Blabbergraben at the former Blabbermühle (water mill) in the village Görsdorf. The Blabbergraben is a stream in the District Oder-Spree, Brandenburg, Germany. Coming from the „ Herzberger See“ the stream connects five small, long lakes in the municipalities Rietz-Neuendorf and Tauche and drains them into the river Spree. Including the lakes the flow length is 13,7 kilometers.