Rikugien Garden, as one of the representative circuit style gardens from the Edo period, possesses a 300-year history with diverse changes in water conveyance methods for its pond. These water features are integral components that cannot be overlooked when examining the garden's overall historical context. This study focuses on the water level fluctuations in Rikugien Garden and their relationship with the Senkawa-josui (waterworks). Specifically, we target the An-ei (1773~1781) and Ten-mei (1781~1789) eras, including the period of the Senkawa-josui, to investigate whether the waterworks was used to supply water to the garden's pond where information about the water source remains scarce, and the purpose of this study is to clarify the changes in the water level of the ponds in Rikugien Garden and the changes in the landscape caused by these changes. By analyzing "Enyu-Nikki" (1773~1785), a diary written by Nobutoki YANAGISAWA, the third lord of the YANAGISAWA family, and utilizing historical records such as "Rakushido Nenroku" (1658~1709) by the first lord, Yoshiyasu YANAGISAWA, significant water level fluctuations in the garden throughout different seasons were revealed. The findings also suggest that during the Ten-mei and An-ei eras, people may have paid attention to the changes in the landscape caused by fluctuations in the water level of pond.
