In the legal tussle between Karnataka and Goa over Mahadayi river water share, the issue of demand of societal needs and the threat to ecological destruction are the key. The verdict of the Mahadayi Water Disputes Tribunal has apportioned the water between Karnataka, Maharashtra and Goa. However, Goa is the worst hit as its ecology is at stake. Karnataka has flouted environmental laws and gone ahead with the construction of canals, claims Goa. Almost 2 decade old dispute has now reached the Supreme Court. It will be a challenge for the Goa government to protect its environment as MWDT has already upheld Karnataka’s demand of water on the basis of principle of societal needs. This chapter analyses the options available before Goa to protect its environment.