Background During the socialist regime, almost all the land of the Great Hungarian Plain was exploited by large scale intensive agriculture. This resulted in less fertile floodplains, the draining of inland waters and the large scale use of chemicals in agriculture. Consequently, the problems were as follows: - The diffuse nitrate contamination of groundwater, caused by the increasing use of chemicals for intensive farming, was polluting the riverine and marine areas. - The old drainage canals in the unused agricultural fields were causing desiccation of the area. - The Tisza river in Hungary used to be 1419 km long. It flowed through the Great Hungarian Plain, which is one of the largest flat areas in central Europe. Since plains can cause a river to flow very slowly, the Tisza used to follow a path with many curves and turns, which led to many large floods in the area. The control of the Tisza River, which started in the 1830s and was completed in the 1950s, radically changed the natural processes of the river. The new length of the river in Hungary was 966 km, with 589 km of "dead channels" and 136 km of new riverbed. The meandering character of the flow had been terminated and only 30% of its original length provided the riverbed capacity for the flowing water, resulting in an acceleration of the flow. The original floodplains had entirely disappeared, so the high water levels and floods had to be carried down the floodplain between dikes. Objectives The project aimed to implement an innovative water management system for handling the risks associated with very high floods, river contamination (eg. cyanide or heavy metals), nature conservation, agricultural production and integrated rural development, and was to involve all the relevant stakeholders. The project was to apply for the first time the FOK (natural depression in a flood plain) water regulation system, and a new land use system. The pilot project was located in the southern part of the 35.000 ha area of the Kis Hortobágy (also called Borsodi mezőség) in the Hungarian Great plain, bordered by the River Tisza. It was envisaged that the FOK method could be transfered to other areas of the Tisza river basin (Ukraine, Romania, Slovakia, Hungary and Yugoslavia). Results The project was successful in applying a FOK (natural depression in a flood plain) water regulation system and a proper land use system by establishing a natural water supply in the 35.000 ha Borsodi mezőség area. The following works were carried out during the project: - Reconstruction of an existing small capacity sluice at Tiszavalk obtaining a reversible sluice with a maximal capacity of 5-10 m/s of water importation from the river Tisza into the protected side. - Construction of smaller sluices for the regulation of water levels on the protected side. - Construction of a sluice gate with boat passage. - Regulation of the channel basins with dredging (about 20 kms). - Construction of dikes (about 3 kms). - Recultivation of areas. - Construction of a wide spillway to regulate water flow. - Silt removal from the channels. - Cement crest of flood-protection embankment. - Apart from the reconstruction works, flooding scenarios were run on DTM and maps detecting minimal and maximal water covers were prepared. The new water management system was also partly able to handle the occasional high floods in the area, which can reach a water level which is 8-10 times higher than the minimal level in the riverbed. Furthermore, the new land use plan was in keeping with the changed environmental circumstances following the introduction of the FOK system. The two main pillars of this plan are the extensive cattle breeding and fisheries whose operation is coordinated by the nature protection authority, the Bükk National Park. The demonstration character of the project is important because the complex water management and land use system can be applied in most of the Tisza River’s catchments area. Before the project, the land of Borsodi mezõség was dry and unproductive. After the site rehabilitation, the land can now be used for different purposes, ensuring incomes for the local population as follows: - extensive animal husbandry: 1 family farm / 100 ha = 300 - 350 family farms 3 - 6 persons / family farm = 900 - 2100 persons will have productive work and income - rural and green tourism (line-fishing, hunting, bird watching, rowing, etc.): generating approximately 5-7 % of the income of the population - handicrafts: 2-3 % of the income of the local population.