The Alfsee is a reservoir in the north of the district of Osnabrück in the state of Lower Saxony in north Germany. It has an area of 2.2 km². It acts as a flood retention basin for the catchment area of the Hase and as local recreational area.
Wikipedia https://en.wikipedia.org/wiki/Alfsee
Official Website https://www.nlwkn.niedersachsen.de/startseite/hochwasser_kustenschutz/landeseigene_anlagen/hochwasserruckhaltebecken/hochwasserruckhaltebecken_alfhausen_rieste/hochwasser-rueckhaltebecken-alfhausen-rieste-42055.html
Address 49594, Germany
Coordinates 52°29'13.317" N 7°58'29.718" E