Excavation work will come to a grinding halt at the Polavaram project site with the advent of rains. A formidable chunk of rock and earth has already been excavated till date.
As much as 67.58% of rock and earth has been excavated till Thursday, according to figures released by the Department of Water Resources. Chief Minister N. Chandrababu Naidu took stock of the excavation work to be stopped with the advent of rain after laying the foundation stone for the cofferdam and an iconic bridge across the spillway of the Polavaram Dam on Thursday.
The amount of rock and earth excavated for the different sections of the project were released by the department after the review meeting. As much as 713.27 lakh cubic metres (L Cum) out of the total 1,055 L Cum has been excavated till date.
The work done on the different sections of the project, however, varies to a great extent. A lot of work needs to be done on the approach channel that brings water from the main river to the spillway (the section of the dam with gates). Only about 20% of the work on the 2.- km channel, that is 28.09 L Cum, has been excavated and 102.91 L Cum is still pending, according to the figures released.
The excavation needed for the construction of the spillway with the capacity to discharge a flood of 50 lakh cusecs has already been completed. As much as 161 L Cum has been excavated to create space for the spillway foundation. Only half of the 163 L Cum of a hill (Hill 902) that is partial obstruction in the spill channel (the 2.56-km channel that leads from the spillway back to the main river) has been excavated. As much as 79.3 L of Hill 902 has been excavated, leaving another 83.7 L Cum has to be tackled. In a difficult achievement, 80% of the 288 L Cum of rock and earth from the main stretch of the spill channel has been excavated, but another 27.13 L Cum is still pending.
Besides Hill 902, the spill channel has two other components created for logistic convenience. The part that comes immediately after the spillway has been separated from the rest of the spill channel.
As much as 116.12 L Cum of rock and earth has been excavated from the section of the spill channel that comes immediately after the spillway. Excavation of another 27.88 L Cum is still pending in this section. This section has been marked as top priority in the next season that will start after the monsoon.
The target given for completion of these works is April 2018, after which water should go into the canals by gravity.
