ENVIRONMENT and ENERGY
33
Fire and water
Cape Town recently had a spate of intense wildfires that were out of control at times across the peninsula. Some may argue that the fires were started by arsonists, but this is unsubstantiated. Whatever the reason for the fires, it has had devastating effects on natural resources, property, and animals, both wild and domestic.
By
Andrew‘ Andy’ Camphausen
Cape Town’ s average rainfall patterns are less than half of the world average. The Cape has had water restrictions for a while now, with the most recent, Level 3, having entered in full swing in November 2016.
While travelling from George to Cape Town recently, I noticed exactly how dry the landscape is. It does not paint a good picture for the once picturesque Cape.
With the fires in mind, a question came to mind: what are the effects on water quality and erosion behind wildfires?
The bad news Streams, rivers and dams can experience increased sediment loading following a wildfire. Run-off from erosive upland areas can transport sediment to surface waters. The loss of vegetation, which prior to the fire assisted with holding streamor riverbanks together, can lead to instability and erosion. Increased sediment loads in surface waters can affect aquatic habitat, food webs, and fish-spawning grounds, and in severe cases can directly cause fish mortality rates. Downstream, higher sediment loads can fill dams and reservoirs used for drinking water and it can increase processing requirements for water treatment plants. The deposition of ash into water bodies can also affect fish by limiting visibility and clogging gills. High nitrate levels in water that has been eradicated from the fire in plants that is used for drinking water can be a concern for human health. The ash or carbon that falls to the forest floor is water retardant. When rain falls onto the ground following a fire, the earth cannot absorb the water and growth nutrients that are present in the water. This rainwater that starts at the top of a hill or mountain cannot be absorbed, which can eventually become a flood of mud, or the risk of mudslides become more prominent. With this in mind, domestic houses that are built below the flood line of a river and the flood being imminent from the hill or mountain, thus drastically increases the very real risk of loss of human life and property.
Andrew Camphausen
Andrew( Andy) Camphausen has been in the building / plumbing industry for over 20 years. During his six years in the Free State, he was nominated and served as the vice-chairman of IOPSA Free State. He was offered a Regional Management position at Cobra Watertech, which is still his employer today. In 2011, Andy was promoted to National Channel Manager of the Commercial Sector, where he was transferred to the head office in Bryanston, Gauteng.
The good news While the effects of a severe fire( like in Cape Town recently) can be devastating, the effect of low to moderate intensity fires can be rejuvenating to the health of an ecosystem. Low to moderate intensity wildfires can encourage vegetative succession and promote diverse habitats. Prescribed fire( firebreaks for example) can be used as a tool not only for forest health but also for long-term water quality management.
The fact remains that the Cape is currently under immense water and drinkingwater pressure, which these fires have made so much more difficult for authorities to overcome. It is going to take many years to rehabilitate both the fire-stricken areas and the potential health to our potable water system. PA
February 2017 Volume 22 I Number 12