This study completed the assessment of the sediment environment of the Tseng-Wen and Baihe
Reservoirs, considering the factors of sediment-related disasters to evaluate the threat of sediment production and
plan the requirements of soil and water conservation works for the reservoir watersheds. Case studies suggest the
post-typhoon Morakot sediment environment of the Tseng-Wen and Baihe reservoir watersheds in 2014 has recovered
well after remediation, but is still in a relatively poorer condition than pre-typhoon Morakot. Further, to limit the
occurrence of secondary disasters in disaster-prone creek watersheds, this study suggests a list of watersheds requiring
improvement to their sediment environments under the suggested potential sediment production classification.
Consequently, there are 37 areas located in the Tseng-Wen and Baihe reservoir watersheds still requiring soil and
water conservation works. These observations can serve as the basis for effectively managing reservoir watersheds,
planning of disaster prevention work and reducing the risk of rapid sedimentation in reservoirs during the flood season.
Key Words : Sediment environment assessment, reservoir watershed, typhoon Morakot.