Water Quality State in the Hydro – System Danube – Tisza – Danube*

Dragana Milijašević, Jovana Brankov,Ana Milanović, Geographical institute ”Jovan Cvijić“, Serbian Academy of Sciences and Arts, Belgrade, Serbia

Apstract Hydro – system Danube – Tisa – Danube is a unique system of channels for drainage, irrigation, fishing, transport, tourism, water supply of settlements and industry. Channel system runs on about 12 700 km2 between the rivers Danube and Tisa in the north of Serbia (Vojvodina). Total length of channel is 929 km. Water quality examines the Republic Hydrometeorological Service of Serbia. The problem of pollution and protection of surface water must be specially treated, since it is one of the most valuable water resources in the area. The aim of this paper is to analyze existing state of water quality in the Danube – Tisa – Danube hydro–system and suggest measures of protection.

Key words:hydro – sistem, Danube – Tisza – Danube, canal, water quality

Introduction

Small amount of rivers were formed in Vojvodina, because of its plain-like terrain, high air temperature, higher water evaporation, low quantity of rainfall (annually about 600mm) and the length that rainfall passes to the nearest water flows. This deficit is compensated with the abundance of transit waters, which are significantly more present in Vojvodina than in other parts of Serbia. This knowledge should be taken into consideration in the assessment of waterpower importance of rivers in Vojvodina, planning of their protection and the policy of economic development (Bjeljac, Kovačević, Milanović, 2003). Vojvodina, situated in southern part of Pannonian plain, has big water resources in the surface waters of the rivers: the Danube, the Sava and the Tisza, as well as in the developed canal system Danube- Tisza- Danube. The system of canals stretches over about 12 700 km2 between the Danube River and the Tisza River, in the regions of Vojvodina –Bačka and Banat in north Serbia. Disastrous floods and even more frequent droughts in this region have endangered the existence of population for ages. Hydro-land-reclamation measures started in the sixth and the seventh century, but even after 13-14 centuries they have not given the wanting results. In the period from 1958-1976. the reconstruction was made, as well as new canals in the existing system of canals which were made even during the time of Austria-Hungary. Eighty-four bridges were built then- 62 carriageway bridges, 19 railway and 3 pedestrian ones. A dam was raised at Novi Bečej on the Tisza River, as one of the most important constructions. The total length of the canal is 929 km, including new and old canals and tributaries which were partly, or as a whole, integrated into the system of canals. In the canal network there are 51 objects (24 gates, 16 locks, 5 safety gates, 6 pump stations and 180 bridges). The Danube-Tisza-Danube hydro-system enables drainage of 760000 ha in Vojvodina. The greatest success in drainage of Banat was achieved by cutting the watershed between the Tamiš River and the Karaš at Potporanj, by which excess water turned from marshes of Vrsac and ran off into the Danube. The most important drainage canal in Banat are Kikinda`s canal, and Novi Bečej-Botoš-Banatska Palanka, and in Bačka: Bački Petrovac-Karavukovo and Jegrička. (Bjeljac, Radovanović, Milanović, 2004). The canals of the system DTD enable irrigation of 510000 ha. The degree of their use is very small and it is 10%. The reasons for this are: the lack of modern equipment for irrigation, the lack of experts for exploitation of hydro-system, insufficient intensity of agricultural production etc (Stojšic, Bugarski, 1997). Inland navigation is possible on the length of 603,7 km, and in the system of canals there are 14 ports for loading-unloading of the freight (Dukić, 1967).

* Paper is a part of the research within the project 146011, supported financially by Ministry of Science and Technological Development of the Republic of Serbia BALWOIS 2010 - Ohrid, Republic of Macedonia - 25, 29 May 2010 1

The most important rivers and the canals of the DTD drainage basin

The biggest and the most important river on this area is the Danube which flows through Serbia on the length of 588 km. According to its natural characteristics its flow can be divided into 3 different sectors: Pannonian, Djerdap and Pontic (Gavrilović, Dukić, 2002). The Danube in the Pannonian sector has average fall of the river canal for 0,05 m/ km, the average velocity of the water is 3-4 km/h, and the average discharge is about 3500 m3/s. (Bjeljac, Kovačević, Milanović, 2003). The Tisza River is the largest tributary of the Danube and it flows through Serbia on the length of 164 km (Gavrilović, Dukić, 2002). The Tisza River has very small fall on the middle and the lower part of the basin, in average 4,57 cm/km, which causes increased intensity of lateral erosion and the formation of winding riverbed. In the past it often caused minor or bigger floods in Potisje, and somewhere even- the formation of marshes and spongy ground. Cutting of 136 meanders (23 on our territory) shortened the flow for 453 km or 31,9 %, which caused the increase of river fall and the velocity of its runoff into the Danube. The velocity of the water on the Tisza River is small and it is about 1 m/s. The value of average discharge is 870 m3/s. (Bjeljac, Kovačević, Milanović, 2003). High water level of the Tisza River is in April, because of snow melting from the Carphatians Mouintains, and the lowest water level is in October. During the high water level The Tisa River influences the level of water on the Danube River.

Table 1.– Hydro – sistem Danube – Tisza - Danube Canal name Overall length (km) Navigable(km) Begeč – Bogojevo 90,0 90,0 Vrbas – Bezdan 90,0 89,9 Novi Sad – Savino Selo 80,9 80,9 Bajski kanal 39,1 39,1 Odžaci – Sombor 12,7 12,7 Bački Petrovac – Kravukovo 52,0 52,0 Prigrevica - Bezdan 31,7 31,7 Kosančić – Mali Stapar 21,1 21,1 Jegrička 65,4 - Banatska Palanka – Novi Bečej 147,3 147,3 Begej 34,6 34,6 Plovni Begej 31,4 31,4 Stari Begej 37,1 - Kikindski kanal 50,3 32,0 Zlatica 35,0 - Tamiš 116,8 3,0 Karašac 5,8 - Brzava 19,9 - Moravica 17,4 - Rojga 12,6 - Total 929,0 603,7

Other rivers cut their valleys in the river terraces and loess plateaus. Contrary to the Danube and the Tisa which during the whole year have lot of water, smaller rivers dry up during summer or partly turn into bogs, while in spring and in rain seasons significantly rise. It will be mentioned some smaller rivers: the Čik River, the Krivaja River , the Mostonga River, the Zlatica River, the Begej River , the Tamiš River, the Karaš River and the Nera River. The route of the main canal of the hydro-system Danube-Tisza –Danube starts from Bezdan, where large electric sluice gate was constructed, and then it goes in the direction Prigrevica-Srpski Miletić- Savino Selo-Vrbas and it continues until the entry into the Tisza River at Bečej. This part of the hydro- system is known under the name Veliki Bački Canal. Downstream from Novi Bečej, on 62 km from its confluence with the Danube, the Tisza River is dammed with large sluice gate with ship lock. The sluice gate enables gravitational turning of the necessary quantity of water in Banat`s part of the route of the main canal, which then goes into direction Novi Bečej-Jankov kamen-Klek-Botoš (here canal is

BALWOIS 2010 - Ohrid, Republic of Macedonia - 25, 29 May 2010 2 cut by the Tamiš River)-Potpotoranj-Banatska Palanka, where canal enters the Danube River. The branches of the main canal were constructed in such way that river canals, bogs and other recesses in the ground are maximally used. That is how the canals of the Mostonga River, the Jegrička Bara, the Zlatica River, the Galacka River, the Stari Begej River, the Tamiš River and the Karaš River were used. The network of the main canal also included already existing canals, whose muddy canals were deepened, as well as canalled flow of the Begej River (Dukić, 1976).

Figure 1. Water quality of hidro – system Danube – Tisza – Danube in measuring profiles

Irregular and unequal quantity of river water created huge problems during the whole year. In time of maximal water levels, rivers drained, flooded inundation planes and went deep into the areas of low altitudes. This water remained almost during the whole year and damage the cultivation of soil. The biggest floods were when the maximal water level of the Danube River was decreasing in time of the maximal water level of the Tisza River, or when the maximal water level of the Tisza River was late and it coincided with the maximal water level of the Danube River. Then the water accumulated at Đerdap`s gorge, runoff was slowed down and vast quantity of water overflowed not just alluvial planes but river terraces as well, all of which caused disastrous floods. At the same time, with high water level of rivers, groundwater appeared on the surface. It also caused floods. Terrains which were flooded by groundwater were considerably lower than surrounding ground, so there were no runoffs towards the rivers.

The quality state of rivers and canals in DTD system

Although the emphasis in this paper will be directed to the canals of the DTD hydro-system, in the beginning of this chapter it is necessary to briefly give the state of the water quality of the most important rivers on this territory. When the Danube River is concerned, Serbia is one of the rare countries of the Danube River Basin which can commend that on its territory the quality of the Danube water has been improving. The measurements which are regularly performed by the Republic hydrometeorological Service of Serbia (RHMZ) show that according to the objective criteria the quality

BALWOIS 2010 - Ohrid, Republic of Macedonia - 25, 29 May 2010 3 of the Danube water on the exit from Serbia is significantly better than on the entry. This comes from the fact that the pollution of the Danube River, which is created on the territory of Serbia, is considerably lower than the ability of self-purification of the Danube flow (at some extent thanks to the accumulation in Đerdap which acts as big depository). The situation would be even more favourable if some of the Danube tributaries, on whose quality Serbia cannot have big influence, were not in bad quality state. (the Sava River, the Tisza River, the Tamiš River, the Velika Morava River ) (Ocokoljić, Milijašević, Milanović, 2009). When the water quality is in question, Serbian part of the Danube can be divided into two sectors, upstream, Pannonian part (from Bezdan to the Sava River mouth), where the Danube is more polluted and has characteristics of the third, and more rarely the fourth class and the downstream (Pančevo-Bulgarian border), where the Danube is a little bit more purified with mostly the third and the second class of the river water quality (Ocokoljić, Milijaševiš, Milanović, 2009). The ecological state on the Tisza River is very bad and it is one of the most polluted flows of the Pannonian plain. Its waters are mainly in the third or the fourth class, and in the analyzed five-year- long period of research (2003-2007) the second class was not found. The Tisza River comes from Hungary with the third class but it empties into the Danube sometimes even with the forth class. Therefore the quality of its waters is somewhat worsened in Vojvodina by the influence of industry, agro-technical measures, water power infrastructure and especially by the canal network. From the harmful substances iron and increased concentration of mercury were found (RHMZ,2007). Also, saprobiological state of the river Tisa is unfavourable. Organic pollutions with saprobity index from beta–mesosaprobic-alpha-mesosaprobic zone, or more precisely from the second to the third class of bonitet. (RHMZ, 2007). In the five-year –long period from 2003 to 2007. deterioration of the water quality of this river was registered in relation to the period of nineties of the previous century (Ocokoljić, Milijašević, Milanović, 2009). The Tamiš River flows from Romania and its waters are extremely overloaded with industrial waste waters from both Romania and Serbia. The Tamiš River is in its total flow through Serbia (118 km) one of the most polluted rivers. It enters our country as completely degraded water flow, mostly with the fourth class, and it is often according to the analyzed parameters a classless river flow. The state of the Tamiš water is insignificantly improving, from the third and the fourth class on the border and Botos, remaining in the third or the fourth class in Pančevo. If the condition of the Tamiš waters does not improve, in the future it can be used only as the navigable waterway. For a long period water of the Begej River was in the third class (Dalmacija, Ivančev-Tunbas, 2004). Increased concentration of organic substances in the Begej water is result of discharge of unfiltered industrial and fecal waste waters of Temisvar and Zrenjanin. Because of its small discharge and insignificant water velocity, the Begej River has small power of self-purification, so it cannot overcome entered load. The Begej River, from the biological standpoint, is classified in the most polluted water flows on our territory. Apart from the aforementioned river flows, the Republican Hydrometeorologic Service of Serbia also makes systematic analysis of the water quality on the established profiles in the basic canal network of the DTD hydro-system on the following routes: -route Vrbas-Bezdan, on the profiles Sombor, Mali Stapar, Vrbas I (upstream from the sluice gate) and Vrbas II (downstream from the sluice gate); - route Bečej-Bogojevo, on the profiles Savino Selo, Srpski Miletić and Bačko Gradište; - route Novi Sad-Savino Selo, on the profile Novi Sad; - route Bački Petrovac-Karavukovo, on the profiles Bač and Bački Petrovac; - canal Jegrička on the profile Žabalj I; - canal Kikinda on the profile Novo Miloševo; - route Banatska Palanka-Novi Bečej, on the profile Melenci, Vlajkovac and Kajtasovo; - canal Nadel on the profiles Uzdin and Starčevo; According to the data from the table 2, it can be concluded that the best water quality in the canal network is registered on the profiles Vrbas I and Novi Sad I. On the profile Žabalj I, the analysis of the water quality shows the forth class. The worst quality is on the measuring profiles Vrbas II, Bačko Gradište and Bač where in the five-year-long period (2003-2007) classless state was registered. The tendencies on the analyzed profiles in this hydro-system generally show that the water quality is without some larger changes in the analyzed period.

BALWOIS 2010 - Ohrid, Republic of Macedonia - 25, 29 May 2010 4

Table 2. – Water quality in canals for period 2003-2007.

2 2 pH HPK Smel BPK-5 Colour Colour %of O %of substrate substrate The most The most Dissolved Dissolved saturation supstance Suspended Suspended Actual class class Actual Dissolved O Dissolved Station name Station name of coli germs of coli germs Required class Waste substrate substrate Waste probably number number probably Saprobity degree degree Saprobity

Mali IV IV III II II II II II I I I I III/IV IIA Stapar

Vrbas 1 II VK III III II II/III II/III II II I I I III IIB

Vrbas 2 VK VK VK VK III IV IV II III I - VK VK IIB

Srpski III IV III I/II II III II/III II I/II I I I III/IV Miletić IIA

Bačko VK VK VK IV II III IV II IV I I - VK IIB Gradište

Novi Sad III VK III I II III II II I I I I IV IIA 1 Bač IV VK IV I/II II II II/III II I I I I IV/VK IIA Žabalj III III III/IV III II II/III III/IV II III I I I IV IIB Vlajkovac III III III I/II II III VK I/II I I I I III/IV IIB

It is characteristic for the canals that they are formed as slow-flowing water flows with weak aeration. The result of this is a change of the content of the dissolved O2 in them from the occurrence of supersaturation to the deficit. The best water quality in the DTD is close to the water intake from the Danube. Considerably poorer quality of water is on the profiles: Vrbas I and Novi Sad, where increased organic load is registered, then increased concentration of mineral forms of nitrogen (on Novi Sad route), and sometimes phenolic elements: Hg, Mn, Cu and Fe. The most unfavourable situation is at Vrbas II after the inflow of the waste untreated waters of settlements Vrbas, Crvenka and Kula, where the water quality is completely degraded (classless).

The sources of pollution of the DTD canal

Water polluters in the DTD hydro-system can be classified into concentrated and dispersed polluters. Concentrated polluters are mostly urban settlements with sewerage systems, industrial and energetic objects, agricultural objects for cattle fattening and organized dumps. Dispersed pollution includes: chemization of soil with pesticides and mineral fertilizers, unorganized dumps of the industrial and communal waste, atmospheric precipitation (acid rains), traffic and settlements without sewerage system. In the structure of registered polluters of the DTD canals -the first place takes industry, after that agriculture, and then settlements and other polluters. In the last group are medical facilities (spas), users of thermal waters, workshops for repairs of traffic means etc. Industry – Industry influences the quality of surface and ground waters in industrial regions, as well as the quality of soil. Approximately 90% of all industrial waste waters are discharged without previous treatment in the rivers and lakes, i.e the main recipients. The lack of appropriate management of industrial waste has great influence on the ground waters and soil (Lješević, 2002a). The biggest polluters according to the quantity and concentration of harmful substances are: refinery (Novi Sad), chemical industry and metallurgy plants (“Agrohem” –Novi Sad), food-processing industries (in Novi Sad - meat industry “Neoplanta”, in Vrbas oil industry “Vital”, meat industry “Karneks”, sugar factory “Bačka”, in Crvenka - sugar factory, in Bačka Topola- agro-industrial combine and other). The status of very harmful polluters have leather factory “Eterna” and armature

BALWOIS 2010 - Ohrid, Republic of Macedonia - 25, 29 May 2010 5 factory”Istra” in Kula, considering the fact that their waste waters are rich with chromium, nickel, zinc, copper and other heavy metals. Agriculture – The influence of the agricultural production on the quality of water flows is complex and it is manifested through chemical pollution of soil and ground waters due to the uncontrolled usage of various pesticides, but also through the influence of cattle breeding, that is cattle farms. When the cattle farms are concerned the effects can be bigger owing to the fact that “degree of the pollution, caused by liquid waste from the farms, pollute water 150 times more than commune waste waters” (Lješević, 2002 b). From bigger farms in the zone of the DTD canals the following stand out: Vrbas (35.000 cattle heads) – DTD canal, Pannonia (20.000 cattle heads) – Кrivaja – Zobnatica accumulation, Srbobran (17.000 cattle heads) – Кrivaja (Miljanović, Kovačević, Milanović, 2004). The settlements – Depending on the realized degree of the public supply of the settlements (heating system, (un)constructed water supply and sewerage network, traffic, organization of green areas, controlled tip), different degrees of canal pollution in the DTD system will appear. Big problem in the zone of the DTD hydro-system is the fact that only 30% of population is connected to the public sewerage system (The group of authors, 1995). The other part of population disposes their waste waters through the ground, through septic tanks or in some other way. Releasing untreated waste waters from industry and households, pollution from agriculture and inflow over the border are the main causes of surface and ground water pollution in the DTD Canal Zone. The example of the most polluted canal in the DTD system is Veliki Bački Canal, which runs from Bezdan to Bečej. At the same time it presents one of the most polluted water flows in Europe. Instead of being use for drainage, irrigation and supplying the industries and fish ponds with clean water, it was often called “dump of death” because of the reasonable doubt that it is a cause of fatal consequences for human health. Therefore, this canal is an object of interest for numerous international organizations. So, The Norwegian Institute for Water Research made the study for analyzing water and mud quality in canal, and the Dutch government invested about 2 million euros in financing the project of treatment of the Veliki Bački Canal. According to the values of BPK5 in waters of Veliki Bački Canal on the location of the measured profile Vrbas II, it was established that the water is at great extent far from the forth class (table 2). In the autumn period the level of content of the organic substances in communal waters reaches high value. Dramatic increase of content of organic substances in canal water in autumn period is a consequence of the work of two sugar refineries which discharge partly treated waste waters into lateral canal and then in Veliki Bački Canal. Only Vrbas discharges more polluted water than whole Novi Sad, and slightly less than Belgrade. This amount of pollution, contributed with, beside the aforementioned, some other industrial and communal polluters as well, Veliki Bački Canal cannot neutralize because of its limited flow power which can maximally reach 25 m3/s. Additional problem is large quantity of mud accumulated in the canal, which contains ions of metal (iron, lead, cadmium, zinc, copper, chromium and manganese). It is scientifically proven that nitrogen and phosphorous from Veliki Bački Canal reach the Black Sea which indicates that even wider Danube Drainage Basin is polluted as well.

Conclusion

The lack of adequate devices for the waste water treatment in factories and unplanned process of urbanization which did not solve the problem of evacuation of the waste waters presents main causes for river and canal pollution. This problem is especially expressed in Vojvodina because of the large number of transit rivers, whose lower parts flow here. These rivers, already at great extent polluted, enter our territory which additonally makes the works on treatment and maintenance of our river resources difficult. The Danube enters Serbia as the river of the second class, but when it receives industrial and sewage water of Belgrade and Pančevo, as well as polluted Sava River, it moves into the third class. The Tisza River comes to the territory of Vojvodina polluted with mainly industrial and agricultural waters, so it is mostly in the third or the fourth class, as well as the canals of the DTD hydro-system (some canals are even classless according to their water quality). Although there are some laws and regulations in our country, it has not been done a lot on the water protection till now. Negligent relation of people towards rivers and light sanctions for not obeying law regulations certainly contributed to it. The solutions in terms of water quality protection and environment in general are in the construction of appropriate devices for the waste water treatment, but also in the concept of “water intake downstream from the place of waste water discharge of the same user”. It should be worked on development of human conscience about general and universal protection of water resources, not on partial, as rivers do not end on national or other borders. One of the special measures is creation of local ecological action plans since they define concrete measures- related to municipality or each problem individually, carrying out of detailed researches,

BALWOIS 2010 - Ohrid, Republic of Macedonia - 25, 29 May 2010 6 measurements as well as monitoring the condition. In such way local community more efficiently involves into solving concrete problems. Therefore it is one of the most efficient measures for solving the problem of pollution of environment.

References

Bjeljac Ž., Kovačević J., Milanović A., 2003: Aspects of using on plain waters resources, Monograph of the conference ”Environmental protection of cities and suburbs”, Ecological Movement of Novi Sad, Novi Sad Bjeljac, Ž., Radovanović, M., Milanović, A., 2004: The River Water Resources of the Plains of Serbia: Theirs Utilization for Agriculture and the Generation of Hidro-Electricity and Some Ecological Implications, The rational Use and Conservation of Water resources in a Changing Environment, International Conference, IGU Commision for Water Suistanabillity, Yerevan State University, NGO International Scientific research Center on Water, Climatic and Recreational Resources, Yerevan, Yermenia Dalmacija B., Ivančev – Tumbas I., 2004: Water analysis – quality control, interpretation of results, University of sciences, Department of chemistry, Novi Sad Dukić D. 1967: The hydro – system Danube – Tisa – Danube, Bulletin of the Serbian geographical society, tome XLVII, N0 2, Belgrade Gavrilović Lj., Dukić D., 2002: Rivers of Serbia, Institute for publishing textbooks, Belgrade Group of authors 2002: Analysis of the amount and characteristics of waste water from the cadastre of industrial pollutants, University of sciences, Department of chemistry, Novi Sad Group of authors 1995: Cadastre of waste water in the territory of Vojvodina, University of sciences, Department of chemistry, Novi Sad Lješević М. 2002а: Environmental Science - Urban Ecology, Faculty of Geography, University of Belgrade Lješević М. 2002b: Environmental Science - Rural Ecology, Faculty of Geography, University of Belgrade Miljanović D., Kovačević-Majkić J., Milanović A., 2004: Еnvironmental Аnalysis in the Zone of Corridor X in Serbia, Bulletin of the Serbian geographical society, tome. LXXXIV, N0. 2, Belgrade Ocokoljić M., Milijašević D., Milanović A., 2009: Classification of Serbia according to the theirs pollutions degree. Collection of the papers, vol.LVII, Faculty of Geography, University of Belgrade. Stojšić, M., Bugarski, N., 1997: Hidrosistem Danube – Tisza – Danube and its role in environmental protection, Monograph of the conference ”Environmental protection of cities and suburbs”, Ecological Movement of Novi sad, Novi Sad Hidrological yearbook – Water quality, tome III (2003-2007),Republic Hydrometeorological Service of Serbia

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