Following workers across London as they race to build an enormous supersewer. The first episode follows the creation of the first stretch of the supersewer in east London.

Following workers across London over three years as they race to build an enormous supersewer on time and on budget. In this episode, construction begins in the heart of London.

Following workers across London over three years as they race to build an enormous supersewer on time and on budget. In this episode, tunnelling in central London finally begins.