1 Social innovation: the bio-centre approach to water and sanitation infrastructure provision in Nairobi’s informal settlement, Kenya ©Elizabeth Kanini Wamuchiru Noackstrasse 20, 64285 Darmstadt, Germany lizwamuchiru@gmail.com +4917682309316 Paper presented at the RC21 International Conference on “The Ideal City: between myth and reality. Representations, policies, contradictions and challenges for tomorr ow's urban life” Urbino (Italy) 27-29 August 2015. http://www.rc21.org/en/conferences/urbino2015/