Wstępna ocena wpływu zbiornika Mściwojów na przepływy w rzece Wierzbiak i głębokości zwierciadła wody gruntowej w terenach przyległych

The main aim of this paper is to evaluate the impact of the reservoir on regulating the flow of Wierzbiak river and groundwater levels in the neighbouring area. The paper contains the results of investigation and reconnaissance curried out at the area of Mściwojów storage reservoir from July 2007 to February 2008 . Mściwojów storage reservoir is located in Lower Silesia, near Wierzbiak river, at 35 + 375 of the river flow. The reservoir has been in use since year 2000. The main purpose of the reservoir is agricultural use but it also has some fire-fighting and flood control functions. The basement researches contain: measurement of water level in Wierzbiak river and the storage reservoir, groundwater levels measurement in neighbouring area of the reservoir as well as measurement of the speed of water flow in designated hydrometric cross-sections. The initial results of the researches indicate that Mściwojów storage reservoir has a significant impact on regulating the runoff at Wierzbiak river. A positive effect of reservoir on the groundwater levels in neighbouring areas has been also observed. The short period of detailed investigations and field observations does not allow to formulate of concrete conclusions. These investigations will be continued in next hydrological years which will also make possible analysing the influence of height and distribution of precipitation on values of flux and their variability in the studied hydrometric cross-sections of the Wierzbiak river. Detailed examinations of the top layers of soils in the upper catchment this river and periodical measurements of water quality in the Wierzbiak river, in the Mściwojów reservoir and groundwaters in neighbouring terrains will be also executed. Several years' investigations and field observations conducted this way will allow to give the detailed opinion on the influence of Mściwojów storage reservoir on regulation of fluxes in the river Wierzbiak, on flood protection and enlargement of water resources in this catchment, and also on the quality of water running off from the reservoir