History of Aichi Prefecture = Owari Province + Mikawa Province
Source: https://www.pref.aichi.jp/global/en/summary/profile/background.html

Mikawa Province = Mikawa no kuni
Source: https://en.wikipedia.org/wiki/Mikawa_Province

Higashi Mikawa = Ho no kuni
Source: https://www.honokuni.or.jp/en/

River Project in Aichi
Kiso River System & Toyo River System
Source:
https://www.water.go.jp/honsya/honsya/english/about/projects.html
https://www.water.go.jp/honsya/honsya/english/about/area_kiso.html

Great Bridge in Toyo River: Yoshida
https://www.roningallery.com/yoshida-great-bridge-on-toyo-river
https://www.artic.edu/artworks/25491/yoshida-great-bridge-on-the-toyo-river-yoshida-toyokawa-ohashi-no-35-from-the-series-famous-sights-of-the-fifty-three-stations-gojusan-tsugi-meisho-zue-also-known-as-the-vertical-tokaido