Access to safe water and adequate sanitation services has proven to be one of the most efficient ways of improving human health. The World Health Organization has estimated the economic costs avoided, and returns gained, by various levels of investment in water supply and sanitation services: every $1 invested in improved water supply and sanitation yields gains of $4 to $12, depending on the type of intervention.

Access to safe drinking water and adequate sanitation services is vital to human health but has other important benefits ranging from the easily identifiable and quantifiable (costs avoided, time saved) to the more intangible (convenience, well-being, dignity, privacy and safety).

An integrated approach to human health and water resources management is urgently required. This should be characterized by flexible planning and implementation, analysis of the cost effectiveness of local options, attention to the most vulnerable groups in urban and rural settings, and a significant reallocation of resources to drinking water, sanitation and hygiene. This is essential to save the lives of millions and ensure considerable long-term economic benefits.