Should new cities be built on greenfields?
Quick poll: Do you feel that new cities should be built on “greenfields” (i.e. previously undeveloped land)?
- Yes of course
- Absolutely not
- It depends
- I have no idea
I live in the city of Lilongwe, Malawi. Malawi has four cities of which two (Blantyre and Lilongwe) are the biggest. Lilongwe is the capital city and Blantyre is the commercial city.
The City of Lilongwe has a population of about 674,448 with an annual growth rate of 4.3 percent, while the City of Blantyre has a population of 661,144 with an annual growth rate of 2.8.
Both the Lilongwe and Blantyre City Councils are responsible for all planning and development control functions in their respective cities through the Planning and Development Departments.
The land use plans, policy and related legal documents provide guidance and strategies in the development and management of the cities in addressing the rapid urbanization and development challenges.
The land use plans for both cities reserve some areas as greenfields. Most of these greenfields are along and/or around watercourses for recreation, environmental, ecological and biodiversity conservation purposes. However most of these greenfields are being highly encroached upon by non-conforming human activities which leave the environment too degraded for meaningful ecological and biodiversity conservation.
Blantyre gets much of its water supply from the Shire River whose source is Lake Malawi. Some of its water supply is from Mudi River. Lilongwe currently depends on only one source of water supply, the Lilongwe River. Originating from mountains, both the Mudi and Lilongwe Rivers are sustained largely by ground water resources. This implies that the catchment areas of these two rivers need to be preserved and protected at all costs if water supply is to be sustained in these two cities. Unfortunately, in practice, the opposite is true.
So my response to the quick poll question above would be “It depends” – being mindful of other factors that come into play.
In the tropics where the environment is drier than in the temperate regions it is not advisable to built on green fields. This is based on the common understanding that in this context “greenfields” mean areas preserved for wetlands and any areas around and/or along watercourses. Such areas in the tropics, arid or semi arid areas need to be preserved at all costs otherwise we will end up with dry cities where water supply for domestic use will be a serious challenge. This is apart from the aesthetic, fresh breeze, recreational, ecological and biodiversity conservation contribution that greenry adds to the urban fabric.
In the tropical part of the globe where I live some cities have not given green areas the much needed preservation attention that they deserve. Construction of buildings and agricultural activities have taken place along river banks and in wetlands. Some of these areas though not built upon have been cleared of trees and other ground cover. The result is that the greenfields that have been subjected to this kind of development have dried up.
Thus, apart from living in a dry environment, the city residents are facing the challenge of shortage of water supply for domestic use. During the rainy season when the water supply problem is supposed to ease, the water boards are faced with the challenge of high costs of treating the water to make it suitable for domestic use (suitable for human consumption, to be more specific). This is because the water becomes more turbid due to high surface runoff pouring muddy waters together with all sorts of pollutants from the built up environment and areas devoid of natural vegetation cover into the water intakes.
Another challenge in the tropics is that of flash floods during the rainy season which may result in loss of both life and property for those cities built in or along water courses.
Crudely speaking, it might be worth noting that in the tropics (arid and semi arid areas) when you pull down one tree the whole square kilometer dries up, ground water resources get depleted as evaporation rate gets accelerated due to lack of vegetation cover. Unlike in temperate regions where glaciers are always melting and continuously feeding into the rivers and other water courses, we can afford to make verandas of our buildings from part of river banks without fear that one day we may have a dry city. However, even in such regions greenfields need to be preserved for ecological and biodiversity conservation because it is a necessary component of our lives. There is need to strike a balance.
Thus in the tropics, those in authority need to take bold steps to make and abide by development policies that seriously protect greenfields. Global efforts need to be taken to sensitise those in highest authorities including politicians all over to be conscious of the need to conserve greenfields and be seen to be more committed to ensuring that the greenfields are conserved and protected at all costs. Experience has shown that brilliant development policies are always put in place but never implemented.
About the author: Catherine Kulemeka is a member of the Lilongwe City Council, Malawi.
Tuesday, August 13th, 2013