Which is longer, the Madera Canal or the All-American Canal?
Madera Canal: The Madera Canal is a 35.9 mi aqueduct in the U.S. state of California. All-American Canal:  The Imperial Dam, about 30 miles (48 km) northeast of Yuma, Arizona on the Colorado River, diverts water into the All-American Canal, which runs to just west of Calexico, California before its last branch heads mostly north into the Imperial Valley.
i don't know