PAMBA IRRIGATION PROJECT



Salient Features

1.GENERAL

State

KERALA

District

PATHANAMTHITTA

Taluk / Village

Ranni Taluk / Vadasserikkara Village

Latitude

9ordm; 20rsquo;N

Longitude

76ordm; 53rsquo;E

River

River Kakkad, tributary of PAMBA

2.STRUCTURAL FEATURES OF DAM

Type

A central spillway portion flanked by bulkhead sections on either side.Bulkheads are straight gravity type random rubble masonry dams with coursed rubble facing. Spillway section is made of Random Rubble Masonry in cement mortar with ashlar ogee portion and R.C.C upstream face.

Top Width

5.48 M

Bottom Width

13.25 M

Length

115.22 M

Maximum Height from bed level

16.76 M

Slope upstream and down stream

1.Bulk Head on either sides Upstream face - 1:10 from 18.29m 21.62m and Vertical from 21.64m top Down stream face - 1:1.1 from18.28m to 21.64m,0.65:1 from 21.64m to 24.69m,0.4 :1 from 24.69M to 30.78m, and vertical from 30.78 to 36.88m

2. Spill way portion

Upstream Face ndash; same as that of bulk head Down Stream face ndash;Ogee profile is based on the model studies conducted at KERI,Peechi. Transition between the bowall and the floor is provided as a stilling basin with a curved floor of radius 6.70M

3.HYDROLOGICAL FEATURES OF DAM

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Catchment Area

287 Sq.Km

Probable Maximum Flood (PMF)

1280 cumecs

Method of Estimating PMF

By Ryversquo;s formula

4.SPILLWAY

Location

At the centre of the barrage

Type

Random Rubble in cement mortar with Ashlar Ogee facing and R.C.C upstream face

Total Length

64.31 M

Crest Level

29.26 M

Design Capacity of spill way

1287 cumecs

Number, type and size of gates

5 nos. Vertical Lift type ndash; size 10.70M x 5.50M

5.RESERVOIR FEATURES

Top Bank Level

36.83M

Maximum Water Level

35.35 M

Full Reservoir Level

34.62 M

Minimum draw down level

29.26 M

Dead Storage Capacity

Gross storage capacity

8 Mm3

Free board over F R L

2.21 M

Free board over M W L

1.48 M

Area of Reservoir at F R L

1.08 Sq.Km

6.HEAD SLUICE

Spill way

31.09 M

Spill Channel

No spill channel

Instrumentation

Nil