The Khwae Noi meets the Nan River on the border of Makham Sung and Chom Thong .
Makham Sung lies within the Nan Basin , which is part of the Chao Phraya Watershed .
The Khwae Noi meets the Nan Basin   on the border of Makham Sung and Chom Thong .
Makham Sung lies within the Nan Basin , which is part of the Chao Phraya Watershed .