1
9 February 2006
Memorandum
Floods update 2
Will Alexander
Why did the climatological community fail to forecast the widespread, heavy, drought-breaking rainfall over large regions of southern Africa?
Are floods beneficial or undesirable? These questions are discussed briefly below, but first read through the following news reports and try to balance the pros and cons of the floods using humanitarian, economic and environmental criteria.
News from Namibia
South African news reports received via granddaughter in Australia
Date: Thu, 09 Feb 200620:22:54 +1300
JOHANNESBURG
Flash floods cause havoc
A flash flood swept away two cars in Honeydew, Johannesburg and heavy rainfall continued to batter Gauteng and the Free State early on Thursday. Many accidents and traffic jams have been reported in Johannesburg's early morning traffic, while the Free State has reported flooded bridges and homes.
"The two cars were washed off a low-level bridge, each with one person in them," said ER24 spokesman Nick Dollman. "Both the drivers have been found, but the cars are still in the river." At 7.30am Dollman said the river water had subsided and the bridge, on Paul Kruger road where it turns into Nico Diederichs, was accessible.
In the Free State, the two bridges in and out of Wepener are under water, some roads are impassable and houses have been flooded. "The CaledonRiver is in full spate," said Sergeant Thandi Mbambo. "It is difficult to get in and out of town."
The road between Bloemfontein and Brandfort in the southern Free State was under water, according to the SABC. In the Thaba Nchu area, some roads were impassable and several houses in Ladybrand in the eastern Free State had been flooded.
Meanwhile, Johannesburg emergency services spokesman Malcolm Midgley said vehicles had been dispatched "to see how people are doing in the informal settlements in the flood plains".
He said reports of flooding had been received from StrubensValley, Boskruin and Wilgeheuwel. "Roads are under water," he said.
Sapa
______
JOHANNESBURG
Rainfall causes traffic chaos
Thu, 09 Feb 2006
Heavy rainfall caused traffic chaos across Gauteng on Thursday morning, sweeping away at least one car and flooding several bridges and homes. At least 40 accidents were reported since 6am. Emergency Services said they were stretched to the limit and were responding to several calls.
In Honeydew Ridge, the search for a man who was washed away in his car ended after he was found alive and well. The vehicle was swept off a flooded bridge early on Thursday morning. Security guard JT Mbula helped rescue the man, he said it was very difficult to get the motorist out of the water.
In KemptonPark, Ekhuruleni Metro Police Spokesperson Jimmy Maboko said several roads and bridges were also flooded. In Boksburg, an eyewitness reported seeing at least four cars floating under a railway bridge on Trichard Road.
Emergency Services Malcolm Midgely warned motorists to drive carefully.
In Alexandra, in northern Johannesburg emergency personnel remained on standby as they monitored the levels of the Jukskei river, which is renowned for flooding during heavy rains.
Emergency Services also reported a call about a house that's flooded in Fontain Bleu and a tree fallen across the road in Edenvale.
Highways in the area are reportedly slick with water.
Eyewitness News
______
MORE SA NEWS
BLOEMFONTEIN
Heavy rain submerges roads, bridges
Thu, 09 Feb 2006
Heavy rainfall over most of the interior over the past 24 hours has left two bridges and the road between Bloemfontein and Brandfort under water, SABC news reported on Thursday.
The Water Affairs Department said the CaledonRiver was flowing strongly and traffic authorities have advised motorists to use alternative routes. Emergency services in Bloemfontein say so far there is no danger of flooding.
Elsewhere in the Free State streams were flowing strongly in the Thaba Nchu area and some roads were impassable. Several houses in Ladybrand in the eastern Free State were flooded after a heavy downpour.
Heavy rains have also fallen in Lesotho.
Sapa
______
Swamped residents refuse to go
09/02/200608:50 - (SA)
Johannesburg - Residents of Somalia informal settlement near Boksburg are refusing to evacuate their flooded shacks and be evacuated to a community hall, an Ekuhurleni spokesperson said on Thursday. "Five shacks are under water and the residents won't be moved," said Kobeli Mokhoseng. "The homes are more than one metre under water. It is up to my knees as we speak," he said at 08:00.
"The shack owners want to stay here until the water subsides." They were not in danger of being swept away, because "there is no river nearby". "The area is a wetland. We keep on telling them not to build here everyday." Mokhoseng said emergency vehicles and tow trucks were also in Trichardt Road, Boksburg, which was flooded. "Two cars are trapped there, in the water."
Heavy rainfall continued to batter Gauteng and the Free State early on Thursday at 08:30.
Many accidents and traffic jams had been reported in Johannesburg's early morning traffic, while the Free State has reported flooded bridges and homes. "The two cars were washed off a low-level bridge, each with one person in them," said ER24 spokesman Nick Dollman. "Both the drivers have been found, but the cars are still in the river." At 07:30 Dollman said the river water had subsided and the bridge, on Paul Kruger road where it turns into Nico Diederichs, was accessible.
Meanwhile, Johannesburg emergency services spokesperson Malcolm Midgley said vehicles had been dispatched "to see how people are doing in the informal settlements in the flood plains". He said reports of flooding had been received from StrubensValley, Boskruin and Wilgeheuwel. "Roads are under water," he said.
# Send us your flooding pictures
______
JOHANNESBURG
Weather service warns of more rain
Thu, 09 Feb 2006
The SA Weather Service (SAWS) has warned of more rain for the flood-hit
provinces of Gauteng and Free State. This came as traffic chaos and reports of cars and people being swept away in Gauteng dominated early morning news reports on Thursday.
In the Free State, reports indicated that homes had been flooded, and bridges were under water.
More heavy rain till next week
"We are expecting more heavy rain, all the way to next week Tuesday," said
SAWS forecaster Abel Moatshe. It was "tropical moisture" which was normal
during this time of the year. The weather warning, on the SAWS website, said isolated heavy rainfalls were expected to persist over the eastern interior of the Eastern Cape, southern parts of KwaZulu-Natal, Lesotho and the extreme southern parts of the Free State.
Localised flooding
"Further showers and thundershowers may result in isolated heavy falls and
localised flooding for the remainder of the week," the website warning said.
Commuters in Johannesburg reported traffic chaos, saying it had sometimes
taken 45 minutes to travel 10km.
Residents refusing evacuation
Meanwhile, residents of Somalia informal settlement near Boksburg are refusing to leave their flooded shacks and be evacuated to a community hall. Ekuhurleni spokesperson Kobeli Mokhoseng said at 8am: "Five shacks are under
water and the residents won't be moved. The homes are more than one metre
under water. It is up to my knees as we speak. The shack owners want to stay
here until the water subsides." They were not in danger of being swept away, because there was no river nearby. "The area is a wetland. We keep on telling them not to build here everyday."
Roads flooded
Mokhoseng said emergency vehicles and tow trucks were also in Trichardt
Road, Boksburg, which was flooded. "Two cars were washed off a low-level bridge, each with one person in them," said ER24 spokesperson Nick Dollman. "Both the drivers have been found, but the cars are still in the river." At 7.30am Dollman said the river water had subsided and the bridge, on Paul Kruger road where it turns into Nico Diederichs, was accessible.
Free State flooding
In the Free State, the two bridges in and out of Wepener are under water, some roads are impassable and houses have been flooded. "The CaledonRiver is in full spate," said Sergeant Thandi Mbambo. "It is difficult to get in and out of town."
Sapa
______
Gauteng cars started floating
09/02/200622:38 - (SA)
A car carefully negotiates a road in Northriding, off Paul Kruger Drive,
Johannesburg, during the latest deluge. (Dezy de Lima, News24 user)
Related Articles
# N1 flood fears
# Two girls drown in flood
# More flooding forecast
# Swamped residents refuse to go
# Heavy rain causing havoc
Carina van Wyk , Beeld
Johannesburg - When Deon Fourie's Mazda 626 "literally started floating"
under a railway bridge in Plantation, Boksburg, on Thursday, 11-year-old son
Frikkie thought it "was hair-raising". But, of course, he wasn't scared. "My shoes got wet when the water seeped into the car," said Frikkie, but was adamant he wasn't nervous.
His sister, Michelle, seven, said: "All I know is, I like the idea of not having to go to school." Their car was one of at least four that were washed against bridges in
Boksburg on Friday after heavy rain. Riaan van Niekerk, 39, of SunwardPark, was also stranded under the railway bridge in Hospital Road in his luxury car. Van Niekerk thought he would be able to negotiate the water in his Mercedes-Benz. But, "a bakkie coming from the opposite direction caused such a wave that my
car stalled and there we were, at the mercy of the elements".
Two children drowned
The rest of the East Rand also was hit by floods. Two KwaTema primary school pupils drowned near Springs when they were swept away on their way to school. In the Anglo squatter camp near Lillianton, Boksburg, about 105 homes were flooded.
According to Martin van der Vyver, 24, of Northside All Round Towing
service, a woman had to swim to safety in Trichardt Road when her BMW also
was also caught under a railway bridge. "That BMW was full of water - only the roof could be seen." By 09:00, Van der Vyver had already towed away six cars which had stalled because of the flooded streets. "Normally, we have many accidents on rainy days, but on Thursday the main problem was stalled cars or others becoming stuck in the mud."
16 roads flooded
In Kempton Park, about 16 roads were flooded. Two of them - Vlei Avenue and the R23 in Pomona - were closed between 07:00 and 11:00.
______
Failure to forecast the heavy rainfall
When I criticise climate change enthusiasts they (politely) refer me to the published literature. However, they obviously never took the trouble to read my publications (202 at the last count). They also failed to read my many memos during the past three years, or my presentations at SASAS conferences during the past ten years, or my four flood alerts in November and early December. Had they done so, they would not have made the monumental mistake of not being able to forecast the heavy rains and floods over the African subcontinent. These started within six weeks of my flood alerts, which were disputed at that time. The heavy rainfalls are likely to continue for the rest of this season.
What went wrong?
Download my paper from the WaterSA website: Development of a multi-year climate prediction model.Water SA, Vol 31, No2. April 2005, 209-217.
Are floods undesirable or beneficial?
There are many references in the climate change literature to the effect that global warming will result in ‘an intensification of the hydrological cycle’ with consequent increases in the frequency of damaging floods and droughts. See for example John Houghton’s Global warming – the complete briefing p 126, etc. The implication is that floods will be an undesirable consequence of global warming. However, floods can also be beneficial. Loss of lives, livelihoods, damage to structures and interruption of overland communications are the principal negative effects. But the present floods have broken the drought, saturated agricultural soils, filled dams and restored ecosystems.
Would you not agree that the net benefit of the floods so far amounts to tens of millions of Rands worth of stored water alone and that the beneficial effects far outweigh the adverse effects?
What it all adds up to is that floods are generally beneficial and not undesirable, as climate change enthusiasts would have us believe.
The immediate future
A positive aspect of the floods so far has been the minimal loss of life. (Only four reported drownings on Thursday.) Emergency services have been very active and people living in vulnerable areas appear to be aware of the risks. The refusal of shack-dwellers to leave their homes, as confirmed in the above news reports, remains a worry.
With full rivers and dams the emphasis will now shift away from people living along streams and drainage systems to the very real possibility of serious floods in the larger rivers. The major concerns will be damage to structures and interruption of overland communications. Road communications may be temporarily disrupted as has just happened, but if the approaches to bridges or the bridges themselves are destroyed, this could have more serious consequences. Communities could be cut off from schools, jobs and medical facilities.
Dams are subject to stringent design standards so failure risks should be very small. However, there is always a degree of uncertainty when operating dams with gated spillways.
Engineers have learned a lot in recent years, so structural damage should be minimal. I like to think that I have played a major role in this field with my two books, many presentations and short courses.
I will discuss the above and other issues in more detail in later memos if the floods continue.
Regards
Will