This is a nearly continuous creek near the Punakha Valley that is for the most part read and run. Most of the rapids are straightforward Class IV, but due to the continuous nature of this run you'll want to be a solid Class IV paddler.
Like many runs in Bhutan finding the put-in is a little tricky to find so you'll want to go with someone who has done it before.
Mile 0: Put-in at Phil's put-in. This spot is just below a big Class V rapid and pioneered by Phil DeRiemer. Below here the rapids are nearly continuous.
Mile 0.9: The Boof (IV+) is a distinct drop with a boof line on the left. This rapid can been seen from the road above and there is an eddy behind a big rock on the right above here that can be used to scout or portage.
Below the boof the rapids come in quick succession for the next two miles. Most are read and run but you want to have great boat control and water reading skills.
Mile 3.7: Take-out at a bridge near Bhutan Army barracks in Wangdue. You an also continue paddling down to the Puna Tseng Chhu.