It's a rare testimony to our advances in engineering sciences in the past. It's a rocky structure sandwitched between layers of sand, conclusively proving that it's a man-made structure. All versions of Ramayana elaborately describe the Setu bandhan events. Sculptures in ancient temples have portrayed the Setu bandhan events in details.
Risk to Thorium Deposits and Strategic interests: Our political leadership is selling out critical national interests, they are literally letting people steal thorium rich sands (4% yield, highest ever found anywhere else in the world) and shipping it out. There are FIRs registered for such instances. So this is happenning!! They want to use the canal for cheaply transporting out 'the sand'. Our former president/scientist Prof. APJ Abdul Kalam has stressed on nuclear self-reliance and in particular, a plan based on our thorium reservoirs. And such plans go haywire if thorium deposits vanish like this. The SSCP may result in erosion of thorium-rich sand deposit along the south indian coast.
US Navy refuses to acknowledge India-Lanka historical waters between India and Srilanka. The SSCP is cleverly drawn along the median making way for an international line and hence international waters.
Environmental Impact: SSCP is a sea-based channel and hence comparing it to Panama or Suez canal (both of which are land-based) is absolutely incorrect. Such a project has never ever been executed anywhere else in the world, still there are no proper impact