Polavaram Irrigation Project

Polavaram Project is located in Andhra Pradesh on the river Godavari, near Polavaram village about 34 Km upstream of Kovvur, Rajahmundry and 42 Km upstream of (Godavari Barrage) Sir Arthur Cotton Barrage. It is a multi-purpose irrigation project as the project once completed will provide Irrigation benefits for the upland areas of East Godavari, Visakhapatnam Districts under Left Canal and West Godavari, Krishna Districts under Right Canal and will generate 960 MW of Hydro Electric Power. In addition, this project will supply 23.4TMC of drinking water to Visakhapatnam city and also to Vizag steel plant through its left canal. It will also facilitate an inter-basin transfer of 80TMC annually to the Krishna river basin through its Right canal. It will also provide indirect benefits such as development of Pisciculture, tourism and urbanisation.

History of Polavaram Project

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 350,000acres (140,000 ha) over two crop seasons through this project, but also planned for a 40 MW hydroelectric plant within the project.

The old final designs of Polavaram dam was planned at full reservoir level (FRL) 208 ft MSL (Mean Sea Level) with 836 TMC gross storage capacity and 150 MW hydroelectric plant. It was named as the "Ramapada Sagar Project" since the backwaters of the reservoir would touch the Lord Rama temple at Bhadrachalam. Subsequently, FRL has been reduced to +150ft (46 m) with gross capacity of 194.6 TMC and total water utilization of 322 TMC

Works on the project commenced in 2005. Site clearance was obtained from the Centre on 19th September 2005, environmental clearance on 25th October 2005, R & R clearance on 17th April 2007, wildlife sanctuary clearance on 19th Sept 2008, forest clearance on 26th Dec 2008 and technical advisory committee clearance on 20th January 2009.
The Project has been accorded national project status by the union government in 2014 (under Section-90 of A.P. Reorganization Act, 2014). Polavaram Project Authority was formed in Jan 2015 under Ministry of Water Resources to expedite the project execution. Since 2015, the project has gathered pace of construction and is planned to be completed in 2019.

The Polavaram Project proposals consist of the following major components:-

1. Head Works: The Head works consist of Earth-Cum-Rock Fill dams across the main river with spillway on the right flank, and power house on left flank on downstream slopes.

The Earth -Cum- Rock Fill dam (Gap-II ) in the main river course is 1750 m. long with a maximum height of +53.320 m. (175 ft.), top width 15 m and with single plastic concrete Diaphragm wall of thickness 1.5 m.In addition, there are two Earth Dams (Gap-I and Gap-III) with a length of 564 M with top width 12.5M and a Length of 140 M and top width 12.5 m respectively proposed on either side of earth cum rock fill dam. Upstream and Downstream Coffer Dams are also proposed to be constructed during the construction of ECRF Dam for diverting the River.

The Spill Channel for a Length of 2920 m and bed width of 1000 m is proposed at downstream of spillway. Pilot Channel of Length 650 m with a bed width of 660 m is proposed at the end of Spill Channel to River confluence. An approach channel is proposed on the upstream side of spillway to divert water from river for a length of 2310 m and bed width 660 m.

The Spill Way has a length of 1054.40 m over flow section and non over flow of 37 m on either side with total length of 1128.40 m. It is having a 48 Nos. radial gates to pass a maximum flood discharge of 1.41 lakh cumecs (50 lakhs cusecs PMF).

Right side and left side connectivities: Series of structures/components are proposed such as regulators, tunnels with suitable entry and exit channels, saddle dams etc for connecting the main reservoir to the Right Main Canal and Left Main Canal of the Polavaram Project.

Protective Embankments: To avoid any sort of submersion in the territories of Orissa and Chhattisgarh, the protective embankments are proposed to be constructed to a length of 30.20 Km in Orissa and 29.12 Km in Chhattisgarh with a top width of 5 m and Average base width of 50 m. The protective embankments with adequate drainage sluices and pumping arrangements would help in the mitigation of loss of crop production due to submergence and preserve bio diversity in the area.

2. Right Main Canal: The Right Main Canal takes-off from the Head Regulator and runs to a length of 174 Km crossing major streams like Kovvadakalava, Yerrakalava, Gunderu, Tammileru and Ramileru etc., before emptying into Budameru above the existing diversion Regulator at Velagaleru near Vijayawada. The waters meant for diversion to Krishna river will then pass through the existing Budameru diversion channel and join Krishna River about 8 Km upstream of Prakasam Barrage.

The Right Main Canal is proposed as a lined canal and designed to provide irrigation facilities to an extent of 1.29 lakhs Ha. (3.194 lakhs Acres) of ayacut in upland areas of West Godavari and Krishna Districts besides diversion of 2.266 TMC (80 TMC) of Godavari waters into Krishna river near Vijayawada.

3. Left Main Canal: The Left Main canal takes off from the Nelakota subsidiary reservoir and runs for a length of 181.50 KM crossing major streams like Sarada, Mamidivaka gedda, varaha, Thandava,yerra,buradakalva etc. The Left Main canal is proposed as a lined canal and designed to provide irrigation facilities to an extent of 1.619 lakhs Ha (4.00 Lakhs acres) of ayacut in East Godavari and Visakhapatnam Districts besides industrial and water supply of 23.44 TMC. of Godavari Waters in and around Visakhapatnam city.

4. Power House: The power house is located at the down stream with necessary tunnels for penstocks and tail race channel with installed capacity of 12 units of 80 MW. ie., 960 MW

Technical Features

Slno	Description	Details
1	Earth-Cum-Rock fill Dam
(a)	Length	2454.0m
2	Spillway
(a)	Type	Gated Spillway with Ogee profile
(b)	Length of spillway	1128.40m
(c)	Crest level	+ 25.72m
(d)	No. of gates	48 Nos. 16 m x 20 m (Radial Gates)
3	Power house	960 MW (12 X 80 MW)
4	Right main canal	174.00 km (1.29 Lakh Ha) in West Godavari and Krishna districts.
5	Left main canal	181.50 km (1.62 Lakh Ha) in East Godavari and Visakhapatnam districts

Project Benefits

Polavaram will benefit all the 13 districts of A.P, directly or indirectly. Some of the main benefits to the State are as under:

• 7.2 lakh Acres of new ayacut to be created for irrigation
• Stabilization of 23.5 lakh acres
• Water Diversion: 80 TMC of Godavari water to be diverted to Krishna river
• Domestic & Industrial water Supply: 23.44 TMC of water to the industries in and around Vishakhapatnam including Vizag steel plant and Vishakhapatnam city.
• Drinking water Facility: Drinking water facility to 540 villages to a population of 28.5 Lakh enroute canals

Benefits to Other States

• Odisha and Chhattisgarh shall be benefitted with 5 TMC & 1.5 TMC of irrigation water respectively
• Odisha and Chhattisgarh can develop & exploit pisciculture and boating facilities in their own territories
• 80 TMC of water in Krishna river shall be saved on account of diversion of equal amount from river Godavari.
• The water saved in river Krishna shall be shared between Andhra (45 TMC), Karnataka (21 TMC) & Maharashtra (14 TMC)