Masinga Hydroelectric Power Station Explained

Masinga Hydroelectric Power Station
Name Official:Masinga Power Station
Location Map:Kenya
Coordinates:-0.8892°N 37.5944°W
Country:Kenya
Location:Embu County/Machakos County, Eastern Province
Purpose:Power
Status:O
Construction Began:1978
Opening:1981
Dam Type:Embankment dam
Dam Crosses:Tana River
Dam Height:60m (200feet)
Dam Length:2200m (7,200feet)
Owner:Tana and Athi River Development Authority
Dam Volume:4950000m2
Spillway Type:Over the dam
Res Capacity Total:1560000000m2
Res Surface:120km2
Plant Operator:Kenya Electricity Generating Company
Plant Commission:1981
Plant Hydraulic Head:49m (161feet) (max)
Plant Turbines:2 x 20 MW Kaplan-type
Plant Annual Gen:129 - 232 GWh

Masinga Hydroelectric Power Station, also Masinga Dam, is an embankment dam on the Tana River, the longest river in Kenya and straddles the border of Embu and Machakos Counties in Eastern Province and is located about 106 km. (66 mi.), by road, northeast of Nairobi, Kenya's capital and largest city.[1] Construction of the dam began in 1978, and was completed in 1981. It is owned by Tana and Athi Rivers Development Authority (TARDA). The dam is used for power production and is part of the Seven Forks Scheme.

Dam

Masinga Dam is a 60 m tall and 2,200 m long embankment dam with a volume of 4,950,000 m³. The dam contains a spillway and a bottom outlet.

Reservoir

At full reservoir level (maximum flood level of 1,056.5 m) the reservoir of the dam has a surface area of 120 km² and its total capacity is 1,56 billion m³.[2] Minimum operating level is normally 1,037 m. On June 26, KenGen shut down the power plant because the operating level had fallen to 1,035.5 m. At the time of the closure the plant had been producing 14 MW.

Because of its large volume, the reservoir is crucial in regulating the flow of water for the other 4 hydroelectric power plants downstream.

Power plant

The run-of-the-river hydroelectric power plant went operational in 1981. It is owned and operated by Kenya Electricity Generating Company (KenGen). The plant has a nameplate capacity of 40 MW. Its average annual generation is between 128 (in 2008) and 232 (in 2007) GWh, depending on the water flow of the Tana River.

The power plant contains 2 Kaplan turbine-generators with 20 MW each. The turbines were provided by Escher Wyss, the generators by ABB. The maximum hydraulic head is 49 m, maximum flow per turbine is 45.9 (45) m³/s.

History

Capital cost of the dam was US$172 million.

Feasibility studies were made in the 1970s and they confirmed the viability of a cascade of hydroelectric power plants along the Tana River: Masinga, Kamburu, Gitaru, Kindaruma, Kiambere, Karura, Mutonga, Low Grand Falls, Usheni, Adamsons Falls, and Kora. Only the first five of them have been built so far.

Plans to raise the dam by 1.5 m in order to increase the volume of the reservoir up to 2 billion m³ were finally cancelled. The cost would have been US$15 million.

In February 2018, KenGen resurrected plans to raise the Masinga Dam wall by 2m (07feet), and install pumping equipment to recycle the downstream water discharge back to the dam for steady electricity output though the dry seasons. The French Development Agency (AFD) agreed to lend the KSh21 million (€169,000) required to conduct a fresh feasibility and environment impact assessment. AFD selected EDF Group, a French company to carry out the study.[3]

Heavy rains beginning in March 2018 led to major flooding throughout the Tana River area. On 17 May 2018, it was announced that the Masinga dam had reached capacity and had begun to overflow one week after the deadly failure of a smaller embankment dam in Solai. While safeguards in place prevented the dam from failing, other dams downstream had already reached capacity and authorities advised the evacuation of the towns of Garissa, Garsen, Hola, and Bura.[4]

See also

Notes and References

  1. Web site: Distance between Nairobi Central, Nairobi, Kenya and Masinga Dam, Kenya . 19 February 2018 . 19 February 2018 . Globefeed.com . Globefeed.com.
  2. Web site: Tana and Athi rivers Development Authority .
  3. Web site: KenGen signs fresh deal to upgrade Masinga dam wall . 19 February 2018 . Neville . Otuki . 19 February 2018 . . Nairobi.
  4. News: Okuoro. Sara. Masinga Dam overflows. 18 May 2018. The Standard. 17 May 2018.