Conversation so far:
where does water come from in south africa
The Katse dam in Lesotho is an important source of water supply for the arid Gauteng area around Johannesburg, the industrial heartland of South Africa.
what is the katse dam
The Katse Dam, a concrete arch dam on the Malibamat'so River in Lesotho, is Africa's second largest double-curvature arch dam.

Question: who constructed the dam
Self-contained rewrite: who constructed the katse dam