Package - 6
Kaleshwaram Project - Major Lift Irrigation Project
The Package-6 of the ‘Kaleshwaram Project’ is a lift irrigation project that envisages the lifting of 146.24 tmc of water with a total discharge capacity of 634 cumecs. The water is required to be lifted, almost vertically, to a height of 110 m, one of the highest lifts in Asia.
The project consists of twin tunnels, each 9.534 kms in length and 10 m dia, to bring the water into the surge pool. This surge pool, designed to withstand a sudden rise in water if ever the pumps trip, is the largest man-made cavern in India (375 m x 25 m x 67 m). The water from the surge pool is fed into each of the pumps through 7 draft tubes, each with a 5.8 m dia.
The underground pump house complex – L:210 m, H:50 m, W:25 m – houses 7 pumps of 124.5 mw each, requiring a total of 898MW. All the pumps have 5 m dia independent delivery lines. These steel lined delivery lines will carry the pumped water 110 m up, on a 45-degree gradient, to the delivery cistern.
NEC also had to face geological surprises during the construction of this technical masterpiece. When a natural calamity caused an unexpected cave-in in the earth’s surface, work was brought to a grinding halt. The engineers at NEC, with the assistance of researchers at the National Institute of Rock Mechanics, moved swiftly to competently tackle the problem, using rib cage structures to fortify the weaker portions.
A construction on such an enormous scale, especially 100 m under the ground, requires grit, determination, discipline and engineering ingenuity. It is precisely these qualities that enable NEC to succeed, even in the most unforgiving conditions.