Further, from 2000 to 2050 Asia’s urban population is predicted to increase by nearly 2 billion people (IHT 2008). Cities are voracious consumers of water and environmental resources such as timber and mined construction materials that are often extracted from river basin regions at levels many times greater than those appropriated for rural uses. Much of the destruction of the upstream ecologies, even when located in a different country, is the result of the growth of cities and their unrelenting demand for natural resources and hydropower, supplied by very large dams that have system-wide impacts. A good number of these cities -Dhaka, Mumbai, Kolkata, Rangoon, Phnom Penh, Ho Chi Minh City, Jakarta, Manila, Hong Kong and, to a lesser extent or indirectly, Bangkok and Shanghai - are port cities created in colonial times, that have since become the principal city regions of their respective countries.