Following the heavy rains last week, the City of Cape Town assured residents that all have been done to reduce the risk of flooding in their area.
Several houses were flooded in Belmont Park last winter when a blockage resulted in the Plantation Road retention pond overflowing its banks.
Rob Quintas, the City’s Mayco member for urban mobility, visited the pond on the border of Wallacedene and Belmont Park last week to ensure that the work done since last year July has secured the pond to reduce the flood risk.
The detention pond adjacent to Plantation Road was constructed about 26 years ago to collect and detain stormwater during a flood situation and to let the water out within the 48 hours after the flood, once it is safe to do so.
“The pond is designed to accommodate a 1:50 year flood event. A normal blockage will clear itself due to the pressure of the water, however, an unknown and unforeseen blockage in the 300 mm diameter outlet resulted in the pond overflowing its embankment on 28 June 2021,” Quintas said.
“We have ponds like this one across the city and their purpose is to control water flow and make the surrounding areas safe. Last year, when we were informed about the flooding, sandbags were provided to residents as a temporary measure, while officials started working on a more permanent solution.”
A new 375 mm pipeline was constructed to enable drainage and the embankment was raised with milling to channelise the overflow.
Furthermore the sanitation department embarked on a massive clean-up action to remove all solid waste, mostly litter that end up in the pond through the stormwater system, and cleared the partially blocked outlet structure. This entailed the reconstruction of about 10 m of outlet pipe. A grid was also placed at the outlet to restrict litter from entering the pipes downstream.
“This pipe system is now recognised and marked as a ‘Red gulley’ item, meaning that it will be inspected and cleaned before the winter each year. The reconstructed pond will significantly reduce run-off and is now able to withstand extreme weather conditions,” he said.
“I must also appeal to all to please refrain from dumping litter and objects into our stormwater system. Last year’s incident demonstrated the devastating impact illegal dumping has on surrounding communities.”
