After the enactment of R.A.3601, creating the NIA, there were only two(2) regional centers in Mindanao with headquarters in Davao City, and another at Molave, Zamboanga del Sur. Later on, in 1973, three(3) regional offices were established, namely; Region 7 with headquarters in Molave, Zamboanga del Sur; Region 8 at Davao City and Region 8-A at Koronadal, South Cotabato.
With the adoption of new regionalization scheme for the Island of Mindanao (MC #12,s.1978) Region 8 was renamed as Region XI covering the Provinces of Surigao del Sur, Davao del Norte, Davao del Sur, Davao Oriental and South Cotabato. Later, Surigao del Sur was transferred to the jurisdiction of Caraga or Region 13; and replaced by Sultan Kudarat of Region XII which was recalled after two(2) years.
Executive Order No. 36 dated September 19, 2001 returned South Cotabato and Sarangani to Region XII and all NIS and CIS making Region XI limits within Davao Provinces only.
At present, NIA XI operates and maintains nine (9) National Irrigation System (NIS) and ninety nine (99) Communal Irrigation System (CIS) under four (4) responsibility centers which covers the Davao Provinces and Compostela Valley.