HEC

Project location:Nam Rom river - Lai Chau province

Construction time:- Pa Khoang reservoir: 1974 - 1980
- Nam Rom weir: 1963
Project manager:Tran Tien Han, Do Van Huong, Luong Van Nguyen, Pham Van Thuc
Project duties:
- Irrigating 2950 ha of Muong Thanh field
- Power generation (Thac Bay hydropower) N = 2400 KW
- Tourism

Major technical parameters of Pa Khoang reservoir
- Work grade: III
- Total storage capacity: 37 million m³
- Effective storage capacity: 34.0 million m3
- Dead storage capacity: 3.0 million m³
- Main dam crest length: 187m
- Dam maximum height: 26m
- Spillway width: 7.8m
- Spillway discharge: 435 m³/s
Scale of project works:
- Earth dam
- Free, stepped spillway
- Canal system

Dien Bien irrigation project is a cascade one, it starts from Pa Khoang reservoir on Muong Pang mountain where top-ranking general headquarters of General Vo Nguyen Giap was located in the historical Dien Bien Phu campaign. The reservoir is placed at the location which is 400 m higher than Dien Bien Phu hollow. The reservoir water is discharged downward to supplement Huoi Pha - Nam Rom project.

Nam Rom weir was constructed of stone masonry coated with concrete. The weir is 55m long, 0.9m high, spillway discharge: 486 m³/s, irrigation discharge: 3.7 m³/s.

Water of the system is conveyed on 30 km of canal over 17 aqueducts to supply water for irrigation and domestic use of people in the area. In addition, there are 12 small reservoirs irrigating 700 ha.

Water of Pa Khoang reservoir is also supplied to Thac Bay hydropower with capacity of 2400 KW which supply power to Dien Bien city.

Owing to irrigation water, cultivation area of Dien Bien province increases rapidly, in the past it was 10 - 15 ha/crop, at present it is 46 - 55 ha/crop. In recent years, total food production of Dien Bien has been increasing, in 1962, it was 17,259 tons, in 1994 it increased to 151,018 tons. Average food reaches 430 kg per person per year.