Client:                 Hydraulic Project Investment and Construction Management Board 8

Location: DakLo and DakLe streams in Loc Ngai and Loc Duc communes, Bao Lam district, Lam Dong Province

Objectives and Tasks:

• The two headworks Dak Long Thuong and Dagle reservoirs, of the Dak Long Thuong Water Resources Project have the following functions:
  • Irrigation: Irrigating 3,689 hectares of industrial crops, including:
    • Dak Long Thuong Reservoir: Gravity irrigation: 2,276 hectares; Supplementary Source irrigation: 800 hectares
    • Dagle Reservoir: Gravity irrigation: 333 hectares; Supplementary source irrigation: 280 hectares
  • Domestic water supply: Supplying water for 3,000 people with a standard of 60l/person/day and night.
    • Maintaining a downstream flow of 0.045 m³/s during the dry season.
    • Additional functions: Flood mitigation, aquaculture, environmental improvement, and tourism development

Main technical specifications:

• Grade of works, Storage capacity:
  • Dak Long Thuong Reservoir:   grade II. Storage capacity: 11.663×10⁶m³
  • Dagle Reservoir:                         grade III. Storage capacity: 2.301×10⁶m³

Dam type:

• Dak Long Thuong Reservoir: Earth-fill dam with two zones, maximum height Hmax=37.2m, dam length 340m
• Dagle Reservoir: Homogeneous earth dam, maximum height Hmax=15.6m, dam length 200m.

Water intake:

• Dak Long Thuong Reservoir: Crest elevation: 881.75m. Lc=159.35m , sluice demension Þ100cm, Qdesign=1.72m³/s
• Dagle Reservoir: Crest elevation: 875.0m. Lc=64.0m, sluice demension Φ60cm, design discharge Qdesign=0.36m³/s.

Spillway:

• Dak Long Thuong Reservoir : free spillway with labyrinth weir,          connected to a sloping apron and bottom energy dissipators. Constructed of M200 reinforced concrete. Physical width Bspillway=18.0m, effective width Beffective =38.0m; Design discharge Qdesign=116.13m³/s.
• Dagle Reservoir: free spillway with labyrinth weir. Followed by a stilling basin and a 40m long canal connected to a sloping apron. bottom energy dissipators, constructed of M200 reinforced concrete. Physical width Bspillway=8.0m, effective width Beffective=14.0m; Design discharge Qdesign=23.13m³/s.

• Total investment amount/Construction: 438.798 billion VND (First Quarter of 2009)
• Duration:
• Commencement: 2008
• Completed: 2011