As Taiwan is an island country, water storage is predominantly dependent on reservoirs. To maintain
reservoir storage capacity, the government has set annual targets for sediment reduction volume and conservation of
reservoir watersheds. Therefore, in this study, the existing permanent deposit facilities and sedimentation facilities such as existing sabo dams and farm ponds in the Deji Reservoir catchment area were assessed to determine their suitability as permanent deposit facility sites. A total of 158 sites for permanent deposit facilities were selected, including three potential locations, six existing sabo dams, and 149 farm ponds. Of these, a potential location on the mainstream river offers the most sand-settling benefits. However, important Sakura habitat is present in the catchment area of the Deji Reservoir, and this ecological consideration reduces this site’s potential feasibility. The D29 Qijiawanxi No. 3 dam has the highest sedimentation efficiency of existing sabo dams but is in a wildlife conservation area. The D31 Nanhuxi No.2 dam is recommended as the main sedimentation space because it has the second highest sedimentation efficiency.Farm ponds are the type of facility with the greatest feasibility and maneuverability; this is because farm ponds are located on conveniently accessible roads. In the future, deforestation of farmland backfill may be a solution to problems concerning widespread vegetable planting and soil loss in the Deji Reservoir watershed. The results show that the six existing sabo dams can provide approximately 33,800 cubic meters of deposit volume, accounting for 10.2 % of the total sedimentation target (330,000 cubic meters). The farm ponds can provide a 41,400 cubic meter deposit volume,accounting for approximately 12.5 % of the total sedimentation target.
Key Words: Deji Reservoir, Permanent settling facility, Sedimentation benefit, Feasibility assessment, Farm pond.