The paper deals with examination of financial profitability of the introduction of rainwater utilization system (RWUS) in multi-family residential buildings. The aim of the work was to build a simulation model of such system and mak_e an LCC analysis of some options of rainwater utilization system. The proposed conception of a new method of selecting the most cost-effective option of RWUS includes: building of simulation model of such system, making the LCC analysis and using a scenario analysis for supporting decision making process with uncertainty. This new method has been applied to a dwelling house in Poland. The results obtained from the analysis demonstrate the unprofitabiliry of the introduction o fRWUS in multi-family residential buildings for the adopted location in Poland. The presented method can be used by individual designers and managers to decide on the selection of the most appropriate water supplying option for a specific location.

As part of the work, experiments were carried out on a laboratory scale to assess the effectiveness of the use of composite capsules based on halloysite and sodium alginate for the adsorption of copper from rainwater. The halloysite was subjected to acid activation prior to the encapsulation process. The characteristics of the capsules obtained were determined by means of SEM surface imaging, nitrogen adsorption by the BET method and pH PZC measurement by the suspension method. Adsorption was studied using various operational parameters such as adsorbent dose, contact time, pH and concentration of copper ions in the rainwater. A high percentage of copper ions removal was demonstrated, i.e. 72% for halloysite (H), and 83% for activated halloysite (HA) for a dose of 2.0 g/L. Adsorption of Cu (II) was consistent with pseudo-second order kinetics. The adsorbents showed a high adsorption capacity at the level of 11.03 mg/g, determined by the Langmuir isotherm model. This model fit well with the experimental data.

The aim of this study was an assessment of feasibility of conversion of sewage holding (SH) tanks to rainwater harvesting (RWH) tanks in Poland. Such a conversion may partly solve the problem of water scarcity for irrigation of plants in individual small gardens and reduce tap water consumption. Seven methods of RWH tanks sizing were applied to an example of a small harvesting system of the roof area equal to the garden irrigation area of 100 m² for three different irrigation doses. A new criterion was introduced to optimize the tank capacity. Economic optimization was provided for new RWH tanks and for the tanks adapted from abandoned SH tanks. Results obtained for a system sited in west-central Poland in an average year have shown that design capacity of RWH tanks varied markedly between sizing methods. The conversion of SH tanks to RWH tanks is profitable, especially for irrigation due to scarcity of water in relatively dry west-central regions. Conversion of individual SH tanks in a good technical state to RWH tanks is relatively simple and cheap. The potential increase in storage volume due to the conversion of individual SH tanks to RWH tanks could reach all over Poland 215–350 dam³ per year, and individually can save up to 18–25% of total annual water use.

The paper aims to answer the following questions: What are the trends in streetscape design? And how can streetscape become more resilient to climate change in the coming years? Although the research questions of exploratory nature also challenge theoretical claims, this is a hypothetical study, designed to foster a discussion about the visions of the future streetscape and new technology for an urban sidewalk. It covers a description and a cross-case comparison of an experimental product – the Climate Tile, implemented in Denmark in 2018, and a theoretical solution – the Sponge Pavement – a model system based on the structural soil foundation and permeable surface, evolved as an idea in 2018 in Poland. The cases are examples of innovations selected to describe a new type of water-permeable surfaces matching the urban context. Both solutions share common features: they are in that there is no need to place heavy equipment on the project site; they match the urban context of a dense city, being smooth, resistant and easy to clean. The comparison of the Climate Tile and the Sponge Pavement allowed determining the optimal application for the given solution. It also proved the trend towards the rainwater management-oriented direction of the development of the streetscape of the future. The study results could contribute to the discussion of the streetscape of the future. We would like to focus on the idea of the Sponge Pavement for further development in laboratory tests and as the pilot project.

European cities face urban, demographic and climate challenges. According to forecasts, annual extreme phenomena will intensify – including torrential rains. Comprehensive solutions (also those based on nature), climate adaptation strategies, runoff management, incorporation of new design (e.g. sponge cities) are urgently required in order to strengthen urban resilience and to minimise the effects of extreme weather events (droughts, floods or heat islands).
The aim of the research was to develop a methodology for activating selected elements of blue-green infrastructure within areas of natural and cultural protection as an adaptive tool of urban planning. Modelling of infiltration possibilities, programmed with SCALGO Live Poland software, was performed as a case study based on a research city – Sandomierz (in Poland). Selected parameters (stormwater surface runoff, chosen runoff areas, land cover) are strongly correlated with urban indicators relating to the vegetation coverage (biologically active area – BAA).
Results pointed out urban units, which BAA is lower than 25% (e.g. Old Town Square, courtyards of tenement houses). Modelling was carried out for these units by concentrating on the undeveloped area for which the BAA was increased. The enhancement assumed values in the range of 41–45%. In analysed cases, an improvement (decrease) in runoff volume was obtained, even by 8.69%. Simultaneously, infiltration increased by 19.61%, calculated over entire runoff area. Implementation of solutions based on these results, in the form of appropriate planning provisions, can raise the quality of environment (e.g. improving water infiltration) and life (e.g. more effective air cooling on hot nights).

Scarcity of freshwater is one of the major issues which hinders nourishment in large portion of the countries like Ethio-pia. The communities in the Dawe River watershed are facing acute water shortage where water harvesting is vital means of survival. The purpose of this study was to identify optimal water harvesting areas by considering socioeconomic and biophysical factors. This was performed through the integration of soil and water assessment tool (SWAT) model, remote sensing (RS) and Geographic Information System (GIS) technique based on multi-criteria evaluation (MCE). The parame-ters used for the selection of optimal sites for rainwater harvesting were surface runoff, soil texture, land use land cover, slope gradient and stakeholders’ priority. Rainfall data was acquired from the neighbouring weather stations while infor-mation about the soil was attained from laboratory analysis using pipette method. Runoff depth was estimated using SWAT model. The statistical performance of the model in estimating the runoff was revealed with coefficient of determination (R2) of 0.81 and Nash–Sutcliffe Efficiency (NSE) of 0.76 for monthly calibration and R2 of 0.79 and NSE of 0.72 for monthly validation periods. The result implied that there's adequate runoff water to be conserved. Combination of hydrological model with GIS and RS was found to be a vital tool in estimating rainfall runoff and mapping suitable water harvest home sites.