NISHANTH MARATI (13891A0128)

IDUKKI DAM

INTRODUCTION

IDUKKI DAM

This is one of the largest Arch Dam in Asia.

 It is constructed across the Periyar River in a narrow gorge between two granite hills Kuravan and Kurathi in Kerala, India. At 167.68 meters.

 It supports a 780 MW hydroelectric power station in Moolamattom, which started generating power on 4 October 1975.

Technically, the dam type is a concrete, double curvature parabolic, thin arc dam.

This dam was constructed along with two other dams at Cheruthoni and Kulamavu.

 Together, the three dams have created an artificial lake that is 60 km² in area.

The stored water is used to produce electricity at the Moolamattom Power house, which is located inside nearby rocky caves.

The Government of Canada aided in the building of the dam with long term loans and grants.

history The idea of constructing a dam

for power generation was first conceived in 1919.

In 1947, a preliminary investigation report was prepared and submitted by Sri. P. Joseph John.

The project report was prepared in 1961 and the Planning Commission accorded sanction for implementing the scheme in 1963.

In 1964, under the leadership of Sri. E.U.Philipose, Superintending Engineer, preliminary works of the project were started.

Storage of water in Idukki reservoir commenced in February, 1973.

Commercial operation of the Power Station was Commissioned on 12 February 1976 by the then Hon. Prime Minister Smt. Indira Gandhi. 

Type of Dam Concrete, double curvature parabolic, thin arch dam.

Impounds on Periyar riverHeight 168.91 m (554 ft)Length 365.85 m (1200 ft)Dam volume 450xConcrete volume used 478x

FEATURES

DAM

RESERVOIRTotal capacity 1996xActive capacity 1459xInactive capacity 536xCatchment Area 649.3Surface Area 60 Normal elevation 732.62 m (2404 ft)

POWER STATIONCommission date 1975Turbines 6x130 MW Pelton

TurbinesInstalled Capacity 780 MW

The Turbines installed here are pelton turbines.The reservoir is impounded with the power tunnel and two underground pressure shafts to an underground power house at moolamattam. The regulated waters from periyar falls with a drop of about 669.2 m is used for power generation in the underground power house.

POWER GENERATION

POWER TUNNEL Power Tunnel 23 feet dia (7.01 m)

finished horse shoe concrete lined (18 inches i.e. 45.7 cm minimum 22 inches average i.e. 55.9 cm).

Length 6652 Ft (2027.53mts)

SURGE SHAFTType Restricted orifice type

with inclined shaft completely underground.

Size 28 feet 6 inches (8.69 m) dia. finished 250 feet (76.25 m) long and inclined at 53°

PRESSURE SHAFTNo of pressure shafts (under ground)

2 nos

Length 3259Feet (993.34 mts)

UNDER GROUND POWER HOUSE No of machines 6Capacity of each 130MWPower Factor 0.9Size of power house 463 feet (141.1 m)

length.65 feet (19.8 m) width113.5 feet (34.6 m) height

Turbines 6 nos vertical pelton wheel type

Normal speed 375RpmRunaway speed 625 rpm

SWITCH YARDSwitch yard area 821 feet x 282 feet

(250.24 m x 85.95 m)Transmission lines One double circuit line

to Kalamassery one single circuit line to Tamil Nadu One single circuit line to Pallom and three feeder bays for future.