Home Postcodes by state VIC 3580 Postcode 3580 3580 is the postcode for Koondrook, VIC. Localities with postcode 3580KoondrookVIC Postcode 3580 State or territory Victoria (VIC) Localities 1 Council area Gannawarra Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 3579 · Postcode 3581