Tirohia te wāhanga i raro nei, kātahi ka whakautu i te pātai i muri mai i te reo kotahi me te wāhanga:  Passage: I tīmata te rangahau ā-ipurangi i runga i te awaawa o Eifel i te rau tau 19. Ko C.A. Eick te kaiwhiwhi o te puna tawhiti rawa atu i Cologne i Grüner Pütz tata ki Nettersheim (i te 1867). Ko te rangahau raupapa o te awaawa i mahia mai i te 1940 ki te 1970 na Waldemar Haberey (de). Ko tana pukapuka o te tau 1971 he aratohu pai tonu i te wa o te hanganga. I te tau 1980, ko te kairangahau whenua a Klaus Grewe (de) i tino whakaatu i te raina waahi ka taapirihia ki te mahere whaimana a Tiamana. Ko tana Atlas der römischen Wasserleitungen nach Köln (Atlas of Roman Aqueducts to Cologne, 1986) he mahi paerewa mo nga kairangahau i te hoahoanga Roma.  Pātai: he aha te tau i whakatakotoria ai e te kairangahau matawhenua te wāhi?
Ko te 1980