The Ipoly is the boundary line separating the region, the river basin of joint importance. The protection of the river, its joint water use, its environment and nature protection, its flood protection is of common interest. The joint activity enables the reduction of pollution, the exploration and preservation of ecological and natural values through the regulation of water uses. Up till now no channel survey of the same scale and extension has been prepared in the river basin concerning the flood inundation areas. Only the handover of the own data measured by the two parties takes place in the framework of transboundary cooperation. River basin planning resulting from the Water Framework Directive necessitates the integrated survey of the river: - for the joint elaboration of appropriate channel maintenance priorities - for the appropriate foundation of forecast, - for the operative flood preparation and for the - water management, environmental and nature protection planning On the other hand there are no utilisable surveys available in the present situation on the river, on its own status and its immediate environment´s status, the latest survey was conducted prior to the above mentioned regulation, in the 60-ies. Apart from the regulations of the Convention aiming at the protection and sustainable use of the Danube (Sofia, June, 1994) the transboundary waters conventions take already into account the Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 - the Water Framework Directive - when evolving operational activity. Achievements: The Ipoly/Ipeľ is the boundary line separating the region, the river basin being of common importance. The protection of the river, the joint use of its water, its environment and nature protection and its flood protection is of common interest. Previously no channel survey of the same scale has been prepared in the river basin concerning the flood inundation areas, therefore the goal of the project partners (KDV-KÖVIZIG and SVP) was to produce a professionally coordinated joint survey about the protection of the boundary river. Thereby the joint work could contribute to the reduction of flood risks, channel maintenance tasks, and to water management and river basin planning activities.