The Krumme See in the municipality of Fredersdorf-Vogelsdorf, OT Vogelsdorf is approx. 3.3 hectares in size and a maximum depth of 4.5 m. The lake is elongated and has a narrow west and east bank, where in some places you can reach the shore. The “crooked” north and south banks with several bays and peninsulas are built up with land and are not accessible. On the peninsula on the southeast bank there is a small, park-like area with access to the lake and at the deepest point on the east bank there is a small swimming area with benches. There have been problems in recent years due to the lowering of the water level, which meant that the bathing area was no longer usable.
An inflow into the Krummen See occurs via the Zehnbuschgraben, a tributary of the Fredersdorfer Mühlenfließ - but only if it also has water. There is no surface drainage from the lake. When I visited in February 2024, the lake was quite full, which was certainly due to the extensive rainfall in the previous months and the high water level in the Fredersdorfer Mühlenfließ.