The life of a river

Through his obsessive search for the source of Johannesburg’s Jukskei River, journalist Sean Christie has journeyed below the city and dug up some fascinating, and at times squalid, insights into this river and how the city above it functions. For example, did you know that water has an isotopic signature, so hydrologists can trace where the water in your trap really comes from (in Johannesburg, the answer is likely Lesotho)? Or that there is a phenomenon known as sewage mining, which causes havoc in an already outdated system?