The unique ecosystem of the Danube island and side-arm is threatened by a rock-fill dam, which was constructed in 1982. As a consequesnce of this closing, the continuous waterflow has stopped in the side-arm that enabled fast sedimentation process. If no action would be taken, the island would grow together with the riverbank and it will disappear in some decades.
The rockfill-dam was constructed for river regulation purposes. Some years later two large capacity hydraulical delivery pipes were placed on the dam, therefore the dam is so high, that only the largest floods flow over it. Therefore during the year the side-arm is blocked and is mainly a standing water body with colmated sediment. The standing water and colmatation produces unfavorable living conditions for protected riverine fish species (e.g. Danube Roach, sterlet) that depend on the special hydraulical conditions of the side-arm in one or more phases of their life cycle. A naturally flowing river-arm can provide better conditions for drinking water supply, reducing this way the chemicals used for purification.
The project last between 1 January 2009 and 31 December 2013. Preparatory actions (technical design and permissions) ended in April 2011. Implementation of forestry activities started in the end of 2010, and the planting finished in February 2013 with nursery till the end of 2013. The dredging and the waterpipe relocation was done between July 2012 and April 2013, then finally the rockfill dam was disassembled.