Polavaram Project Status: Progress Under YS Jagan Govt in AP

4 Jan, 2021 10:43 IST|Sakshi Post

Polavaram status as compared to the five year period from June 2015 to June 2019 (Then) and the 18 months thereafter (Now)

1)Spill way: Total spillway blocks 53. Length 1118.4 metres. Foundation level -18.5 to + 10 mtrs. Spill way crest level + 25.72 mtrs. The previous government has completed +34 mtrs level spill way concreting up to  June 2019 whereas

Now; the length of spillway being 55 mtrs of which nearly +54 mtrs works are completed as of now.

2) Radial gates Spillway crust level is + 25.72 meters. The total number of gates is 48. The width of the gate is 16 meters and the height is 20 meters. By closing these 48 gates, the reservoir can store 194.60 billion cubic feet of water up to the full level +45.72 meters. To fasten these gates, the spillway pillars must be completed up to a height of +54.00 m. But the spillway pillars were not completed to a height of 54 m (at a height of +34 m) and the iron foil was temporarily fastened like a gate. It was advertised as radial gates installation completed then.

Now; 9 radial gates have already been installed for a total of 48 radial gates. Work on the remaining gates is expected to be completed by April, 2020

3) Spillway Bridge Concrete girders
Each spillway bridge is supported on 4 vertical girders. A total of 48 slabs have 192 vertical girders. The length of each girder is about 21 meters. Out of a total of 192 girders, only 22 girders have been completed in 5 years then.

 Now; a total of 170 girders were completed during these 18 months.

4) Spillway Bridge Slabs The Spillway Bridge Slab can be used to lift and lower gates from one side of the spillway to the other and for continuous inspection and monitoring of the gates by officers and staff.  Slabs should be constructed on the top of 48 columns. Each slab is approximately 21.5 mtrs long and 9.75 mtrs wide. The thickness is 0.45 mtrs.

 Not a single slab of work on these 48 slabs has been started in the last five years then.
 Now; construction of 40 slabs completed for a total of 48 slabs. Work is in full swing to complete all the slabs by February 15, 2021.

5) Trianon girders To install, operate and maintain the 48 gates on the spillway, 49 trianon girders are to be installed on the slope below the 49 pillars water flow. The arm girders of the radial gates are connected to these to operate the gates. The total weight of the gate, which weighs 300 tons, is based on these trianon girders. Trianon  girders must be completed to install the dam gates but they are not complete. To tighten the hydraulic cylinders the fulcrums should be fitted at a height of +45.00 m. But it’s not tightened. The level of the pillars should be at least 54.00 meters. None of this has been completed in the past five years, so the work of the Trianon girders has not started then.

Now; 40 girders were completed for a total of 49 trianon girders. All other trianon girders will be completed by the end of January, 2021.

6) Excavation works for foundations of Power House The Polavaram Power Station is designed to generate a total of 960 MW of electricity with 12 units each with a capacity of 80 MW. It is needed to  excavate from +135 m to +12 m for the powerhouse. Excavation work from +135 m to +110 m was completed before 2014.

The previous government excavated only 18 meters from +110 meters to +92 meters i.e. excavation work is still to be done at a height of 80 m i.e. from +92 m to +12 m. The Average height of 30 m is completed partially and still 90 meters is to be done.

Now; excavation started at +92 meters and average of 6000 cubic meters per day work is being done. The front of 1 to 6 units is almost complete for a total of 12 units. All excavation work will be completed by March

7) Rehabilitation and Resettlement (R&R) The construction of the Polavaram project has inundated 371 settlements of 222 villages in the East and West Godavari districts. Of these, a total of 1,05,601 displaced families are to be rehabilitated . In the last five years only 1846 houses have been completed in 15 rehabilitation centers. There is also a severe shortage of infrastructure in these rehabilitation centers then.
Now; Construction of 11,500 houses in 47 R&R colonies is almost complete in the last 19 months. The government is taking steps to rehabilitate 17,860 displaced families by May, 2021.

8) Spill Channel: Due to the unplanned construction of the Coffer dam, the entire spill channel was filled with flood water and mud due to the floods of 2019. The conditions were such that water and mud had to be removed to do the rest of the work. The spill channel is 2,920 meters long and 1,000 meters wide. This requires the completion of earthworks and the construction of 10 m long and 10 m wide concrete blocks with a thickness of 1 m. Not only works were started, but the major designs were not even approved. The soil on the left and right embankment slopes of the spill channel is slippery. Key designs for embankment slopes were not approved.

Whereas Now, About 1 TMC of water had to be pumped from the spill channel to start work after the floods. It took from November to February to complete the pumping of water. Then work began but due to the Covid-19 lockdown work had to be done very sparingly from March to June. Again in July 2020, floodwaters receded from the spill channel, disrupting the work of the spill channel. Floodwaters have been pumping into the spill channel since October. It will be completed this week. The concrete block is being laid while removing the mud and silt. All these works will be completed by the end of April this year. Major designs are all approved and steps have been taken to complete it by the end of April.

9) Coffer Dam In order to build the Earth cum Rockfill Dam uninterruptedly, upper and lower cofferdams must be constructed to prevent incoming floodwaters. If the upper and lower cofferdams are not built, it will be impossible build the main dam as water will reach to it. The upper Coffer Dam is 2,340 meters long and is to be built up to a level of 42.50 meters. Only 1200 m long, +28.00 m to + 33.00 m high in the middle of the Godavari has been partially completed in the last five years. The lower Coffer Dam is 1617 meters long and is to be built up to a level of 30.50 meters. It was partially built over a length of 950 meters. The important jet grouting, and linking of D wall, crucial permeation grouting works of Upper Cofferdam were not done and works of Upper Coffer Dam are stalled at various stages. Floodwaters and silt accumulated in the spill channel due to the diversion of flood water through the spillway and spill channel. This caused the project work to be delayed by two years.

Whereas, Now; the upper and lower cofferdam works are in progress as planned and the work is scheduled to be completed by June, 2021    

10) Gap-III Concrete dam
The length of the concrete dam is 153.50 meters, the width above is 8.5 meters and the average height is 22.32 meters, and the entire Gap-III dam consists of 9 blocks. In the last five years, during the previous government, the dam designs were not submitted and not even a single task was started.

However, in the current government, the designs were sent and were approved by the Central Water Energy Council and the work has also begun. So far, the foundation works in 12000 cubic meters were completed, while a total of 16000 cubic meters of concrete work is under process and estimated to be completed by April 2021.

11) Gap-I clay and stone construction
The length of Gap-I Earth-cum-Rockfill Dam is 564 meters, the width above is 12.5 meters and the average height is 29.32 meters. Similarly, the length of the diaphragm wall is 388 meters and has a total of 84 panels. The previous government had not submitted any designs of Gap-I Earth-cum-Rockfill Dam and work has not begun. In the current government, the designs have been approved by the Central Hydropower Board and the foundation works in two rigs are going at a fast pace. All other works are expected to be completed by June 2021.

12) Works on tunnel to supply water to right and left canals During the previous government term work on left canal did not start. The twin tunnel lining work was not done on the right side. Whereas during the 19 months there was much progress. To provide water to the left canal 919 mtrs long tunnel with 18 mtr  diameter should be built. About3.65 cubic mtrs stone should be dug of which 1.75 lkah cubic mtrs work is completed. The remaining work including lining is planned to be completed by December 2021. The right side twin tunnel should be dug, designs are done and the work is planned to be completed by December 2021.

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