Narmada, one of the most sacred and virgin rivers of India, originates at Amarakantak and meets the Arabian Sea near Bharuch, Gujarat. This is a life - line of the area through which it flows. To utilize its water Narmada Valley Development Project is going on. It is inclusive of many major and minor dams. Sardar Sarovar Project is one of the biggest and most prestigious projects undertaken by the Narmada Control Authority. The resulting huge water body will affect the life of all living organisms. Looking to the inevitability of the project it is better to assess the loss and suggest measures to conserve it. To assess biodiversity of this area a 9-grade scale system has been devised. Out - come of this study indicates that 941 wild and naturalized plant species are going to be affected. Out of which 49 species are threatened. A new method for calculation of degree of risk for threatened species has been evolved. Apart from suggesting means to conserve these 49 species, diverse species of plants as a source for different purposes for the tribals have been documented and measures for their conservation are also suggested. Many colored photographs and line drawings are given which would be helpful for better identification of the vegetative wealth of the area. This area along with its vegetation is going to be submerged and the green wealth would be a story of the past.