Matsya Purana — Rite and Layout for Consecrating Ponds
गर्ताश्च तत्र सप्त स्युस् त्रिपर्वोच्छ्रितमेखलाः सर्वतस्तु सवर्णाः स्युः पताकाध्वजसंयुताः //
gartāśca tatra sapta syus triparvocchritamekhalāḥ sarvatastu savarṇāḥ syuḥ patākādhvajasaṃyutāḥ //
There should be seven defensive ditches (garta) there, furnished with raised rampart-belts in three tiers; and on all sides they should be uniform in appearance, equipped with pennants (patākā) and banners (dhvaja).
This verse does not address Pralaya; it is a Vastuvidya instruction describing defensive infrastructure—moats, rampart tiers, and the use of flags—within a planned fort or city.
It supports rajadharma by prescribing orderly, standardised fortifications and visible royal insignia (dhvaja/patākā), reflecting a king’s duty to protect the realm and maintain disciplined civic planning.
Architecturally, it specifies seven moats and three-tier rampart-belts with uniform design; symbolically, the pennants and banners mark authority, auspicious presence, and organised guardianship of the settlement.