Giant Machines Drill 38km Tunnel Through African Mountains

Two football-field-length machines just fired up to drill through an African mountain range, and the result will bring water security to millions of people across two nations.

Ministers from South Africa and Lesotho unveiled the second tunnel-boring machine today at the Polihali Construction Site in Mokhotlong, Lesotho. The 423-meter-long giant will dig from one end of the Maluti Mountains while its twin works from the other, meeting in the middle to complete a 38.5-kilometer underground water highway.

Each machine carries a cutting head nearly as wide as a two-story building is tall. They'll work continuously through solid rock, drilling and installing concrete walls in one smooth operation as they go.

The tunnel will connect two massive reservoirs, moving water from Lesotho's highlands to South Africa's economic heartland in Gauteng. Right now, the Lesotho Highlands Water Project delivers 780 million cubic meters of water annually to South Africa. This expansion will add another 490 million cubic meters, bringing the total to 1.27 billion cubic meters each year.

The first machine started drilling at Katse Dam in February 2025. Now both are working toward each other through the mountains, transforming raw rock into a finished water transfer system as they advance.

The project goes far beyond just the tunnel. Engineers are building a 165-meter-high dam at Polihali with storage capacity for 2.3 billion cubic meters of water. They're constructing the 800-meter Senqu Bridge, new access roads, and resettlement housing for communities affected by the reservoir.

Water and Sanitation spokesperson Wisane Mavasa explained that the completed tunnel will dramatically enhance regional water security. As a bonus, the rushing water will generate clean hydropower for Lesotho, turning the nation's natural mountain geography into renewable energy.

The Ripple Effect

This collaboration between Lesotho and South Africa shows how neighbors can turn geographic challenges into shared solutions. The mountain kingdom gets revenue and clean electricity, while South Africa secures water for its industrial core. Communities along the route receive new infrastructure, and both nations invest heavily in environmental and public health programs to protect the region's ecology.

The project creates thousands of construction jobs and builds technical expertise that will serve the region for decades. Young engineers and technicians are learning to operate some of the world's most advanced tunneling equipment on home soil.

When those two machines meet somewhere deep inside the Maluti Mountains, they'll complete one of Southern Africa's most ambitious infrastructure achievements, proving that big challenges inspire even bigger cooperation.