Water management model for the purpose of providing water for irrigation systems in the Biđ-Bosut Field
The Biđ-Bosut Field (BBF) spreads on app. 3,415 km2, 83% of which lies in Croatia. For the largest part it is of lowland character, with only the westernmost part having upland character. In administrative terms, the BBF covers parts of Vukovar-Srijem, Brod-Posavina and Osijek-Baranja Counties. This report analysed the area bordered by the West lateral canal of BBF on the west, the Republic of Serbia on the east, the Vuka watershed on the north, and the Sava River on the south. The analysed area is characterised by a number of depressions with large reservoir capacities and a particularly developed hydrographic network with wide discharge profiles and particularly small longitudinal slopes. The main receiving body in this region is the Bosut River, and its most significant tributary is the Biđ watercourse. The entire region is characterised by a large number of interventions in the hydrographic network, resulting in a significantly modified natural water regime.
Since the BBF area is focused at the development of agricultural production, so far several irrigation projects have started that build on the abstraction of water from the existing hydrographic network, primarily the Biđ and the Bosut. Earlier design documents had analysed the possibility of providing additional quantities of water by abstracting it from the Sava River and storing it in the system, which is directly related to the construction of the multi-purpose Danube-Sava canal or the feeder drainage canal. However, storing the water in the canal reduces its discharge capacity, which directly affects the safety of the landside area in terms of high water protection.
The analyses made using mathematical models have indicated the need to reconstruct the control and regulation structures or the management methods in order to create preconditions for irrigation in agricultural areas where irrigation isn’t possible today due to insufficient water quantities, without disturbing high water protection. In addition, the criterion of using the water for irrigation has to be coordinated with the requirements for maintaining the environmental flow in the hydrographic network, as well as the functionality of the wastewater collection system. It is precisely the sophisticated quality of the water regime that implies the conclusion about the need to analyse in detail the demands of all the stakeholders related to the Bosut water regime and to very carefuly define the management criteria for the control and regulation structures in order to achieve optimum operation of the system in different hydrological situations in technical and functional terms, at all the points of the BBF which are in the zone of impact of the control and regulation structures.
