 Badia del Vallès is a young city (incorporated in 1994 with land segregated from Barberà del Vallès and Cerdanyola del Vallès) formed in the 1970s mostly with people who emigrated south of the Iberian Peninsula.Thus the swallow was chosen as the symbol of migration, while the colors of each partition represent the two original municipalities (gold for Barberà and sinople for Cerdanyola).Badia del Vallès uses an heraldic flag which follows the same pattern as its shield, and is defined as an "Oblong flag of proportions two high by three long, two-tone yellow and green vertical stripes, with the black swallow with the white chest of the shield, height 5/7 of the cloth, centered in the middle of the partition."