Tree planting plan to curb siltation at key power stations

The government is set to implement the final phase of a major afforestation project that aims to tackle siltation that threatens operations at the Sondu Miriu and Seven Forks hydro power stations.

The contractor to carry out the job on Koguta Hill in Sondu and the Nyambene Hills forest reserve in Meru will be picked tomorrow when bids are opened, the Energy and Petroleum ministry said. “The contractor must plant 1,600 tree seedlings per hectare, evenly distributed at a distance of about 2.5 metres by 2.5 metres,” the ministry said in a statement to bidders.

Koguta Hill is part of the Sondu River catchment which is critical to the operations of the 80-megawatt Sondu Miriu hydro power dam. Nyambene Hills form part of the upper River Tana catchment, which is one of the country’s critical ecosystems sustaining River Tana which provides water resources that generate nearly half of the total electricity generated in the country.

“The hill is steep and highly degraded. During the rainy season, various types of sediment are swept downhill into the power station, and occasionally the rocks block channels through which water flows from Sondu River to the turbines” the ministry said.

Similar challenges have been experienced in River Tana catchment because parts of the Nyambene Hills are highly degraded and when it rains, soil erosion takes place. This soil is normally swept downstream to the Tana River, where it ends up contributing to siltation of the Seven Forks dams.

The afforestation project is the final of a four-phase phase programme, with the first phase implemented in 2011/12 and the other phases in subsequent years. “The objectives include arresting loss of forest cover, protecting the soils from erosion and ultimately improving water quality and supply through the Seven Forks power stations as well as Sondu Miriu hydro power station,” the ministry said.

The future of Sondu Miriu hydropower dam is also threatened by massive destruction of sections of the Mau Forest catchment area.
Kenya plans to add 5,000 megawatts of power generation capacity by 2017 to the existing 1,664 megawatts to accelerate economic growth, which is expected to push power demand up to 15,000 megawatts by 2030.

The country has for a long time had to contend with frustrating blackouts that affected key sectors of the economy such as manufacturing.

Last week, the government said an additional 70 megawatts of geothermal power had been loaded to the national grid, raising hope for cheaper electricity. “It has taken a bit of time but we are getting there,” Energy and Petroleum secretary Davis Chirchir said.

The 70 megawatts is part of an ambitious programme by KenGen to add 280 megawatts of power to the grid by the end of the year. The company shall have delivered 210 megawatts to the grid by today with the remaining 70 megawatts expected in November.

“We are looking at overall savings of about Sh28 billion per year in fuel cost charges when the final 70 megawatts come online in November,” he said.

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