IDANHA DAM

PURPOSE - Irrigation / Hydroelectric
LOCATION GENERAL FEATURES
District - Castelo Branco
Municipality - Idanha-a-Nova
Site - Cabeço Monteiro
River Basin - Tejo
River - Ponsul river
Promoting entity - IHERA
Owner - Associação de Regantes e Beneficiários de Idanha-a-Nova
Engineering by - JAOHA
Construction by - Virgílio Preto, JAOHA
Project year - 1935
Year of completion - 1947
HYDROLOGY RESERVOIR
River basin area - 359 km2
Mean annual rainfall - 707 mm
Mean annual runoff - 91526 x 1000 m3
Flood runoff  - 700 m3/s
Reservoir area - 6780 x 1000m2
Gross capacity - 78100 x 1000m3
Effective storage - 77300 x 1000m3
Dead storage  - 800 x 1000m3
Normal water level (NWL) - 255,5 m
Maximum flood level (MFL) - 258,5 m
Minimum operating level  - 228 m
DAM
Concrete - Gravity dam
Height above foundation - 51 m
height above streambed - 44 m
Crest elevation - 258,5 m
Crest length - 143 m
Crest width - 5,2 m
Foundation - Granite
Volume of dam body
- 66 x 1000 m3
SPILLWAY BOTTOM OUTLET
Location - Left bank
Control type - Uncontrolled
Spillway type - Shaft spillway
Sill elevation - 255,5 m
Sill length - 80 m
Maximum discharge - 700 m3/s
Energy dissipation - Inexistent
Location - Thalweg
Type - Through the dam
Section - 2 x d 1,5 m
Upstream control  - 2 sluice gates
Downstream control - 2 butterfly valves
Energy dissipation - Inexistent
POWER PLANT
Type - Dam toe
Number of installed units - 1
Type of units - Francis turbine
Mean annual energy output - 4,5 GWh


ARROWA.GIF (181 bytes)            homeicona.gif (359 bytes)