For decades, Tanzania has been experiencing a phenomenal urbanization, which is characterized by exploding population growth amid declining public capacities to plan and manage urban growth. The negative consequences of rapid growth include acute community infrastructure deficiencies, urban sprawl, depletion of natural resources, and aggravated environmental degradation including pollution. While the rapid urban growth trend in Tanzania, just as many other countries in sub-Saharan Africa, is largely attributed to the socioeconomic and political changes in the country, the major driving forces of urbanization have been high birth rates, wide disparities in basic services between rural and urban areas, and increasing rural poverty. According to the 2002 National Population Census, the country's urban population grew from 2.1 million (12.7 percent) in 1978 to about 10.0 million in 2002, representing about 29 percent of the total population. Dar es Salaam's primacy is more striking than that in other urban centers; since 1968 the city population has grown threefold, but more or less doubled between 1988 and 2002.
Even though urbanization is inevitable and a necessary condition for diversifying national economies and boosting productivity, the public capacity deficits in urban planning and management have given rise to severe environmental, social, and economic problems, which are often interlinked in a complex manner and cut across many sectors. The traditional instruments established since the colonial days, such as master plans and structure plans, are unable to cope with the increasing demands and challenges in urban development.