8470 and its subsequent ratification by plebiscite on 7 March 1998 separated from Davao del Norte's first and second districts a total of eleven municipalities to create the new province of Compostela Valley (now named Davao de Oro), which itself was apportioned into two new congressional districts.
The creation of Compostela Valley (Davao de Oro) resulted from a legislative act (Republic Act No. 8470) that was ratified through a public vote on March 7, 1998. This act separated eleven municipalities from Davao del Norte and subsequently divided the former into two new congressional districts.