ABSTRACT Turkey Has a Coastal Line of 1200 Km Along the Mediterranean Sea

Home , Antalya Province, Berdan River, Demre, Finike, Kumluca

SEAWATER INTRUSION IN COASTAL AQUIFERS OF THE MEDITERRANEAN COAST OF TURKEY

Gültekin Günay

ABSTRACT Turkey has a coastal line of 1200 km along the Mediterranean Sea. At the coastal plains which are situated in the east-west direction along this coastal line seawater intrusion is observed. Among the coastal plains situated along .the Mediterranean, Dörtyol-Erzin, Mersin-Berdan and Efrenk plains, Silifke-Ovacık plain, Içel-Gilindire plain, Gazipa,sa plain, Finike-Kumluca plain and Demre plain, located from the east to the west, respectively, are the ones at which the problem of salinity is most frequently observed. In this article, the geo - graphical and socio-economic features of the mentioned plains, general problems in the coastal aquifers and the geology and hydrogeology of these plains are studied separately and the maps and cross-sections of the plains are presented. The present state of seawater intru - sion at the plains is also comprehensively studied.

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INTRODUCTION south direction. On the upper sections of these rocks, Cretaceous-aged limestones are placed. Geographical and Socio-economic The eastern part of the Dörtyol-Erzin plain Features is composed of serpentines extending from North The Mediterranean Region is situated in sou- to the South. Cretaceous limestones is located on thern Tur k e y . The total length of the coastal line is the serpentines. In the North and the Northwest of 1200 km. Along the coastal line, plains, at which the area, Miocene sandstones are observed. seawater intrusion is observed, are also located. In The alluvium is formed by very coarse grai- this present article, some of these plains will be stu- ned alluvial cones in the East, in the middle sand died with respect to their certain features. and gravel and towards the coast, fine grained The coastal section is generally an uneven material of sand and silt. The basalt eruptions has area. Highly elevated mountains with plains at their been started in Pliocene which is also continued slopes dominate the region. Majority of the popula- in Quaternary. tion in the region are agricultural workers and cities The study area has been undergone Caledo- like Adana, Mersin and Antalya are also industrial nian, Hercynian and Alpine orogenesis. At several areas. The total number of people who are settled times the study area has been uplifted, subsided, along the Mediterranean coast is 5 millions. Most folded or faulted. The basaltic eruption taken pla- of these people work on land and the rest are ce in Pliocene and Quaternary is caused of the employed in industrial and tourism sectors. change in the structure. The cretaceous limestones and serpentines contain some amount of General Problems in Coastal Aquifers groundwater due to the existence of fissures and The most serious problem in the coastal sec- cracks. Also excessive replenishment is dischar- tion is seawater intrusion especially during the ged by means of springs. summer months, seawater intrusion increases due The favourable formations for groundwater to groundwater overpumping. As a result of the are conglomerates, basalts, sands and gravels. salinity, which develops in the alluvium aquifer, The basalts are encountered in the northwest of in some of the plains, wells that reach lower kars- the plain. tic aquifers are formed. Another serious problem Berdan Efrenk Plain: Sedimentary and in the coastal plains is the intrusion of seawater metamorphic rocks in the Mersin-Berdan and through drainage canals due to tidal effects. In Efrenk plains take over are whole area (figure 2). Adana plain this type of intrusion occurs at appro- Sedimentary rocks cover the north part of the ximately 30 km into the land. This intrusion cau- area. These rocks are; limestone, marl, sandstone, ses over-salinity in the plains. For the salinity in sandstone interbedded with clay, sandy limestone these plains to disappear, seawater intrusion ad marl, their ages are Tortonien of Miocene; should be hold back and then the soils should be Lower Miocene limestone and Palaeozoic crysta- rain-washed for at least 5-6 years. llized limestone. The metamorphic rock outcrops on a very little area and it is seen in the north part of the area on the north part of the area on the east GEOLOGICAL CONTEXT of Ziyaret mountain. The metamorphic rock is formed as clayey schist. The plain is a delta plain, Regional Geology of Coastal Areas which is collapsed and sedimented by alluvial material from the streams. Dörtyol-Erzin Plain The main streams of the area are Berdan At the Dörtyol-Erzin plain, (figure 1) the River and Deliçay, Efrenk and Mezitli Creeks. eastern section of the plain is constituted by ser- These streams form the delta. There is no impor- pentine rocks. These rocks stretch in the north- tant spring in the investigation area, but there is a

266 SEAWATER INTRUSION IN COASTAL AQUIFERS OF THE MEDITERRANEAN COAST OF TURKEY

Figure 1- Hydrogeologic map of the Dörtyol - Erzin Plain.

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Figure 2- Hydrogeologic map of the Mersin - Berdan and Efrenk Plains. group of springs in the west of Berdan which is The trend of old geosynclines generally formed by the intersection of the topography and appear at continuous and high peaks. The old base the groundwater table. rocks is formed continuous and high peaks. The The water bearing formation of the area is old base rocks is formed by sedimentary rocks only the Quaternary’s sandy gravelly levels. The which can be found at the border of the plain or thickness of this formation is 200 m in Berdan under a thin alluvium layer. This old base rock and the aquifer is of free type near the lower generally trends in NE-SW direction. Although boundary of the forest and it is in artesian aquifer the appearance of the plain is due to tectonic ori- type towards to the seaside. The thickness of gin, it is also due to the erosion of soft sedimen- water bearing formation is 100 m in Deliçay pla- tary rocks of the old base. The water bearing for- ne and the aquifer is of free type. The thickness of mations in Ovacık area are mainly various limes- the water bearing formation is 10-80 m and it is tones and the alluvium. The drainage area of the spread over the left side. limestones are greater in comparing with the other formations. Ovacık Plain . The formation in the Ovacık plain (figure 3) Içel-Gilindire Plain . are the sedimentary rocks from Cambrian to Qua- The formation in the Içel-Gilindire plain ternary. Igneous rocks are not observed. Trans- (Gilindire, Sipahili and Büyükeceli plains) are gressions, at the beginning, seems to be move into the Palaeozoic complex series at the basement the places which being bended down. (micashist, ,seyl, limestone and undiff e r e n t i a t e d

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Figure 3. Hydrogeologic map of the Silfke-Ovacñk Plain. Sñlñfke ve Ovacik Cñvari Jeolojñ Harñtasi. series) takes place. Over this basement com- Gazipa,sa Plain plex, there are Mezosoic limestone, Paleocene- Oldest formations in the investigation area Miocene limestone and at the plain there are (figura 5) are Devonien schist: clay schist, chlori- a l l u v i u m . de schist, micaschist and quartzite which are for-

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quartzite, and ophiolites. Their ages change between Palaeozoic and Mesozoic. Alakır Çayı Group outcrops in the north and northeast part of Kumluca district center. Th i s group is formed by limestone, radiolarite, ophioli- te and detritic rocks. These rocks in Mesozoic age. Çataltepe group outcrops in the north and west part of the Finike district center. It is usually formed by carbonate and layered rocks. This formation is in Mesozoic age. Neogene sediments which are formed or marl and clayey limestone interbeds, outcrop in the east of Salır Mountain. It is seen as flysch facies. The conglomerate which is under the alluvium can be a Neogene sediment. Volcanic rocks are extrudes along the north- south directioned fault in the north of Kumluca district center and they are formed by serpentine and peridotite.

Demre Plain The oldest formation of the investigation area is Mesozoic limestone (figura 7). This limestone is formed on the Eocene flysch as an overthrust. Besi- des that, (from old to young) Cretaceous limestones, Figura 4- Hydrogeologic map of the ñçel - Gilindire Plain. Eocene limestones, Eocene flysch and Neogene ming the foundation of the basin. Upon these for- marly limestone and conglomerates are covering this area. The Quarternary’s clayey, sandy and gra- mations stratigraphically follow rocks are velly alluvium is in the surroundings of Gölova, encountered such as Permian limestone; Neogene Karagöl, Avlan Lake and Kasaba, Akçay and Dem- conglomerate, clayey gravel, clay, Quaternary re plains. The alluvium is sandy and gravelly near clay, gravel, sands. the stream beds and clayey near Eocene flysch. Limestone and Schist forming Alanya mas- Akçay and Demre (between A l a k e n t - sif are folded and fissured by the Alpine tectonic Kö,skerler) plains are suitable for ground water. movements and highest places of the plain are Sandy and marly layers of alluvium contains formed by schist and limestones. ground water in these parts and in Elmalı (west part of Balıklar Mountain) Mesozoic limestones. Finike-Kumluca Plain The geologic units which show complex stra- tigraphy locate near the investigation area (figura 6). CHARACTERIZATIONS OF These formations are named Antalya Nappes and COASTAL AQUIFERS separated into three groups, Tahtalı Dag group, Alakır Çayı group and Çataltepe Group. Dörtyol-Erzin Plain Tahtalı Dag Group outcrops in the east part Dörtyol-Erzin plain extending between of the plain. This group is formed by carbonate Amanos Mountains. and Mediterranean Sea in the and detritic rocks, shale, dolomitic limestone, Northwest of Iskenderun Bay, is situated between

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36° 45’-37° 01’latitudes and 36° 03’-36° 46’lon- 0-250 m. from the sea level. It is under the gitudes. The length of the plain from the North to influence of Mediterranean Sea climate; the pre- the South is about 28 kms, and width from the cipitation is abundant. The average annual preci- East towards the West is 3-18 kms. The plain is pitation is 1135.7 mm. and the average tempera- inclined in the East to the West with an altitude of ture is 18.9 °C.

Figure 5.- Hydrogeologic map of the Antalya - Gazipa a Plain.

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Figure 6.- Hydrogeologic map of the Finike and Kumluca Plains.

Transportation in the study area is maintained merates. The average hydraulic values of the water by the Adana-Iskenderun highway and rail-road. into conglomerates. The average hydraulic values In the study area perennial streams are Dört- of the water yielding formation are given below: yol-Deliçay and Payas streamlets. In basalt; T=3500 m3/day/m. Specific capa- During the irrigation season, the whole city:50 l/s/m. amount of available waters are used. In conglomerate; T=2000 m3/day/m. speci- The largest springs are Ya n ı k d e g i r m e n , fic capacity: 16 l/s/m. Yeniköy, Araplarsuyu springs which are respecti- The recharge of the plain is through infiltra- vely originated from the basalts, conglomerates tion from precipitation and surface run-off. The and the alluvium. discharge is through springs, artificial run-off, In the plain, at 87 locations, 128 exploitation swamps and sea. wells are drilled. Among these wells, 117 wells in The groundwater budget is given in the 82 locations are contained water and drilling per- following table: formance for exploitation wells are continued. In several places, 5 oil-wells have been dri- RECHARGE x106 m3/year DISCHARGE x106 m3/year lled by TPAO (Turkish Petroleum Company) Through precipitation 113 Through springs 65.5 In the common aquifer direction of water Through surface run-off 15 Through artificial run-off 8.0 flow is from the Northeast to the Southwest. In the Through sea and swamps 59.0 east and middle of the plain, alluvium is more per- meable which is transmitting the water into conglo- TOTAL 128 TOTAL 132.5

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boundaries of Mersin province. The drainage area is 2571 sq. kms and the plain area is 290 sq. kms. The altitude of the plain is 0-30 m from the sea level. The climate of the investigation area is Mediterranean climate. It is hot and dry in summer and warm and rainy in winter. The annual average precipitation is 617.4 mm. Mersin province, Tarsus District and 71 villages are placed over the investigation area. According to the census of 2002, the population of Mersin is 733660, Tarsus is 348205 and the total population of the investigation area inclu- ding the villages is 250.000. The main branches of the economy are agriculture and industry. A little amount of water is obtained by the caliche, which surrounds the area by caisson wells. There are 6 wells drilled for drinking, 11 wells drilled for industry, 51 wells drilled for exploration, 20 wells drilled for deep drainage, 143 wells drilled for shallow drainage at the end of the year 1971. the depths of bore-holes are changing between 16-300 m. The static levels change beteen –57.25 m. and +6.50 m. Figure 7.- Hydrogeologic map of the Antalya - Demre Plain. The transmissivity coefficient of Berdan plain for exploitation area is 300-2900 m3/day/m, Eventhough, the aquifer is excepted to be and the specific capacities of the wells are betwe- common in the plain, the recharge and discharge en 0.6-23 l/s/m. of basalts are calculated separately. For this rea- The transmissivity coefficient of the aquifer son, the discharge of basalts through springs is in Deliçay change between 376-65850 m3/day/m resulted the separate calculation for the safe yield. and the specific capacities of the wells are betwe- The annual safe yield for basalts is en 0.08-20.01 l/sc/m, the storage coefficient chan- 6 3 3 7 x 1 0 m / y e a r and for alluvium and conglome- ge between 0.16-0.0001. 6 3 rate it is 48.6x10 m /year. The total annual safe The transmissivity coefficient of Efrenk yield is (37+48)x106 m3/year=85x106 m3/year. plain is 340 cu m/day/m. The wells of Mezitli are The suitable areas for exploitation are deter- uneconomic. mined by the evaluation of drilled wells and boun- The recharge of the groundwater is from daries of hydrogeological map are illustrated. precipitation and surface run off. Besides, there is The seawater interference along the coast of a recharge from Berdan River in Berdan, the area the plain is calculated in between 630 m 1120 m. between diversion dam and the bridge. ranges. The discharge of Berdan plain is by drainage channels, to the river and by the eucalyptus Mersin-Berdan and Efrenk Plains forest. The investigation area is situated in the Medi- The discharge of Deliçay area is by outflow terranean Sea Region, between 36° 43’-37° 01’ lati- and by the industry wells. The discharges of tudes and 34° 27’-34° 58’longitudes between the Efrenk and Mezitli plains are by ouflow.

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The grounwater budget are the following Palaeozoic complex series at the basement figures for the Berdan-Efrenk plains. (micashist, seyl, lime, stone and undifferentiated Berdan plain: Recharge 48,5x106 m3/year, series) takes place. Over this basement complex, Discharge: 48.5x106 m3/year there are Mesozoic limestone, in the plain there Deliçay plain: Recharge 16,5x106 m3/year, are alluvium. Discharge:16,5x106 m3/year Efrenk plain: Recharge 4.0x106 m3/year, Finike Kumluca Plains Discharge:4,0x106 m3/year Finike-Kumluca plain situated in the Mezitli plain: Recharge 1,0x106 m3/year, south Anatolia, between 36° 00' latitudes and Discharge:1,0x106 m3/year 30° 00'-31° 00' longitudes on the Mediterranean Total Recharge 70x106 m3/year, Total Dis- Coastal band. It is 110 km for from the west of charge:70x106 m3/year Antalya Province. The communication is possible The 39.0x106 cu m/year, of ground water is in every weather condition over the plain. The represented as a reserve for exploitation in Berdan important settling centers are Finike and Kumlu- plain and 23.5x106 m3/year of it is still used. Be side ca district centers. that 15.5x106 m3/year of ground water can be used. The plain is surrounded by the south edges 12 . 0 x 1 0 6 m3/year of ground water is calculated of West Taurus and Mediterranean Sea is in the and it can be obtained from the exploitation reserve. south. The investigation area covers 1516 sq. 3 . 0 x 1 06 m3/year of groundwater can be Kms and the plain area is 102 sq. kms. The plain obtained in Efrenk and 0.70x106 m3/year of is separated into two sections and these are Fini- ground water can be obtained in Mezitli. ke and Kumluca. The quality of the ground water is good and According to Finike Meteorology Station, it is in the C2S1 irrigation water classes. The sur- the annual mean precipitation is 953 mm, and the face drainage water is salty especially and betwe- annual mean temperature is 18.4 °C. The climate en the coast and the Deliminnet-Ye,silkuyu Villa- of the are is warm and rainy in winter, hot and dry ge line. The Karabucak and Ali Rızzaki discharge in summer. channels water is C2S1 class from spring to Deli- The area is underdeveloped in the economic minnet bridge. Only Çatalkeli and Aynaz dischar- progress. The economy is based on the agriculture. ge channels water is in bad quality because of the There is no industrial foundation except cotton gin. salty base water. The ground water budget for The agriculture of citrus fruits (orange, Demre plain are given below: lemon, etc.) are very important. Beside cotton and 6 3 R e c h a rge: 12x10 m / y e a r, Discharg e : green house planting is done. 6 3 12x10 m /year. There is no perennial stream in Kumluca The annual safety yield of Demre plain plain. There are three streams in Finike plain; 6 3 8.5x10 m /year. Karasu stream, Akçay stream and Alakır stream. The groundwater quality of the investiga- These streams pass through the plain. Karasu tion area is C1S1 and C2S2 irrigation water class stream has 4,5 m3/s, Akçay stream has 1.9 m3/s, (except the south side of Karabucak-Köprüba,sı and Alakır stream has 2.33 m3/s discharge. line of Demre plain). There are 300 dug wells in these plains. Only Çatalkeli and Aynaz discharge chan- These wells have depths change between 10-15 m nals water is in bad quality because of the salty and the purpose of these wells are irrigation. The- base water. re are 12 bore-holes drilled in different times (bet- . ween 1963-1976) to explain the groundwater Içel-Gilindire Coastal Plains . situation and their depths are between 24-180 m. The formations in the Içel-Gilindire plain Gravel and sand levels of alluvium and (Gilindire, Sipahili and Büyükeceli plains) are the Neogene conglomerate are water bearing forma-

274 SEAWATER INTRUSION IN COASTAL AQUIFERS OF THE MEDITERRANEAN COAST OF TURKEY tions. These two aquifers are common. T h e Mediterranean which are carrying seasonal water. transmissivity coefficient is 1000 m3/day/m. Shallow wells are drilled near by streambed in The groundwater device which passes order to produce groundwater. through the east of Alakır stream is in the north- 16 drilled wells were drilled in the plain. south direction. The west part of the ground Depth of the wells varies form 10 to 175 m. water water device is Finike section, the east part of it, bearing formations are alluvium and Neogene is Kumluca section. aged conglomerates. Alluviums are found in the The groundwater budget for the Finike- streambed. The thickness of alluvium varies from Kumluca plains are the followings: 10 to 60 m. Finike plain: Recharge: 56.0x106 m3/year, Tranmissivity coefficient of alluvium aqui- Discharge: 56.0x106 m3/year . fer varies between 608 to 1777 m3/day/m. and Kumluca Plain: Recharge: 8.0x106 m3/year, 3200-4164 m3/day/m. Transmissivity coefficient Discharge: 8x106 m3/year. of conglomerate aquifer in drilled wells varies The annual safe yield of Finike section is between 41-1580 m3/day/m. 33.5x106 m3/year and the annual safe yield of In accordance to piezometric contours, exis- Kumluca section is 5.5x106 m3/year. ting line of ground water division is extended The aquifer characters of Kumluca and from the well Nº 5551 at south of Bıçkıcı stream Finike sections are the same. For this reason to Kı,sla township and Beyobası location. North when there is no groundwater exploitation the of this line is investigated as a first and South as length of Sea Water intrusion is calculated as a second group. Generally groundwater recharge 187.5 m for both section. When the whole of the in the plain occurs through precipitations and ground water safety yield is produced the Sea infiltration from surface run-off. Mostly ground- Water intrusion length will be 625 m. water recharge occurs through precipitation fallen The quality of ground water is good. It is on waterbearing formations and infiltration

C2S1 irrigation water class. through surface run off in the drainage area. Groundwater discharge occurs through withdra- Gazipa,sa Plain wal from shallow wells, influent flow to Medite- Ga z i p a ,sa plain is situated in the southtern rranean and evapotranspirations. Evapotranspira- Anatolia region, on the Mediterranean cost, between tion occurs from the stream beds where the water- 36° 00' and 36° 30' latitude, 32° 00'-33° 30' longitu- table is high. de. Gazipa,sa township is the essential settling center Groundwater budget for the Gazipa,sa plain in the plain and 176 km long highway connects to are the followings: Antalya province. Investigation are is surrounded by Section I: Recharge 9x106 m3/year; Dis- the Taurus mountain range at North, South and East charge:9x106 m3/year. and opens to Mediterranean in west. The plain area Section II: Recharge 13x106 m3/year; Dis- is 38 sq. km. and drainage area is 719 sq. km. charge: 13x106 m3/year. Annual mean precipitation is 767.5 mm. Most important amount of Groundwater in and annual mean temperature is +18.8 °C in discharging to the Mediterranean occurs through accordance to meteorological data of Gazipa,sa the opening of water bearing formations to sea Meteorological Station. The plain is prevailed by such as, Neogen Conglomerates and alluvium Mediterranean climate, summers are warm and materials the first and second groups. According dry winter are mild and rainy. Economy of the to calculation, groundwater flow to Mediterrane- plain, mostly citrus fruits like lemons and oran- an in first group is 65x106 m3/year. During the ges, bananas and pea-nut are main crops. exploitation period 0.60 percent of this water esti- There are not perennial streams in the plain. mated to be withdrawn and boundary of the salt Delice, Bıçkıcı and Hacımusa stream flowing to and fresh water encroachment in the first group

275 TURQUÍA shall be extended to 454.5 m. of the shore. Th e 19 exploration wells, 2 observation wells, 7 amount of Groundwater flow to Mediterranean in exploitation wells and 1 drinking well were drilled in second group is 10x106 m3/y e a r , during the exploi- di f ferent times for searching the ground water condi- tation period 0.60 percent of this flowing water tions. According to these wells and geophysical estimated to be withdrawn and boundary of the investigations, Begi,s, Gölova and Kasaba plains are salt and fresh water encroachment shall be exten- not suitable for ground water. Elmalı (west part of ded to 799 m of the shore. Quality of groundwater Bacontains ground water. Besides those, the ground is good and C2S1 irrigation water class. water can be produced from the Eocene limestones Calculated amount of annual safe yield in which are in the north part of Demre plain. It is section I is 5.50x106 m3/year and in section II is brought to light by a borehole which is drilled during 3.00x106 m3/year. the investigation. The transmissivity coefficient is changeable and it is lower where the material is thin Elmalı, Akçay ve Demre Plains and clayey. The transmissivity coefficients of allu- The investigation area is situated in the vium are changing between 100-4000 m3/s ) . southwest part of Turkey, in the west Mediterra- Begi,s, Gölova and Kasaba plains have more nean Sea Region. It is in the boundaries of Elmalı clay, for this reason these plains are not suitable and Ka,s sub-provinces, between 29° 35'-30° 10' for ground water and so ground water budget is east longitudes and 30° 10'-37° 00' north latitu- not prepared for these plains. des. Begi,s, Gölova, Elmalı-Karagöl, A k ç a y, R e c h a rge: 12x10 6 m3/ y e a r, Discharg e : Kasaba and Demre plains cover whole of these 12x106 m3/year. plains covers 3175 sq. kms. The investigation The annual safety yield of Demre plain area is seperated into four sections: 8.5x106 m3/year. 1) Begi,s and Gölova plains, 2)Elmalı plain, The ground water quality of the investiga- 3)Akçay plain, 4) Kasaba and Demre plains, tion area is C1S1 and C2S2 irrigation water class The climate of the area is Mediterranean cli- (except the south side of Karabucak-Köprüba,sı mate. It is warm and rainy in winter, hot and dry line of Demre plain). in summer and transitive from Mediterranean to continental climate from south to north. The tem- Methods of Study and Applied Tec h n i q u e s perature and the precipitation values of the south For the prevention of seawater intrusion are higher than the north. The annual average observed at the coastal plains in the Mediterrane- temperature of Elmalı is 12.9 °C an annual avera- an region, in accordance with the Groundwaters ge precipitation is 512 mm and annual average Law decree number 167, the General Directorate temperature of Demre plain is 18.4 °C. of State Hydraulic Works takes the necessary From north to west Eskihisar creek, Akçay measures to ensure the pumping of only the safe- creek, Kıbrıs stream, Tokluca stream and Demre yield in these plains. Furthssermore, the neces- stream are the most important streams. These sary project studies are currently continuing for streams generally have less water during summer. the prevention of seawater intrusion through drai- There are many differences between the dischar- nage canals as a result of tidal effects. ges of these streams. The investigation area is rich for the springs. Especially there are many high discharges of these increase and decrease depen- CURRENT STATE OF SEAWATER ding on the precipitation. Kazanpınarları and INTRUSION Gömbe springs are the most important fresh water springs. In Demre plain, Kokarçay and Küçük Seawater intrusion occurs in all of the coas- Dalyan springs have big discharges, but the water tal plains situated in the east-west direction along wualities of these streams are not good. the Mediterranean coast. From among these only

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Dörtyol-Erzin,. Mersin-Berdan and Efrenk, Silif- At some points it may occur as 125 m, and in ke-Ovacık, Içel-Gilindire, A n t a l y a - G a z i p a,s a , some other areas. it was calculated as 600 m. Finike-Kumluca and Demre plains have been In the Içel-Gilindire plain, the total length of chosen for detailed study. The total length of the seawater wedge has been calculated as 1357 m. In coastline is 1200 km. All of the plains mentioned some areas, it was calculated also as 1250 m. The above are affected by seawater intrusion. The length is 400 m in Sipahili plain, 35 m in Gilindi- effects of seawater intrusion in these plains are re plain, 350 m in Gözce plain, and 65 m in Aksaz generally seasonal in character. A s i g n i f i c a n t plain. amount of the seawater is notably reduced by In the Finike-Kumluca plain, the depth of winter precipitation. The effects of the seawater seawater wedge is 66 m and its length is 200 m. become observable again toward the end of sum- In Gazipa,sa plain the depth of seawater mer months. Seawater intrusion in these plains wedge is 66 m and its length is 200 m. If the has increased drastically during the last decade. groundwater in the area was exploited, the length The rates of salinity generally range between of seawater wedge would be 455 m. In some sec- 3000-4000 µmho/cm. tions this length may even increase to 800 m in such a case. In the plains listed above, the depths and MANAGEMENT lengths of seawater wedges are constantly being monitored. Groundwaters Law decree number 167, which took effect in Turkey in 1960, is a rare legislation. With the law, the drilling of wells has REFERENCES been made subject to legal permission since 1960. . Monitoring and Control of Seawater Intru- D SI, 1973. Gazipa,sa Plain, Hydrogeological sion is the most important of the methods that are investigation report, state Hydraulic works used as management tools. Apart from this, with . Groundwater Division report. the advising to farmers method, local farmers are DSI, 1974 Dörtyol-Erzin plain, Hydrogeological discouraged to use water wastefully and to over- investigation report, state Hydraulic works pump from the aquifer. Conjunctive Use of Surfa- . Groundwater Division report. cewater and Groundwater method is also applied, DS I, 1978. Mersin-Berdan ve Efrenk Plains, Hydro- especially in those localities where there are stre- geological investigation report, state Hydraulic ams. In these regions, and especially in Dörtyol- . works Groundwater Division report. Erzin and Gazipa,sa plains, with the application of DSI, 1978. Finike-Kumluca plain, Hydrogeologi- the artificial recharge method, aquifers are made cal investigation report, state Hydraulic to recharge from the streams. In some other areas, . works Groundwater Division report. impermeability curtains are being constructed. D SI, 1978. Elmalı, Akçay ve Demre Plains, Hydrogeological investigation report, state Hydraulic works Groundwater Division CASE STUDIES . report. D SI, 1978. Elmalı, Akçay ve Demre plains, In the Dörtyol-Erzin plain, the thickness of Hydrogeological investigation report, state fresh water level is 156 m. 75% of the safeyield in Hydraulic works Groundwater Division the plain can be obtained as fresh water. In this report. case, the thickness of the fresh water level will be Gü n a y , G and et.al, 2000, Guide Book, Karst 2000 reduced by 50%. In the Mersin-Berdan and Efrenk symposium, sept. 17-26. 2000, Marmaris, plains, the total length of seawater wedge is 372 m. Turkey (Hacettepe University UKAM).

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