The water mats in Oberaargau are the last remnants of a form of cooperative meadow irrigation and fertilization that was formerly widespread in the Swiss plateau. They are typical for large parts of the former cultivated land. They are best trained today in the river valleys of the Langeten, Önz and Rot. The origin can be traced back to the 9th century. Its emergence is mainly due to the amelioration of the Cistercian monks from the St. Urban monastery in the 13th century.