While the whole month of Tamil month Aadi is considered to be auspicious there are certain days that are more significant.Aadi pathinettam perukku is one such festival that importance of water.It falls on 18th day of Aadi when monsoon is in peak.The word peruku signifies overflow/rising.The rivers & lakes will be overflowed with water during this time.
This festival is celebrated in an elaborate manner in the banks of Kaveri particularly in villages.Women wear new clothes. Some even take a dip on the holy rivers.Families join together and have lunch with prepared rice varieties on the banks of river.Sambar, rasam is not prepared during this day. Instead prepared rice varities such as Lemon rice, tamarind rice, curd rice, kalkandu rice/sakkari pongal is made (This is easy for picnicing to the river as well)
Though I did not have much chance to participate in the actual celebration near the rivers , we still prepare the rice varieties at home. This day is also auspicious to buy gold and to sow seeds.