Not for after this source the Trisuli joins the Bhote kosi that flows from Tibet; the two river joining in some pretty fearsome looking gorges that are visible on the way up to the Langtang Trek. By Betrawati the gradient has eased and after this is becomes a more mature and powerful river which later adds many other major river its flow - the Buri Gandaki, the Marsyangdi and the Seti. When the Kali Gandaki joins it, shortly before the plains, it changes its name to the Narayani. Here, it is a truly mighty river - peak flows in the Monsoon have been measured at 25,700 cumecs (extreme, instantaneous discharge) about 900,000 cubic feet per second or fifty times the typical flow of the Colorado River through Grand Canyon!
Normally the flow on the main rafting section of the Trisuli is about half that of the Grand Canyon, and in many ways the rapids are smaller scale versions of those on the Colorado; they are formed mainly by boulder outwash from tributary streams and are characterized by big green shoots, holes either side, and huge exploding waves down the bottom. The river has carved some truly impressive gorges in its lower part as it cut its way through the 2000 m high Mahabharat Range. These gorges are also the route followed by the prithvi highway is some way from the river itself. The opposite side to the road is relatively wild and uninhabited and you should see plenty of wildlife, a profusion of colourful birds, including eagles and vultures, especially ture if you continue on down in to Chitwan National Park where you may see crocodiles and rhino by the riverside.
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Asia Nepal Outdoor: Water Drifter Canoeing/Kayaking/Rafting