Mongi-Bulum hydropower project – pre-feasibility study

Client: PNG Power Limited
Location: Morobe Province, Papua New Guinea
Date: July 2013 – July 2014

Exploring potential sites for new hydropower generation projects, to increase the supply of reliable, clean and cost-effective power in Papua New Guinea


With rapidly growing demand for reliable electricity in Papua New Guinea, PNG Power Limited (PPL), is eager to assess the country’s untapped hydropower potential and to explore new options for increasing the generation of clean and cost-effective electricity.

Entura assisted PPL to identify potential sites for the proposed Mongi-Bulum hydropower scheme and undertook the pre-feasibility study. The chosen site is located 70 km from Lae, capital of the Morobe Province, in a challenging geographical setting.


Entura prepared a preliminary feasibility study, including assessment of alternative options, engineering geological reconnaissance, preliminary design of the project, energy assessment, project implementation schedule, cost estimation, and project economic analysis.

The adopted layout has two 27m-high diversion dams, intake structures, underground desilting chambers close to the headworks, three reinforced concrete lined tunnels totalling 21 km, a forebay chamber, a 1630m-long steel-lined inclined shaft from the forebay to the power tunnel, a surface power station housing 3 x 38.7 MW Francis turbines (total 116 MW), with a net head of 247 m and a design discharge of 54 m3/s.


Entura’s studies showed that the Mongi-Bulum project is financially viable, despite its remote location, and the cost to produce electricity compares favourably with other modes of power generation.

Entura’s preliminary feasibility study identified some significant topographical, hydrological and geological risks, and our preliminary design took a conservative approach to manage these. During the full feasibility study, these risks would have to be further assessed to ensure that the appropriate measures are adopted to deliver the project.