Benzing, p. 11 and the Appending with maps. The Konstanzer Niederung received the signature 030/031.22. The next higher units are Central Hegau Untersee Depression (with signature 030/031.2) and Northern Lake Constance and Hegau Basin (with signature 030/031). Neighbouring regions are: in the East, the Obersee (with signature 030/031.0), in the East the Untersee (030/031.20) and the island of Reichenau (030/031.21), in the North the hill country of the Bodanrück (030/031.23) and in the South the hills of the Seerücken (no signature, because they are in Switzerland). (In 1998, the Department for the Environment of the state of Baden-Württemberg called for an updated version of Benting's list. In this new version, the old 030/031 was replaced by 030 "Hegau and Western Lake Constance Basin", see www.xfaweb.baden-wuerttemberg.de[permanent dead link])
