The purpose of the analysis in this article was to determine the conditions for establishing the discharge curve of the old mill dam construction in comparison to the gage located above the bridge. The analysed object – Siekierka, is located on the Zwoleńka river. It is located in the closing section of a partial research catchment. The reconnaissance scope covered the section of the river necessary to assess the impact of the upstream and the downstream flow conditions on the weir waterflow. This included the flow area in the upper reach of the object, the spill-weir construction and the area adjacent to the downstream section. The weir sill raised above the river bed shapes the flow conditions in the upper water section and in the line of the bridge passing. The bridge has a river bed protected from the erosion and the weir width does not exceed 10 m. For this type of bridges the accumulation of the upper water level is allowed as well as the subcritical motion may occur on the crossing section. High bottom water conditions occurring below the weir indicate that the capacity of the object largely depends on the hydraulic conditions of the weir outlet. The article includes the results of studies on determining the impact of the lower water area and the construction of the weir sill on the outflow.

The paper presents the influence of Suchedniów (V_NPP = 226,000 m³) and Rejów (V_NPP = 1,165,000 m³) water reservoirs, located in Kamionka catchment above Skarżysko-Kamienna, on the reduction of flood wave with a maximum flow intensity equals 50.40 m³ · s^-1. Analyzed flow hydrograph was obtained from measurements and observations conducted by the service of the Suchedniów reservoir from 26^thAugust to 6^th September 2010. Carried out the multi-variant analysis shows little effect the Suchedniów reservoir on the transformation of the flood wave at the current operating condition. In the case of Rejów reservoir, at the normal storage level, it is possible to reduce flood peak about 11.40 m³ · s^–1. Further increasing the efficiency of the reservoir, and thus safe running analyzed flood wave trough the town area Skarżysko-Kamienna needs to increase its flood control storage capacity.

Abstract: The aim of this work is to assess the influence of the landfill near the local earth masses streams, created during the construction of the S7 expressway route, on the silting of the water in Suchedniów. On the basis of direct field measurements, it was found that the amount of material in the reservoir from the road construction 2009–2011 amounted to about 7.8 thousand m³. Under normal operating conditions average retained in the reservoir is about 2.44 thousand m³. An additional amount of material hitting the tank significantly increases the rate of silting. In addition, there was also a partial loss of recreation, which served as „Suchedniów” reservoir. Fine sediments clayey material in large quantities in the Kamionka river inlet intended for use by the Sport and Recreation (marina, beach) prevented the opening of swimming in the 2010 season and hampered the use of floating equipment.

In the frame of performing control activities the workers of the regional water managements boards run often into problems concerning the right water management estimation according to issuing administrative decisions. These problems are concerned among other things reserve flow preservation in situation when the way of its realization is not defined, this paper presents the legal and the practical aspects of reserve flow realization and problems resulting from imprecise notations in water law permits concerning this flow.

Calculation of junction and bifurcation river joints is complex problem because of necessity of fulfilling of both balance equations of water flow and stream intensity, for changing simultaneously hydraulic and sediment transport values. A trial of finding of satisfying and universal method that could be used for different river joints was taken up. In the first phase the bifurcation river joint was calculated. After water division flowing in arms of a river behind bifurcation, sediment transport parameters were determined. These parameters were changing in sorting process, that makes possible fulfilling of fundamental condition as the balance of sediment transport intensity. In the second phase calculated parameters were entered the calculation programs of junction river joints. The results of calculations in the form of curves of both stream intensity (as the function of water flow) and course of equivalent diameters, expressing new composition of sediment transport in arms of a river behind bifurcation or in a main river bed behind junction along with the change of roughness coefficient were finally presented.