Matsya Purana — Purūravas Beholds the Divine Himalayan River
हितां सर्वस्य लोकस्य नाकमार्गप्रदायिकाम् गोकुलाकुलतीरान्तां रम्यां शैवालवर्जिताम् //
hitāṃ sarvasya lokasya nākamārgapradāyikām gokulākulatīrāntāṃ ramyāṃ śaivālavarjitām //
A water-body should benefit all people, bestowing the path to heaven; its banks should be thronged with cowherds’ settlements, delightful to behold, and free from algae and slimy growth.
This verse is not about Pralaya; it focuses on dharmic public works—describing the qualities of an ideal, merit-giving water-body rather than cosmic dissolution.
It supports the duty of lokahita (public welfare): maintaining or creating clean, pleasant water resources that benefit everyone is presented as a high-merit act that leads to heavenly reward.
Vastu-wise, it prescribes a water-body that is aesthetically pleasing, socially integrated (near inhabited banks), and hygienic—explicitly free from śaivāla (algae/slime), implying upkeep and purity as part of sacred civic design.