Cape Town -
After one of the worst fire seasons in decades, Cape Town has started preparing for the next challenge – the start of the winter rains which wreak havoc in low-lying areas.
City departments are hard at work, unblocking drains, clearing canals and digging channels between dwellings in informal settlements to divert water away from homes, according to Enock Kopele, head of Cape Town’s winter readiness task-team.
“During planning for the winter rains, everyone ups their game,” said Kopele during a tour of Khayelitsha on Friday. “I can say we’re on the ball.”
The winter rainy season in Cape Town and surrounding areas, which starts about mid-May and continues until the end of September, causes soil in low-lying areas to become saturated as the groundwater table rises.
Some wetland areas where informal houses have been built can be covered in water for weeks.
Kopele said the city was also stocking up on flood relief packs, and was busy clearing vegetation around retention ponds and canals to help keep water away from informal settlements.
In public awareness drives, the city has also urged residents to implement flood mitigation measures.
These include digging makeshift trenches around homes to divert water, fixing leaks, and not dumping solid waste in drains.
Kopele said it was impossible to say when flooding would start, but the period between the last two weeks of May and August were high risk, and floods could be expected.
He added that the city worked closely with the SA Weather Service in a bid to be prepared. When heavy rain was predicted, city officials were put on standby and media alerts issued.
Infrastructure in some particularly high-risk areas had also been upgraded since last year’s floods, Kopele said.
In the Green Park informal settlement between Delft and Mfuleni, for example, 90 shacks are being moved from low-lying areas to three solid earth platforms that raise them 60cm off the ground.
In Flamingo Crescent in Lansdowne, which experienced extensive flooding a year ago, dwellings have also been raised, and new access roads built.
Kopele said the winter preparedness task-team was considering which areas to designate as “high risk” this year, which means they will receive special attention. This will be announced next week.
Dr Kevin Winter, of UCT’s department of environmental and geographical science, said 200 or more informal settlements in Cape Town were at particular risk of flooding as they were situated in low-lying wetland areas, on land that is typically not zoned for housing.
While these settlements remained dry in the summer months, with the onset of winter rain groundwater was recharged, and the soils of the Cape Flats Aquifer became saturated.
“Since these wetlands are often at the lowest point on the Cape Flats, there is no place where water can naturally drain,” he explained.
Winter said some “interim” solutions could help mitigate the effects of flooding in the short term.
These included building houses on stilts or raised platforms, ensuring that most houses had rainwater tanks to retain water, and reducing the amount of water that drains into lower-lying areas.
With an eye on a long-term solution, UCT is investigating how the Cape Flats Aquifer could be managed to use groundwater during the summer months, Winter said.
This would make room for more water to infiltrate the aquifer during the rainy season.
“An improved understanding of the aquifer and the recharge rate might create an opportunity to reduce the flood risk,” he said, adding that more research on the issue was needed.
Weekend Argus