Ganesh Chaturthi is the celebration of Ganesh's birthday. It's a 10 day long festival, marked by prayers, religious ceremonies, and large processions which ultimately culminates to a Visarjan on the last day. This year, the Visarjan falls on September 9th.
"Visarjan" = to respectfully lay a deity to rest, also means, immersion
Once upon a time...
In 1892 (around the time most of our GREAT grandparents were born), there was a man named Lokamanya Bal Gangadhar Tilak.
He was an Indian nationalist, and the first leader of the Indian Independence Movement. The British colonial authorities called him "The Father of the Indian unrest."
He's also credited as the architect of present day Ganesh Chaturthi celebrations.
Tilak saw the need to further unite Indians against the ruling English party, and realized nothing can bond people more than a common idol, equally worshiped by all.
He noticed that Lord Ganesh was considered "the God for everyman," worshipped by the rich and poor, leaders and followers alike.
A "crowd favorite," if you will.
The First Celebration
In 1892, Tilak organized the first Ganesh Utsav as a social and religious function in the streets of Pune and Mumbai. It was he who turned a rate intimate celebration into a grand 10 day spectacle.
Not surprisingly, he's also the man behind the tradition of immersing the huge Ganesh statues in a body of water, on the tenth day of the festival.
What is Visarjan?
At the beginning of the festival, devotees place a new Ganesh idol made of perishable materials like clay, paper pulp, lime paste, or other materials around the house.
On the last day of Ganesh Chaturthi, the people then practice Visarjan, directly translating to immersion. Just as Ganesh's mother, Goddess Parvati created him out of clay, his symbolic statue is as well.
Why is this done?
It is believed that the celebration of Ganesh Chaturthi also denotes the significance of the cycle of birth, life and death.
In addition to this, Ganesh is worshipped as the "remover of obstacles."
With the immersion of the idol, it is believed Ganesh is returned to the celestial realm. In addition, it also takes away the various obstacles of the house.
Nowadays, there have been rising concerns of pollution when immersing the idols in running water.
As a result, some towns have been implementing artificial bodies of water for the immersions. In addition they have encouraged more eco-friendly idols and performing the ceremony at home.