La Punilla multipurpose scheme

The Punilla multipurpose project will be built on the Ñuble river, about 70 km East of Chillán in the Ñuble region (Central-South of Chile). The main purpose of the scheme is to secure and improve the irrigation in the valley. Additionally, the scheme is equipped with a powerhouse which uses the irrigation water releases to produce power (approx. 500 GWh/yr). The project main features are: - a 32 m high upstream rockfill cofferdam; - two diversion tunnels (D=10 m, L=850 m and 1'015 m) designed for an AEP 1:30 return period flood discharge of 1’800 m³/s; - a 137 m high CFRD (Concrete Face Rockfill Dam) which impounds a 625 Mm³ reservoir; - a gated spillway located on the left bank equipped with three radial gates (BxH=11,0 x 17,5 m) and a chute ending with a ski jump, designed for a discharge of 4'800 m³/s (AEP 1:1’000); - a bottom outlet (B=2.5 m, H=3.5 m, radial gate) located in a diversion tunnel; - a 410 m long penstock in tunnel and buried (D=5.2 to 2.2 m); - an external powerhouse equipped with two 47 MW Francis turbines (Q=2*52 m³/s); - a bottom outlet with two Howell Bunger dissipating valves (D=1.55 m) installed in dissipation chambers; - a substation of 220 kV.
Country
Chile
Reference location
Ñuble Region, 400km south of Santiago
Final client
Astaldi SpA
Is Consortium
False
Start of works date
End of works date
Start of services date
1/1/2016
End of services date
12/31/2018
Services
Preliminary studies; Construction supervision; Civil designs; Electromechanical designs; Special studies