So what constitutes a wetland? Why are they so special?
The Ministry of Environment, Water & Climate considers the Ramsar Convention definition of wetlands to have wide applicability in order to cover the whole world: “areas of marsh, fen, peatland or water, whether natural or artificial, permanent or temporary, with water that is status of flowing, fresh, brackish or salty…”
It prefers the more focused definition of the US Fish and Wildlife Service which considers wetlands as “lands transitional between terrestrial and aquatic systems where the water table is usually at or near the surface or the land is covered by shallow water” (Breen et. Al 1997)
The South African Department of Environment Affairs defines this, inter alia, as follows: “Marshes, bogs, swamps, vleis and sponges are examples of wetlands”
You should know the following facts about Harare’s wetlands
1. Harare’s major water source originates from the vleis and open green spaces around the city. Many are now being sacrificed to development for short-term monetary gain, they are being polluted by waste and destroyed by informal urban agriculture.
2. A vlei is an important type of wetland typical of the Mashonaland Plateau. It is a low-lying, marshy grassland, covered with water during the rainy season and even though it may seem to be dry during the winter season and droughts, it is actually storing water under the ground which it releases slowly into the streams and rivers – a natural regulator. A vlei ecosystem can be kilometres wide in extent with the drier fringes moving down to the wetter mid and central areas. All areas have an essential role to play in the provision of water.
3. Greater Harare and its environs sit in the headwaters of the Manyame and Gwebi catchment basin. 6.5 million people rely on this invisible source for their water supply. There is no higher place from where Harare can source its water. Many people are unaware that Lakes Chivero and Manyame are downstream of Harare and that this lake water needs to be pumped back up to Harare!
4. The City’s present water reticulation and sewage system is already totally inadequate. This is confirmed by the fact that:
• 40% of the residents of Harare do not receive clean water daily and the same number lack adequate sanitation. • Once prolific boreholes are now drying up and the water table has sunk in a decade from 15 to 30 metres on average.
• Only 600 00 million cu.m. of the daily city requirement of 1.2 million cu. m. is being treated, with the city’s sewage plants discharging thousands of cu.m. of wastewater and sewage into Lake Chivero.
5. Harare’s vleis and open grasslands provide numerous services, cost-free, for its residents. These include:
• Recharging of rivers, headwaters and aquifers of the Mashonaland watershed. (Headwaters and aquifers contain 97% of the Earth’s unfrozen fresh water).
• Highly effective filtration of this recharged groundwater – a task which would otherwise fall to the City’s over-extended and very expensive treatment works.
• Are a more efficient carbon sink than forests (Carbon dioxide accounts for at least 60% of the effect of global warming).
• Control of groundwater flow, which prevents river siltation and land erosion, as well as depositing nutrients to maintain wetland biodiversity.
What civil society can do is to jealously guard any existing wetlands, because if these are destroyed, it will be a case of “no wetlands – no water.” Let’s all work together to keep our wetlands intact! And, next time you drink water, think about where it came from and what it took to get it into your glass!!
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