Figure of the week: Comparing Tanzania’s modern urban form to its original urban plan

While many sub-Saharan African cities are perceived to be unplanned, many larger cities have enacted some degree of urban planning. Still, many cities that did have urban plans seem unstructured. A recent report on the effectiveness of urban planning in Tanzania analyzes the links between the planning process and managing better urban growth.

The main study of the report investigates the impact and effectiveness of urban planning on city spatial development in seven secondary cities in Tanzania. In particular, the study compares how the city has currently developed with what it was initially planned to be. The authors found that, in all cities studied, only about 35 to 45 percent of city centers remained aligned with the initial urban plan.

For instance, Figure 3.1 below shows how Arusha compares to its 1985 urban plan. The horizontal bars represent the total area designated for each of the categories listed on the y-axis. Each of these bars is then broken up into what the actual land cover has become. For instance, of the total area designated to be forest and shrubs, only roughly 20 percent of it has remained as such, while the majority has been transformed into agricultural space.

Source: World Bank Group

Overall, for all cities in the study, the authors found residential conformity in core urban areas to remain moderate to high, ranging from around 48 to 78 percent conformity with the original urban plan. In contrast, economic uses such as commercial and industrial areas retained relatively lower levels of conformity, averaging about 17 and 25 percent, respectively. An important finding from the report claimed that cities with urban plans existing from earlier decades did not show better conformity compared to cities that adopted urban plans later, highlighting the complexity of this issue.

This leads the authors to raise the question, why were urban master plans ineffective at guiding urban development regardless of when they were introduced? The authors provide the following reasons for the ineffectiveness of urban master plans in the Tanzania cities studied:

1. Inherent weaknesses in the urban master plans themselves.
2. Disconnect between spatial planning, sector or infrastructure plans and budgeting, and investment planning decisions.
3. Lack of coordination among key agencies.
4. Lack of or ineffective development controls.
5. Unrealistic planning standards and regulations.
6. Limited capacity and resources for enforcement.

In fact, Tanzania’s current urban form is the product of growth in the absence of continued monitoring, implementation, and enforcement of urban plans. The authors propose more can be done to empower local authorities as they have the best on-the-ground knowledge. However, coming up with innovative yet practical solutions will be challenging.