Ponnaiyar River
The South Pennar River is a trans-boundary river India.
Outskirts of Bangalore, Tiruvannamalai, Cuddalore are the important cities on the banks of South Pennar river. Where as, Hosur and Chengam are the major industrial settlements.
The river originates in the Nandi Hills in the Chikkaballapura district of Karnataka and flows through Tamil Nadu before emptying into the Bay of Bengal. It has a catchment area of located in Karnataka and Tamil Nadu states. Small dams of Kelavarapalli and Krishnagiri Dams are built across this river near Hosur and Krishnagiri. The largest dam on this river, Sathanur Dam with 7.3 Tmcft Gross Capacity is built near Tiruvannamalai. Moongilthuraipattu Sugar Factory is also situated on the bank of river.
The river is dry for the most part of the year. Water flows during the monsoon season when it is fed by the south-west monsoon in catchment area and the northeast monsoon in Tamil Nadu. However this water flow raises the water table throughout the river basin and feeds numerous reservoirs/tanks.
The old river Dakshina Pinakini does not exist anymore.
Substantial part of Bangalore's sewage enters this river via Bellandur and Varthur Lakes and other channels.
The sand build of the river is quite impressive, suggesting that it may have been a perennial river with much larger water flow in the past. Mention of the river is found in Sangam and medieval literature, where it is depicted as rich with lush vegetation on its banks. There are various temples on its banks. It irrigates Krishnagiri, Dharmapuri, Tiruvannamalai, Vizhuppuram and Cuddalore districts and empties into the Bay of Bengal .
This river is now looted for its rich availability of sand. As the water flow will be only in monsoon seasons, the river is dry in remaining parts of the year.
