Dusi 2010

Tuesday 26th January

The weather co-operated, the river quality monitoring intensity was stepped up and the two main municipalities (Msunduzi and eThekwini) pulled out the stops to get their sewer systems in order. The result was possibly the best water quality we have had a on a Dusi in the last 10 years.
The senior managers from the Msunduzi Municipality’s sewer maintenance section attended the pre-race “Officials and Helpers” dinner at the Natal Canoe Club on the evening of Tuesday 19th January, and were publicly singled out by Dusi Chairman Cameron McKenzie for the additional effort they had put in to make this possible. Thokozani Maseko, head of Water and Sanitation and Acting Deputy Municipal Manager said to me, “I wish every day was Dusi Day. Now that we have got the river like this, we need to keep it like this”. And we can all say “Amen” to that. We are by no means out of the woods yet, but there is hope.
DUCT will be surveying the Dusi paddlers over the next few weeks to check how many experienced symptoms of Dusi Guts either during or after the race, and we will report back via the KNCU and CSA newsletters, and via our website. There is still heaps of work to do on and around the rivers of course. For one thing, although the hyacinth and pistia was not as bad as in 2009, there is still far too much of it in the rivers. We will see what we can do in the year ahead to get that better controlled.
 
Tuesday 19th 13h05
Results for the samples taken yesterday by Umgeni Water show a continued improvement, although there are still issues in the Baynespruit. These are being dealt with and will be sampled again today. The data in from Durban (see table below) is also encouraging. With clean water being released from the dams (Henley, Nagle and Inanda) it looks like we can expect unusually good water quality for this year's Dusi. There is some light rain predicted for tomorrow, but this will be spread through the day and not enough to make much difference in the quality.
 
 
Dusi aboveEdendale weir 2 480 E coli/100ml
Dusi Campsdrift at NCC 2 760
 
Dusi at Low Level 1 350
Dusi Moto X 1 200
 
Campbells put in 1 000
 
 
 
Slangspruit Newport rd 4 000
Slangspruit at Duzi conflluence 20 000
Baynespruit Sobantu 88 000
Baynespruit Greytown rd 46 000
 
Monday 18th 10:21 am
What a pleasure to be the bearer of good news for a change. The results of yesterday’s sampling are as follows -
Dusi aboveEdendale weir 13 300 E coli/100ml
Dusi Campsdrift at NCC 1 300
Dusi at Mussons 2 800
Dusi at Low Level 4 300
Dusi Moto X 2 100
Dusi Grimthorpe rd 1 700
Campbells put in 400
 
Slangspruit Newport rd 17 200
Slangspruit at Duzi conflluence 3 100
Baynespruit Sobantu 10 000
Baynespruit Greytown rd 28 000
 
Conclusions : Msunduzi have clearly dealt with the major problems that were causing 1 000 000 + readings in the Baynespruit last week. However, it appears that there is still some contamination in the upper Baynespruit and upper Slangspruit to look into.
 
Paddlers, don't forget that on race day 3/4 of the flow is Henley water, which registered 40 E Coli/100 ml when tested on 11/01/10, so this does improve the quality significantly, whatever the base status is.
 
Umgeni Water is sampling this morning – will update you again tomorrow.
And a big thanks to Ian Bailey’s lab at Umgeni Water for processing the above samples on a Sunday!
 
Some data from Durban has just come in. (18 January 11h00). Note, while these levels are not too bad, just as the Duzi quality is improved by the Henley release, the uMngeni quality will be improved by the Inanda release.
 
E Coli results along the MGENI River for the month of January
Sample Point Location E.Coli (12 Jan) E.Coli (15 Jan) E.Coli (18 Jan)
R-MGENI_08 Umgeni River at Kennedy Road 1000 1500 500
R-MGENI_13 Umgeni - South end Ellis Brown Viaduct 500 4000 2500
R-MGENI_70 Umgeni River at Riverdene 1500 3000 1500
R-MGENI_71 Umgeni River below NWWTW 500 5500 500
R-MGENI_75 Combined Nkutu / Molweni Rivers 4500 1000 0
R-MGENI_80 Weir below Inanda dam 500
R-MGENI_91 Umgeni - North end of Connaught Bridge 500 3500 0
R-MGENI_92 Umgeni - North bank at Browns Drift 1000 7000 500
 
 
 
 

Quality Trend - uMsunduzi (PDF Download) Quality Trend - Blue Lagoon (PDF Download)
Pietermaritzburg - Latest Standard Data (PDF Download)    

Note - Water Quality for races on the Duzi River

Water is always released from the Henley Dam for the canoe races in Pietermaritzburg. The quality of water released from Henley is typically very good (less than 500 E.coli per 100ml). As this is a higher flow than the flow in the river without the release, this Henley water does significantly improve the quality of the water that paddlers are exposed to.

Interpreting the results
If you are a microbiologist or a seasoned paddler the stats above might mean something to you… but if not, you might find the following table useful when trying to interpret what the E.coli count means for you as a paddler.

Paddling is defined as a secondary contact sport and internationally the accepted safe level is 2 000 E.coli per 100ml. However, on the uMsunduzi and uMngeni Rivers paddlers often paddle with higher E.coli levels without suffering any ill effects. In years when the quality of the Duzi has been 10 000 or lower, the incidence of “Duzi guts” during events such as the Dusi Canoe Marathon has been low. In years when it has been high (in the 20 000 to 100 000 range) due to major storms, the incidence of “Duzi guts” has been high (up to 50% of the paddlers being affected).

After consultation with Umgeni Water and Water Affairs scientists, DUCT recommends the following guidelines for paddlers:

E. coli count / 100 ml Canoe use class
   
0 - 2000 Excellent
2001 - 5 000 Good
5 001 - 10 000 Acceptable
10 001 - 25 000 Tolerable
25 001 - 50 000 Poor
50 000 - 150 000 Unacceptable
>150 000 Dangerous

 

 

Thanks to Talbot Laboratories, Umgeni Water and WSP Environmental for monitoring the water quality in Durban and Pietermaritzburg on a weekly basis. DUCT does additional sampling at strategic times and places. null