| S.No | Sub Basin List | Area | Rivers | District Covered | Reservoirs under WRD Control | No. of Tanks under WRD |
|---|---|---|---|---|---|---|
| Total Varahanadhi basin Area 7466.947 sq.km | ||||||
| 1 | Varahanadhi | 1827.874 sq.km | Varahanadhi, Ginjiyar Thondiyar Pambaiyar | Tiruvannamalai Villupuram | Vidur | 280 |
| 2 | Nallavur | 1031.097 sq.km | Nallavur Ar | Villupuram | – | 98 |
| 3 | Ongur | 639.623 sq.km | Nedungal Ar Ongurar Saram Ar | Kancheepuram Villupuram | – | 232 |
