Zambia to bear cost of Kariba Dam rehab

 ZAMBIA will shoulder the financial burden of the rehabilitation of Kariba Dam, the double curvature concrete arch dam designed by Coyne et Bellier and constructed between 1955 and 1959 by Impresit of Italy.

Zimbabwe’s Finance and Economic Development Minister, Patrick Chinamasa, revealed the role that the country’s northern neighbour will play in the work that is set to begin in May this year.

“Let me take this time to appreciate our friend and partner Zambia on agreeing to undertake the financial commitment on behalf of the two countries. Without this generous act, the project would not have been a reality,” Chinamasa said in Kariba last week.

The dam is managed by the Zambezi River Authority (ZRA), which is jointly owned by Zambia and Zimbabwe in equal proportions.

ZRA was established as a corporate body in October 1987 by parallel legislation in the Parliaments of Zambia and Zimbabwe following the reconstitution of its predecessor, the Central African Power Corporation.

The ZRA council of ministers approved the mobilisation of funds for the rehabilitation in October 2009. Between 2009 and 2012, the ZRA engaged European consultants, Tractebel Engineering, to identify and design solutions to rectify safety concerns.

Two remedial measures were prescribed for the dam. The first one was the reshaping of the plunge pool and protection of the fault zone in the plunge pool by using reinforced concrete mattress.

The plunge pool was formed by water released through the dam wall’s floodgates and it is feared that its continued deepening will affect the wall.

“There are also fault lines that run underneath the dam wall and if the water continues to dig in the plunge pool there is a risk that once that happens the water from there could then sip under the wall and that could cause the dam to fail,” Farai Furusa, the dam maintenance engineer, said.

The second measure prescribed by the consultants was the refurbishment of the spillway to improve the operation and reduce the risk of possible failure of the upstream spillway control facility.

The European Union (EU) ambassador to Zambia, Alessandro Mariani, explained that the project formed part of their partnership with Zambia in the energy sector under which a  244 million-euro grant was set aside for the period from 2014 to 2020.

The Kariba plunge pool project will get a 50-million euro grant from that fund. Reshaping the plunge pool will slow down the scouring of the natural rock and will consequently protect the dam’s foundations. The fault area will also be strengthened.

The reshaping project will take approximately three years to complete and will require significant quantities of excavation and demolition works. The entire rehabilitation project will need about eight years and will cost US$294 million in grants and concessionary loans.

The EU will contribute a total of US$100 million in grants, while the World Bank will contribute US$75 million in loan financing; Sweden will give a US$20 million grant and the African Development Bank (AfDB) will contribute a US$39 million loan as well as a US$36 million grant.

ZRA will contribute US$19 million.

In January 2013, the council of ministers approved the resources mobilisation committee chaired by the two countries’ ministries of finance to marshal resources for the identified works.

In the end the project financing agreement was reached with the AfDB, the EU, Sweden and the World Bank.

Last week, they signed the deal with Zambia and French contracting firm Razel-BEC, which won the contract to do the rehabilitation. The money will be repaid through revenue generated by the ZRA, according to the company’s chief executive officer, Munyaradzi Munodawafa.

ZRA derives its revenue from water sales to Zambian power utility Zambia Electricity Supply Authority (ZESCO) and the Zimbabwe Power Company (ZPC) and rental income from leases of owned properties.

Munodawafa says the project will deal with all identified concerns about the dam’s safety. Kariba Dam’s well-being is not only critical for the energy and economic needs of the two countries but any collapse would be catastrophic for the lives of around three million people who live downstream in Malawi, Mozambique and Tanzania.

On the Zimbabwean side, the area from Kariba up to Kanyemba on the south bank of the Zambezi is a national parks territory with no human habitation and on the Zambian side there are not more than a thousand inhabitants.

According to Furusa, there is a real risk that the dam could fail without the rehabilitation project and he expects between 120 and 160 people to be employed during the reconstruction, with most of the work being done by heavy machinery.

Meanwhile, the generation of electricity at Kariba South Hydroelectric Power Station, Zimbabwe’s main source of electricity, will go up by 70 percent this year after the ZRA reviewed upwards the amount of water it allocates to the plant for power generation. This was first reported by this newspaper last month.

The plant will be generating 485 megawatts (MW) on average up from 285 MW in the prior year. This is the first time in two years that ZRA has adjusted upwards the power station’s electricity generation capacity.

In November last year ZRA increased water usage for hydropower generation from 20 billion cubic metres to 30 billion cubic metres which ZPC and ZESCO’S Kariba North Bank Power Station must share equally.