Your Tihanuaco world is at least Post-Flood as the world before the Flood had completely wiped out.
Yes Tiahuanaco is post-Noachian/Great Flood. But so is Atlantis: only Atlantis sank not the whole world; Atlantis was a separate landmass to Old World and Opposite Continent (while there was one landmass in Genesis 1, and the continents didn't split until flood or Babel or Peleg in the bible).
Tiahuanaco has an event described in very similar words to the "flood(s) & quake(s)" sinking event of Atlantis. They also have a version of Joshua's long day maybe-about the same date. Tiahuanco has matches for any/all of the proposed dates of Atlantis (9000 yrs, 900 yrs, 9000 months, etc).
There are two versions in Peruvian, one has Tiahuanaco before flood (matching Atlantis, and matching postflood copy/memory of preflood Enoch), other has it after flood (matching Great Flood). The legend of a lost sunken city of Wanaku in southern lake Titicaca also matches both Atlantis and the Tiwanaku. Huinaymarka name of southern Titicaca also means "eternal city", again relating to both.
I've just been looking for candidate matches and origins of the name Tiwanaku/Tiahuanaco/Tiaguanaco (Akapana, Kalasasaya, Pumapunku) around the world.
Biblical: Tubal (b/v/w interchange, l/n interchange, meaning/metals match)? Enoch? Asshur/Calah (matches with both Atlantis and Tiahuanaco in nature/meanings, called a "great city", compare Calah & Kalasasaya)? Anak/Anakim? Zoan? Tanak? Zion? Teman (m/w interchange)? Tubal-cain? Tiras (n/r interchange)?
Mesopotamian: Anaku "tin land" (compare Wanaku)? Iatukki (Dilmun land, compare Iatuk- & Tiahu-/Tiagu-)? Du-ku "heavenly mound"? Unug/Uruk/Warka (compare Unug/Warka with huanaco/wanaku)? E-anna/E-ana? Zi-ana "spirit of heaven"? Awan? Tianu/Tidanu (West/Syria-Palestine)? Dil-mah-ilani or Dur-ili/Dur-ilu or Dur-ash ("great fortified place of the gods", Dilmun, matches in nature)?
Transoxania/Turmenistan: Anau?
Indian: Dwarka?
Chinese/Taiwanese: Taiwan? Huanki? Tian/Tien "heaven"?
Maori/Polynesian: Hawa-iki?
Mexican: Teotihuacan? Tenoch(titlan)? Tehuantepec?
Peruvian: Wanaku (a legendary lost city in southern lake Titicaca)? Huinayamarka "eternal city"?
African: Tenbuch/Timbuktu?
Ethiopian: Tana? Ezana?
Norse/Germanic: Heaven?
Roman: Janicula/Janiculum (Dianus/Janus)? Tuscan?
Greek: Atlantis (matches in nature/details)? anax/wanax "king"?
So there is no doubt this city Tiahuanaco was early and reknowed around the world, and matches Atlantis city, and matches one of those Biblical & Sumerian names/places. Jim Allen and Zecharia Sitchin and me also showed other links of Andean with Sumerian.
The only major ancient high civilizations outside of the India, Greece, Egypt area are Peruvian, Mexican, Etruscan, Chinese. And we know Atlantis was west of Italy, Libya, Greece, Egypt, Asia, and so Atlantis can only be Mexican or Peruvian. Mexican doesn't match large rectangular plain surrounded by "highest" mountains. Peruvian is the only major civilisation in the tropic of capricorn latitude band or southern version of the norther 10-40 block (tropic of cancer latitutde band or pyramid belt).