Concern as dams remain low despite rains
MASERU – Water levels remain low in the Lesotho Highlands Water Project (LHWP)’s major dams which almost ran out of water to supply South Africa and generate electricity at the ‘Muela hydropower station last year. Lesotho takes advantage of water released to South Africa to generate electricity at ’Muela station in Botha-Bothe, which generates a portion of the country’s electricity– 72 megawatts.
So dire was the situation last year that the Lesotho Electricity Corporation (LEC) was forced to import “more and expensive electricity from ESKOM – a South African electricity public utility”. This had been a closely guarded secret until it was revealed recently in a Tariff Review Application for 2020/2021 submitted to the Lesotho Electricity and Water Authority (LEWA) by the LEC.
“The Lesotho Highlands Water Project (LHWP) reservoirs have not received sufficient water in the recent past rainy season. As a result, in March 2019, both Katse and Mohale reservoirs respectively recorded 35.49 percent and 19.90 percent,” LEC disclosed in its application.
It said the accumulated water in March last year “was insufficient to meet water transfer to South Africa and electricity generation requirements at ‘Muela plant”. Due to this water shortage crisis, the Lesotho Highlands Development Authority (LHDA) had to review water transfer options that were implemented in the current financial year which started on April 1, last year, and ends on March 31.
According to the LEC, the reviewed terms of water transfer to South Africa had an impact on electricity generation at ‘Muela. “This situation dictated LEC to import more expensive electricity from ESKOM. To avoid the same situation, the company in the period under review, will review up its import purchases forecast with a view of ensuring stable security of supply,” it said.
Public Eye was unable to get a comment from the LHDA this week. The possibility of Lesotho dams running dry still looms large on the horizon because of the persisting shortfall in rain across the country that has further crippled water harvesting.
As at Sunday, March 1, Katse Dam – a critical source of the LHWP – was 33.80 percent full, while Mohale Dam was 13.24 percent full. Not much is expected to change soon. This looming water crisis poses a threat to the generation of electricity at the ‘Muela power station which produces only 72 megawatts.
The country’s remaining energy requirements, more than 70 megawatts, are imported from South Africa and Mozambique. Before the station was built, Lesotho was 100 percent dependent on South Africa for electricity.
For LEC, the prospect of the ‘Muela station shutting down due to shortage of water seems almost too much to bear. It has made an application to LEWA for allowable revenue of about M1.2 billion, which would translate to a hike of 32.6 percent across consumer categories from April 1.
The submission, which is available on LEWA’s website, includes a request of over M503 million for electricity purchases from ESKOM and Mozambique’s EDM. LEC expects to spend only M55 million to buy electricity from ‘Muela.
In August last year, this publication reported that Katse Dam, Africa’s second largest double-curvature arch dam, had hit the lowest mark since the reservoir first filled with water in 1997. At that time, Katse dam was 18.21 percent full.
Public Eye reported that the low water level in the Katse Dam raised the prospect that for the first time, water transfer to South Africa could be suspended if there were no sustained rains in the highlands as it would be practically impossible to keep releasing water.
There is a water level below which the Katse Intake Tower cannot be able to draw water from the dam. The intake tower is located approximately 18km north of the dam. Due to its position and design, there is a certain volume of water in the reservoir that cannot be accessed via transfer tunnels. This dead storage is approximately 430 million cubic meters (m3). The total capacity of the reservoir is 1 950 million m3.
Lesotho gets about R700 million a year from selling that water to South Africa. The LHDA said then that “it is important to note that currently there is no flow of water from the Mohale Dam into the Katse Dam while the tunnel connecting the two dams is closed for maintenance”.
“Therefore, the water level in the Katse Dam is gradually falling as the water is being transferred to South Africa. This is one of the reasons why the water level in the Katse Dam is now at 18.21 percent,” it said. Through the LHWP, the multibillion-dollar, multi-dam water project developed in partnership between the governments of Lesotho and South Africa, and signed into life in 1986, Lesotho supplies 40 percent of Gauteng’s water.
The project is considered Africa’s largest water transfer scheme. Water from Katse Dam and Mohale Dam flows through a series of underground tunnels to the Vaal Dam which serves as a muscle behind the economy of Gauteng as it supplies water to Sasol and Eskom.
These two industries are at the centre of Gauteng’s economic fortunes. The water from the LHWP is used in six provinces of South Africa. It cools the Eskom power stations in Mpumalanga, keeps Sasol and the Free State gold mines operational and supplies the vast industries and sprawling urban areas of Gauteng. It also provides life to some of the southern towns of Limpopo and the platinum mines of North West, as well as the diamond mines and people of Kimberley and surrounding areas. Under drought conditions, emergency water can, and has been transferred to the Caledon River and to the Eastern Cape and southern Free State through the BloemWater network.