Upper Nirar Dam is constructed across Nirar River which takes its source from the Kattamalai Hills and takes the name of Kallar subsequently after its confluence with some of the streams. It falls into Edamalayar, the major tributory of Periyar River and finally falls in Arabian Sea.
Water will be diverted from this Reservoir through the unlined horse shoe shape Upper Nirar Tunnel to the adjacent Sholayar Basin.
By this reservoir Coimbatore District is benefitted. Valparai taluk is benefitted by this reservoir.
The construction of dam was started in the year 1970 and completed in the year 1976.