susceptible a karst limestone system is to pollution and to what extent and depth such pollution may travel, and contamin­ ate a groundwater system.

8.4.2.2 Table Olives Processing Factory

Two table olive processing factories are situated in the Molai Plain, one at Molai town and one at Assopos. The Molai factory is not operating at present but the Assopos plant has been in operation since 1973. This factory reportedly uses about 1000 m^ of brine per year, of which about 800 m^ are 3 utilized in the olive canning and the remaining 200 m are discharged into a dug pit wherein the brine infiltrates into the soil. The brine is strongly sodium chloride type water, with a conductivity of 63.000 mmhos (Table 8.7); depth to groundwater is 20 metres. The factory is located on the north bank of the Assopos river and it may be assumed that the sediments are relatively permeable. On Platee.1, it may be noted that west of Assopos, along the river channel, the groundwater is a sodium chloride type whereas the bordering waters are a calcium chloride-bicarbonate type. It is surmized that the groundwaters have been po)luted by brine. 8.4.2.3 Garbage Disposal

Some of the Molai Plain Conuiuinities deposit waste and trash in excavated depressions where it is burned. No sanitary precautions are taken with the remaining waste, and infil­ trating waters can carry salts and undesiroable substances to the Neogene water table. Further, in the drainage system to the sinkhole, uncontrolled waste matter are dumped which in turn can be carried by tho drainage waters to the sinkhole. Of particular concern is the large amount of plastic material; 155

the sinkhole, though having a large entrance, rapidly decreases in size, and the actual inflow takes place through numerous small openings. The plastic material along with the high clay content of the inflowing waters may one day plug the solution openings in the sinkhole which would then result in widespread flooding of the northern plain.

8.5 CONCLUSIONS AND RECOMMENDATIONS

8.5.1 Conclusions

Following an extensive water sampling programme for chemical analysis, and to identify the quality status of the Molai project area, the following are concluded:

i) The water of the limestone reservoir in the Molai Plain varies from a bicarbonate to bi­ carbonate-chloride or chloride-bicarbonate; at depth the watern are strongly sodium chloride type, and are in contact with sea water. On the other hand, the Neogene waters are strongly calcium bicarbonate waters in the northern half of the Plain, then, are bicarbonate-chloride to chloride-bicarbonate south of Assopos (small area of sulfate-bicarbonate or sulfate-chloride water near the town of Assopos). Below or south of Papadhianika, the Neogene groundwater is a calcium chloride water. The.chemical change of the Neogene waters follows a typical degradation pattern of:

HC03 : HC03 + Cl : Cl + HC03 : Cl + S04 and/or SO, + Cl : Cl 4 ii) Average salinity of the limestone upper groundwaters is about 1.200 mmhos; In the lower portion of the reservoir, the salinity increases to 3.000 to 4.000 mmhos and up to 25.000 mmhos. For the Neogone, the salinity varies from 0.6000 to 3.000 mmhos; in the northern two-thirds of the Plain the average salinity is about 0.800 mmhos; from Assopos to below Papad­ hianika, it is 1.200 mmhos; and the last two kilometres to Plytra, it is 2.000 mmhos. 156

Iii) In regard to use, the following is summarized:

a) Agriculture; in the irrigated areas, the water from the Neogene group water source is generally of low sodium content but of high salinity; near the coast the waters are of medium sodium hazard and very high salinity hazard. The former waters can, as far as sodium is- concerned, be used on almost all soils; however, due to the salinity, the water should only be used on soils with good drainage. As to the latter, in regard to sodium, the water can be used, if leaching occurs and with plants with a moderate salt tolerance; however, with the very high salinity, the waters are not suitable for irrigation use under ordinary conditions.

b) Urban: general standards have been established giving permissible limits of certain constituents or characteristics. Water from the limestone and Neogene aquifers, except for the saline waters near the Plytra shoreline meet the standards and are suitabl'3 for human consumption.

c) Industry: as almost all industry in the Molai Plain is agriculturally oriented, the limestone and Neogene waters, except for the high saline waters are suit­ able for most industrial uses as its quality can be improved at relatively low cost.

iv) Pollution of the water resources is occurring due to a fixed supply and an ever-increasing demand. The problem, particularly for the southern Neogene aquifer, is becoming serious, and management will be required.

a) Salinity of water: chemically, the limestone waters show evidence of pollution by chloride waters, particularly at depth. In regard to the Neogene waters however, in the Plytra area and at the mouths of the Assopos and Molai rivers there is indication 157

of sea water intrusion. More serious, however, in the Plytra area there appears to be recycling of the irrigation water. This is probably due to local over-development, thereby neutralizing the natural hydraulic gradient of the water table, and the salts are not carried-out and discharged to the sea. Without a leaching fraction, it can be assumed that as the salinity of the groundwater (and soil water) increases, there will be a probable decrease in agriculture yield.

b) Industrial wastes: waste oil and wash water from olive oil factories is discharged to the surface water drainage system which in turn carries the waste to a sinkhole wherein the waste enters the limestone reservoir. Further, as the waste is high in organic content, and already the limestone reservoir serves as the water supply source for two communities, action should be taken to restrict this arbitrary waste discharge. In Assopos, olive brine is discharged into an infiltration pit and may be polluting the groundwater.

c) Urban wastes : Several of the Communities carry their waste to selected areas in the Plain where it is burned, however, no sanitary precautions are taken to ensure that polluted fluids do not infiltrate downward to the water table. In addition dumping of waste, particularly sheet plastics in the drainage systems may result in plugging of the sinkhole and subsequent wide-spread surface flooding.

8.5.2 Recommendations

The demand for water is ever-increasing in the Molai Plain and is creating, for the Neogene aquifer, a two fold problem: first, the supply-demand relationship is in delicate balance and without control, extraction will exceed replenishment; and second, the Neogene aquifer is of relatively small permea­ bility and the over-concentration of wells in the Assopos and 15«

Papadhianika areas is locally creating a problem of over­ development, reducing the hydraulic gradient of the ground­ water table, and inducing salinity through recycling of irrigation water, and soa water intrusion. In the hydraulically more complex limestone system, saline waters exist at depth, and a well-managed pumping regime will have to be established. A management' plan for the development, use and protection of the Molai water resources must be enacted to safeguard current and future agriculture investment. The essential component of the plan would be a basin-wide water quality programme in ¿ order to limit the degradation of the basin's water resources.

i) Management of the resources through:

a) enforcement of available water legislation controlling well drilling and well spacing.

b) monitor resource, both quantitatively and qualitatively.

c) improve efficiency of water use.

d) restrict pumpage of water from wells showing an increasing or high salinity water.

ii) Pollution control through:

a) prior treatment of waste before disposal.

b) disposal of waste only in approved sites.

iii) Experimental studies:

a) carry-out studies in the Papadhianika/Plytra area on the effects of the water salinity on irrigated agriculture. Such studies would require detailed soils information, salinity of soil water, crop water requirement along with leaching requirement, and the effect of « salinity on quality and quantity of agriculturo output. 159

Chapter 9

LAND AND WATER USE

9.1 INTRODUCTION

9.1.1 Objectives

The main objectives of this chapter are:

i) evaluate at a preliminary level the present agriculture situation with special attention to soils, land capab­ ility, and land and water use;

ii) identify areas with a potential for future Irrigation development;

ill) recommend future land use in the areas selected for irrigation davelopment;

iv) recommend future land use in areas of deteriorating water quality;

v) quantify present and future agricultural, urban and industrial water demands.

9.2 PROJECT AREA 2 2 The project area,covering 300 km of which 72 km is taken up by the Molai Plain,is located in the province of Lakonia in the southern Péloponnèse (Figure 3.1). The population is prim­ arily engaged in agriculture, with some minor emphasis to agro- industry (olive oil). The agricultural production is based on four principal crops : olives, figs, citrus and vegetables; wheat is an important winter crop in the northern part of the Molai plain. Of the principal crops, vegetables are irrigated as well as citrus. In 1966 the irrigated area was 230 ha and in 1972 German Water Engineering (GWE) reported 800 hectares under irrigation in the Plain; since then the number of wells has almost doubled and in 1979 approximately 1100 hectares were estimated to be under irrigation (Table 9.10). Some irrigation also occurs in the interior valley of Apidia in the Project 160 catchment area. In general, most of tho Project area is ' utilized to a varying degree. The relatively flat lands are in olive, fig, almond, citrus, vegetables and cereals; sloping lands and highlands in olive and almonds; and the mountainous slopes are to a limited extent used for grazing.

9.2.1 Agriculture study area

The Project is concerned with the evaluation of the water resources of the Molai area in order to define irrigation potential. The area designated for possible irrigation devel­ opment is the Molai Plain wherein topography and soils combine to provide favourable conditions for irrigation. Within the Plain, generally within the 100 metre contour line, there is a gross irrigable area of 7 200 ha (Figure 9.1).

In general appearance, the Molai Plain appears as a relatively flat""plain with a gentle slope to the southwest; both side boundaries are old fault scarps and there is an abrup' change in elevation. The flank areas are hilly to mountainous with an average elevation of about 400 metres. The Plain has an elevation of approximately 100 metres in its northwest corner, and descends to sea level at Plytra, with an average slope grad­ ient of five percent. The drainage is unique in that the northeastern half of the Plain drains to a sinkhole at Metamorphosis. The central portion of the Plain is drained by the Molai River which follows the western boundary for about eight kilimetres before turning west to disch.-ir^e into the Gulf of Lakonia. The southern portion of the Plain, as well as the eastern boundary is drained by the Assopos River which runs diagonally across the Plain from north­ east to southwest; the river also discharges into the Lakonian Gulf. The community population for the years 1961 and 1971 is shown in Table 9.1; it is important to note that during the reference 10-year period, the population decreased in number by about 8 percent. In the Lakonia area the outflow of popul­ ation was close to 20 percent over the same period. From this it may be deduced that probably the youth were moving from this farming area, and that tho average age of the farmer has increased significantly. ' 161

Llmlf of the Molol cotchment Limit of Agricultural study area Non Irrigable area Grow irrigable area

Agricultural area In the Molai plain 162

Analyses of population data by community clearly indicate that the outflow oí! population in villages with irrigation from ths N'eogane aquifer, Assopoa sr>d Papadhianika, was minimal compared to the migration in villages with only dry farming. Molai town is also an exception due to its administrative and commercial role and the migration was only 2 percent In 10 years. Preliminary data obtained from the agricultural office in Molai, also shown in Table 9.1, would indicate that between 1971 and 1979 the population stabilized and the outflow of population was negligible, however the data will have to be confirmed with an additional survey. Assuming an average family size of five persons, and 85 percent of the population being engaged in farming, the total number of farming families comes to 1460. The data supporting this chapter on land and water use has been partly abstracted from a,report by D. Castanis (1966). The maps on soils and land classification are also taken from that report. Tho units of area are the hectare and the stremma. One stremma is equal to one tenth of a hectare.

Table 9.1

COMMUNITY POPULATION FOR THE YEARS 1961 -1971 AND 1979

Population Decrease Population Community 1961 1971 , 1961 1971 1979'" % (preliminary)

Molai 2 526 2 484 2 2 484 Pakia 798 680 15 682 Assopos 1 322 1 262 5 1 263 Papadhianika _ 1 817 1 806 1 1 806 Finiki 708 568 20 569 Sikea 1 318 1 134 14 1 133 Metamorphosis 770 657 15 547

Total 9 259 8 591 8 8 484

Total for • Lakonia 118 661 95 844 19 163

9.3 SOIL RESOURCES

9.3.1 Gene-ral

Throughout tha Plain, the underlying geologic formation con­ sists of unconsolidated to semi-consolidated marine and terrestrial sediments (Neogene formation) of probable Miocene age which occur at various depths below land surface. The exceptions are in the northeast corner of the Plain where limestone underlies a thin soil veneer. Locally along the northern boundary small alluvial fans at < the mouth of stream channels are of limey clastic material. In this area the soils are mainly residual clays deposited by surface runoff fr-om the limestone catchment and are red in colour and sticky (terra rossa) . Except for the sinkhole area, the area in vicinity of the Molai-Sikea road and the mouths of the Molai and Assopos Rivers where flooding may occur, the soils tend to be well-drained.

9.3.2 Soil surveys

A preliminary soil reconnaissance in the Molai Plain was carried out in 1966 (Castanis, 1966) by the Land Reclamation < Service, Ministry of Agriculture. The reconnaissance covered , an area of 7 200 ha and included an assessment of land capability. ' Pedologists are- presently collecting samples in over 200 units in the Molai area. The entire plain is being surveyed (7 000 ha) and over 140 profile pits are being dug to study soil: horizons. The samples will be analysed in the Soil Science V Institute in Athens and will result in a detailed soil map of the Molai Plain to be presented in April 1981. ¡^''f

' <,)>< From the already available data it can be concluded that soils will not present a serious constraint to groundwater devel­ opment in the Molai Plain. Broadly,three groups of soils can be distinguished : the deep, well drained aluvial clay-loam soils (1 000-1 500 ha); the deep well drained alluvial sandy loam alfisoils (2 000-3 000 ha); and the eroded alfisoils (4 O00 ha). The main limitations already detected are: 1. Erosion of alfisoils in half of the Plain (mainly the southern part) 2. High calcium carbonate content of some soils limiting the spectrum of advisable crops such as citrus 164

3. Drainage problems in a patch of roughly 300 ha northwest of Sikea village due to a layer of low permeability at 30 to 40 cm depth resulting in stagnating water in winter.

The most interesting conclusion of this preliminary review however is that regular leaching of salts accumulating in the soil with irrigation will be possible due to the good drainage capacity of most soils in the Plain. Moreover the soils situated close to exploratory wells like EB-2 and RB-1 are generally of very satisfactory quality and irrigation from these wells would not present any major problem (in some areas around RB-1 the calcium carbonate content is somewhat high). It would be advisable to await the final results of the soil mapping before finalizing the design of the distribution systems so as to eliminate all areas with potential deficiencies like drainage, erosion,and CaCO^ content.

9.3.3 Soil classification and mapping units

The classification and mapping of the soils wa3 made (Castanis, 1966) at a scale of 1:20 000 and followed the "Soil Survey Manual, USDA". The conclusions drawn were made on the basis of field observations and were related to auger samples, soil profiles observed in trenches and laboratory and field analyses. Pedologically, two categories of soils were encoun- • tered in the Plain : ' i) soi." •. -cently formed under continuous evolution but without distinct soil horizons? and ii) soils formed in situ and having genetic horizons.

Taking into consideration the morphological features, the following soil series have been identified (Table 9.2 and Plate 9.1 )

i) Series A: Colluvial soils, stony, eroded and locally with steep slopes. Those are shallow soils of very limited use for agriculture and cover seven percent, of the Plain (Cl!) . 165

iij Series B: Old alluvial soils found on the Holocene and Ncogene formations, are deep and vary in colour from red/red-brown to yellow-red. The soils are deficient in calcium carbonate throughout their profile. The texture of the sub-soil is fine and there are no problems of erosion or salinity. Within the series three soil types were encountered: sandy loam (SL) sandy clay loam (SCL) and clay (C). The soils are of normal permeability and low organic content. The crop yields are satisfactory to very satisfactory. This serios constitutes the predomin­ ant type in the Plain and occupies 45 percent of the area. iii) Series C: Alluvial soils of medium to large depth and with a brown-red to red colour. The Boil profile is slightly a "<«lii-i and of very low organic content; permeability *. normal to nigh. Salinity, alkalinity and dr-xnage are not major problems, however the series is susceptible to arosion especially on hills. Two soil types a tu found in the series : loamy sand (LS) and sandy loam ,SL). The calcium carbonate content of the soil varios between one and three percent in the superficial layers, from 0.4 to 4.6 percent in the oub-soil. The fertility is fair and with appropriate measures, it can be improved. The run-off and drainage of the soils are very satisfactory. The series C soils are found on 22 percent of the Plain.

iv) Series D: Residual soils of shallow to intermediate depth and evolving on limestone. The soil colour is red and the sub-soil has a heavy texture. There are no problems of run-off or drainage though without appropriate control, some light erosion may occur. Only one soil type was found in this series, a sandy clay loam (SCL). The superficial horizon of the soil is depleted of calcium carbonate; the sub-soil has a calcium carbonate content of 2.7 percent. The soils occur in some of the foothill areas and cover six percent of the Plain. 166 v) Ser Las E: Residual soils of intermediate to large depth and evolving on marl and crystalline rocks. The soil colour varies from red to yellow-red with a light to medium surfaclal texture and a medium to heavy sub-soil; permeability should be satisfactory. There are no drainage or erosion problems. Two soil types were encountered: sandy loam (SL) and loam (L) in the sub-soil the predominant soil type is sandy clay loam (SCL). The soil profile is generally completely devoid of calcium carbonate, however the soils are fertile to very fertile. This soil series constitutes 17 percent of the Plain area.

Table 9.2

AREA OF SOIL SERIES AND SOIL TYPES

Area A B C D E (ha)

LS 536 536 SL 1 T30 1 016 332 3 128 L 372 372 SCL 904 448 388 1 .740 CL 500 172 672 C 552 552

500 3.236 1 552 448 1.264 7 000 Settlements 200 " Grand Total 7 200"

Table 9.3

LAND CLASSIFICATION SUMMARY

Irrigability Area in Percent of Category ha Total

II 2 692 37.4 III 46.7 3 360 IV 448 6.2. V 500 6.9

Total 7 000 97.2 Settlements 200 2.8 Overall total 2 200 100.0 167

The soil map should also be of a tremendous help to the agronomists in designing an adapted cropping pattern, and later to the extension workers in advising farmers on the soil poten­ tial of farms. Further close cooperation with the Soil Science Institute is recommended particularly concerning the relation­ ship between soils and irrigation with water with an EC of 1 to 3 mmhos/cm.

9.4 LAND CLASSIFICATION

As the objective of the project is to evaluate the possible availability of the water resources for irrigation development, the land has been classified according to its suitability for irrigated farming. The land classification follows the standards of the U.S. Bureau of Reclamation and takes the following criteria into î consideration : i) Soil condition (S) : pertains mainly to the soil characteristics including depth, mechanical composition, permeability, pH and salt content.

ii) Topographical character (T) : relates to land slope and surface irregularities.

ill) Drainage condition (A) : pertains to the depth of the groundwater level, the frequency of surface flooding and soil permeability (infiltration).

Using the above criteria, the scale of each of which varies from one to five, four categories of land irrigability have been delineated in the Molai Plain (Table 9.3 and Plate 9.2) and are described as follows:

Category II : Good, suitable for irrigation. Ill : Good, moderately suitable for irrigation. IV : Moderate to poor suitability for irrigation. Irrigation is possible however, under specific conditions, v : Soils unsuitable for irrigation development.

Table 9.3 shows that the irrigation categories II and III predominate, and together include 84 percent of the potential irrigable lands. 168

9.5 LAND USE

9.5.1 Agriculture

The Project area can be divided into two main regions:

i) Molai Catchment, which is the mountainous area (with interior valleys) above the 100 m contour line.

ii) The Molai Plain area,approximately within the 100 m contour line.

In the Molai Catchment area, the agriculture lands are limited to the interior valleys where there is some minor irrig­ ation. The discussion therefore is restricted to the Molai Plain. The information on existing land use has been obtained primarily from the agricultural office in Sparti and from the agriculture extension office in Molai. Only minor survey work was carried out by Project staff to supplement missing data. The Molai Plain of 7 200 ha is included within seven different community areas each of which also covers part of the immediately surrounding hilly area (Figure 3.2). Table 9.4 shows the total area of the concerned communities as well as that portion of each community that lies within the Plain.

9.5.1.1 Present land use

i) Acreage The part of the Molai Plain included in the present study comprises an area of 7 200 ha, the use of which is üh. ..i on Table 9.6. In Table 9.5 the land use of the entire Molai Area is shown. The number of farms in the Plain is about 1 440 and the average farm size is 5.0 ha,'of which 4.2 ha are cultivated. At present, the dominant land use is for orchard farming (olive and figs),which accounted for 74 percent of the land use in 1966. 'Table 9.7 shows a break-down of the cropping pattern during the reference year. Table 9.9 although relating-to the agriculture production of the overall communities that constitute the Molai area is, never­ theless, representative for relative crop importance in 1978. It is noteworthy that during the reference year, olive and figs constituted 35 percent of the land 169

Table 9.4 COMMUNITIES OF THE MOLAI AREA

Total Area vlthln Molai Percent community lands Area (ha) Plain (ha) within Molai Plain

Molai 4 000 1 070 27 Pakia 3 «00 650 19 Assopos 2 uoo 1 340 56 Papadhianika 3 800 1 330 35 Finiki 1 400 510 36 Sikea 5 000 1 •480 30 Metamorphosis 2 200 830 38

Total/Average 22 200 7 200 32

Tabic 9.5 COMMUNITY DATA, MOLAI AREA

Cultivated area Pasture! 0 ther area Farms Total area Community ha % 1/ ha % ha % cultivated/ ,< farm ha Molai 1 510 38 2 360 59 130 3 422 3.6 Pak la 1 760 52 1 580 46 60 2 116 15.2 Assopos 1 700 70 590 25 110 5 215 7.9 Papadhianika 1 690 45 1 990 52 120 3 307 5.5 Finiki 1 010 72 350 25 40 3 97 10.4 Sikea 1 850 37 3 040 61 110 2 193 9.6 Metamorphosis 910 41 1 260 57 30 1 93 9.8

Total 10 430 47 il 170 50 600 3 1 442 7.2

Total for 100 220 229 100 33 980 22 000 4.6 Lakonia

Table 9.6 MOLAI PLAIN COMMUNITY LAND USE IN i960

Farm Pasture Other Area Settlement Total Cult.area/ Community land(ha) ha ha ha Area(ha)farm in the Plain(ha) Molai 900 100 70 1 070 2.5 Papadhianika 1 100 80 40 lio 1 330 3.6 rinikl K00 70 40 V 510 4.1 Sikea 1 300 130 50 1 480 6.7 Metamorphosis 700 90 40 830 7.5 Pakia 550 60 30 640 4.7 Assopos 1 150 60 40 90 1 340 5.3 Total 6 100 (85%) 590 (8%) 310 (41) 200 (3%) 7 200 4.2

—'Percent of total area (ha) aa shown in the.table nbovp 170

use; a decrease of approximately 40 percent since 1966. The crops showing the greatest increase in cultivation during the 1966-1978 period are wheat and vegetables. In particular, during the years 1978-1979, the use of plastic hot-houses for growing early crops of egg plants and tomatoes increased significantly.

ii) Use of pesticides and fertilizers (

There is a growing consciousness on the use of fertilizers and pesticides. This is illustrated by the figures for 1979,: when approximately 4 000 000 kg of fertilizers and 80 000 kg of pesticides were applied. The average use of fertilizers and pesticides was 656 kg/ha and 13 kg/ha respectively. Further field experi­ ments are required to determine the optimum quantities and types of fertilizers to use,particularly with irrigation, as well as the time and method of application. Local demonstrations and instructions are also needed in the selection, use and method of application of pesticides. Farmers should also be informed on the restrictive use of pesticides in accordance with the European Common Market (EEC) regulations. ill) Livestock

Sheep, goats and pigs are reared with considerable success and the number of head in 1979 was estimated at 12 138, 14 359 and 1 329 respectively. There is very little beef raising in the Moiai area (see Table 9.11). There is also no improved pasture although occasionally the goats and sheep are grazed in the areas of young winter wheat and barley. In general, these animals are taken for grazing in the natural vegetation of the foothill areas.

The small farmer keeps two or three animals from which he can obtain milk and perhaps raise a kid or lamb to sell. There is no organized dairy in the area. Never­ theless the Molai farmers are self-sufficient in meat, milk, cheese and eggs and are perhaps small exporters of meat and dairy products (See Table 9.12). 171

Table 9.7

CROPS IN HOLAI AREA, 1966 (HA)

Papadhia­ Community Meta­ Molai Finiki Pakia Assopos Total nika Sikea morphosis

1. Perennial Crops a. Trees Olive trees 420 400 140 500 250 200 390 2 300 Fig trees 250 450 220 400 110 200 570 2 200 Citrus 3 60 17 1 1 1 47 130 Almond ------b. Vines 40 25 3 22 10 5 35 140

2. Annual Crops Vegetables 10 40 5 7 10 13 35 120 Garden crops 35 10 - - 1 25 70 Pulse 100 100 Wheat 149 90 5 . ' 200 276 30 50 800 Barley 27 » 14 43 84

Papillous • in combination (100) (150) (50) (150) (100) (50) (100) (700) desseminated Pear trees (150) (200) (250)- (300) (50) (50) (100) 1 100

Total Farm Land 900 1 100 400 : 1 300 700 550 1 150 6 100 Combination 100 150 50 • -150 100 50 100 700 Crops f

TablaTâblei;9._' 9,8

IRRIGATEDIATED- ARE*,AREA,, 1966 (HA)

Community Citrus Vegetables Total

•'•¡ xjf •UE.jf'iM .•ii'.ÍÍL*VÍ.'.7o, - ' • Molai 3 4 Papadhianika .60 40 135 Finiki 17 5 32 Sikea 1 1 Metamorphosis 1 1 Pakia 1 1 2

Assopos 47 23 35 105

Total ' 130 70 80 280 Table 9.9

PRESENT LAND USE (HA) A\D AGRICULTURAL PRCCUCTTON (TONS)

Area Prod. Area Prod. Area Prod. Area Prod. Area Prod. Area Prod. Area Prod. f ;ea 03ncunity Olive Trees Fig Trees Almond Trees Vineyards Cereals (viieat Hay etc) A. Non-Irrigated Crops Molai 850 400 380 620 151 150 40 280 150. 267 80 380 Assopos 780 320 603 850 10 15 6 60 250 . 460 95 /380 Metamorphosis 460 220 80 160 70 50 13 45 395 655 110 360 1 Pakia 710 210 720 550 87 65 85 30 150 247 59 205 Papadhianika 840 370 638 950 18 40 25 175 150 370 115 440 Sikea 760 280 215 300 19 30 55 280 610 825 295 700 ilniki 240 150 80 270 45 45 17 45 65 80 44 115 Total 4 640 1 950 2 716 3 600 400 395 164 915 1 770 2 904 801 2 580 Total for Lakcnia 51 730 16 000 3 850 6 150 970 850 1 316 6 750 10 165 16730 3 820 10 800

Citrus Trees Table Olives Melons Potatoes Tara toes Egg Plants Green Peas Other Vegetables B. Irrigated Crops Molai 3 45 25 110 8 225 10 270 1 45 3 175 40 108 14 185 Asscpos 57 950 58 140 63 1 265 20 340 25 550 9 400 3 8 8 140 Metamorphosis 5 12 10 5 10 1 20 9 4 10 15 4 25 Pakia 5 70 10 40 20 330 2 40 7 210 6 160 40 88 12 170 Papadhianika 80 1 700 45 100 5 120 19 580 25 750 5 200 30 60 29 450 Sikea 3 20 75 35 19 530 28 400 15 650 18 600 25 75 23 480 Finiki 20 150 6 15 6 180 6 65 2 80 2 70 10 15 6 85 Total 168 2 940 231 450 121 2 660 86 1 715 75 2 294 43 1 609 158 369 96 1 533 Total for Lakonia 5 500 55 000 4 200 3 300 4 660 8 325 756 9 830 995 2 963 231 6 618 399 942 1 540 18 350 173

Table 9.10

ESTIMATED PRESENT CROP PRODUCTION IN THE MOLAI AREA

Area-' Production Yields ha tons tons/ha

Non Irrigated Crops Olives 4 640 1 950 0.42 (Oil) Figs 2 716 3 600 1 .33 (Dried) Almonds 400 395 0.99 Vines 164 915 5.58 Cereals 1 770 2 904 1 .64 Hay 801 2 580 3.22

Sub-total 10 491 --

Irrigated and Semi-Irrigated Crops

Citrus (mainly young oranges) 168*' 2 940 17. 50 Table Olives 231 450 1.95 Melons 121 2 660 22.00 Tomatoes 75 2 294 30.60

Egg Plants 43 1 609 37.40 • Green Peas 158 369 2.34 • Other Vegetables 96 1 538 16.00 Potatoes 86 1 715 20.00

Sub-total 978

Total11 46S-7

—'Double cropping and intercropping is estimated at 1 039 ha or 10% of the total cultivated area which is 10 430 ha (see

Table 9.5) >; 2/ —'The latest estimates on irrigated citrus reveal a total of 270 ha of which 238 ha are navel oranges, 17 ha lemons, 4 ha ' mandarines and 11 ha other citrus. The total irrigated area could then be 1 080 ha. 174

Table 9.11

NUMBER OF ANIMALS Molai Province Molai as Type Area Lakonia % of Province

1. Number of Animals Horses 648 4 214 15.4 Mules 259 3 725 7.0 Donkeys 1 047 10 772 9.7 Dairy cattle 67 8 804 0.8 Pork 1 329 15 331 8.7 Sheep (under cover) 1 096 8 733 12.6 Sheep (outdoors) 11 042 82 289 13.4 Goats (under cover) 4 074 38 227 10.7 Goats (outdoors) 10 285 111 715 9.2 Rabbits 5 050 33 416 15.1 Chicken 45 650 397 250 11.5 Honey bees, Greek 80 6 616 1.2 Honey bees, foreign 1 840 30 966 5.9

Table 9.12

BREAKDOWN OF ANIMAL PRODUCTION IN THE MOLAI AREA

Total kg kg/head 1. Milk Production Sheep (indoors) 166 000 151 Sheep (outdoors) 1 053 000 95 Goat (indoors) 717 000 176 Goat (outdoors) 922 000 90

Total/Average 2 858 000 100

Total kg 2. Cheese Production Fresh cheese (poor quality) 77 000 Cheese soft type 410 000 hard type 7 000

3. Butter Production 3 000 Total Weight/ 4. Meat Production Head Weight(kg) head(kg) Lamb ( < 1 year ) 16 130 130 800 8 Sheep ( > 1 year ) 450 9 000 20 Goat ( < 1 year ) 20 200 166 200 8 Goat ( > 1 year ) 450 9 000 20 Pork 800 64 000 80 Beef 25 5 000 200

5. Other Animal Producta Tons 1000 Units Eggs 184 1 506 Honey 8.3 253 Wool and goats hair 15.9 157 175

iv) Irrigated farming

The Molai Plain has a long history of irrigation though never as a major activity. Water availability has always been a constraint to irrigation development; the areas of greatest development are in the Plytra-Assopos-Papadhia- nika area where depth to water varies from one or two metres to about 25 metres. In 1966, Castanis estimated that 280 ha were under irrigation (Table 9.8); in 1971, the GWE placed the size of partially or fully irrigated lands at 800 ha. Dug wells predominated throughout the Plain and the number of wells was estimated at 300. In 1979 the number of wells was approximately 500 and the area of partial or full irrigation was estimated to be 1 080 ha. The drilling of veils has become common practice and it has made more water available to more people. However the result has been that in some areas the wells have become too closely spaced (Figure 7.4) which has caused a deterioration of the water quality. This causes or may soon begin to cause a decrease in crop yield (see section 8.3.1.2.C and Tables 9.7 and 9.9). The drilling of wells also enabled the farmers inland from the coast to put land under irrigation. Only in the northern one-third of the plain, there is almost no irrigation.

The crops grown with irrigation (1966) are: citrus, garden produce and vegetables (Tables 9.8 and 9.9); the irrigated crops have not changed in pattern in recent years but in 1979-80 the growing of tomatoes and egg plants in hot-houses has assumed greater importance.

9.5.1.2 Factors affecting land use

i) Soil and topography

The soil and topography effects on land use have already been discussed (Section 9.3).

ii) Climate \

The Molai Plain has an average annual precipitation of 500 mm, most of which falls during October-March. 176

No month is statistically dry although the precip­ itation during Juno, July and August is normally negligible. The air temperature varies on an average between an absolute low of 0.5 C in January and an absolute high of 34°C in July. During clear nights in winter and early spring cold, stagnant air is sometimes encountered over the northeastern part of the Plain and the temperature can remain below 0°C for a maximum period of 1-2 hours during an average year and up to about 14 hours once every 5 years. Winds are normally strong and gusty in November-April, moderate in June-August and weak during the remaining months. iii) Vegetation .

The Molai Plain which in the past probably was a macchie area (Huxley and Taylor, 1977) has at present an introduced orchard type cover,primarily olives, figs, almonds and citrus. In the catchment or mountain ous area, the macchie still exists. It is suitable mainly for grazing.

iv) Drainage

Impeded drainage and/or flooding affects the areas near the Metamorphosis sinkhole, the areas north and south of the Molai-Sikea road and the lower areas of the Molai and Assopos river. The poor drainage does not appear to control land use. However, in the 2 Metamorphosis sinkhole area, an area of up to 2 km may be flooded (see Section 6.2.8) whenever run off exceeds the capacity of the sinkhole. No trees of any type exist in this area, in which during winter cereals are grown. v) System of land tenure

Freehold ownership is the principal basis of occupancy in farm operation in Greece, and in particular, in the Molai Plain. There is a tendency however for the small land holdings to get smaller by fragmentation on inher­ itance. At present the average land holding in tho 177

Plain is about 5.0 ha. No cadastral maps were ever made and only for half of the parcels descriptive titles exist. With many of the young people leaving the Molai region and families emigrating there might be a decrease of the rate of fragmentation. There is some land rental, but very little land selling outside of the immediate families or close friends. Prices between 80 000 and 120 000 Dr/stremma are currently paid for olive groves within the Molai Plain.

vi) Problems of the small farmer

The problems of the small farmer in the Moloi plain are diverse. The farmer with olive, almonds and figs, sometimes with winter-cropping, faces erratic rainfall, strong winds and inadequate and expensive seasonal labour when required for the harvesting. Other farmers especially those engaged in garden produce and vegetables often face problems of farmgate prices, marketing as well as transport difficulties.

Most farmers probably realize the benefits of fertilizers pesticides and farm machinery but are probably not fully aware of their efficient use. There is for example, a tendency to over-use pesticides and to plough too deep with heavy tractors. In the future other methods of plant protection will have to be developed because in becoming a member of the European Common Market, there are regulations that limit the use o pesticides.

9.5.2 Urban land use

The principal towns of the Molai Plain are, from north to south: Metamorphosis, Molai, Pakia, Sikea, Finiki, Assopos and Papadhianika (including Plytra). ,A11 of the towns and villages are located on the flanks of the Plain except Assopos and Plytra. The total area of land designated for urban use is estimated at 200 ha.

9.5.3 Industrial land use

Within the Plain proper there exist ten olive oil factories, a mill, a machine shop and Borne storage facilities, which together occupy an estimated 10 ha. , 17e y.6 PRESENT AND FUTURE WATER DEMAND

9.6.1 Agriculture

The Project area is predominately agricultural and hence the water demand for irrigation is much greater than the demand for urban and industrial use. As stated in Section 9.5.1 the evaluation of the present and future water demand relates solely to the Molai Plain. In order to determine the present water demand for agricul­ ture, it is necessary first to define the acreage of the various crops grown within the Plain and their water requirements. Necessary allowance for conveyance losses has to be made when determining gross water requirements. For the optimal water use under full agricultural develop­ ment, reference is made to Section 10.4 wherein, on the basis of land capability, farm gate income, water requirements and cost of water, the most favourable cropping pattern is presented.

9.6.1.1 Present area under irrigation

Present approximate area ¿of land irrigated or semi-irrigated in the Molai Plain is about 1 080 ha. The surface method (gravity flow) is gradually being replaced by more modern techniques mainly trickle and mini-sprinklers. The breakdown of the various crops under irrigation are: Crop Area (ha) Citrus 270 Table Olives 231 (seui-irrigated) Vegetables 579 (green peas receive occasional irrigation) Land capability studies (Table 9.3) show that an additional . 5000 ha can be brought under irrigation if more water is available. 9.6.1.2 Present water utilization ^

At present most of the irrigation and domes*ic water require­ ments of the Plain are met by groundwater supply. An abreviated water well inventory is presented in Appendix 9.1. Tho presence of a pump for each well is indicated. Molai, Pakia, Sikea and Finiki get part of their domestic supply from springs. The irrigation water extraction in cubic metres from the 179

principal sources in 1980 is estimated as follows: ,

Source - Quantity in m^ Neogene aquifer 4 400 000 Limestone aquifer (1 well) 5 000 Spring flow 10 000

Taking into account the efficiency of the present irrigation system, which would correspond to an overall farm efficiency of about 50 percent, the crop water requirements in addition to effective rainfall are sv.bstantially bigger for any irrigated crop than the available quantities of water with present prod­ uction rate. Consequently, the irrigated area, 1 080 ha, is far from being efficiently utilized. Except for a single well tapping the limestone aquifer irrigation water wells pump from the Neogene aquifer. Its capacity is, however, insufficient to satisfy the increasing irrigation water demand, even if more efficient methods of irrigation are used, like mini-sprinklers, drip systems and lined canals.

9.6.1.3 Total irrigable land available

As was explained in section 9.4 above and illustrated in Table 9.3, out of a total irrigable area of 7 000 ha, 948 ha have been referred to as class IV and class V land, which is not suitable for development of irrigated agriculture. For th - 6052 ha which belong to classes II and III a recommended cropping pattern is given in Table 10.8. The recommendec* changes from present cropping patterns are preliminary, pending a detailed soil survey. They are based primarily on an adjustment of the cropping pattern to the land capability in order to increase the overall agricultural prod­ uction.

9.6.1.4 Water requirement £or different cropping patterns

The cropping pattern proposed in Table 10.8 is based on a number of factors such as soil type, land capability and present economic importance of the crops as well as water quality. If the future marketing and economic circumstances, such as the entry into the European Common Market, dictate any change in the 180 cropping pattern, the water requirements for the new crop(s) should be re-adjusted. 9.6.2 domestic Water

9.6.2.1 Population and current water demand

The total population of the seven communities of the Molai Plain (Figure 3.2) in 1971 was 8 484 persons, a decrease of about eight percent since 1961 (see Section 9.2.1 and Table 9.1). Many of the villages (Molai, Pakia,, Sikea, Finiki) have relied upon springs for their water supply but as the dry season flows are relatively small and summer demand high, the villages are gradually turning to wells located within the Molai Plain to meet their demand. At present, seven towns and villages take all or a part of their water requirements from wells all of which extract water from the Neogene aquifer except for two limestone wells (E-1 and E-10). The present average per capita water consumption is estimated at 100 litres per day. The figure is somewhat low by internat­ ional standard because in summer sufficient water is not available to meet demand. Therefore using tho above consumption rate the average annual water consumption based upon a population of 9 000 is 320 000 m3. However, since in summer the population increases by at least 10 percent, the annual consumption is probably about 400 000 m3.

9.6.2.2 Projected population and total water requirements for the year 2000 The prese.»:: trend of negative population growth is expected to chango to status quo with the foreseen agricultural development in the Molai area. The summer touriBm will most probably grow and 100 percent increase during the next 20 years of the number of visitors during the summer months has been assumed. With more water becoming available for the various domestic water supply schemes and with an expected increase of the standard of living, the average per capita consumption 1B expected to reach 150 1/day towards the end oí the century. In Bumming up, the projected annual domestic water consumption by the year 2 000 is expected 3 to be around 650 000 m . 181

9.6.3 Industrial

9.6.3.1 Existing industries and their water requirements

The Project area in general, and the Molai Plain in partic­ ular, is predominantly an agriculture area with very little industry. The most important water demanding industries are the olive oil factories which need water for washing. Details of the present annual water consumption are given below:

Factory Location Annual Water Consumption Olive oil factories (10)1-/ Throughout Molai 150 000 m3 Plain Table oil factories (2) Molai and Assopos 400 Mills (1) Assopos 300 Machine shop Sikea 700

9.6.3.2 Future industrial water requirement

No information on any proposals for additional industry within the Molai Plain or the Project area is available at present However, the isolation of the area and its limited size and population make any significant industrial development unlikely, except perhaps for some canning factories. In any case, it is not anticipated that the industrial water requirements will increase significantly during the next 20 years and is not expected to exceed 200 000 m /year.

- Operate November to March 182

Chapter 10

DEVELOPMENT PROPOSAL

10.1 INTRODUCTION

The main objective of this Chapter is to present a proposal for the agricultural development of the Molai Plain in accordance with the resources of water, soil, and manpower. The proposal contains recommendations for an immediate, though limited, development of groundwater in two areas. Project costs and benefits are quantified and an economic evaluation is presented. Costings of the water distribution system and on-farm irriga­ tion systems are preliminary and are evaluated from data in projects currently under execution in other areas in Greece. The proposed cropping pattern on which future project benefits are based will have to be refined once the detailed soil map of the Molai Plain becomes available (expected in April, 1981).

10.2 DESCRIPTION AND SCOPE OF THE DEVELOPMENT PROPOSAL

The proposed project aims at developing two separate areas for irrigated agriculture in the Molai Plain. The areas selected for immediate development are small compared to the total irrigable area, because of lack of experience among farmers and extension personnel in irrigation with saline water and also because of the unknown behaviour of the limestone aquifer under exploitation. The unit area gross annual water requirements have been 3 3 calculated at 7500 m /ha with a monthly peak demand of 1250 m /ha in June and July; see Chapter 5 and Working Document No 6 f (Samuelsson, 1980°). In these calculations it has been assumed that:

i) the irrigation water has a salinity corresponding to an electrical conductivity\,(EC)' of 2.0 mmhos/cm;

ii) the water loss between borehole and farm gate is five percent;

iii) the efficiency of the selected irrigation syetem (trickle) is eighty percent; and 183

iv) the crop water requirements are based on the cropping pattern presented in Table 10.8

» The proposed irrigation schemes are expected to contribute significantly to the regional and national economy because they would: 1) create a seasonally more balanced and higher paid labour employment, thus preventing further migration of, particularly, young, active people;

ii) generate foreign exchange through export of early fruits and vegetables or import substitution (e.g. pistachio nuts) with a minimum of foreign capital requirements;

ill) increase tho productivity of the area and contribute to the Gross National Product (GNP) of the country; and

iv) improve the economic situation for approximately 400 farmers and their families and thereby contribute to a more even distribution of income between urban and rural areas.

10.2.1 Location and water supply of development areas

The two areas are primarily supposed to be supplied with irrigation water from the limestone reservoir. As an alternative, however, the possibility of feeding one of the areas with water imported from the lower Evrotas River Basin has been studied. Area I comprises 400 ha located between the 100 m contour line in the north, the Molai - Sikea road to the southwest and the Assopos - Metamorphosis road to the southeast (Figure 10.1). This area was selected for its proximity to the planned sites of the boreholes, and to two of the moBt populous villages, Molai and Metamorphosis, and also for the quality and uniformity of its soils. The area is covered to over 90 percent with rainfed olive and fig trees. Five interconnected boreholes in the limestone reser- voir would produce 200 m /ht each during a maximum of 20 hours per day and 25 days per month. Area II is located in the southern part of the Molai Plain which is now irrigated with water from existing boreholes drilled in the Neogene aquifer but increasingly subject to intrusion of )84

Location of proposed project areas, well fields and pipelines

FIGURE ¡0.1 185

sea water due to overpumping. The main objective in this area is to provide supplementary water and thus prevent further hap­ hazard private drillings. Water can be brought to the area in two ways: Development option I: Five boreholes with the same capacity as those for Area I would be drilled in the limestone reser­ voir and water would be piped nine kilometres to the Assopos - Papadhianika area. It is assumed that 25 percent of the water would be ased to substitute for overpumping while 75 percent of the water would irrigate approximately 300 ha, presently under dry farming. Salinity levels of the water from the limestone • in oxp<^cted to range between 2.0 and 3.0 mrnhos/cm-r'

Development option il: in the GWE ntudv ^r 1°72 the convey­ ance of water from wells in the Lower Evrotas Plain to tliu Molai Plain was envisaged as an alternative solution. Ten deep bore­ holes equipped with submersible pumps operating a maximum of 20 hours per day during 25 days per month at a rate of 250 m3/hr per well, would produce enough water to irrigate 1 000 ha. The water would be conveyed through a 13.5 km long pipeline via a pumping station at Asteri. The advantage of this option is mainly the better quality of the water (less than 1.0 mmhos/cm).

10.3 OTHER DEVELOPMENT OPTIONS

10.3.1 Use of the water from the "Group II" boreholes on the Northern Plain

The water from the "Group II" boreholes (Figure 10.1) can ' be used for a project in Area III, identical to the Area I project. The capital costs may be slightly higher, because the conveyor to Area III would be three kilometres long while the conveyor from the Group I borehole to Area I is only two kilometres long.

r This Chapter was completed before tho results of borehole EB-4 were available. The poor quality water (EC 5.0 mmho/cm) encountered in EB-4 makes the development proposal Area II, Option I less attractive. However, the calculations on costs and the economic evaluation are retained because they give an idea of the influence of the conveyor length on the economic feasibility of the project. 186

10.3.2 Use of Lower Evrotas water on the Northern Plain

In principle this is an extension of the development proposal of German Water Engineering {GWE, 1972). It includes the transfer of water from the Lower Evrotas Plain by pipeline to the Northern part of the Molai Plain. Instead of developing Area II the water could be used to irrigate 900 ha (Area IV) in the northern part of the Plain, while still part of the Evrotas' water would be diverted to the overpumped area in the Southern Plain. The advan­ tages of this option would be:

i) from a labour distribution point of view development of the Northern Plain should have preference over a further increase of the irrigated area in the Southern Plain;

ii) the soils in the Northern Plain are, in general, of, better quality than those of the Southern Plain, and

iii) the absence in the Northern Plain cf irrigation systems belonging to individual farmers facilitate the construc­ tion of a water distribution system.

10.3.3 Combined U3e of water in the Northern Plain

A combination of Areas I, III, and IV into a single management system of 1700 irrigated hectare has the advantage that the quality of the irrigation water will improve consider­ ably because the water from the limestone reservoir can be mixed with water from the lower Evrotas Plain. Hence less leaching will be required.

10.4 PROJECT COSTS

10.4.1 Capital investment requirements

Area I Capital investments are given in Table 10.1 for a 400 ha project to be situated in an area with good soils on both sides of the Molai-Metamorphosis road. Five interconnected boreholes costing 3.7 million Dr each (see Appendix 10.2) would be drilled and equipped each with a 8" centrifugal turbine pump (shaft drive). A 2.0 km conveyor of a capacity of 280 1/sec would bring the water to the project area. The average coBt of the distribution system is estimated at 206 000 Dr per ha and is tho major cost 187

element in required government expenditure (67 percent). Farmers will be required to purchase the on-farm irrigation equipment and also to bear the costs of new orchards and plastic hothouses for vegetable growing. Most farmers will have to borrow the equivalent amount from the Agricultural Bank of Greece, which would require capital resources as shown in Table 10.1.

Table 10.1

CAPITAL INVESTMENT REQUIREMENTS FOR 400 IIA (1 000 Dr)-/

Unit cost Cost Cost item (Jan 1980 par Total % prices) ha

1. Total Government Expenditure 1. Boreholes 3 700 46 18 500 15.0 2. installed 8" pump 1 600 20 8 000 6.5 3. 2 km conveyor 7 000/km 35 14 000 11.4 4. Distribution system 206/ha 206 82 500 67.0 Total Government Expenditure - 307 123 000 100.0

Agricultural Credit Requirements - Planting costs (including plastic hothouses) 58 58 23 000 32.0 - On farm irrigation equipment 124 120 48 000 68.0 Total Credit Requirements - 178 71 000 100.0 Total Project Costs - 485 194 000 -

Area II, Option I

Government expenditure for Area II with the necessary infra,- •'i structure would be similar to that for Area I as given in Table 10i1. The principal difference is the length of the conveyor (9 km) required to bring the water from the groups of boreholes situated on the northern slopes of the Molai Area. The additional costs would be 49 million Dr. The total Government expenditure would increase to 172 million Dr or an investment of 573 000 Dr/ha. Although 25 percent of the water dispatched for the Assopos- Papadhlanika area is for substitution of water pumped from the

-•' Detailed breakdown of each cost item can be found in Appendix 10.2 to this chapter. 188

Noogono aquifer, investments in terms of distribution system and on-farm irrigation systems will not be considerably lower than in Area I. A distribution syscem for the full 400 hat will have to be implemented and the savings on existing on-farm equipment will be negligible. On 300 ha only irrigated crops will be introduced thus reducing the requirements for agricultural credit for planting costs by 2 5 percent.

Area II, Option II

The capital investment, expressed in 1 000 Dr, required to dispatch water from the Lower Evrotes Plain to the Assopos- Papadhlanika area is given in Table 10.2.

Table 10.2

CAPITAL REQUIREMENTS TO BRING WATER FROM THE LOWER EVROTAS PLAIN

Unit cost Tota1 cost ( 1 0 0 0 Dr) 10 deep wells (17.5", 200 m) 3 700 37 000 10 submersible pumps 1 000 10 000 One balancing reservoir at outlet of Asteri-Molai Pipeline 1 500 1 500 One pumping Station at Asteri (4 000 kwh output including collection basin, and pumphouse) 50 000 50 000 pipeline Astnri-Molai (13,5 km) 20 000/km 270 000

Total 368 500

Costs as shown above have been derived from those appearing in volume VIIÏ of the feasibility study by German Water Engineer­ ing (GWE, 1972). The cost for the distribution system, 206 000 Dr/ha,has to be added in order to arrive at'total Government expenditure. A more detailed study will have to be made to refine the investment requirements as well as operation and maintenance costs for this development option. 189

In Table 10.3 a summary is made of tocal project costs. It appears that the per ha requirements for government expenditure are significantly higher when Area I is combined with Area II option II than if combined with Area II option I. In Appendix 10.1 all project costs for Area I including operation and maintenance expenses, are summarised. Similar tables are attached for the other project options as well. The capital investment requirements were increased by 15 percent because the computer model starts in year one of the project where as as a matter of fact major capital expenses occur in y»ar zero.

Table 10.3

TOTAL PROJECT COSTS (1 000 Dr)

Itan Government Agr. Credit Total Expenditure Requirements Project Costs

Total per ha Area I + Area II (Option I) 700 ha 295 000 421 136 000 431 000 Area I + Area II (Option II) 1 300 ha 697 000 536 202 000 899 000

10.4.2 Operation and maintenance of the project

Operation and maintenance costs inulude the following three major items - Energy costs for pumping - Maintenance of project equipment and replacements - Staff requirements

10.4.2.1 Energy costs for pumping t 3 To pump one m of water from the limestone aquifer at an average depth of 150 m will require approximately 1.08 kwh (Appendix 10.4). The price per kwh is currently 2.2Ï, Dr for a consumption below 250 kwh/day which is the case in this project. The pumping cost per m3 will therefore be 1.08 kwh x 2.28 j^. = 2.46 Dr More details about electricity pricing are given in Appendix 10.4 . 190

10.4.2.2 Maintenance and replacement costs

Coefficients for maintenance of the project's components are shown in Table 10.4 and are applied annually. Entir i compo­ nents are replaced at the end of their expected lifetime (e.g. pumps are replaced after 15 years).

Table 10.4

LIFE EXPECTANCY AND ANNUAL MAINTENANCE COSTS

Item Life Expectance Annual Maintenance in % of initial costs

Boreholes 25 0.5 Pumps 15 5.0 Conveyor 40 0.3 Distribution System 40 1 .5 On-farm irrigation system 15 5.0

10.4.2.3 Staff requirements, buildings and equipment t i) Agency in charge of the project operation and maintenance Operation and maintenance of irrigation projects is usually the responsibility of a local office of the Directorate of Land Reclamation (DLR) of the Ministry of Agriculture. In the case cf Molai groundwater development project the local office in charge would be the Branch office of the DLR situated in Tripolis. However a separate permanent sub-office would have to be establi­ shed in Molai town. This office should not only be in charge of

the operation and maintenance of the project but should also t supervise the water distribution. The following personnel, and equipment would be required:

Personnel Dr/year , 1 Senior hydrogeologic engineer -100 000

1 Water use officer (Engineer, in charge nnri of distribution system) JbU üü0 2 Technical assistants (Irrigation) 360 000 1 Clerk 115 000 1 235 000 191

Equipment Dr/year 2 Vehicles, purchased every 5 years (excluding taxes) 600 000 Rent of offices, equipment, running expenses of two vehicles 500 000

ii) Reinforcement of the agricultural office in Molai

The agricultural office in Molai will have to be reinforced for two purposes : ¡¡

a) To set up immediate field trials in at least two areas close to wells drilled during the exploratory drillinr programmo (see Chapter 7). The field trials would familiarize the agrono­ mists with specific problems related to Irrigation with moderate saline water and would allow them to introduce salt resistant crops not cultivated in the area at present (for example artichokes, asparagus, pistachio, etc.) b) To advise farmers in the two project areas and supervise planting of crops and installation of irrigation equipment. The agricultural office in Molai should be reinforced with Personnel 1 Agronomist 360 000 1 Agro-economist 360 000 2 Field assistants 360 000 1 Clerk 115 000 1 195 000 Equipment 2 Vehicles, purchased every 5 years (excluding taxes) 600 000 Rent of offices, equipment, running expenses of two vehicles 500 000

In particular the agronomist should study relations between yield and water quality and supervise field trials. The agro-economist should Btudy costings and marketing problems related to irrigated crops (farm-management) and advise farmers accordingly. Preferably, the agricultural officers and the local staff of the DLR should have one and the same office to enable close co- •:l operation and frequent contacts. Only 75 percent of these expenses are included as project f- • 192 costs In the economic evaluation because all farmers of the Plain will ultimately benefit from the results of field trials should tho project be expanded after the first phase.

10.4.3 Monitoring of water use and soils

To allow a close monitoring of the water use in the project a computerized waterbilling system will have to be implemented based on regular readings of watermeters. This is particularly important for the supervision of leaching practices by the farmers. Soil samples have to be sent regularly for examination to the soil laboratory of the National Soils Institute in Athens to check the salinity levels.

10.4.4 On-farm irrigation systems

10.4.4.1 Trickle irrigation and salt content of the water

Higa salinity at the edges of trickle wetting areas has led many investigators to see a potential salinity problem in this method of irrigation. However Black (1976) found that neither plant growth nor chloride content of the plant differ signific­ antly between areas under trickle and areas under mini-sprinklers. Trickle and mini-sprinklers .(for tree crops) have a marked advan­ tage over traditional sprinkler systems when poor quality water is applied insofar as high leaf chloride content and poor plant growth is prevented. Moreover the farmers in the Molai Plain are familiar with the system wh' :h has the additional advantage of being labour saving provided the instaLjj^fcion ÍB equipped with mixers for fertilizers and weed killingragents.

10.4.4.2 Unit costs

Cost estimates of recommended on-farm irrigation systems for crops included in the cropping pattern are given in Table 10.5. Trickle or mini-sprinkler systems have been selected for their low labour requirements, high irrigation efficiency and suitability vis à vis the water quality problem. (Potential chloride problems in citrus dan be avoided; moreover trickle and mini-sprinkler systems are not affected by wind). The cost 193 estimates are based on prosent price ranges used by the Agricultural Bank of Greece when evaluating offers from suppliers to individual farmers and technical reports of other projects. Annual maintenance was estimated at five percent, while every 15 years the on-farm irrigation equipment will be replaced.

Table 10.5

ESTIMATES OF UNIT COST OF ON-FARM IRRIGATION EQUIPMENT

Cost/ha Crop Irrigation Method in 1 000 Dr

Citrus 108 Trickle/rnini-sprinkler Olive/Deciduous fruits, Nubs 108 Trickle/mini-sprinkler Table grapes 119 Trickle Artichokes 129 ' Trickle Vegetables : Early Trickle Sumner 151 Trickle Winter 76 Portable sprinkler Fodder crops 76 Portable sprinkler

10.4.5 Establishment costs

Establishment costs of all proposed perennial crops (Table 10.6) include material, labour, and machinery inputs and also transplants and replacements. These costs are considered as capital investments and will be financed with agricultural credit. Early vegetables also require investments in the form of arches and plastic sheets for hothouses. In Table 10.6 a summary of establishment costs in the first and second year of the project is shown.

10.4.6 Estimated water cost

The cost of water has been calculated for a range of discount

rates (Table 10.7); using the following formula: Table 10.6

ESTABLISHMENT COSTS IN 1 000 DR/HA

Crop Year 1 Year 2

Citrus Lemons 19 Oranges 32 Mandarines 36

Olives existing 10 table 21

Grapes : table 3 64

Deciduous fruits 17

Nuts Pistachio 71 Almonds 7

Early Vegetables 182 61 195

40 40 — OMn 's- CIn n 1 (1+i) 1 Water cost = 40 Vn n 1 (1+i) where n = project duration OMn = annual operation and maintenance costs in year n CIn = Capital Investment in year n i = discount rate Vn = Volume of water in year n

i) Area I ' The operation and maintenance cost of the water sold to 3 3 farmers will be approximately 3.6 Dr per m (2.5 Dr/m for electricity consumption and the remaining 1.1 Dr for maintenance, replacements, rents, and salaries). According to legislation governing the land reclamation projects the farmers arc «.niy charged for the administra­ tion, operation and maintenance costs of the works while construction costs are paid by the Government through the budget of Public Investments. This price of 3.6 Dr/m3 is much less than the average, price of 6 to 7.5 Dr/m3 paid at present in irrigated areas in the Plain. Exceptional water prices of 7 to 9 Dr/m3 have been paid during 1980. The total cost of the irrigation water amounts to 8.6 3 Dr/m at 10 percent interest rate. This rate was used in the economic analysis by crop. However if the farmer will 3 be charged only 3.6 Dr/m he will not necessarily select crops with the highest returns per unit volume of water. ii) Area II, Option I At 10 percent interest rate the total cost of water is 1.9 Dr higher than in Area I due to the longer conveyor. However, the operation and maintenance cost to be charged • to the farmers is only marginally higher. Iii) Area II, Option II . |. The total cost of water for this development option is significantly above the costs in both former casos and reaches 11.8 Dr per m3 at 10 percent interest rate. Table- 10.7

FSTIMATED WATER COSTS DR/M3 AT 1980 PRICES

AREA I AREA II OPTION I OPTION II • discount rate 10% 15% 10% 15% 10% 15%

Operation and nviintenance element 3.6 3.6 3.7 3.7 3.7 3.7 Capital investment 5.0 6.8 6.8 9.3 8.1 11.3 Total water cost 8.6 10.4 10.5 13.0 11.8 15.0

Care has to be taken when comparing costs of water of different projects. The high annual inflation rate of recent years affects considerably the energy element in the cost of water(e.g. electri­ city or oil for pumping). Therefore should the water costs pres­ ented above bo compared with costs of a similar project of 1978

then at least twice 15 percent would have to be added to the:1978 • costs to make them comparable.

10.5 PROJECT BENEFITS

10.5.1 Cropping pattern and agricultural production %

The proposed cropping pattern together with expected yields, are shown in Table 10.8. The yields correspond to culture practices with i.a. high fertilization. It should be emphasized that this cropping pattern is preliminary and certain elements: e.g. » data on frequency and duration of frost in the northern part of

the Plain, see r-h.npter 5, have not been taken into consideration.; : Moreover, conclusions from the soil mapping will only be *0$ffifFfj$fy •' coming in /.pril 19^81 . However at this stage the following have been taken into consideration: '' '' ' ' '

1. Present knowledge of soils, general climate and water quality. 2. Experience with orchards planted recently on newly developed fields irrigated with groundwater from the Ncogene aquifer. 3. Future market prospects for agricultural produce with special reference to the imminent entrance of Greece into the Common Market. 197

4. The availability of labour in the villages in the Molai area. 5. Maximization of returns to farmers.

The economic crop analysis has shown that in order to maximize returns to the project and to farmers the area would have to special­ ize in early vegetables, preferably in high tunnels or low tunnels (see Appendix 10.3). However, it has been observed in new irrig­ ation areas that farmers often prefer to plant oranges with their relatively low economic returns mainly for the flexibility in labour requirements and low risks. Growing high quality early vegetables requires skill and discipline which farmers often lack. Risk of posts and diseases is also higher. Therefore the proportion of vegetables in the cropping pattern was chosen as low as 20 percent while 15 percent of the area was assumed to be planted with citrus.

Farmers should be encouraged to grow a diversified mix of citrus (lemons, mandarines and valencia oranges). Some salt resistant crops like artichokes and pistachio were also introduced in the cropping pattern. Farmers are presently not familiar with these crops for which the overall market outlook is good. Therefore immediate field trials should start in the Molai area to acquaint the local agronomists with the cultivation practice of these particular crops. A separate analysis was made in Appendix 10.6 concerning the economics of irrigating existing olives. It was concluded that in the Molai Plain it would only be advantageous to irrigate and improve very young orchards which should then be made more effic­ ient through interplanting with mora trees (up to 400 trees per ha) and/or through intercropping, at least the first four years. Improvement and irrigation of well established orchards was proven to be uneconomic with the relatively costly water from the limestone aquifer.

10.5.2 Accounting Prices

Accounting prices used in the economic evaluation, Table 10.9, are based on average farm gate prices for *.he three year f 1977-1979 period (see Appendix 10.5) obtained from the Agricul­ tural office in Molai. Except for figs no major subsidy element 198

Table 10.8

PROPOSED CROPPING PATTERN (400 HA MODEL) FOR THE NORTHERN MJLAI PLAIN

Area Planted Expected Total Expected Observations % ha ' yield production t/ha

1. Tree Crops Citrus mix 15 60 35 2 280 .50% with inter- Jcropping first Table olives 10 40 15 600 4 years Improved existing 15 60 27.2 90(oil) with intercrop­ olives ping 50% Table grapes 5 20 15 300 Irrigated almonds 7 28 15 128 and pistachio Deciduous fruits (Peaches, Plums) 10 40 20 900

Total tree crops 62 248

2. Vegetable Rotations Early vegetables 10 40 30 2 190 crop intensity 1.5 Summer vegetables 5 20 35 756 — Winter vegetables 5 20 25 670 — Artichokes 8 32 16 640

Total vegetables 28 112

3. Irrigated Forage Crops Alfalfa 3 12 18 Barley/wheat 7 . 28 70

Total Fodder Crops 10 40 Grand Total 100 400

had to be deducted. Prices of citrus were cut substantially to take into account the downward price trend predicted in several commodity price forecasts. Fig prices include a small subsidy element which was deducted from the average producer price. Ninety percent of the harvost is of the "B" quality and received 2.5 Dr subsidy on top of a price 199 of 28.5 Dr per kg. In the estimates of the present returns of the project the subsidy will not be accounted for.

Table 10.9

ACCOUNTING PRICES IN DR/KG FOR ECONOMIC EVALUATION

Average Producer Price Adopted trop 1976 - 1979 Accounting Price

Citrus Oranges 7.1 6.5 Lemons ' 12.4 10.5 Mandarines 11.5' 10.5 Olives oil 76.3 76.0 table 41 .6 32.0 Grapes table n.a 16.0 Deciduous fruits n.a. 17.0 Nuts pistachio n.a. 95.0 almonds 31 .2 25.0 Vegetables Early n.a. t5.0 Summer 12.0 10.5 Winter n.a. 9.5 Artichokes n.a. 19.0 Fodder (Alfalfa) 7.80 7.0 Figs 31.0. 28.5

10.5.3 Economic crop ^analysis Method i

The following economic indicators were calculated for each crop considered in the cropping j^att^ern:

i) Economic Internal Rate^of' Return (IRR) (This indicator is only significant for perennial crops)

ii) Net Present Value (NPV) per ha 3 iii) Returns per m of irrigation water

iv) Returns per labour day

v) Benefit Cost Ratio (BCR)"

In Table 10.10 appears a summary of results based on dis­ counting of benefits and costs with a 15 percent interest rate. Jon

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In Appendix 10.3 detailed results for each crop are given. The total (economic) cost of water, estimated at 9 Dr per m3, was used in the analysis and a wage rate of 700 Dr per man- day was applied.

nesult3

An examination of the indicators obtained for each crop leads to the following conclusions:

i) Economic Returns are highest for annual crops, especially vegetables and artichokes.

ii) Oranges and table grapes show only marginal returns when discounted at 15 percent interest rate. Of the citrus varieties only lemons and mandarines are profit­ able.

iii) Irrigated pistachio, almonds and table olives show reasonable returns.

iv) Irrigation of existing olive trees is not economically justified. Only when continuous intercropping is practiced do returns become positive.

The preliminary nature of these conclusions should be emphasized.

10.5.4 Project benefits foregone

Benefits fornannc- are the total benefits of the Project area .iUiuiiL .my major new investment. In the Molai Plain obviously the present benefits are determined mainly by the production value of olives and figs from which on-farm production costs are deducted. Present benefits are low due to the low productivity of existing olive and fig trees. Moreover in the last two years a fungus disease has been attacking young fruits and reducing the yields considerably. Research is being undertaken to find the proper means to stop the fungus attacks. Based on data on production costs for olives and figs the net present benefits in the project have been estimated at 5 000 Dr/ha after deduction of all labour costs, including those of family labour, valued at 700 Dr per man-day.

10.5.5 Benefits due to the Project

Detailed benefits are shown in Table 10.13 for each year of the estimated project duration. These figures are based on 202

MONTHLY LABOUR REQUIREMENTS PROJECT 400 Ho Man-Month

400-

300-

200

100-

189 209 223 3041256 84 1431 294 258 298 302 M M N Month

FIGURE 10.2 the production value resulting from the proposed cropping pattern and the accounting prices listed in Table 10.9. From the produc­ tion value, on-farm costs and labour costs were deducted. In Table 10.11 the gross and net benefits per ha are given. Net benefits amount to between 218 000 and 251 000 Dr/ha.

Table 10.11

GROSS AND NET BENEFITS, OF THE PROJECT 1000 DR/HA

AREA II AREA I Option I Option II

Production Value 367 367 401 Value added 336 336 370 Agricultural Revenue 218 218 251 203

10.5.6 Labour requirements

10.5.6.1 Without the Project

As already indicated in Chapter 9 the Project area is covered mainly by olive and fig trees. The areas to be selected for irrigation (except part of AREA II where 20 percent of the area is already irrigated) are all grown with these crops for which the monthly labour requirements are shown below. Particul­ arly in the first five months of the year labour requirements are very low and farmers are unemployed especially since ploughing is now fully mechanized. Thus there is scope for irrigated early vegetables provided farmers are supported with a good extension service during the conversion period.

PRESENT LABOUR REQUIREMENTS FOR OLIVES AND FIGS (MAN-DAYS/HA)

Crop/Month J F M A M J J A S 0 N D Total

Olives Ha 1 3 1 1 1 2 1 1 10 25 25 19 90 Figs Ha 4 2 2 4 - 18 - 6 18 2 - - 58

For an area of 400 ha covered with approximately 300 ha of olives and 100 ha of figs a total of 32 800 labour days would be required.

10.5.6.2 With tne Project

In Table 10.12 the monthly labour requirements for crops included in the cropping pattern are given. Based on these per hectare figures overall labour requirements have been calculated and are shown in Figure 10.2. Except for July and August, the labour requirements are fairly equal month by month which is important for this area where seasonal labour, if required on a large scale, would not be so easily available. Total annual labour requirements, given in column 4 of Table 10.13, are 68 000 man- days when all crops are in full production. The average require­ ments per ha would be 170 man-days compared to 82 at present. On an average the project would double the employment in the area and thereby satisfy one of the main objectives of the project: to halt the migration of people from the Molai Area. 204

Table 10.12

MONTHLY LABOUR REQUIREMENTS AT FULL PRODUCTION STAGE (MrtN-DAYS/HA) USING MODERN IRRIGATION TECHNIQUES

CropAlonth JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Annual

Citrus Lemons 25 40 45 15 2 1 1 2 2 5 14 20 172 Valencia 5 23 50 20 12 2 1 1 1 1 1 - 117 Navels 1 1 1 2 2 2 15 35 30 10 103 Mandarines 44 3 0 2 1 1 1 1 1 1 55 60 170 Olives Existing 1 4 1 1 1 2 1 1 17 45 35 45 154 Table 1 8 1 1 1 2 1 1 77 26 78 26 223 Grapes 19 17 19 3 32 10 102 Deciduous 12 6 1 29 67 67 1 1 1 - - 1 186 Nuts Pistachio 7 3 1 3 1 1 1 3 21 64 - - 105 Almonds 7 3 1 2 2 2 0 140 69 - - - 226 Vegetables Early 31 24 38 41 '44 23 5 -- - 1 26 233 Suinner -- 8 10 64 59 56 20 - - - - 217 Winter 16 - - - 13 - 2 2 8 17 18 30 106 Artichokes 14 21 14 18 11 - 1 22 33 17 12 15 178 Fodder - - - 2 3 4 5 5 4 2 - - (Alfalfa)

10.5.6.3 Shadow wage rate

In the economic evaluation a shadow wage rate of 700 Dr per • man-day was assumed. It is expected that in future wages will move upwards faster than average prices. Wages paid for seasonal hired labour are about 650 Dr for women and 750 Dr for men per eight to 10 hr.working day during the peak olive season. For pruning of trees 1 000 Dr per day is paid. Foreign youngsters are paid 600 Dr per man-day to harvest strawberries. 203

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10.6 ECONOMIC EVALUATION

10.6.1 Arca I; 400 ha

Several economic indicators have been calculated and are shown in Table 10.14. The Internal Rate of Return (IRR) for Area I is slightly over 24 percent which is considerable for an agricultural development project. Net Present Values (NPV) at 10 percent and 15 percent interest rates respectively, and Benefit/Cost Ratio (BCR) ut the same interest rates are all satis­ factory.

10.6.2 Arca II, Development option I? 300 ha

The IRR of this development option is 19 percent which is satisfactory. The combination of Area I with this option would result in a project with an IRR above 20 percent. The only drawback of the project is the salinity of the irrigation water, between 1.0 and 2.0 mmhos/cm, which means higher annual water requirements (the soil has to be leached regularly each year to wash away the accumulated salts) and consequently increased pumping costs and on-farm production costs. As a pre­ caution, yields were slightly lowered for citrus compared to the normal potential of the area.

10.6.3 Area IIDevelopment option II; 1 000 ha

This option has a lower economic IRR of close to 16 percent due to the high pipeline costs required to bring the water from the Lower Evrotas Plain. Nevertheless this option is feasible and has a great advantage because the quality of the water is very satis­ factory. The combination of this option with Area I would slightly increase the IRR of the overall project to an estimated 18 percent.

Table 10.14

Î ECONOMIC INDICATORS .,

Economic Interest . 'V Area II indicators rate x" Option I Option II IRR, % 24.4 19.3 15.7 NPV, Dr/ha 10 294 200 241 400 446 000 1 5 122 300 72 300 32 000 BCR, Dr/ha 10 1 .83 1 .59 1.41 15 1 .42 1 .21 1 .04 207

It can be concluded from the above that both alternatives for development, 700 ha and 1 300 ha, respectively, are econom­ ically feasible. Moreover the Molai Plain has good soils, a relatively mild climate with moderate winds and has a potential for production of early vegetables and fruits which could obtain better than average prices. This has not yet been taken into account in the project evaluation due to the absence of detailed monthly farrogate prices.

10.6.4 Sensitivity analysis

The sensitivity ôf the economic IRR of the Area I model was tested for upward and downward changes of the shadow wage rate with seven percent, and of the crop yield with 10 percent. (See Table 10.15) . An increase of daily wages from 700 Dr to 750 Dr would reduce the IRR from 24.4 percent to 22.8 percent while a reduction to 650 Dr would increase the IRR to 25.9 percent. The effect of a 10 percent decrease of crop yield is more outspoken: The IRR drops by 4.7 percent. Such a yield decrease could, for instance, be the result of negligent salinity control. On the other hand, an increase of the crop yield by 10 percent would increase the IRR by 6.3 percent.

Table 10.15

SENSITIVITY TESTS:CHANGES IN IRR OF AREA I

Sensitivity test + - Normal

Change in shadow wage rate (+ 7 %) 22.8 25.9 24 .4 Change in crop yields (+ 10 %) 30.7 19.7 24.4

10.7 PROJECT IMPLEMENTATION

A timetable for further actidn after completion of the explor­ atory drilling programme and presentation of final results of the groundwater development studies is given in Figure 10.3. A cadastral survey of two areas has to be made as soon as it has been decided where the project will be located and what the design of the major components of the conveyors and distribution 1?B0 V)?A 1982 19*3 ACTIVITY 2 0 " X) ' F ." ; V .r J A J o " : ,.' y :í ; v J J A j o :: D I 7 M - .H J J 4 ¿ O K D

1. Basic Studies

1.1 ¿nd of exploratory drillia0-

1.2 Fisal Report jro-inJwater reso

1.3 ôoil Dapping, report

2. Project Flanr.iai

?.1 Selection project areas

2.2 Cadastral 5UTT»j

2.3 Eäsign of distrib, s jatea

•im1* ' Tendering and contract awards for drilling, puips and distr. sjsta« -

3- Field Trials (S3-1. E3-2)

3.1 Selection of two sites

3.2 Installation of puaps and irrigation équipaient

3.3 Peei-aitnent of additional personnel for Molai

3»1* First Tr^l season

Execution of Infrastructure

'».l r-rillins of 2x5 boreholes

k.2 Inpleaentation of coiYeyor ajid distrib. systea

''».3 rljntiny a.-.d purchase of fir* irrig, équipaient

íecruiioent personnel

^'3 ?irsï Irrigations ¿eaoon

1 t'l'J'JHe; 10.3 209

systems would be. Tendering documents will have to be prepared for two groups of five boreholes each to be equipped with five 8" pumps and electric motors. (For technical specifications and bill of quantities see Working Document 11 (Johnson and Zander, 1980)) . During the planning stage of the project, field trials could be made using water from two exploratory boreholes. Two km from borehole EB2 excellent soils are found representative for Area I. Similarly around borehole RB1 good soils representative of Area II can be found for immediate field trials. 210

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