| Polavaram Project | |
| Dam Crosses: | Godavari River |
| Location: | Polavaram, Eluru district, Andhra Pradesh |
| Country: | India |
| Dam Type: | Concrete spill way (1128 m), Non over flow concrete dam (140 m) & Earth cum rock fill dam (2454 m) |
| Dam Length: | 37220NaN0 |
| Dam Height: | 39.280NaN0 up to top of earth dam above the lowest river bed. |
| Spillway Type: | Chute spillway |
| Spillway Capacity: | 3,600,000 cusecs at 140 ft msl |
| Construction Began: | 2004 |
| Opening: | 2029 July (Expected) |
| Status: | Under construction |
| Owner: | Government of Andhra Pradesh |
| Operator: | Andhra Pradesh |
| Res Name: | Polavaram Reservoir |
| Res Capacity Total: | 194 tmcft at FRL 150 ft msl |
| Res Capacity Active: | 175 tmcft (above 25.4 m msl crest level of spillway) |
| Res Capacity Inactive: | 19 tmcft (below 25.4 m msl) |
| Res Catchment: | 307800km2 |
| Res Surface: | 600km2 |
| Res Max Depth: | 32.08 m at FRL 150 ft msl |
| Plant Operator: | APGENCO |
| Plant Turbines: | 12 × 80 MW Kaplan-type (left bank side) |
| Plant Capacity: | 960 MW (under construction)[1] |
| Plant Annual Gen: | 2.29 billion kWh |
| Plant Commission: | 2026 |
| Location Map: | India Andhra Pradesh |
| Purpose: | Hydroelectric, irrigation & water supply |
| Coordinates: | 17.2892°N 81.6514°W |
| Website: | , |
The Polavaram Project is an under construction multi-purpose irrigation project on the Godavari River in the Eluru District and East Godavari District in Andhra Pradesh. The project has been accorded National project status by the Central Government of India.[2] [3] [4] Its reservoir back water spreads[5] up to the Dummugudem Anicut (i.e. approx 150 km back from Polavaram dam on main river side) and approx 115 km on Sabari River side. Thus back water spreads into parts of Chhattisgarh and Odisha States.[6] [7] It gives major boost to tourism sector in Godavari Districts as the reservoir covers the famous Papikonda National Park, Polavaram hydro electric project (HEP) and National Waterway 4 are under construction on left side of the river. It is located 40 km to the upstream of Sir Arthur Cotton Barrage in Rajamahendravaram City and 25 km from Rajahmundry Airport.
In July 1941, the first conceptual proposal for the project was mooted by the erstwhile Madras Presidency. Diwan Bahadur L. Venkatakrishna 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 envisaged cultivation of 350,000 acres (140,000 ha) over two crop seasons through this project, but also planned for a 40 MW hydroelectric plant within the project.[8] The project, when it was conceived in 1946–47, was estimated to cost Rs 129 crore.
In 1980, then Chief Minister of Andhra Pradesh Tanguturi Anjaiah laid the foundation stone for the prestigious Polavaram irrigation project. In the year 2004 Y. S. Rajasekhara Reddy performs bhoomi pooja with the estimation cost of 8,261 cr and the administrative sanction was accorded for construction of right and left canals at a cost of Rs 1,320 crore and Rs 1,353 crore.
After decades of delay, the main Polavaram Dam construction began under the next successive government of N. Chandrababu Naidu. After 2014 elections, then Chief Minister-elect N. Chandrababu Naidu has refused to be sworn in unless an ordinance is issued merging seven mandals of Khammam district with divided Andhra Pradesh, stating only then can the Polavaram Project be completed without further delay in future.[9] The Polavaram Project Authority was constituted by the Union Cabinet in May 2014 and the construction of project head works were taken up earnestly.[10] The Naidu government has acquired the complete lands that required across the right canal by solving court petition issues of farmers who lost their agricultural lands from both districts of West Godavari and Krishna and the Pattiseema Lift Irrigation Project has been launched in order to pump the Godavari river water and sent to Krishna river.[11] [12] In June, the state was bifurcated under the Andhra Pradesh Reorganisation Act. In December 2017, it was reported that the project contractor, Transstroy was seeking a deadline extension and a budget escalation.[13] Transstroy was reported to have its ₹4,300 crore loan turn NPA in July 2015.[14] In January 2018, the state government signed a new contract for the project spillway, spill channel and stilling basin concrete work with Navayuga Engineering[15] By June 2018, 1,10,355 acres of the required 1,68,213 acres had been acquired.[16] On June 11, 2018, the Polavaram diaphragm wall was completed marking a significant milestone in the project construction.[17] On January 7, 2019, The Polavaram project in Andhra Pradesh entered the Guinness Book of World Records by pouring 32,100 cubic meters of concrete in 24 hours by Navayuga Engineering. The project beat the existing record of 21,580 cubic meters which was achieved by Abdul Wahid Bin Shabib, RALS Contracting LLC and Alfa Eng. Consultant (all UAE), in Dubai between May 18 and 20 in 2017.[18] The Chief minister of Andhra Pradesh N. Chandrababu Naidu unveiled the first crest gate of Polavaram project on 24 December 2018.
| Spill way concreting work | 30 December 2016[19] | mostly completed as of May 2021 |
| Diaphragm Wall of earth cum rock fill (ECRF) dam | 1 February 2017[20] | 11 June 2018 |
| Jet Grouting | January 8, 2018 | October 29, 2018 |
| Upper coffer dam grouting | June 8, 2017[21] | Jan 8, 2018 |
| Lower coffer dam grouting | June 8, 2017 | Under construction |
| Spill channel concreting work | Apr 23, 2018 | Under construction |
| Right bank canal head works | Under construction | |
| Left bank canal head works | Under construction | |
| Navigation tunnel | Under construction | |
| Right bank canal works | 2016 (90% completed) | |
| Left bank canal works | Under construction | |
| Hydroelectric power plant | Under construction | |
| Blocking the natural course of the Godavari by raising the upper coffer dam level above the crest level (17.3 m MSL) of river sluice vertical gates (10 nos) provided in the spillway to divert the Godavari water through these gates. | 27 May 2021 | |
| Godavari water flows diverted fully through the river sluice gates of the spillway via the approach channel | 11 June 2021 | |
| Upper coffer dam works completed. | 31 January 2022 | |
| All the 48 barrage gates are fully erected and water can be stored in the reservoir to the extent permitted by the upper coffer dam design. | 30 June 2022 | |
| Lower coffer dam works completed | 17 February 2023 | |
| Completion of inspection and field investigation of damaged diaphragm wall during the 2020 Godavari floods and the decision was given to rectify the damage that took place. | 5 March 2023 | |
| Repair works of damaged diaphragm wall | 8 March 2023 | |
| ECRF dam | yet to start | |
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.[22] As a part of this plan, surplus water from the Himalayan rivers is to be transferred to the peninsular rivers of India.[23] This exercise, with a combined network of 30 river-links and a total length of at an estimated cost of US$120 billion (in 1999), would be the largest ever infrastructure project in the world.[24] In this project's case, the Godavari River basin[25] is considered as a surplus one, while the Krishna River basin is considered to be a deficit one.[26] As of 2008, 644 tmcft of underutilised water from Godavari River flowed into the Bay of Bengal.[27] But as of 2017 over 3000 tmcft are drained unutilised into Bay of Bengal.[28] 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.[26]
The capacity of right and left canals are 17,500 cusecs each. During the monsoon months (July to October), nearly 360 tmcft of Godavari flood flows at the rate of 3 tmcft per day can be diverted into the canals.[29] At least another 190 tmcft water from the water stored in the Polavaram reservoir along with lean season inflows, excluding the downstream Godavari Delta water requirements, can be diverted into these canals. Thus the total annual water utilization capacity of the Polavaram project is 550 tmcft. The water storage available in Sileru river basin is used as usual for the full water requirements of the Godavari Delta.
The hydropower plant (960 MW) will generate 2.29 billion kWh green or renewable electricity annually.[1] Polavaram reservoir will also create the potential to install nearly 1,58,000 MW high head pumped-storage hydroelectric plants in the future.
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 Ghats into plains covered with deep alluvial sandy strata.[30] 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.[31] 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 hydroelectric station. The progress up to the year 2012 in construction of dam structures and the hydro electric station is almost nil.[32] The alternate site located in the gorge stretch is still worth of re-examination to reduce the ever-increasing cost of Polavaram dam.
The spillway and non-overflow dam are founded on Khondalite bedrock in Polavaram Project.[31] 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.[33]
The project reservoir has live storage 75.2 tmcft at canal's full supply level of 41.15m (135.01feet) MSL and gross storage 194 tmcft thereby enabling irrigation of 23,20,000 acres (including stabilisation of existing irrigated lands) in Krishna, West Godavari, Eluru district, East Godavari, Visakhapatnam, Vizianagaram and Srikakulam districts of Andhra Pradesh.[34] [35] The silt free dead storage water of nearly 100 tmcft above the spillway crest level 24.5m (80.4feet) MSL, can also be used in downstream lift irrigation projects (Pattiseema lift, Tadipudi lift, Chintalapudi lift, Thorrigedda lift, Pushkara lift, Purushothapatnam lift, Venkatanagaram lift, Chagalnadu lift, etc.) and Dowleswaram Barrage during the summer months.[31] [36] [37] [38] Chintalapudi lift / Jalleru project will supply water to irrigate most of the highlands in Eluru district and NTR districts including the existing command area under Nagarjunasagar left canal in AP facilitating 40 tmcft saved Krishna river water for diversion to Rayalaseema from Srisailam reservoir.[36] GoAP announced the decision to construct Purushothapatnam lift irrigation scheme to transfer water at the rate of 3,500 cusecs to Polavaram left bank canal and further pumping at the rate of 1,400 cusecs to Yeleru reservoir for feeding Yeleru canal which is supplying water to Vizag city.[39] [40] Uttarandhra Sujala Sravanthi lift irrigation scheme will also use the Godavari water and a sanction of ₹2,114 crores was made in 2017 for its first phase.[41] [42] All the irrigated lands under these lift schemes can be supplied from Polavaram right and left canals by gravity flow when Polavaram reservoir level is above the canal's full supply level of 41.15 m MSL. However these lift stations are to be operated every year during the dry season to draw water from the substantial dead storage available behind the flood gates of the Polavaram dam. So these lift schemes are not for few years operation till the Polavaram dam is constructed but for permanent operation regularly for at least four months in every year. Nearly 80 tmcft live storage capacity available to Andhra Pradesh in Sileru river basin can also augment the water availability additionally to the Polavaram project during the dry season.[43]
The dam construction involves the building of a 1.5-m-thick concrete diaphragm wall up to depths from 40 to 120 m below the river bed under the earth dam which is the first of its kind in India.[44] The purpose of diaphragm wall is to secure the river bed stability for withstanding the water pressure across the dam. The project would constitute an earth-cum-rock fill dam of length, spillway of with 48 vents to enable discharge of 5000000cuft/s of water.[45] The spillway is located on the right bank of the river for which nearly 5.5 km long and 1.0 km wide approach and spill channels up to river bed level is envisaged involving nearly 70 million cubic meters earth/rock excavation which is nearly 2/3rd of the project's total earthwork. The maximum flood level at Polavaram is MSL and lowest water level is MSL. Two cofferdams are planned, one up to MSL, to facilitate faster pace of work on earth-cum-rock fill dam to complete the first phase of the project by June 2018.[46] With coffer dams inclusion and the bed level of the approach and discharge canals of the spillway increased to MSL, the spillway related rock excavation is reduced by 70% leading to substantial cost reduction in the project's head works cost. Ultimately, the material of cofferdams would be excavated and reused for the peripheral portions of the main earth-cum-rock fill dam. On the left side of the river, 12 water turbines, each having 80 Megawatt capacity, were to be installed. Without removing the upper and lower coffer dams after the construction of the ECRF dam, the 960 MW hydropower plant can not be commissioned as they are blocking the water passages of the powerhouse. The right canal connecting to Krishna River in upstream of Prakasam Barrage (long) discharges 17500cuft/s at head works and left canal (long) discharges 17500cuft/s of water.[34]
Indira Dummugudem lift irrigation scheme starting at is under construction to supply irrigation water for 200,000 acres in Khammam, Krishna, Eluru and West Godavari districts drawing Godavari River water from the backwaters of Polavaram reservoir.[47] This is a joint project between Andhra Pradesh and Telangana states. This project was shelved and merged with another project by the Telangana state.
The revised cost of the total project including the 960 MW power station is 47,726 crores at 2017-18 prices.[48]
In December 2016, NABARD handed over ₹1,981 crores, as part of its loan from the Long Term Irrigation Fund (LTIF) under the Pradhan Mantri Krishi Sinchayee Yojana (PMKSY).[49] NABARD provided a loan of ₹2,981.54 crores during 2016-17 and ₹979.36 crores during 2017-18 under the LTIF to the National Water Development Authority (NWDA) for the project.[50]