A study was conducted concerning the perceptions of a future reservoir (4.7–8.9 square kilometres, 42.2 million cubic metres) by residents, tourists, and visitors; the location in question was the former Kotlarnia sand pit in the catchment area of the Bierawka River (tributary of the Oder River in southern Poland). Divergent concepts for the reclamation and development of the former sand pit emerged; the construction of a reservoir was initially the dominant option but was eventually abandoned despite it having the greatest acceptance among the respondents (out of the 134 respondents, 43.3% favoured the creation of a water reservoir, 29.9% favoured introducing nature protection arrangements in the area to enable spontaneous nature regeneration, and 16.4% favoured reforestation). A clear discrepancy arose between the public’s expectations related to the reclamation and development of the former sand pit in order to create a reservoir and the official position of the land user and administrator of the potential reservoir, which indicated that it no longer intended to create such a reservoir. This study indicates that in the process of developing concepts related to the reclamation and development of former mineral workings, it is essential to obtain the results of public consultation based on a diagnostic survey conducted among representatives of the local community. This is an effective tool for predicting the optimal use of sites regenerated after the damage caused by open-pit mining provided that all technical considerations related to the planned project are taken into account in advance.