Umzimkulu River – Thrombosis Gorge

Thrombosis Gorge, or “Thrombi” as it is commonly known, is one of the most popular technical sections in the country. The section includes Thrombi Falls, an 11m waterfall that is probably the most regularly run waterfall in the country.

  • Ideal for : Kayak
  • Grade: 4, at high level 5
  • Length: 1) 8km 2) 25km
  • Duration: 1) 2-4 hours, depending on amount of scouting. 2) 6-7 hours
  • Type: Pool-drop
  • Put-in: Bridge across river. First turn-off to Coleford from R617 when coming from Bulwer to Underberg.
  • Take-out: 1) Farm 2) Polela confluence
  • Levels paddleable: Look at low-level bridge at put-in. If small pillars are under water, the level is very high.
  • Dam controlled: No
  • Permits: Permission from farmer at first take-out

Umzimkulu Polela map

The most difficult rapids are the first 5 or 6 rapids after the put-in. They are all short and easy to scout, with decent pools between them. After them come a couple of long technical rapids which can be scouted doing eddy-hopping. A natural weir follows, which should be scouted but can also be run. Not a long way after this, a solid class 4 rapid forms the entry to the 11m waterfall. Get out on the left before the rapid and walk down to scout the fall. It has been shot many times, but a good couple of fellows almost came short on it. Don’t be pressured to run it, and if you do run it, stay away from the left.

Most paddlers take out at the waterfall. The walk is long and uphill, you basically have to ascend the hill on the right of the river. If you don’t run the waterfall, paddle upstream from the rapid on top of the waterfall for about 100m. Get out on the river right and start your hike. This take out is on private farmland. Definitely don’t use the take-out without prior arranging it with the farmer.

If you do the long section, you will encounter some of the best rapids on the whole section, soon after the waterfall. They are all runnable, but scout the bigger ones. The scenery is also awesome on the second section, making the long trip really worthwhile. Lots of play-waves can be found on the whole stretch.

Dewet Machau
Dewet Machau
Dewet Machau
Dewet Machau
Shaun Biggs freewheeling Thrombi Falls
Shaun Biggs freewheeling Thrombi Falls
Graeme Anderson reverse freewheeling Thrombi Falls
Graeme Anderson reverse freewheeling Thrombi Falls

Detailed trip report on Adrian Tregoning’s blog: Thrombosis Gorge – The Seldom Run Full Section

All pictures by Celliers Kruger, unless credited otherwise.

This river description is taken from my book “Run the Rivers of Southern Africa”.
If you have any pictures or recent information on this section of river to share, please contact me:
I appreciate any contributions to keep this content up-to-date.