Matsya Purana — Cosmography of Śākadvīpa and Successive Dvīpas: Mountains
तत्र मेघास्तु वृष्ट्यर्थं प्रभवन्त्यपयान्ति च तस्यापरेण सुमहाञ् जलधारो महागिरिः //
tatra meghāstu vṛṣṭyarthaṃ prabhavantyapayānti ca tasyāpareṇa sumahāñ jaladhāro mahāgiriḥ //
There, clouds arise and pass away for the sake of rainfall; and beyond that lies a very great mountain—the mighty, water-bearing range.
It does not describe Pralaya directly; it presents a cosmographical mechanism of rainfall—clouds forming and dispersing—supporting the Purana’s orderly functioning of the world rather than its dissolution.
Indirectly, it underscores dependence on timely rains and water-bearing regions—key concerns for kings (governing agriculture, irrigation, and famine prevention) and householders (sustaining dharmic livelihood through cultivation and water management).
No explicit Vastu or ritual rule is stated, but the focus on rain and water-bearing geography supports Vastu priorities like siting settlements near reliable water sources and acknowledging natural hydrology in planning.