MIWD is located in the southeastern portion of Province of Iloilo. Its service area covers Iloilo City, which consists of 6 districts of Arevalo, City proper, Jaro, Lapaz, Mandurriao and Molo; and 7 surrounding municipalities of Cabatuan, Leganes, Maasin, Oton, pavia, San Miguel and St. Barbara.

Springs

Although the service area is endowed with many natural waterways, springs with significant yield are typical in the area with the exception of a spring with a relatively small discharge. It is located about one km from Maasin, however as the name of the municipality denotes, the spring has a considerable salinity. The saline water is most likely inherent in the locality, which is caused by some chemical compounds.

Surface Water

There are several watercourses that crisscross the services area of MIWD. Most of these rivers and streams emanate from northwestern mountain range of the province of Iloilo. Three important rivers serve as natural drainage systems of most of the barangays in the service area, to wit: Tigum, Aganan and Sibalom.

Ground Water

Based on the Rapid assessment of water Supply Sources made by the then National Water Resources council, the DPWH and private drilling companies constructed most of the wells in the MIWD. A total of 173 shallow and deep wells had been inventoried in the service area. Water sources for domestic needs from these areas can be easily treated for bacteriological pollution, however, these are susceptible to pesticides and fertilizer contamination particularly those areas located near the agricultural land