Mahamaham is celebrated every 12 years at Kumbakonam, when people take a dip in the holy mahamaham tank. Does this also qualify as a kumbha mela? What is its scriptural background?
In order to answer does it qualify as “kumbha mela” would be necessary to understand the properties or meaning of some event to qualify as a kumbha mela. Definition of kumbha mela. But it would be entirely different issue. However, if we look at “kumbha mela” as certain brand name and event protected by UNESCO, Mahamaham does not qualify, it is in a different place and called “Kumbha Mela of the South” oftenly.
If we look at the aspect of origin and spiritual effect or importance it definitely qualifies. Origin is related to “kumbha” what is the holy pot of Amrita. It is involved in Mahamaham and Kumbh Mela. There is an astrological connection too. Mahamaham as one of the kumbha melas is in Maghā Nakshatra. Kumbakonam is a sacred place of great importance on its own rights. I would say that what you seek in Kumbha Mela you would find and achieve in Mahamaham (“Kumbha Mela of the South”).
To paraphrase from http://mahakumbhfestival.com : It provides us this great opportunity to purify our soul by bathing in holy water and serving saints. Kumbh mela south Wiki - Mahamaham