Mullaperiyar dam was one of the earliest instances of inter-basin transfers in the peninsular India. While it met the demand for water on one hand, it led to the deterioration of water quality downstream of the river. Salinity intrusion and pollution dispersion problems arose in the lower reaches of the Periyar due to non-availability of sufficient quantity of water for flushing. Another inter-basin transfer from the Periyar to the Muvattupuzha river due to the Idukki project has further adversely affected the downstream flow in the Periyar river.