Berkman Regulator and Hydroelectric Power Plant is located 11 km to the northwest of the Province of Osmaniye, within the borders of Central District and on Ceyhan River. The approximate head is 21 m between the upstream Aslantaş Dam and HEPP and downstream Cevdetiye Irrigation Regulator. This head is planned to be utilized through upstream Oşkan HEPP and Berkman HEPP.
Osmaniye is located in the eastern part, Adana section of the Mediterranean region. It is surrounded by Gaziantep in the east, Adana in the west, Hatay in the south and Kahramanmaraş in the north. Being one of our southern provinces, Osmaniye is quite close to the İskenderun Gulf (20 km) and has no coast. It is a province with a special position through which E-5 that links Turkey to Syria and roads that link the Central Anatolia Region and Mediterranean Region to the Southeastern Anatolia Region pass through. It has a surface area of 3037 km2. Kadirli, Sumbas, Düziçi, Bahçe, Hasanbeyli and Toprakkale are its districts.
Population coming from cities is much higher than the one coming from villages in the Province of Osmaniye. The major reason for this is the fact that industry and trade sector is quite developed in the economic structure of the province. The people of the region make their living from agriculture, industry and trade.
In the province, plains are wide, irrigation problem is largely solved and agriculture has a large share in the economy as the climate conditions are appropriate for agriculture. Plains occupy large areas particularly in Osmaniye, Kadirli, Toprakkale and Düziçi. Important agricultural products are peanut, cotton, soybean, corn and wheat. Citrus fruits agriculture and greenhouse cultivation have also developed in recent years due to warm winter conditions. The district of Kadirli has an important place in radish production of Turkey.
The ponds and streams within the province borders are utilized in the fisheries industry. Osmaniye has an intense commercial activity because of its special location as it is located on important highways and railways.
The province of Osmaniye is located to the east of Çukurova. In the eastern part of the city borders lie Amanos Mountain Ranges, which are recognized as the beginning of South-eastern Taurus Mountains and the height of which exceeds 2000 m from place to place while Central Taurus Mountains lie in its north. For this reason, land forms and elevations vary to a great extent even in short distances. In other words, plains with little elevation are next to high mountains. Eastern and northern parts of it are mountainous while southern and western parts are bottom lands which are a continuation of Çukurova. As the central district, Osmaniye is established on a fill land formed by accumulation of materials brought by Hamus Creek and Karaçay that spring from Amanos Mountains (118 m). From place to place volcanic stony areas and basalts are encountered on these fills. Furthermore, the presence of Erzin Mineral Spring in our immediate vicinity and Haruniye Thermal Spring within the Province borders (Hatay) proves that we are on a faulted structure in geological terms.
The province of Osmaniye is located in the Mediterranean Region. It has a sultry weather as summers are hot and humidity level is high. For this reason, transhumance has become a life style. Plateaus are accessed in short distance as plains and mountains are side-by-side on the province borders. Its important plateau is Zorkun Plateau, on which various media organizations prepare and present programmes for promotional purposes.
Zorkun Plateau is on the Amanos Mountains, has an altitude of 1500 m and can see Syria and Çukurova from a bird’s eye view. Because of its cool weather, natural beauties, cold water resources and as it is at a short distance and has adequate infrastructure services, it has attracted the attention of people of our region and its population reaches 100 thousand in summer months. Certain institutions and organizations arrange various social and cultural events in tableland season on Zorkun Plateau such as Zorkun Child Festival. Apart from Zorkun, the plateaus on the Amanos Mountains are Küreci, Tuztaşı, Dervişpınarı, Mitisin and Fenk plateaus. Almanpınarı, Tutlupınarı and Başpınar plateaus are located in Hasanbeyli district. Furthermore, Maksutoluğu, Çığşar, Akarca; Bağdaş (Sumbas) plateaus on the Central Taurus Mountains are also important plateaus.
While snowfall and frost are not observed much in lower plateaus with little elevation, snowy and frosty days are experienced in higher regions. Spoiled Mediterranean climate properties are seen in these parts. Climate properties vary in short distances with the effect of elevation. As a result of this, transhumance is a feature of the region.
Vegetation formed three different vegetation zones vertically.
Maquis: It is the natural vegetation composed of evergreen, small shrubs and trees. It is more prominent in places where calabrian pine trees have been destroyed. This zone continues up to 700-800 m of altitude from the shore.
Forest Zone: This zone starts from the upper bound of maquis and continues up to 1800-1900 metres of height. In lower regions, broad-leaved and mixed forests exist while forests composed of coniferous trees such as black pine, cedar and abies exist in higher zones.
Alpine Layer: It is the natural vegetation that starts from upper bounds of the forest and continues up to 2000-2200 metres of height and is composed of herbaceous species.
The largest river in the province is Ceyhan River. This river, which springs from inner regions, passes through Osmaniye and flows into the sea from Adana. Other important streams are branches of Ceyhan River, which spring from mountainous areas. These are Karaçay, Hamus, Sumbas, Kesik, Savrun, Kalecik and Sabun Creek. Dams were constructed on some of these creeks for various purposes.
Streams of the province of Osmaniye have irregular regimes. As Osmaniye has broad agricultural lands, irrigation bears importance and for this reason, construction of irrigation dams constitutes an important solution. There are no natural lakes exist in the province. However, there are numerous karstic resources, which furnish abundant water due to the karstic structure. The resources in the Bahçe district are upstream and bottling facilities were established on the resources. There is Haruniye Thermal Spring near Düziçi district of the province. This thermal spring is among the fist-degree thermal springs according to criteria of the ministries of health and tourism. It is stated that it contributes to the treatment of rheumatism, gynaecological diseases, skin diseases, nutrition disorders, liver and gall bladder, stomach and intestinal diseases.
Ceyhan is one of the major rivers that flow into the Mediterranean Sea. This river, which springs from northwest of the Mediterranean Region on the Anatolia Plateau, is formed by the merger of Göksun and Hurma Creeks. After merging with Aksu River to the west of Kahramanmaraş and many large and small creeks, it flows in the southwest direction and flows into the sea near Yumurtalık District.
a) Current Use of Lands
The highest point in Ceyhan Basin is 3081 m high from the sea level. The work site is approximately 60 m high from the sea and limited with rugged lands of 157-273 meters. It is surrounded by Göztepesi to the south (204,5m), Çamlıgedik to the northeast (157 m), Küçükbakacak to the southeast (273 m) and Karayüce (230 m) to the west. In terms of topographical appearance, the land looks like Çukurova in regions between the sea and mountain hills that face onto the sea and like typical Central Anatolia in upper parts. Total basin area is 14.842km2.
Berkman Regulator and Hydroelectric Power Plant are situated on a broad alluvial plain near Kumarlı Village. The lake area will not exceed the overflow bed in general. On the right coast of the lake area are Kiriz and Kazmacı Quarters while Karagedik quarter is located on its left coast.
In the location where power plant structures will be established, there is alluvion of Ceyhan River on the bed while Pliocene aged pebble stone is available on both sides. Bearing power of the alluvion and permeability of pebble stone were taken into account in the preparation stage of the project.
The region is developed in agricultural terms. The hillsides on right and left coasts of the project area are covered with spoiled forest lands and maquis. The remaining regions are covered with broad agricultural lands and grazing lands. The products grown are cotton, grains and citrus fruits due to the effect of the Mediterranean climate. Vegetable and fruit cultivation are also highly developed. Forestry is one of the activities carried out in the region, though not as much as agriculture.
There are no recreation areas or places of high landscape values around the project area. However, agricultural lands are available around the area concerned. Since only hydroelectric power plant is planned to be constructed within the scope of the project, no negative impacts are expected to occur on the agricultural lands in the vicinity.
b) Geological and Hydrogeological Characteristics and Natural Disaster Status GEOLOGY
An engineering study entitled “Bakacak Regulator Engineering Geology Planning Report” conducted by the General Directorate of State Hydraulic Works, the Survey and Planning Department in the project area in 1965 is available.
1. GENERAL GEOLOGY 1.1. STRATIGRAPHIC GEOLOGY
Building area of the structures within the scope of Berkman HEPP Project and geological units in its immediate vicinity are listed in the following order from the oldest to the youngest one (from bottom to top).
5 Alluvion Quaternary
4 Terrace Plio quaternary
3 Basalt Plio quaternary
2 Pebble stone-sand stone Pliocene
1 Flysch Alt Eosen
It starts from the place of Karagedik Quarter, approximately 3 km upstream the Berkman HEPP structures and stretches towards north, upstream of Ceyhan River. The Flysch yields crops mostly on the right side of the river and it stretches towards Aslantaş Dam site lake area.
Flysch is composed upon intercalation of thin and medium-thick clay stone, sand stone, marn and pebble stone layers. It has medium and wide joint spaces (20-200 cm) and weak resistance. The Flysch is impermeable on general terms due to clay stone layers.
1.1.2. Pebble stone-Sand stone
They form broad plains on both sides of the river starting from Karagedik Quarter towards upstream until Cevdetiye and Berkman HEPP structures are established on this unit on both sides of the river.
Pebble stone predominates in this Pliocene-aged unit. Pebble stone and sand stone layers are available from place to place as intercalated. The unit is primarily composed of lime stone, sand stone, andesite, fire stone and ophiolite-origin pebbles. Pebble dimensions often vary between 2-10 cm. It has weak cementation. It can be crumbled easily by a hammer impact and by hand by forcing. It is half-permeable in general terms.
Pleistocene aged basalt flows were often observed on the left side, between Karagedik and Karkılı Quarters, mainly at high elevations, on the Göztaşı ridge and on riverside in a narrow section. Its thickness reaches 50m.
Quaternary aged terrace sediments were observed at different elevations on both sides of Ceyhan River. Depending on the place, it stays incompatibly and horizontally on flysch and pebble stone sediments. Terrace, which greatly resembles Pliocene pebble stone in terms of grain type and cementing, can be distinguished by staying incompatibly on the pebble stone and horizontal layering. It also has similar properties with pebble stone in terms of resistance and permeability. Grain sizes are bigger and vary between 3-15 cm.
The alluvion, which generally displays a width of 300-500 m in the survey area, is composed of pebbles and sand of different dimensions. Blocks with diameters of 30-40 cm were observed from place to place on the surface. The grains are generally of lime stone, sand stone, fire stone, andesite and ophiolite origin. It is seen that alluvion reaches a thickness of 35m.
1.2. STRUCTURAL GEOLOGY
Among the units mentioned above, the oldest and most folded ones are flysches. They generally display a slope between 20 and 45 degrees in northern and north-western direction. The pebble stone-sand stone unit staying incompatibly on the flysch are less folded and often a little sloppy in southern and south-western direction. The basalt flow and terrace both on the flysch and pebble stone-sand stone units are horizontal or sloppy- nearly horizontal.
No important faulting has been observed on the survey area.
2. GEOLOGY OF THE CONSTRUCTION SITES The structures related to Berkman Hydroelectric Power Plant planned to be constructed near Kumarlı Village will be established on alluvion on the riverbed and pebble stone units on two sides.
Below are explained the engineering geology properties of pebble stone and alluvion respectively.
2.1. Pebble Stone
While it varies depending on the place, pebble stone, which is generally composed of 2-10 cm pebbles, has often low resistance and half permeability. The main reason for this is that the connector among the grains is clay and lime cementing is weak. Again, the reason of core rate that could be extracted from the bore holes dug in this area by the State Hydraulic Works in 1964 remaining below fifty percent is the weakness of cementing. Due to its above-mentioned properties, pebble stone was classified as “low resistant rock” in line with rock observations and its “uniaxial compression resistance value” was foreseen to be 10-50 kg/cm2 depending on cementing degree.
Permeability of the pebble stone differs again depending on the interconnecting clay and lime cementing rate. According to the results of single tyre pressurized water experiment made in the bore holes dug near the construction sites planned today by the General Directorate of State Hydraulic Works in 1964, permeability coefficient was found (k) 10-4 - 10-6 cm/s level and was considered as half-permeable. The underground water level within the pebble stone is higher in comparison to Ceyhan River and feeds the bed.
It is estimated that the alluvion thickness is close to 35 m in the section where Berkman HEPP structures are situated. Blocks that reach the size of 40 cm were seen on the surface in the alluvion which is primarily composed of pebble and sand of different sizes. Penetration experiment was applied in the bore hole no P-6 where the General Directorate of State Hydraulic Works dug alluvion near Berkman HEPP. However, penetration experiment was carried out in the SK-6 and SK-7 holes dug in Cevdetiye, 4 km downstream. As no great alterations were expected in the alluvion quality, the results obtained were assessed for Berkman HEPP site. In the experiment results, number of strokes (N) from the surface to a depth of 8 m varies between 5-25 and the number of strokes (N) become 50 after 8 m. As this value, which is below 8m, is below the underground water level, allowable bearing power is found to be approximately 5kg/cm from qa=(N-3)/10kg/cm2 correlation. When the correction N = 15+0,5 (N-15) is used by taking the pebble activity in the alluvion into account, qa is found to be around 3 kg/cm2. This value can be assumed to be 1-2 kg/cm2 between 0-8 m. However, it is foreseen that these values, which have been obtained for alluvion with high fine grain rate near Cevdetiye will be higher in Berkman HEPP site.
Permeability coefficient (k) is 10-2 cm/s in the hole of the DSİ no P-6 dug in the alluvion on the area of survey. Underground water level was found at approximately 3m of depth. Surface elevation of the alluvion is between 58 m and 66 m in the section where Berkman HEPP structures are located.
3. CONSTRUCTION FOUNDATION AND PERMEABILITY
3.1.1. Connecting Dike
Elevation of the dike, which will be placed on pebble stone on the right side and on the alluvion in the base, from the riverbed is 15,5 m. It was found appropriate in terms of stability to place the dike filling within a trench formed by excavation of 5 m given the fact that the ponding water can affect the pebble stone with weak cement and clay connector. A striping excavation of 2 m was foreseen in the alluvion. However, stripping excavation can be deepened if necessary depending on the material type to be extracted from excavation. The dike filling will be carried out with the sand-pebble material to be provided from the alluvion.
The spillway structure will be placed on alluvion at 53,5 elevation following an excavation with a depth of 15 m. As has been mentioned above, bearing power of an alluvion of this depth raises.
3.1.3. Power Plant and Switchyard
As the foundation excavation of the power plant structure may be dug to the elevation of 49,5, pebble stone under the alluvion is to great possibility is on the unit. For this reason, there are no problems caused by rock foundation for both of the structures.
As is mentioned above, alluvion and dike filling are permeable while the pebble stone on two sides is half-permeable. An impermeable wall which goes down to the elevation of 40,00 both under the structures within two units and the dike was envisaged to be constructed. This wall, which will go down approximately 20 m from the riverbed, will be left suspending within the alluvion. This depth was deemed to be sufficient for the wall as the dike and wall are not intended to store water, but rather to raise the water to the desired elevation.
It was found appropriate to construct an impermeable wall that will go down to the elevation of 54,00 within and under the cofferdams.
EARTHQUAKE STATUS The survey area is located right to the north of the intersection point of 36 east longitude and 37 north latitude. It is included in the second-degree earthquake zone according to earthquake zone map of the Ministry of Public Works and Settlement.
It is seen in the Turkey’s seismicity (A. Taban, 1970) publication of the Directorate of Earthquake Research Institute that the survey area experienced two massive earthquakes with the magnitudes of 7,72 and 9,42 MM between the years 1600-1964.
The relation between the Modified Mercalli (MM) scale and the greatest acceleration/gravity that corresponds to this is as follows.
BUILDING MATERIAL The material required for dike and cofferdam fillings and the aggregate necessary for concrete structures will be provided from the alluvion. For this reason, there are no problems in terms of distance and quantity.
HYDROGEOLOGICAL PROPERTIES Berkman Regulator, located on Ceyhan River, is approximately 11 km to the northwest of Osmaniye and 10,5 km downstream Oşkan Regulator.
A series of water structures have been designed on Ceyhan River for the development of water and soil resources of Ceyhan basin. The major ones among these structures are Aslantaş, Berke, Sır, Menzelet, Kartalkaya, Kandil II, Kandil I and Kandil respectively from downstream to upstream.
Precipitation area of Berkman Regulator is 14.842 km2 and upstream of it is the Oşkan Regulator with a precipitation area of 14.775 km2.
Hydrogeological status of the formations on the survey site are explained below in detail from the oldest to the youngest one.
Resources with high-flowrates spring from paleozoic (lime stone and its quartzites), paleozoic aged quartzites were observed in the region. Quartzites and lime stones are faulted and crackled.
Mesozoic a) Serpentine: High-flow resources spring from serpentines that constitute the Amanos Mountains in places where they are faulted and crackled. It is promising in terms of underground water.
b) Cretaceous Flysch: It is not rich in terms of underground water as the formation is mostly clay lime stone and crumbled parts fill the cracks and faults although they are
faulted and crackled. Low-flow resources are encountered in some places.
c) Medium Cretaceous Lime Stone: These lime stones, which have yielded very little crop, are not faulted and crackled and very hard and half-crystallized.
Tertiary a) Sitir Fm. (Lower-Medium Miocene): Permeable and not rich in terms of underground water. Low-flow resources were encountered.
b) Kadirli Fm. (Upper Moicene-Pliocene): Permeable and promising in terms of underground water.
Quaternary a) Kaliçi (Ağzıkara Fm.): Permeable and not rich in terms of underground water. Underground water is in pores of the formation. It does not have good conductivity. The water of the percolation wells dug in this formation usually run out in half an hour when they are drawn 1-2 lt/sc.
b) Alluvion: The formation with the richest underground water is Alluvion in the Osmaniye Plain and 25-35 lt/sc water is drawn with common centrifugal pump from 4"-6" driven wells with a depth of 12 m dug within the field. Free aquifers have good water quality and static level varies between 0-2 m while dynamic level varies between 1,5-3 m. In some years, static level rises and base water becomes semi-artesian.
The underground water is used largely in the region for irrigation.
c) Basalt: They are not promising in terms of underground water although they are faulted and crackled.
With regard to the project, opinion of the General Directorate of State Hydraulic Works (DSİ) will be submitted at the phase of obtaining licence from the Energy Market Regulatory Authority (EPK).