Urban water is the water in our built environment. Water in pipes for drinking, wastewater in pipes for disposal and water that runs through the streets and into stormwater systems. All this water represents engineering challenges and management issues related to the dense population associated with urban centers. Provision of sufficient, high quality water and removal of wastewater are critical issues as urban populations increase in density.

The movement of human populations from rural to urban environments has intensified over the past decades and is expected to increase significantly over the next fifty years. In 1960 there were two cities on the planet with more than 10 million in population ( New York and Tokyo). By 2000, there were ten, and by 2050 it is expected that there will be 25. Most of these will be in currently developing countries, where urban infrastructure issues are in crisis. Significant challenges in water availability and provision to increasingly urban populations exist. Engineers must solve these problems.