DUCT News
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Clearing of blockage at Grimthorpe Bridge
DUCT team supervisor Nicholas Gumede and his team spent a day with the Msundusi Municipality’s drainage team, helping to clear pipe blockages at Grimthorpe Bridge.
The Dusi Committee are keen to explore alternative routes for seconders in this year’s Dusi Canoe Marathon. To this end, Duct was requested to remove litter and logs which had become lodged in the pipes underneath Grimthorpe Bridge recently. This blockage was causing the Dusi River to flow over rather than under the bridge. A decision will be made after the water release for this coming weekends race, to see whether the level of water coming over the bridge is safe enough for normal vehicles to cross.
Removal of Water Lettuce on the Drift
To allay fears of a “portaging start” to this year’s Dusi Canoe Marathon, DUCT have been busy spraying the alien weed infestations on the Drift with herbicides arranged by SprayChem of PMB. In the photo above Zamu Ngcobo and Sibusiso Nene of the DUCT drift team can be seem spraying water lettuce.
It is not generally well known that these seasonal flushes of aquatic weeds are due to the high nutrient loading caused by inadequate and poorly functioning sewerage systems in and around PMB.
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| Pietermaritzburg - Latest Standard Data (PDF Download) |
| Quality Trend -Blue Lagoon (PDF downlaod) |
Note - Water Quality for races on the Duzi River
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).
| 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.