There is an interesting tale describing how sage Vashishtha had brought down Gomti from the heaven to earth.
At the time of deluge when the whole world had submerged in water, a lotus flower manifested from Lord Vishnu’s navel on which was seated Brahma. Lord Vishnu instructed him to perform his duty as a creator to which Brahma agreed.
First of all Brahma created his manasputras and sought their help in increasing the population of the world by becoming householders. But, all of them were extremely virtuous and did not show any inclination towards getting married.
Ultimately all of them went to the western coast and engaged themselves in austere penance. Their penance continued for a number of years after which ‘Sudarshan Chakra‘ appeared before them. As all of them looked up in bewilderment, they heard a heavenly voice – “O sons of Brahma! Very soon the almighty Vishnu is going to manifest himself. The ‘Chakra’ you are seeing is his. You all must perform the rituals of ‘ardhya’ in the name of Lord Vishnu to show your reverence towards him.”
All the Manasputras eulogized Sudarshan-Chakra with deep devotion. All of them wished that there were a holy river, with whose water they could perform the rituals of ardhya. But to their utter dismay there was no such holy river nearby. They then remembered Lord Brahma, who immediately understood what they desired.
Lord Brahma instructed Ganga by saying – “Ganga! Go to the earth, where you would be known as Gomti. Sage Vashishth will lead you to your destination. Just follow him like a daughter follows her father.”
Finally, when sage Vashishth followed by Gomti reached their destination, all the Manasputras were delighted. They eulogized Ganga and expressed their gratitude to Vashishth for bringing Ganga on earth.
All of them thanked Vashishth by saying – “Since you have brought Gomti on earth, you would be considered as her father.”
They offered ‘ardhya’ to Gomti and subsequently eulogized Lord Vishnu. Lord Vishnu appeared after being pleased and blessed them – “Your unflinching devotion in me has pleased me no bound. Since you did this penance with the objective of Moksha (salvation), this place would become famous as Moksha Dayak (giver of salvation). This sacrosanct place would also be called Chakra teerth because of Sudarshan chakra, who informed you all of my manifestation on earth. I assure you that I won’t abandon this sacrosanct place even for a moment.”
This way, all the Manasputras were finally successful in their objective of offering ardhya to Lord Vishnu with the holy water of Gomti. At last, Gomti having fulfilled her mission for which she had descended down to Earth merged with the ocean. Lord Vishnu disappeared from there and Manasputras continued to live there.