SILCHAR: Notwithstanding the uncertainty over Barak dam, also known as Tipaimukh Hydro Electric Power Project, several NGOs and organizations have raised concern over the proposed construction of dams in Barak Valley and Mizoram. They have made reference to dams at the upstream of Barak, Rukhni, Sonai, Dhaleswari and Singla rivers which if constructed will spell doom for the people and environment.