Michał Habel

Decisions to build or remove dams and other large engineered hydraulic infrastructures are always entangled in social and environmental impacts, which are often evaluated formally through bureaucratic processes. In Europe dam removals are relatively infrequent, even though extensive hydraulic infrastructure has degraded biodiversity and water quality. The Wilkówka dam in southern Poland was required to be removed rapidly, primarily due to engineering failures during its construction. Using survey methods, we examine the local community's perceptions of the net environmental and social impacts of the Wilkówka dam removal. In surveying the opinions of households, 62% of respondents expressed that decisions about the removal were taken without sufficient community consultation, and 92% felt that the dam had been removed despite their opposition. Although the dam had been built recently and had failed to operate at design capacity, respondents reported strong attachments to the services they perceived it to provide, including water supply, flood regulation and cultural significance. In spite of the possibility of an environmental disaster and long‐term environmental degradation, most surveyed households would have preferred it to have been renovated or reconstructed. In short, the removal of the Wilkówka dam was perceived by local households but also by local officials as bringing about a net loss in socially relevant ecosystem services, despite the urgent need for removal perceived by regional and national authorities. The local community's rapid attachment to the dam despite its potential negative impacts on biodiversity and the local environment were primarily attributable to the high expectations as to the hydrological services that the dam was to provide (water supply, flood regulation and its larger symbolic value as an infrastructural investment in the community). This work provides an empirical demonstration of the importance of understanding the social, ecological and technological context within decision‐making processes regarding dam removals, and its implications may improve the planning and implementation of future dam removal projects.

River deltaic estuaries are dynamic ecosystems characterised by linkages between tidal currents, river water discharge, and sediment from the basin. The present study is based on the application of remote data: multispectral satellite images, DEM, LULC (Land use and land cover), lithology, and hydroclimatic factors. The standardised methodology was based on the adoption of a coupled modelling approach for this work, involving the semi-distributed catchment scale hydrological Soil and Water Assessment Tool (SWAT) model and the statistical Digital Shoreline Analysis System (DSAS) for (1) identifying environmental drivers of sediment transport changes of the estuarine reach; (2) analysis of retrospective changes in shoreline configuration; (3) assessing discharge and sediment dynamics of the estuarine section, and (4) generating future projection scenarios for the estuary’s state to take action for its long-term ecological stability. Our study employs a coupled modelling framework to fill the research gap for Subarnarekha deltaic estuary. Integrating outputs derived from DSAS and SWAT, a comprehensive understanding of the changes in watershed hydrology, water diversions, and damming of rivers have altered the magnitude and temporal patterns of freshwater flow and sediment, which potentially contributed to the receding of the Digha Coast shoreline.