Letter addressed to our most experienced CM by Vundavilli on Polavaram Copperdam issue
The Hon’ble Chief Minister,
Govt., of Andhra Pradesh.
Your proposal to increase the height of COFFER DAM, from 31m to 41m,so that Godavari water can flow into Polavaram canals on gravity..even without building the main dam… is widely published in Telugu dailies.
After consulting with irrigation experts, I am sending you certain observations for your kind perusal.
1) COFFERDAM is a temporary enclousure to create a dry work environment for the major work to proceed. This dam is dismanteled after the ultimate work is completed.
2) Will a 41m height, 1.7 kms length temporary dam COFFERDAM can withstand a flood flowing lakhs of cuses of water ?
3) 2,00,000 cusecs flow is very common in godavari floods.Polavaram is built with P.M.F of 45,00,000 cusecs. Imagine in a second the flow will be ( 28 liters a cusec x 2,00,000 )56,00,000 liters, in a minute it will be 33,60,00,000 liters.
4) A fault in a small bolt to canal gate has caused havoc in Bakra dam in 1954. Diversion of floods to the left side of Srisailam project during the construction, washed away the cofferdam. in 1953, 1986 the consolidated earthen flood banks of river Godavari were breached in several locations and in 2006 it almost threatened the flood banks again. The recent breaches of Polavaram right canal for a meager flow of 3000 cusecs is another classic example.
5) These incidents are being brought to your notice not to discourage, but one has to play safe with non rigid dams like cofferdam. With regard to functioning of a cofferdam to divert 35lakh cusecs flood into canals is like playing games with the river Godavari.
6) In the history of irrigation, nobody played like this with temporary cofferdams
>> and unlike Pattiseema, where you could pump only 8 to 12 tmc in this season, using 80 tmc capacity pumps worth 1600 crores… Any breach to Polavaram will be ending up in a death trap to lakhs of people in Godavari districts.
Vundavalli Aruna Kumar
, Rajahmundry. Dt. 14-9-2016