The anti-eutrophication protection of lakes requires limiting the inflow of nutrients to the water bodies and restraining the growth of algae and plankton. One of the ways to limit the size of algae populations in a lake is to maintain within the surface layer of water the flow conditions that are unfavourable for their growth. With this in view, it was proposed to install an aerator on the Zdworskie Lake (Gostyńsko-Włocławskie Lake District) to ensure a constant waving surface flow. The lake has been provided with barriers against the expansion of algae, and measures have been taken to prevent the water level from lowering and to limit the inflow of biogenic substances. The role of the aerator is to distribute water coming into the lake from the Dobrzyków pump station while maintaining a waving surface flow. Laboratory tests of the aerator were aimed at investigating the influence of diverse hydraulic conditions of the lake on the effectiveness of the device. This influence was modelled by changing the deflection angle of the aerator shield and varying its height and location against the water table.

The article presents the results of six-month public consultations on the basic planning documents for the planning process in water management for the years 2009–2015. The documents were presented for assessment to the general public in Poland by the President of the National Water Management Board in December 2008, whereas the discussion about the consultation process was limited to the area of activity of the Regional Water Management Board in Krakow (RZGW in Krakow). The article discusses the structure and content of the river basin management plans and the programme of measures. The latter consultation process results are divided into four basic categories: results of consultative meetings; results of opinion surveys; positions taken by advisory bodies to the Director of the RZGW in Krakow; and comments coming from the RZGW in Krakow, an institution which manages the water regions of the Upper Vistula, the Dniester and the Danube rivers.

The work was designed to visualise the propagation of pollutants in the compound channel of a river stream by releasing small light floating solid particles into a turbulent flow in a way allowing to trace them with video cameras (Particle Image Velocimetry). Obviously because the turbulent velocity fluctuations are irregular, the results of each trail differ. On average, the particles wander apart from each other and the rate at which they wander apart can be related to the diffusion coefficient. Experimental investigations of that kind were carried out using a 16 x 2.08 m hydraulic model, and their results are discussed in detail in the present paper.

The Ekman model used for describing and analysing wind jet-stream drifts caused by aerodynamic friction can also be applied in studies on large watercourses such as for example river mouths. There, in places with no tides, the influence of wind on the distribution of water vertical velocity can be observed. In this paper, the superficial velocities of water were calculated by Ekman’s model, and the wind-induced changes in the superficial velocity in watercourses were established using the tachoid (velocity curve) equation for the coefficient of turbulent viscosity exponentially changing with height. Various conceptions of the a parameter were assumed in describing the turbulence coefficient. The analysis was carried out assuming the conditions existing in the Lower Odra river.

In aim of limitation of erosion in lower part Dunajec river two water stages was designed. Preliminary analysis of influence of these objects on flow dynamics was executed. It the analysis under attention was taken energetic utilization of water stages, estimation of river bed stability and conditions of fish existence conservation.