The Fivel was a historical river in the province of Groningen in The Netherlans. It received its water from peat bogs around Kolham and Slochteren, flowed past Woltersum, Wittewierum and Ten Post, and meandered north of Winneweer. The Fivel debouched inte a wide estuary of the Wadden Sea. The banks of this former estuary are still recognizably by rows of villages on artificial dwelling hills (wierden):