What is "diveria"

The Diveria ( Walliser German: Churumm Bach; German: KrummBach) is an Alpine river which flows through Switzerland ( Canton Valais) and Italy ( Province of Verbano Cusio Ossola). It is a tributary of the Toce and therefore, via Lake Maggiore and the Ticino, of the Po. The valley crossed by the Diveria, the Val Divedro, is the only one in the Valais to form part of the Po basin rather than that of the Rhône.