Alpine freshwater ecosystems are biodiversity hotspots providing key ecosystem services. They face threats from climate change and anthropogenic activities. Snowmaking reservoirs emerged in the world in response to snow rarefaction and increasing winter tourism. Despite efforts to assess their environmental impact, our understanding of their ecological quality after being built remains limited. Here, we evaluated the representation of snowmaking reservoirs in French Alpine counties and their potential to serve as aquatic ecosystems. A comprehensive approach was employed encompassing ski resort surveys and geographical analyses of 136 reservoirs, complemented by investigations into abiotic characteristics and biodiversity surveys in 28 sampled reservoirs. The findings indicated that the multiplication and proximity of these reservoirs to freshwater habitats make them components of the alpine aquatic landscape. Although sparse terrestrial vegetation was commonly present on their banks, they systematically lacked aquatic vegetation. Faunal diversity appeared limited, consisting of both indigenous and non-native species. Comparisons with mountain lakes revealed similarities in water quality, implying potentially similar oligotrophy and biotic communities. However, differences in conductivity, alkalimetry and pH were observed, possibly linked to distinct water sources or retention times. Snowmaking reservoirs displayed unique habitat features through their structure and functioning. Although reservoirs are attractive for biodiversity, concerns surround their capacity to support species due to observations of drowned mammals, stranded amphibians and dragonflies. Our observations revealed potential ecological traps in the design, exploitation and uses of snowmaking reservoirs. Recommendations are made to enhance existing structures and future designs by increasing ecological processes and better protecting biodiversity.