Water project under threat from sludge



. . . as eroded soil chokes ‘Muela dam

Pascalinah Kabi

BUTHA-BUTHE – Lesotho’s continued ability to fulfil an agreement to supply water to South Africa and generate electricity for domestic use is in jeopardy owing to eroded soil choking the ‘Muela dam which has a hydropower station.

According to Lesotho Highlands Development Authority (LHDA) Divisional Manager Reentseng Molapo, land degradation caused by farmers and livestock in the areas surrounding the 55-metre high dam was severely affecting the hydropower station’s operations.

Mr Molapo told Water Affairs Minister Kimetso Mathaba and his Energy and Meteorology counterpart Khotso Letsatsi that the government needed to urgently avail money to purchase equipment needed to remove the sludge and avoid a complete halt of operations.

The two ministers visited the station this week to see first-hand the challenges the LHDA was facing in implementing the Lesotho Highlands Water Project (LHWP).

The LHDA is the implementing agency of the LHWP, a multi-billion maloti water project agreement signed in 1986 by the governments of Lesotho and South Africa.

Among the key tenets of the agreement is the delivery of 70 cubic metres per second of water to South Africa and utilising the delivery system to generate hydro-electric power for Lesotho.

The ‘Muela Hydropower Station is situated mid-way between the Katse Dam and Ash River Outfall in South Africa.

The station uses water from the Katse and Mohale Dams through the Katse Intake Tower to generate the 70 megawatts (MW) of electricity.

After the generation of electricity, water exits from the three 24MW turbines into the ‘Muela Tailpond, a 55-metre high dam which provides the headwater for water delivery to South Africa.

Water from the ‘Muela reservoir can be released into the Little Caledon River through two outlet valves.  The Little Caledon bypass allows water to be diverted down the Caledon River to supply emergency water to the eastern, central and southern regions of South Africa’s Free State province, as well as Lesotho’s border towns during severe drought conditions.

Mr Molapo said the ‘Muela Hydropower Station was grappling with incrementally high machinery repair costs.

“The hydropower station was built in 1996 with the last machinery being bought in 1998. As a result, our annual machinery repair expenses have been escalating with each passing year,” he said, adding that between 2008 and 2015, LHDA parted with M25.4 million for system repairs.

Mr Molapo explained that the bulk of the machinery was expensive since it had been acquired from Sweden and Britain. He urged the ministers to relay the message to cabinet that the government would need to save money over time for the capital investment.

“The government needs to properly prepare itself to be able to address the challenges facing this station. We need to ensure that the machines don’t break down to the extent of halting operations and failing to generate power,” he said adding there was an urgent need to replace the Katse-Mohale tunnel bypass valve since it was beyond repair.

“Among the challenges we have been facing since 2008 is water seepage. We cannot ascertain where the leaks come from.  During high flows, the seepage can be as high as 60 litres per second.”

Mr Molapo pointed out that their immediate problem was the accumulation of sludge in ‘Muela dam.

“The biggest challenge we are now facing is the increase of sludge forming in the ‘Muela dam due to soil erosion. The eroded soil comes from the fields on top of the dam as a result of land degradation.”

He said that the sludge could eventually affect the ‘Muela Hydropower Station’s ability to transfer water to South Africa and generate power for domestic use.

The area in which the mud was accumulating was under the purview of Lesotho, Mr Molapo said, hence the cost of addressing the problem would be borne by the Mountain Kingdom.

He said the LHDA initially requested for M9.9 million to buy equipment to remove the sludge in 2015 but it was not granted.

Mr Molapo said Matsoku dam was also experiencing a similar problem, adding that the sludge issue should not be taken lightly.

“This sludge can close down the hydropower and water delivery system. If we don’t quickly address this issue, we may reach a point where our operations are stopped,” Mr Molapo said, adding that ongoing revegetation efforts of the surrounding area were not yet yielding fruits.

He also revealed that the Mohale Dam was currently shutdown because of ongoing repairs.

Ministry of Water Principal Secretary Emmanuel Lesoma directed the LHDA to urgently write a discussion paper to sensitise cabinet on the situation.

“We need to start sensitising cabinet, especially the Finance minister now so that by the time the national budget is presented to parliament around September, they fully understand the urgency of this situation,” Mr Lesoma said.

“If this problem is not addressed now, it could reduce the project’s lifespan of 50 years which comes to an end in 2044.”

He also reminded the gathering that they were penalties in the treaty with South Africa in the event one of the parties failed to meet their obligations.

Mr Lesoma said there was time Lesotho was nearly penalised for failing to meet its obligations, adding that it was something that should be avoided.

‘Muela Branch Manager Lehlohonolo Molapo told the Lesotho Times on the side-lines of the tour that the land degradation was a result of poor farming practices.

“The subsistence farmers are situated on the slopes and when they plough the land, they ultimately erode the soil which falls straight into the dam.

“Once the top soil is fully eroded, with the underlying rock exposed, the farmers move to the next place and do the same thing,” he said, adding that the situation was also compounded by overgrazing.

Asked what the LHDA was doing to address the problem of soil erosion, Mr Molapo said they intended to create intensive environmental programme fostering good grazing practices.

He said the most immediate solution would be making diversion furrows to control the movement of water during rainy season and minimise soil erosion.

“The other option would be buying the land from the farmers surrounding the dam and compensating them,” he added.

For his part, Mr Mathaba said the project needed to be rescued at all costs.

“If we don’t deal with these challenges like sludge, they will continue to mount and we might not be able to address them. We might end up failing to reach the lifespan of this project which is supposed to end in 2044,” Mr Mathaba said.

“Now the price of the equipment has since increased from M9.9 million in 2015 to approximately M15 million; a problem that could have been avoided had the LHDA budget been approved.

“Following this tour, we will now be able to advocate, in cabinet, that the project urgently needs the amount of money it requested for the 2017/18 budget because we need to rescue it now.

“If these challenges are not addressed now, this dam will not serve its purpose and we will be penalised for not fulfilling our obligation in this binational project.”

Asked if government was open to the idea of repossessing the farming land and compensating the owners, Mr Mathaba said: “It is difficult to say right now.”

Leave A Reply

Your email address will not be published.