Cape Town - While the aftermath of the intense rainfall last week was still being dealt with, the rainfall figures recorded by the SA Weather Service (Saws) indicated that Monday, June 13, was the single wettest June day on the Cape Flats since at least 1960.
Saws senior forecaster Henning Grobler said for the Cape Flats, last week Monday was the highest recorded rainfall over a 24-hour period in June since 1960. It was recorded at their Cape Town International Airport weather station.
“A significant amount of rainfall was recorded over three days, from June 12 until June 14, mounting up to 120.7mm,” Grobler said.
However, Grobler said this rainfall did not affect their previous predictions that the Western Cape region would experience a relatively dry winter this year, and that they were still expecting a below-normal rainfall winter season for 2022.
UCT climate system analysis group PhD student Stefaan Conradie said: “June is the wettest month on average in Cape Town, its mountain catchments and along the West Coast, and the record was broken by a very large margin, so climatologically Monday’s rainfall was quite an extreme event.”
Over places in Cape Town itself, Conradie said more than the average total rainfall for June fell in a single day, including at the City’s Tygerberg rainfall station, which measured 130mm on Monday last week.
“At the Observatory station, 85.8mm was recorded. As far as I can tell, that is the fourth-highest daily figure in records going back to 1850. In the mountain catchments, well over 200mm has already been recorded at multiple weather stations – much more than had been forecast,” Conradie said.
Department of Water and Sanitation provincial head Ntombizanele Bila-Mupariwa said the significant downpours last week led to higher inflows into some dam storage systems across the Western Cape.
“The Western Cape hydrological report of June 20 shows significant increases in dam levels across the province. The Western Cape Water Supply System (WCWSS), comprising the six largest dams in the Western Cape, is now at 70.83% – a significant improvement from 63.92% last week,” Bila-Mupariwa said.
Local government MEC Anton Bredell said despite the rising dam levels, people should continue to use water sparingly as during the dry summer months they watched with great concern how dam levels inched lower and lower each week.
Conradie added: “Unfortunately, rainfall on the Cape Flats does not equate to run-off into our dams. Almost all of Cape Town's tap water is sourced from rainfall in the mountain catchments of the Boland.
“These areas did get a lot of rain last week (in some places about 300mm), but that still puts their totals so far this year below the long-term average.
“Despite the fact that dam levels rose by almost 7% last week, they are still about 3.4% lower than they were last year this time, when the start of June was also dry,” Conradie said.
Water and Sanitation Mayco member Zahid Badroodien said the increased rain last week came along with sewer and flooding challenges.
The City received approximately 1 900 requests over a two-day period, June 14 and June 15, all of which related to sewer overflows and other services from various areas across Cape Town.
kristin.engel@inl.co.za