Better access to piped water and sanitation reduces the spread of disease, frees up household labor, particularly of women, and helps protect one of the world's most valuable natural resources. The Millennium Development Goal for the environment includes a specific target for safe drinking water: reducing by half the number of people without sustainable access by 2015. If current rates of new connections continue, only one country in five will reach the target and fewer than 10 percent of the poorest countries will reach it.

An increasing number of poor people in Colombia have access to water and sanitation thanks to an innovative approach by the government, which has shared responsibility for these key services with local authorities and the private sector. Colombia's water and sanitation reforms were spearheaded by the cities of Cartagena and Barranquilla.

With World Bank technical and financial support, both cities contracted operations out to "mixed" companies jointly owned by the municipality, a private operator, and local private shareholders, with the city authorities retaining ownership of the infrastructure.

Access to water and sanitation services improved substantially in both cities between 1994 and 2002. More than 80 percent of the new connections were in poor neighborhoods. Services became more efficient and reliable. Metering reduced losses from unaccounted-for water, and the time taken to respond to consumer complaints was dramatically reduced.

Success in Cartagena and Barranquilla became a catalyst for attempting similar reforms elsewhere. About 30 percent of Colombians—many of them poor—live in smaller cities and towns with insufficient water supply and sanitation coverage.

One Bank loan is helping municipalities extend services to poor people by promoting local entrepreneurs in the water sector, creating a pool of small, local service providers who can respond more quickly to demand. While better sewerage services have improved health conditions, the Bank is working with the Colombian authorities to improve the treatment of wastewater that is often left to flow into rivers, turning them into open sewers.

The key to Colombia's success in improving access to water and sanitation services has been devising homegrown solutions and adapting models developed in other countries to its own conditions and needs.

But expanding successful programs requires reaching out to hundreds of municipalities. Additional sources of financing will be required, as public funds and current levels of international aid will not cover all the investment needs.