The Wasgau is drained mostly towards the east by left-hand tributaries of the River Rhine, namely the Queich, the Lauter (called the Wieslauter in its upper reaches) and the Saarbach, which continues as the Sauer in North Alsace. setzt. There it is followed by the Moder, whose catchment area extends southwards via its right-hand tributary, the Zorn, beyond the Col de Saverne.