Early assessments of the project date back to 1989, when the first studies was conducted by the country's Central Engineering and Consultancy Bureau.

Environmental Impact Assessment (EIA) Report of the Uma Oya Project was prepared by the University of Sri Jayawardhanapura and was submitted in November 2010.

The damming of this river creates the Puhulpola Reservoir (PR), which has a gross storage of 634,826 m3 (22,418,700 cu ft).

The two pelton turbine generators of 60 megawatt are fed via a 600 m (2,000 ft) vertical pressure shaft, after passing through the long tailrace tunnel.

68,000 m3 (2,400,000 cu ft) of earth was cleared to create the underground Uma Oya Power Station cavern.

[citation needed] The annual discharge of approximately 145,000,000 m3 (5.1×109 cu ft) of water from the power station is distributed out via a 3,335 m (10,942 ft) cross-basin tailrace tunnel for agriculture use on 15 km2 (5.8 sq mi) or existing land and 45 km2 (17 sq mi) of new lands, including irrigation of 14 separate tanks.