There are big river basins in the province which serve as good source for irrigation. The largest is located in Tago which embraces 30,000 hectares from the municipality of San Miguel down to the coastal town of Tago. The second is that found in Madrid covering 23,657 hectares and the third is in Hinatuan with an area of 18,500 hectares. Watershed areas covering these river basins continue to supply adequate water through the year.