The deterioration of the flood scene in Lakhimpur district following release of excess water from the Ranganadi dam has once again raised serious questions over the viability of mega hydel projects without assessing their downstream impacts as also the very idea of constructing such projects on the Himalayan biodiversity zone. "The Centre's grandiose plans of generating hydro-electricity through big dams in Arunachal Pradesh completely ignore the immense dimensions of the issues involved. This audacious, ill-conceived move would wreak havoc with riparian States like Assam,' noted environmental scientist Prof Dulal Chandra Goswami said. Referring to the 168 prospective hydel power dams in the region, mostly in Arunachal, as