Small Water Reservoirs – Sources of Water or Problems?

Abstract

The design of small water reservoirs in Slovakia and neighbouring countries has common origins in the middle of the last century. Most of them were an alternative source of water for irrigation of field crops. Nowadays, we have to face new problems, such as the problems with the design of hydrological data and real current discharges, the problems with original and new design of the flood wave for the solution of the safety overflow. All of Q 100 flows recorded nowadays are much higher than those which had been designed and built. The safety overflows no longer answer the purpose of the contemporary flows. The problems with the Framework Directive are also importantsmall water reservoirs are not resolved in the Directive as the water bodies of stagnant water because they have an area of less than 0.5 km 2. The same problem is also with the preservation of continuity of the flow and the fact that they should let the fish pass. Unfortunately, the state, administrators of small dams, operators and nature conservationists have different points of view on the above-mentioned problems. The article elaborates these problems and suggests possible solutions to the problems.

Hydrological Performance and Runoff Water Quality of Experimental Green Roofs

“…where is the matrix suction of the soil [L], while on the lower boundary the boundary conditions change from the state of zero flux for unsaturated soil conditions to the state of zero pressure for saturated soil conditions and in consequence free outflow is realized (8).…”

“…The fundamental problem in this case will be a multiple increase of runoff from impermeable surfaces compared to the biological surface, and hence the control of storm water runoff is of key importance for the limitation of the effect of urbanisation on water cycle in these conditions, and it will also be one of the adaptation strategies of cities to climate change [1][2][3][4][5]. Various practices are known, consisting in the management of the runoff of rain waters, including all forms of recreation of green areas, restoring to a varying degree the hydrological properties of areas [6][7][8]. The design of green roofs and the use of the unique abilities for e.g., reduction of runoff are of special importance in addressing the problems of progressing urbanisation, as their use is not restricted by the availability of space, and their construction on newly designed, and existing buildings may mean the utilisation of as much as 40% of non-permeable surfaces in urban areas [9][10][11][12][13][14].…”

New Challenges in Rural Water Management in Poland – Selected Problems

“…Polish water balance analysis shows that the annual average production of biomass from agriculture consumes 65 billion m 3 of water of about 180-185 billion m 3 annually which comes from precipitation, which means high absorption of water in food production. Intensification of agriculture, including increased irrigated area (vegetables, orchards, meadows in river valleys) and increase the production of biomass for energy purposes and projected deficits associated with drought can be evaluated increase in the amount of water needed for agriculture to 10-20 % in 2030.…”

Design and Development of Low P-Emission Substrate for the Protection of Urban Water Bodies Collecting Green Roof Runoff

“…In urban areas, sources of phosphorus (P) in stormwater runoff originate from lawn fertilizers, atmospheric deposition, soil erosion, animal wastes, grass litter, soil microbial communities, vegetative detritus, and detergents [1][2][3]. Urbanization generally leads to higher phosphorus concentration in urban catchments, what is seen in both total phosphorus and dissolved phosphorus concentrations [2,4,5].…”