Peter Newborne of the ODI Water Policy Programme prepared the original text on which Chapter 5 is based, on "Managing the Transition to Improved Water Services" and contributed to the case study in Chapter 6: "Improving Access to Water Services: Mexico" written by Lillian Saade-Hazin.
Chapter 5 highlights the most significant water supply and sanitation "service gaps" in the thirty member countries of the OECD, located in poorer areas/regions, and then discusses how to fill such service gaps - how best to manage the transition from low, to much improved, levels of service. Doubts have been cast in recent years on schemes which have focused on installing a standardised package of relatively high-tech infrastructure, involving big costs (and heavy burdens in terms of cost-recovery) with, it seems, few benefits for the poor. The chapter argues that this "gap-filling" in poor, marginalised zones (urban/peri-urban slums, poor rural areas) may be best achieved by adopting a differentiated approach, i.e.: adopting a range of different types and levels of water supply and sanitation (WSS) provision.
Mexico provides an example, for Chapter 6, of a middle-income country which nevertheless has low-income regions in which significant gaps exist in the "first-time" provision of WSS services, particularly in rural areas, where widely dispersed and marginalised communities lack access to basic water services, and in peri-urban areas, where informal settlements surround rapidly growing cities (e.g.. Oaxaca city or "Oaxaca de Juarez" ). An overview of water services in the country is provided, followed by a more detailed focus on the three southern States of Oaxaca, Chiapas and Guerrero, where the greatest water service gaps currently occur (amongst other aspects of poverty).