i mentioned this before. it is part of a jihad for tamil nadu's glory by the dmk types.
the part about the destruction of what is believed to be rama's bridge by hindus does not enter into the picture at all. naturally. hindus after all have no power to preserve things that are important to them.
the large-scale dredging there will result in unpredictable side-effects. much like all the US Army Corps of Engineers dredging and straightening of rivers and whatnot in the Mississippi Delta and in Florida have created huge problems. this is why i am skeptical about the river-linking project too. i'm afraid we'll open up a pandora's box.
in terms of setting up a trans-shipment container terminal, the best bet would have been vizhinjam, with its draft of 56 feet. instead, the christian govt of oommen chandy got it moved to the christian-dominated town of cochin. there should be no investment in southern kerala because there are hindus there, naturally. the big investments should go to southern tamil nadu or central kerala because that's where the christians are, and of course the dmk is a christian construction. vizhinjam getting the container terminal would have made a lot of sense: it is 300 nautical miles closer to the international shipping lanes in the arabian sea than cochin is.
neither cochin nor tuticorin has a big comparative advantage when it comes to deep water suitable for large container ships. i seriously doubt if after dredging and destroying rama's bridge, there will be any benefit at all to tuticorin. colombo and trincomalee both are far better ports than tuticorin.
you may think there's an element of regional bias here, and you will be right. however, the basic points are correct. sethusamudram is an ecological and archaelogical disaster in the making.