Working accordingly to their tasks hydrodynamic structures tends to negatively modify the river bed disturbing its function as ecological corridor for migration of living organisms between separated areas laying up and down the river. To neutralize to the certain point the negative influence the hydro-technical structures has to be supported with devices helping the living organisms in the migration. The main problem on this structures is to handle the great difference between the water levels before and after the structure and with it a lot of potential energy. While accomplishing this main task as less as possible from available free space and discharge can be taken. The costs needs to be limited and the proper conditions for migration of living organisms have to be secured. Fish ladders are used for this purpose. Classical solutions in this constructions have proven to be unsuccessful and the biological fish ladders require a lot of space as well as unacceptable portion of discharge and are cost-ineffective. The optimal solution balancing usefulness and limiting the negative effects can be achieved be using the rock fishways.

Tributaries of large rivers are characterize by the substantive changeability along their length. While the upper parts of the mountain character with strong slope and bed build from gravel and pebble the lower parts already in the big tributary valley close to the river mouth meandering with small slope and bed with mostly sands and organic bottom coming from main river floods. Changed on short distance water movement conditions creates challenge for existence of plants and animals. But the ecological evaluations of the river as any of ecosystems can be to the certain point achieved through environmental indication using species witch can only exists in positively developed and differentiated ecosystem. The practical way to rich this aim is to obtain the information’s about hydraulic parameters of water movement on the analyzed river part and confront it with results from environmental indication. What kind of parameters can be used to describe the river and what is the human influence on them? Answering this questions takes the hydraulically and hydrological analyzing of water movement into consideration. The paper presents the analysis of water quantity and quality (temperatures) parameters in the Skawinka River on the lower part close to the mouth with the Vistula River where the thermal-electric power station of once-through cooling system returns water withdraw from Vistula. Long term retuning large amounts of water has changed and formed morphologically Skawinka bed and on the same time in upper parts of this stream and on its tributaries a positive ecological indication is been made proving its possible good water condition. How is it possible to evaluate this two opposite information’s? Is there an immediate thread for the endangered species and which of the water movement parameters shall by taken by this evaluation into consideration? –this are the issues aimed in this paper.

As a result of expoloatation of brown coal deposits in the Lęknica region (south-western Poland), which was performed here until 1974, developed the characteristic of anthropogenic reservoirs, folded of over 100 water reservoirs. The article presents results of hydrological balance calculations for some anthropogenic reservoirs and their drainage basins, which are located south-western part of lubuskie district, and created in effect of brown coal mining. The aim of this work was to analyze of water balance components diversification and their influence on quality of environment. The study showed that the annual balance open drainage basins reservoirs analyzed in anthropogenic reservoris in Lęknica has a negative retention (–14,14 mm), and positive retention – (+276,90 mm) for closed ones. Overall had a moderately negative water balance of the lake region, which indicates the possibility of restoration of individual tanks, but in limited extent.

The work included the development on the three types of objects which are: stone current with increased roughness, cascading stone current and the current with habitat elements. In this project, laboratory measurements and numerical modeling to determine the optimal speed in fishways was performed. As a result the current distribution and hindering of fish migration as well as the stability of bed material, was discovered. Based on the analysis of the results obtained from physical and computer modeling sensitive verticals were chosen to analyze the speed limit parameters. The aim of this project is to applicate obtained results into a computer algorithm for engineers establishing the pass conditions of selected fish with the determination of insurmountable zones. To facilitate the work of the program “Przepławka 1” is equipped with a graphical user interface supporting the process of entering and editing data and presentation of results. Data entry module analyzes their correctness, which reduced the risk of unexpected software crash and loss report.

Kunów is one of the oldest towns over the Kamionka river. The city and the adjacent areas, to the west and south, are limited by the Świślina and Kamionka river valleys. Going to the south of the city, you will find the Ciolek drain with its tributaries that drains rainwater from the catchment area of 4.17 km², that caused risk flood to Kunów city. Therefore, the implementation of a cascade of three reservoirs located in examined drains was considered. The article assumes that the dam of the dry reservoirs will be constructed as boulders of local stone in the troughs of residual streams, or gabions in the event of a deficit of thick stone or earth with drain and overflow. The calculations showed that the vessels of stonedams slightly affect the flattening of the wave, much better result was obtained in the case of flattening of the earth dams.

The results of shear strength parameters of soils from Chalakówka, Owczary and Szymbark are presented in the paper. Determination of the influence of moisture content on values on values of angle of internal friction and cohesion and assessment of usefulness of Matsushi-Matsukura method for evaluation of shear strength of unsaturated soils were the subject of the tests. Shear strength tests were carried out in standard direct shear box on samples of dimensions 60 × 60 × 19 mm. Results of tests revealed that the increase of moisture content causes decrease shear strength of tested soils, which mainly is caused by the decrease of cohesion. Values of shear strength determined using Matsushi-Matsukura method give good agreement with results of shear tests in case of majority of tested soils.