Arakawa No. 1 Retention Basin

Arakawa No. 1 Retention Basin is a water storage facility spanning multiple administrative areas in Sakura-ku and Toda, managing water levels through an extensive network of control systems and storage zones. The site consists of several connected sections designed to absorb and regulate water flow during peak periods.

The basin was built as Japan's response to severe flooding concerns in the early 1900s, particularly after devastating floods in 1910. This project shaped how the country approached systematic water control in urban areas for decades.

The Saiko Nature Learning Center within the basin teaches visitors about water management and demonstrates how Japanese engineering addresses environmental challenges. The facility shows how infrastructure integrates with local nature in practical ways.

The site can be explored on foot, with pathways leading through various storage zones and control areas. Wear weather-appropriate clothing, as conditions near large water areas can be exposed and windy.

The site operates simultaneously as a public learning space and flood protection system, with visitors able to observe how engineering function and environmental education work together. This dual purpose is uncommon and reflects a practical approach to land use.

Location: Sakura-ku

Location: Toda

Website: https://ktr.mlit.go.jp/arajo/arajo00150.html

GPS coordinates: 35.81758,139.62772

Latest update: December 7, 2025 19:32