Polavaram Project is a multi-purpose irrigation project which has been accorded national project status by the central government. This dam across the Godavari River is under construction. It is located in West Godavari district in Andhra Pradesh state of India.
National River-Linking Project, which works under the aegis of the Indian Ministry of Water Resources, was designed to overcome the deficit in water in the country. As a part of this plan, surplus water from the Himalayanrivers is to be transferred to the peninsular rivers of India. This exercise, with a combined network of 30 river-links and a total length of 14,900 kilometres (9,300 mi) at an estimated cost of US$120 billion (in 1999), would be the largest ever infrastructure project in the world. In this project’s case, the Godavari Riverbasin is considered as a surplus one, while theKrishna River basin is considered to be a deficit one.As of 2008, 644 tmcft of underutilised water from Godavari River flowed into the Bay of Bengal. Based on the estimated water requirements in 2025, the Study recommended that sizeable surplus water was to be transferred from the Godavari River basin to the Krishna River basin.
In July 1941, the first conceptual proposal for the project came from the erstwhile Madras Presidency. Later Diwan Bahadur L. Venkata Krishna Iyer, then chief engineer in the Presidency’s irrigation department, made the first survey of the project site and made a definitive proposal for a reservoir at Polavaram. Sri Iyer not only visioned cultivation of 350,000 acres (140,000 ha) over two crop seasons through this project, but also planned for a 40 megawatt hydroelectric plant within the project. The entire project was estimated to cost about ￼65 million (US$990,000). The old final designs of Polavaram dam was planned at full reservoir level (FRL) 208 ft MSL with 836 tmcft gross storage capacity and 150 MW hydroelectric plant. By 1946–47, the estimated cost rose to ￼1.29 billion. It was christened as Ramapada Sagar Project since the backwaters of the reservoir would touch the Lord Rama temple at Bhadrachalam. In the old finalised project design by Dr.K.L. Rao, the right bank canal of Polavaram project was extended to south of Krishna River to serve irrigation needs in old Guntur district by envisaging aqueduct across the Krishna River.
The project presently under construction is scaled down to FRL 150 ft MSL. The project cost estimate in 2004 stood at ￼86.21 billion.
In 1980, then Chief Minister of Andhra Pradesh T. Anjaiah laid the foundation stone for the project. However the project stayed idle until 2004 when the Y. S. Rajasekhara Reddy-led government came to power.In 2004, the Government of Andhra Pradesh sanctioned ￼13.2 billion (US$200 million) for the project. Soon after, tenders were issued for the commensurate worth of services for the right canal of the project. For the left canal, another ￼13.53 billion were sanctioned by the state government.
The dam could not be taken up for construction during the last century on techno economical grounds. The proposed dam site at Polavaram is located where the river emerges from the last range of the Eastern Ghatsinto plains covered with deep alluvial sandy strata. At Polavaram, the river width is about 1500 m. In view of large depth of excavation which is more than 30 m deep, to reach hard rock at this dam site, the dam project was not found economical to take up. However a lucrative alternate site is feasible located in upstream of Polavaram site where the river passes through deep gorges of Papi hill range. The width of river is about 300 m only in the rocky gorge stretch. Thirty years back, this alternative was found technologically challenging task to connect the reservoir with the irrigation canals via tunnels across the ghat area. Also costly underground hydro electric station is mandated compared to river bed based hydro electric station. When the project was actually taken up in the year 2004, the old finalised designs at Polavaram site are adopted without re-examining the latest cost of upstream alternate site in view of state of the art construction technology of tunnels and underground hydro electric station. The progress up to the year 2012 in construction of dam structures and the hydro electric station is almost nil. The alternate site located in the gorge stretch is still worth of re-examination to reduce the ever increasing cost of Polavaran dam.
The spillway and non-overflow dam are founded onKhondalite bed rock in Polavaram Project.Khondalites, which are feldspar-rich, often contain soft graphite, hard garnet, etc. in addition to other minerals. Khondalites are highly weathered and hence unsuitable at dam site.
As of 2004, the proposed project would hold 75.2 tmcftthereby enabling irrigation of an additional 232,000 acre in Krishna, West Godavari, East Godavari,Visakhapatnam, Vizianagaram and Srikakulam districts of Andhra Pradesh.
The project would constitute an earth-cum-rock fill dam of 2,310 metres (7,580 ft) length, spillway of 907 metres (2,976 ft) with 44 vents to enable discharge of 3,600,000 cu ft/s (100,000 m3/s) of water. To its left, 12water turbines, each having 80 megawatt capacity, were to be installed. The right canal connecting to Krishna River in the upstream of Prakasam Barrage (173 kilometres (107 mi) long) discharges 17,500 cu ft/s (500 m3/s) at head works and left canal (182 kilometres (113 mi) long) discharges 17,500 cu ft/s (500 m3/s) of water. The proposed project would displace 276 villages and 44,574 families spread across three districts of Andhra Pradesh. Tribals constitute 50% of such a displaced population. Human rights activists came out against the project because of these reasons. In addition, one activist pointed out that this interlinking of the rivers will harm the interests of the Telangana and Rayalaseemaregions of the state. Environmental activist Medha Patkar said that the project not only will displace several thousands of families, it will also submerge severalarchaeological sites, coal deposits, a wildlife sanctuaryand several hectares of farm land.
Sixty-four years after the initial conception of the project, the Government of Andhra Pradesh secured the environmental clearance from the central agency in 2005. This clearance was obtained after the state government prepared a ￼4,500 crore forest management plan and rehabilitation and resettlement proposal covering 59,756 hectares that were being lost under the project. In addition, ￼40,000 was to be allotted for each dwelling to be constructed for the displaced as against ￼25,000 provided by other states. Despite this clearance, the project faced political roadblocks. The Communist Party of India (M) and Telangana Rashtra Samithi were troubled with the issue of submerging agricultural lands and the detriment to Telangana, respectively.
Meanwhile, work on the project began in April 2006 and was expected to be completed by February 2007.After 30% work of excavation work on the canals and 15% of the spillway works had been completed, the work was halted in May 2006 to seek clearance from the Ministry of Forests and Environment.
The neighbouring state of Orissa also expressed its concern on the submerging of its land and decided to study this together with the officials from Andhra Pradesh. In response, Chief Minister of Andhra Pradesh Late Y. S. Rajasekhara Reddy clarified that neither Orissa nor Chattisgarh would be affected by the construction. The problem continued until 2010, when Chief Minister of Orissa Naveen Patnaik remained steadfast in his demand for compensation and rehabilitation of tribals of his state who would be displaced due to the submerging of their land.
Orissa and Chattisgarh have filed a petition in the Supreme Court against the Project which submerges large areas of its state and allege that Andhra Pradesh of going ahead with the project without the necessary permissions from CWC and Environment Ministry. The states also allege that public hearing in the effected areas for not held.