The Chiavica Vallazza divides the Fossalta canal, the oldest in the Oltrepò area, to the right of the River Secchia and dating from the 15C, into two stretches historically known as the Fossalta Superiore and the Fossalta Inferiore. The Fossalta Superiore receives waters from the Quistello and Revere areas, since the 16C discharged into the River Po via the Chiavicone di Moglia. The Fossalta Inferiore receives waters from the Sermide area, since the 15C discharged into the river via the Chiavica di Quatrelle.
Today, the Cavo Diversivo, a canal transporting the water of the Fossalta Superiore to the Bonifica di Revere drainage plant at Moglia di Sermide, starts from the Chiavica Vallazza. The waters of the Fossalta Inferiore end up in the Consorzio di Burana network and are carried to the Pilastresi drainage plant at Malcantone di Bondeno.
The Chiavica Vallazza belongs to the Consorzio di Bonifica Burana.