Water Resources Management in Thessaly Region (Greece) and Their Impact on the Regional Development
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Journal of Environmental Protection and Ecology 10, No 1, 244–265 (2009) Environmental management WATER RESOURCES MANAGEMENT IN THESSALY REGION (GREECE) AND THEIR IMPACT ON THE REGIONAL DEVELOPMENT S. SOFIOS, S. PolyzoS* Engineering School, Department of Planning and Regional Development, University of Thessaly, Pedion Areos, 383 34 Volos, Greece E-mail: [email protected]; [email protected] Abstract. Thessaly is a rural region and consequently, the economic development is affiliated with the primary sector of economy. The employment in this sector is related to the size of rural areas, while the agricultural products serve as raw materials to the secondary sector. Water resources constitute a basic factor that influences the quantity of rural production and consequently, the exploitation and their rational management play a decisive role to the economic development of region. The demand for irrigation water, which especially during the summer months is great, shows significant regional variations in water availability. The most important issue is that water resources are not sufficient, while a significant part of water volume leads, mainly during the winter months, unexploited to the sea. in order to overcome the water shortage, several hydraulic public works are implemented. The major hydraulic work is the diversion of the acheloos river to Thessaly. in this paper the economic situation of the Thessaly region, the demand and the supply of water resources as well as the prospec- tive being developed after the construction of the afore-mentioned hydraulic work are analysed. Keywords: water resources management, regional development, water policy, Thessaly. aimS and BaCkgRound The fertile plain of the Thessaly water region covers an area of 13 377 km2 that occupies the central section of mainland Greece. It is surrounded by high moun- tain ranges with altitudes of more than 2000 m (Pindos, Olympus, Pelion, Othrys, ossa and agrapha), encircling a low plain. The Pinios river, descending from the western slopes of Pindos, separates Thessaly in two, passes through the valley of Tempi and meets the sea. Thessaly borders Macedonia to the north, Sterea Ellada to the south, Epirus to the west, and its eastern shoreline lies on the Aegean sea. it has the highest percentage of flat land ing reece, and the mean elevation of the area is 285 m. * For correspondence. 244 Fig. 1. The Thessaly region Source: http://www.water-technology.net/projects/acheloos/acheloos1.html among the mountains, flows the Pinios river which drains into thea egean, after passing through the Tempi mountains. The drainage basin of the Pinios river is 9500 km2 and the main tributaries are the rivers Titarisios, Enipeas, kalentzis, Litheos, etc. The total length of the Pinios river is 206 km and the mean annual flow is 81 3m /s. However, during the summer the river is unable to supply sufficient clean water in view both of the reduced flow and the pollution by agrochemical, municipal and industrial effluents1. The Thessaly region also consists of two more water basins: the drainage basin of the lake karla (1050 km2), rising at the eastern side of the region, and the lake Plastira at the western side. The lake Plastira is a part of the watershed area of the acheloos river which belongs to the water region of West Sterea Ellada. The climate in the area is Mediterranean continental. Winters are cold and summers are hot, with a large temperature difference between the two seasons. The average annual temperature is 16-17oC. The average annual rain height is 700 mm, ranging from 400-600 mm at the central plains to 600-1000 mm on the eastern part, and to over 1200 mm on the mountains. Rain frequency is 100-130 days per year. The total precipitation is 10 426 hm3/yr and the mean annual relative humidity is 67-72%. Snowfall is very frequent on the mountains. impermeable geological structures cover 39.4% of the total area; karstic aquifers cover 16.2% and permeable structures, which occur mainly on the plain, cover 44.4%. The total water availability is about 3094 hm3, which consists of 2558 hm3 surface water and 506 hm3 groundwater. The groundwater, which can be found in the karstic and alluvial aquifers of the region and the entire plain of mainly neogenic sediments, is replenished by the Pinios river and its tributaries, and from direct rainfall infiltration. 245 The lake Plastira, with storage capacity of 400 hm3, is regulated for hydropower production. The installed hydropower capacity is 141 MW, and the power plant produces 250 gWh/year. industrial activities are limited in the cities of Volos and Larissa, and they involve mainly food processing, textile works and iron and steel production. Thessaly has a dense network of motorways and a seaport in Volos that serves the entire area. Concerning the difficulties for the implementation of 2000/60/EC directive in greece, various institutions and administrative authorities with different roles, competences, responsibilities and interests are involved. This is often the major factor of inefficient management of water resources.i n addition, the 2000/60/EC directive could set up major changes to rural sector, which consumes the vast majority of water resources, because the principle of full cost of water pricing could impact the farmers’ income2. In fact, a single authority does not regulate water supply in the region. The larger cities have their own water and wastewater services providers, but there is a number of independent local services, mostly affected through the municipalities, and thus, the pricing of water is a subject of political pressures. Public education for water conservation is limited, and cost recovery is on average poor with the exception of the larger cities. Monitoring results show that surface water in Thessaly is generally in a good condition. The nitrite concentrations in a small number of sampling points exceed the limit values for drinking water, due to the agricultural activities in parts of the drainage basin. in some sampling points, pesticide elevated levels are shown. although urban waste loads in the water are significant, urban wastewater treat- ment plants in the major cities of Thessaly safeguard the good quality of water. The treatment plants constructed in all the major cities of the area are efficient and 45% of the population of the area (80% of the urban population) were connected to the public sewer network by 1998. in the Thessaly region, the demand for water resources is exceptionally in- creased, particularly during the summer period. moreover, most economic activi- ties in the region under review are based on the existence sufficient in quality and quantity of water especially for irrigation purposes. The structure of production is based on cultivation of irrigated and non-irrigated areas (about 40% of agricultural areas is irrigated). The percentage mentioned above increases every year. The water demand for industrial and urban usage constitutes only a small percentage, about 5-6% of the total requirements3,4. Water supply is achieved using surface and underground water. in particular, the available and practically exploitable surface water potential includes the basins of the Pinios river, karla lake and artificial reservoirs of the Plastira and Smokovo dams. These basins are supplemented with smaller artificial reservoirs. The recover- able annual quantity of water from surface sources amounts in roughly 340 × 106 m3, while the irrigated agricultural areas amounts in 800 000 m2. This area has always 246 suffered an inadequacy in satisfying the increasing needs for irrigation purposes in agricultural areas (about 3 500 000 m2) given the shortage in water supply. The overexploitation of underground water resources, with continuous excavation of redundant drillings, legal and illegal ones, created new, more complex and hard to solve problems with economic and environmental dimension. indeed, between 1980 and 1995, about 23 000 drillings were excavated, while an unknown number of illegal drillings is not included3-5. The water horizon of the Thessalian plain is supplied through the infiltration of the surface water in the cones of rivers or torrents, in the areas where these descend in the plain. The natural supply of underground water can not substitute the water consumption from the drillings. Consequently, a continuous fall of underground water horizon is presented, in the greatest part of Thessaly3. in this paper, the general situation that prevails given the demand, the supply and the prospects in water resources in the Thessaly region are studied. Indeed the following section presents an analysis concerning the economic and the social situation as well as the importance of water resources to the regional economic development in order to be able to estimate the value of the significance of water resources to the region under preview. in the next sections, data about the needs of region in waters resources, the supply of water resources and the prospective being created after the implementation of the planned hydraulic work are given. The final section of the paper presents the general conclusions and proposals regarding the future of the region in frames of efficient management of allocated water resources. STRUCTURE OF THE ECONOMY OF THE THESSALY REGION The Thessaly region is in the geographic centre of Greece. It has a total area of 14 470 m2 (10.6% of Greece), and population residents (7.1% of Greece). It has been noted a 1.5% increase in the population since 1991 and remains the third largest region in the country population-wise, even though its growth rate is less than the national average for the period 1991-2001 (2.7% versus 6.7%). The mountainous part of Thessaly with absolute altitude over the 200 m has an extent of 9950 km2 (66.5% of the region) while the flat part occupies an area of 4520 km2 (33.5% of the region).