EN
The purpose of the study was to choose the water management alternative for the Upper Narew Basin, considering the conservation of hydrogenic habitats, in particular the Narew Landscape Park. Three main parts of the Upper Narew River Basin can be distinguished: Narew valley from the Siemianówka reservoir to the settlement of Suraż, which is a marshy area becoming dry-ground forest extensively used for agricultural purposes; wetlands of high ecological value within the Narew Landscape Park; and a drained part of Narew valley and Suprasl valley used for intensive agricultural production. For the purpose of simulation of alternative scenarios of the water management system performance, the model NAREW was developed. The model consists of two main parts: water allocation model based on Out-of- Kilter network programming algorithm and simulation submodels of different water users. The simulation studies were carried out using the historical data over the period of 1951-1985. Three groups of water management alternatives were analysed. The alternative called the „reference” alternative, mapped the situation in the Upper Narew Basin, before the Siemianówka reservoir was built. The results of simulation-optimisation computations for this alternative are a reference level for evaluation of the other alternatives. The alternatives called „environment friendly” assumed that the conservation of hydrogenic habitats was the priority task of the Siemianówka reservoir. Another group of alternatives under study was called „economic” alternatives. These alternatives assumed that the priority reservoir tasks were water supply to the City of Białystok, Łapy Sugar Factory and drainage-irrigation systems. The results of computation show that in the case of economic alternatives, supporting flows in Supraśl River from Siemianówka reservoir the environental goals can not be met. However if the channel connecting Siemianówka reservoir and Supraśl River does not operate most of the water user can be supplied and the hydrogenic habitats does not suffer the lack of floods. The detailed situation in the Supraśl catchment has not been analysed.