This paper introduces the Aratama-suido-zu (“zu” meaning original blueprints) proposal for the Aratama-suido project to supply water in Tokyo’s Aratama District. Construction began in 1926, but in 1927, Japan’s government called for the project to be scaled back. The revised Aratama-suido was presented in the 1931 Aratama-suido-shi (“shi” meaning official document). The Aratama-suido-shi noted the number and locations of the project’s buildings in both the original and revised plans, but not the original designs for the buildings. This has made it difficult to compare them with the final designs, though attempts have been made (Masuda, 2006). The author clarifies the original designs, revealing how the engineers’ thought processes evolved.
