Matsya Purana — Division of Bhārata-varṣa
विमला चञ्चला चैव तथा च धूतवाहिनी शुक्तिमन्ती शुनी लज्जा मुकुटा ह्रादिकापि च ऋष्यवन्तप्रसूतास् ता नद्यो ऽमलजलाः शुभाः //
vimalā cañcalā caiva tathā ca dhūtavāhinī śuktimantī śunī lajjā mukuṭā hrādikāpi ca ṛṣyavantaprasūtās tā nadyo 'malajalāḥ śubhāḥ //
Vimalā, Cañcalā, and likewise Dhūtavāhinī; Śuktimantī, Śunī, Lajjā, Mukuṭā, and also Hrādikā—these rivers, born from Ṛṣyavanta, are auspicious, their waters pure and undefiled.
This verse is not about Pralaya; it belongs to sacred-geography material, identifying auspicious rivers and emphasizing the purity (amala-jala) of their waters rather than cosmic dissolution.
By naming rivers as ‘auspicious’ and ‘pure-watered,’ the text supports the householder/kingly practice of tīrtha-bathing and honoring sacred waters—acts associated with personal purification, merit (puṇya), and public religious patronage.
The ritual takeaway is the sanctity of specific rivers—useful for planning tīrtha observances (snāna, tarpaṇa). Architecturally, such river-lists inform where ghāṭas, shrines, and pilgrimage infrastructure may be established, though no direct Vāstu rule is stated in this verse.