Construction of the Mt. Coffee hydropower plant was first undertaken in 1964. The first phase, with an installed capacity of 34 MW from two turbines, was commissioned and put in production in 1967. The project was undertaken by the Government of Liberia (GOL), with financing from the United States Government. Stanley Consultants served as project managers.
The installation of two additional turbines in 1973 increased the installed capacity to 64 MW. This second phase was financed by the World Bank; Motor Columbus served as project managers.
A dam and a 10-bay spillway structure with radial gates were located in the original river channel. Inflows to the reservoir were diverted through a channel to the power house located at a bend in the river. This arrangement, in combination with an excavated tailrace channel, allowed development of the maximum hydraulic head at the Mount Coffee site. The intake structure included provision for six units, although the powerhouse was only constructed for four units. Aside from partial excavation for the extension of the powerhouse substructure, none of the other civil works for units 5 and 6 was completed. Plans to more than double the generation capacity of the Mt. Coffee hydropower plant through construction of the Via reservoir dam and installation of two new turbines were abandoned due to the Civil War.
From 1973 until late 1989, Liberia’s electricity service was largely limited to the capital of Monrovia and environs; around 35,000 customers—almost 13 percent of the population—were served by 1989. Total installed public electricity capacity was 191 megawatts (MW). Nearly half the generation mix of LEC was composed of hydropower from the plant at Mt. Coffee—with a supply capacity of 64 MW during the wet season and 5-10 MW during the dry season—with a balance of 31 percent heavy fuel oil (HFO) and 21 percent diesel. LEC also handled the electricity supply of rural areas outside Monrovia through 10 small isolated power systems with a total installed capacity of 13 MW.
During the period of civil unrest in Liberia, power generation at Mount Coffee had to be stopped and operation of the spillway gates was prevented by the hostilities. Rebel forces under the command of Charles Taylor seized the Mt. Coffee plant in July 1990, halting production and causing the dam to breach. Approximately 180 meters (m) of the 12.2 m high dam, which was founded on overburden, was eroded down to bedrock. Until construction, including lifting of the spillway gates, began in January 2014, uncontrolled discharge continued through the partially open spillway and, in the wet season, through the breach. With the shut-down of generation, the powerhouse was vandalized and virtually stripped of power generation equipment, and much of the gate equipment. The powerhouse cladding was also removed.
The remainder of Liberia’s electricity infrastructure was almost entirely destroyed during the conflict. Efforts have been underway since 2006 to restore the Monrovia grid and expand mini-grid and stand-alone power systems in the interior. Following the restoration of peace, rehabilitation of Mt. Coffee Hydropower Plant was proposed as an important part of the reconstruction efforts led by H.E. President Ellen Johnson-Sirleaf.