Summer rains, is this unusual or just a reset.

[Bex]

For the 2010/2011 rain season we had 786mm. With 52 in Nov and 44 in Des 2010. Jan 2011 322mm. However we had good rain way past the normal season ending with 65mm in June 2011.

According to stats I have I will not bet on accuracy rain started in Oct 1987 with its peak in Feb 1988.
Were still working for Iscor in those days and remember that I were on call in Des 87. We had flooding at the mine and were running around installing pumps.

Sounds like something in between. I hope it is something in between , The river is much more overgrown than it was in 1988 so the same flow will push to higher levels.

[Bex]

This is a very hasty video, no time for editing.
Not much to see on the river side of it, just work done on the levee.
The sparks will fly later on.

[Peter1949]

At my home in Pinetown, KZN we have above average rainfall for Dec and Jan so far but nowhere near the maximums previously recorded.
Should I say (YET).
3 days of Jan. still to come ...

[DCTheron]

Sjo Groenkloof Pta just now:

Also had a huge storm same time, my garden was a river as well as the road in front, almost no tar to be seen.

[Flamand]

Did places like Sutherland, Loxton, Beaufort West get any rain?

Two weeks ago, I drove from via Sutherland and Fraserburg to Beaufort West. They seemed to have gotten rain. water next to the parts of the road, some small seasonal rivers flowing, and certain section of the road that were washed out.

[Rockgobblin]

For the 2010/2011 rain season we had 786mm. With 52 in Nov and 44 in Des 2010. Jan 2011 322mm. However we had good rain way past the normal season ending with 65mm in June 2011.

According to stats I have I will not bet on accuracy rain started in Oct 1987 with its peak in Feb 1988.
Were still working for Iscor in those days and remember that I were on call in Des 87. We had flooding at the mine and were running around installing pumps.

Grips, for comparison, Khumani YTD stats as at PDF.

Jun-Aug 2020: 0mm
Sept 2020: 2mm
Oct 2020: 11mm
Nov 2020: 167mm
Dec 2020: 226mm
Jan 2021: 302mm
YTD total: 708mm

[Mal Hannes]

In 2010 Desember preparing for the 2011 January flood I researched some of the numbers, 1988 flood reached a peak flow of 7700 Cumec, then in 2011 the peak flow was 5400 Cumec, but the total volume of water in 2011 was iirc about double the 1988 volume, the peak was spread by different times of rainfall in different areas and the damms spreading the flow.

For obvious reasons I am very curious about whether the current pattern is closer to 1988 or to 2010.

Jors I see the inflow into Gariep is nearly 6000 currently with them planning to release 3000 so prepare for big days because Van der Kloof is already full.

[Mal Hannes]

Jors I see the inflow into Gariep is nearly 6000 currently with them planning to release 3000 so prepare for big days because Van der Kloof is already full.

Does anyone have photos or videos of Gariep 116% full?

Rose 10% in 24 hours.

[Zapiture]

Not mine but taken yesterday:

[Bex]

I would like to see it today , should be way different if the numbers are to be believed.

[Mal Hannes]

I would also love to see the long bridge close to Bethulie must be flowing like mad.

[Bex]

On the DWAF site it shows an Unconfirmed flow rate at Aliwal Noord of 6154 Cumec, the last time the flow was above 6000 was in 1976 when it reached 6500.
The highest even recorded at that station was 6714 Cumec in 1925.

I often see comments about how the severity of weather events are increasing due to climate change, Looking at historic data I would suggest it has been rather mild recently.

[Mal Hannes]

I spent those 70's on my grandfathers farm between Jamestown and Aliwal and do remember a huge flood but have no idea if it was 1976.

[Commander]

I received a clip on whatsapp from Augrabies where water is running underneath the lower observation deck, unfortunately I can't be sure if it is current or old footage (possibly 2010? ), does anyone know the flow rates through there currently?

[Bex]

It should be about 600 Cumec right now. so old footage.

[Mal Hannes]

Jors or anybody who knows what is the maximum percentage that Gariep has ever been.

Currently about 115 percent and rising fast. How far can it go?

[Zapiture]

Jors or anybody who knows what is the maximum percentage that Gariep has ever been.

Currently about 115 percent and rising fast. How far can it go?

I’d love to know. Also what happens if it gets to high. What countermeasures? 115% seems crazy. Imagine the force on that dam wall and surrounding kloof.

This is what is holding it back:

“The wall is 88 m high and has a crest length of 914 m and contains approximately 1.73 million m³ of concrete. “ Wiki

[Zapiture]

Official opening of Gariep:

https://youtu.be/WW465-z4TvI

[RoelfleRoux]

I don't think the extra 15% adds much in terms of pressure on the wall. The V shape of the valley means that a few cm of water height will give the 15% in volume.
The civil engineers must tell us of pressure on the wall is influenced by volume or just column height. If it is only column height, then I suspect the extra 15% should be OK. I hope!!

[Bex]

I will see if i can find it.
This is the current in and outflow in cumec
Inflow - 6435
Outflow - 1807
The projected outflow looks like it will go up to 118% +