London’s five billion pound Super Sewer is now fully connected and promises a cleaner, healthier River Thames. The 150-year-old sewer network has struggled to cope with the twin challenges of an increase in the population it serves in the capital (from four million people when it was built to over nine million today) together with climate change. With rainfall overwhelming the system, it sometimes discharges into the Thames. With the Super Sewer fully connected, 95% of those spills are stopped.