As per Sec. 5 of Title II of PD 198, water districts are mandated to do the following functions:

(a) acquiring, installing, improving, maintaining and operating water supply and distribution systems for domestic, industrial, municipal and agricultural uses for residents and lands within the boundaries of such districts,

(b) providing, maintaining and operating wastewater collection, treatment and disposal facilities, and

(c) conducting such other functions and operations incidental to water resources development, utilization and disposal within such districts, as are necessary or incidental to said purpose.