Srimad-Bhagavatam: Canto 1 - Chapter 1 - Verse 52
Sanskrit:
स्रोतोभि: सप्तभिर्या वै स्वर्धुनी सप्तधा व्यधात् ।सप्तानां प्रीतये नाना सप्तस्रोत: प्रचक्षते ॥ ५२ ॥
ITRANS:
srotobhiḥ saptabhir yā vaisvardhunī saptadhā vyadhātsaptānāṁ prītaye nānāsapta-srotaḥ pracakṣate
Translation:
The place is called Saptasrota [“divided by seven”] because there the waters of the sacred Ganges were divided into seven branches. This was done for the satisfaction of the seven great ṛṣis.