SOME INDIAN EXAMPLES
The Nagarjunsagar is located near Nandikonda village of district Nalgonda in Andhra Pradesh. The main dam in located at latitude 160 34' 23"N and longitude 790 18' 47"E. It is an earth cum gravity dam and has been dubbed as the giant among the Indian masonry dams. The height of the dam in 125m and cumulative length of the crest is 4,865m. Out of this the earthen part makes 3.415m, masonry part 978m (both non overflow sections) and the spillway section being 472m. The dam consumed 5,610,000M3 of concrete and masonry as well as 2,350,000M2 of earth. It has been built on river Krishna for serving the purpose of irrigation and hydropower. The Ogee type spillway has 26 redial gates each measuring 13.72X13.41m with a maximum discharge capacity of 53,540m3/s. The reservoir area is 285 km2 with its gross storage and effective storage capacities being 11,550,000,000m3 and 6,990,000,000m3 respectively. The available draw down is 24.38m. The catchment area is 2,15,192km2 with a mean annual runoff of 42,360,000,000m3. The catchtment area receives an annual rainfall of 89 cm. The power plant is conventional Fransis vertical types with a generation capacity of 700MW. The construction of the dam started in 1957 and it was commissioned in 1974. Figure 1 shows an image of the dam with X-section of earthen and concrete parts.