Here is your short paragraph on Bera Utsav:
This is celebrated in the month of Bhadra in honour of the deity of water. It started during the reign of Mughal and is celebrated in grand scale in the district Murshidabad of West Bengal. L.S.S. O’Malley wrote in 1914.
This is observed by launching tiny lightships on the river, a spectacle which may be seen to great advantage on the Bhagirathi.
On certain nights in the rainy season thousands of little rafts, each with its lamp burning, are floated down the stream. Their construction is very simple, for a piece of plantain or bamboo bears a sweet-meat or two and the lamp.
The festival is celebrated with much magnificence on the last Thursday of the month of Bhadra (September).
A raft is constructed of plantain trees and bamboos and covered with earth. On this is erected a small fortress, bearing fireworks on its walls. At a given signal the raft is launched and floated to the further side of the river, when the fire-works are let off, their reflection on water producing a picturesque effect.