Possibilities of controlling the river outlets by weirs on the example of notéc Bystra River

Abstract

The possibility of effective control of selected dams in the Notéc Bystra river is analyzed. Such a control is expected to permit inundation of selected arable areas, e.g., peat grasslands, to avoid flooding of the city of Czarnków and the terrains located downstream. The chosen case study is the reach of the Notéc River between the dams Pianowka-Mikolajewo-Rosko. The analysis was made on the basis of simulations of the flow and regulation of dams in flood conditions. The flow peaks of hypothetical flood waves were designed according to the directions of the ISOK project (Informatyczny System Oslony Kraju przed nadzwyczajnymi zagro?zeniami-IT System of the Country's Protection Against Extreme Hazards) as the maximum flows over 10-years (p = 10%), 100-years (p = 1%), and 500-years (p = 0.2%). The obtained results are presented as longitudinal profiles of the water surface, maps of inundated areas and maps of inundated soils. The main conclusion is that the robust control of dams reduces the peak of flow during flood wave propagation and forces inundation of the a priori selected areas. It helps to decrease the spatial range of the flood hazard and significantly reduces risk related to floods.