Multi-purpose river valley projects have dams built on rivers. The water blocked is used for domestic purposes, irrigation, industries, navigation and to generate hydroelectric power. Above all, these projects help in preventing soil erosion and floods.
Some major River Valley Projects are as follows:
1. Damodar Valley Project (ITVP):
Damodar Valley Project is a joint venture of Jharkhand and West Bengal. The project sets an example towards managing our water resources on scientific lines. Before completion of this project, flood in Damodar River caused damage to thousands of people and loss of property worth crores of rupees every year.
So it was called the 'Sorrow of Bihar (now Jharkhand) and West Bengal'. After the completion of this project the river has become a 'boon to' these states. Damodar valley has the largest deposits of black gold i.e., coal. Iron ore deposits of India are also found in its vicinity. The project consists of a series of small dams on the tributaries of Damodar. There are a few hydel- power stations.
2. The Bhakra-Nangal Project:
Bhakra-Nangal Project is a joint venture of Punjab, Himachal Pradesh and Haryana. Under this project, two dams have been constructed over the river Satluj. They are the Bhakra Dam and the Nangal Dam. The Bhakra-Nangal Project is an example of water management on scientific lines on the largest scale.
The Bhakra Dam has been built at a strategic point where two hills on either side of the Satluj are very close to each other. The dam therefore, is not very wide. It is the highest dam in the world. Its height is 26 metres from the river-bed. It is located in the seismic zone, and the hills that act as huge natural walls for storing 7,80,000 hectare-metres of water are made up of unconsolidated matter.
The other dam is 12 km down stream at Nangal. Under this project 1100 km long canals and 3100 kms long distributaries irrigate 14 lakh hectares of agricultural land. The project generates 1204 MW of electricity annually.
3. Hirakund Project:
It consists of three dams including the Hirakund Dam, the largest dam in the world across Mahanadi in Orissa. The canals have the capacity to irrigate 10 lakh hectares of land.
There are two power houses that have helped the steel plants, fertilizer plants and other heavy industries. It has a length of 4801 metres with 21 kilometres long dykes on both sides of the river. Its reservoir stores 8100 cubic metres of water. Its canals irrigate 2.51 lakh hectares of agricultural land. The total power generation capacity of its power house is 270 MW of hydro-electricity every year.
4. Tungbhadra Project:
The Tungbhadra Project is a joint effort of Andhra Pradesh and Karnataka on the Tungbhadra, a tributary of the Krishna river. Its irrigation potential is 4.97 lakh hectares of agricultural land. By 1981 the canals had started irrigating 3.22 lakh hectares of agricultural land. This 2.5 km long and 50 metre high masonary dam irrigates nearly 4,00,000 hectares in the two states.
5. Nagarjuna Sagar Project:
The Nagarjuna Sagar Project has come up in Andhra Pradesh on the river Krishna, near Nandi Konda village, 144 kms from Hyderabad. The dam has 3414 metres long dykes on both sides. There are two canals on each side of the darn, irrigating 8.64 lakh hectares of agricultural land. Canals on right side and left side are 204 and 179 kilometres long respectively. By adopting modern technology many ancient temples were dismantled and reconstructed by stone at new site.
6. Indira Gandhi Canal Project:
Indira Gandhi Canal Project is the longest canal of the world. The water of rivers Ravi, Beas and Satluj are stored in Harike barrage near Firozepur in Punjab. It runs as a feeder canal (201 km) through Punjab, Haryana and western parts of Rajasthan. The rest main 468 km long canal runs through the dry areas of north-western Rajasthan. The Indira Gandhi Canal makes cultivation possible in 'Thar desert' and provides water for irrigating pastures, drinking water and afforestation.