PRACANA DAM

PURPOSE - Hydroelectric
LOCATION GENERAL FEATURES
District - Santarém
Municipality - Mação
Site - Foz da Ribeira de Pracana
River Basin - Tejo
River - Ocreza river
Promoting entity - CPPE, Companhia Portuguesa de Produção de Electricidade, SA
Owner - CPPE
Engineering by - A, Stucky
Construction by - SOLO
Project year - 1947
Year of completion - 1950
HYDROLOGY RESERVOIR
River basin area - 1 410 km2
Mean annual rainfall - 1 000 mm
Mean annual runoff - 611 000 x 1000 m3
Flood runoff  - 3 500 m3/s
Return period  -
1000 years
Reservoir area   - 5 500 x 1 000m2
Gross capacity - 111 900 x 1 000m3
Effective storage - 69 000 x 1 000m3
Dead storage - 42 900 x 1 000m3
Normal water level (NWL) - 114 m
Minimum operating level  - 97 m
DAM
Concrete -  Buttress dam
Height above foundation - 60 m
Crest elevation - 115 m
Crest length - 245,5 m
Foundation - Phyllite and greywacke
Volume of dam body
- 144 x 1 000 m3
SPILLWAY BOTTOM OUTLET
Location - In both banks
Control type - Controlled
Spillway type - Shaft and chute spillway
Sill elevation - 107 and 92,5 m
Number of gates -
1 ccylinder and 1 radial
Maximum discharge -
2 560 m3/s
Energy dissipation - Hydraulic jump
Location - Thalweg
Type - Through the dam
Maximum discharge - 52 m3/s
Upstream control  - Sluice gate
POWER PLANT
Type - Dam toe
Number of installed units - 3
Type of units - Francis turbine
Power installed capacity - 40 MW
Mean annual energy output - 61,8 GWh


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