Stream bank cultivation: Its effects on the environment

STREAM BANK cultivation refers to the practice of growing crops conducted within a 30-metre radius of a wetland such as a river, dam or lake.
Major drivers of stream bank cultivation
Landlessness compels cultivators to seek livelihood from riverine fields. The local political and traditional leadership indicate that local land pressure, drive desperate cultivators to marginal lands.
River basins are ideal for crops and vegetables that require high levels of moisture. The erratic rainfall and the perennial droughts that are being influenced by climate change have led famers to cultivate river banks.
The high urban population being caused by an increase in rural to urban migration is also to blame. This has resulted in an increase in urban pressure and so to sustain the pressure the remaining land has been used as an alternative for farming.
Unemployment and economic challenges have driven communities to practices SBC. It has given an immediate reprieve from the harsh realities of urban unemployment.

Impacts of stream bank cultivation

While the arguments above seem sympathetic to the practice of stream bank cultivation, this cannot be seen as an excuse for the destruction of river ecosystems.
Fertiliser used in the river banks is washed away into the rivers, resulting in eutrophication, which ends up creating dense plant and bacteria colonies that feed from these nutrients, including invasive aquatic plants, one of the culprit plant is the hyacinth weed, that has racked havoc in Lake Chivero and some catchments.
The use of pesticides and herbicides along the river channels results in the deterioration of the water quality. The ingested chemicals result in processes known as bioaccumulation and biomagnification. Sometimes people eat the poisoned fish and the impact can be fatal.
Stream bank cultivation, leads to siltation of the local dams and rivers, which previously used to supply water for livestock and other domestic purposes. Communities downstream of affected water bodies risk losing their livelihoods because they also depend on the same rivers for water for farming and for their livestock.
Stream bank cultivation leads to the destruction of the ecosystem, which will inevitably put the life of many people in danger, as compared to a handful of the community benefiting from this illegal form of agriculture. Streambank cultivation chokes rivers with silt, consequently silting dams to the extent that this creates serious water shortages, which will result in a serious deficit for water for hydropower generation, irrigation, water for domestic use and for animals.
What the law says
According to the Environmental Management Act Chapter 20:27 as read with Statutory Instrument 7 (Environmental Impact Assessment and Ecosystems Protection Regulations):
(1) No person shall, without a licence issued by the Agency, the proof whereof shall lie upon him or her, to reclaim or drain, drill or make a tunnel, introduce any exotic animal or plant species, cultivate, or license the cultivation of, or destroy any natural vegetation on, or dig up, break up, remove, or alter in any way the soil or surface of a wetland or land within thirty metres of naturally defined banks of a public stream, or land within thirty metres of the high flood level of any body of water conserved in artificially constructed water storage work on a public stream or bed, banks, or course of any river or stream
Any contravention of this provision will attract a fine not exceeding ZWL50 000 or both such fine and imprisonment.