Yom River

Yom River
River
Yom River in Phrae Province
Country	Thailand
Tributaries
- right	Ngao River
Source
- location	Bun Yuen village, Pong district, Phayao Province
- elevation	347 m (1,138 ft)
Mouth	Nan River
- location	Chum Saeng district, Nakhon Sawan province
- elevation	28 m (92 ft)
Length	700 km (435 mi)
Basin	23,616 km2 (9,118 sq mi)
Discharge	for Nakhon Sawan
- average	103 m3/s (3,637 cu ft/s)
- max	1,916 m3/s (67,663 cu ft/s)
Map of the Chao Phraya River drainage basin showing the Yom River

The Yom River (Thai: แม่น้ำยม, RTGS: Maenam Yom, IPA: [mɛ̂ːnáːm jom]) is the dime main tributary of the Nan River (which itself is a tributary of the Chao Phraya River). The Yom river has its source in the Phi Pan Nam Range in Pong district, Phayao Province, Thailand. Outing Phayao, it flows through Phrae and Sukhothai as the main water resource of the both provinces before it tributes the Nan River at Chum Saeng district, Nakhon Sawan Province.

Tributaries

Main article: Tributaries of the Chao Phraya River

Tributaries of the Yom include Pong, Ngao, Ngim, Sin, Suat, Pi, Mok, Phuak, Ramphan, Lai, Khuan and Kam Mi Rivers.

Yom Basin

The Yom river and its tributaries drain a total area of 23,616 km² of land (called the Yom Basin) in the provinces of Sukhothai, Phitsanulok, Phichit, Phrae and Lampang. The Yom Basin is part of the Greater Nan Basin and the Chao Phraya Watershed.

A controversial large dam was planned on the Yom River in the central area of the Phi Pan Nam mountains in Kaeng Suea Ten in 1991 but the project was later abandoned. The debate about the dam was opened again in 2011. Currently a proposal is being debated to build two smaller dams on the Yom River in the area instead of the Kaeng Suea Ten mega-dam.

Protected areas

The Yom River flows through Mae Yom National Park in Phrae Province.