;701-704 (Taihō era ): Michimori Ason, the lord of
Sanuki Province, erects the first dam. It was originally called Kaminoike because it was located in Kaminogo, but in the early Heian period, when
Emperor Saga ascended the throne, it was changed to Manoike because prior to ascending the throne the emperor's name was Imperial Prince Kamino. ;818 (Kōnin era, year 9): Mannō Pond dam ruptures due to flooding. ;821 (Kōnin era, year 12): Kukai is dispatched to oversee renovations of Mannō Pond dam, with construction being completed in approximately 3 months. Between the years of 821 and 1184, the Manno Pond dam collapses and is subsequently restored many times. ;1184 (Genryaku era, year 1): After the collapse of the dam in 1184, all rebuilding efforts were abandoned until 1628 (Kan’ei, year 5). During this period, people settled in the basin constructing houses and cultivating fields. The settlement was named Ikeato Mura (After-Pond village). ;1628 (Kan’ei era, year 5): By order of
Takamatsu Domain daimyō Ikoma Takatoshi the
fushin-bugyō Nichijima Hachibe’e begins renovations of the Mannō Pond dam. ;1631 (Kan’ei era, year 8): Takamatsu Domain completes renovations of the dam. ;1854 (Ansei era, year 1): Dam collapses due to earthquake. ;1870 (Meiji era, year 3): Restoration of dam completed. Afterward restorations, the three separate constructions of the Tenkawa headrace began, in order to supplement water intake from the Dokigawa, resulting in an increase of water volume three times. ;1996 (Heisei era, year 8): Mannō Pond selected as one of the
100 Soundscapes of Japan by the Ministry of the Environment. ;2000 (Heisei era, year 12): registered as Japanese cultural landmark- (buildings). ;2005: Mannō Pond dam receives the Dammed Lake Hyakusen certification from the Dam Watershed Environmental Improvement Center. ;2010: Mannō Pond receives the Pond Hyakusen certification from the Japanese Ministry of Agriculture, Forestry, and Fisheries. ;2018: Mannō Pond designed a
nationally designated Place of Scenic Beauty, ==Data==