A Shit Flow Diagram (SFD) is a survey of the adequacy of municipal sanitation services. A recent survey conducted in Nairobi established that the sewerage services can only handle 25 per cent of the of the city’s human waste while 75 per cent largely goes unaccounted for. Mombasa is even more dire, with less than 10 per cent of the waste accounted for. In Kisumu it is only 6 per cent. This is a sanitation crisis.