The present study is concerned with feasibility of the rainfall infiltration facilities in Takamatsu city and offers newly obtained fundamental data such as geological map of surface soil layer, hydraulic conductivity of surface soil layer and groundwater level during rainy seasons. Four issues are discussed. First, a new geological map is presented for surface soil layer at 1m depth, which is closely related to infiltration facilities, based on the re-examination of the existing borehole logs and new boring survey. In urbanized area surface soils of 1m thickness show multiple layers of different soil types, reflecting the past land use change. Secondary, an in-situ permeability test was carried out at 39 locations to correlate the hydraulic conductivity of the surface soil layer at 1m depth and its soil type. Thirdly, the depth of groundwater table from the ground surface is reported with water level variation corresponding to rainfall. Finally, the effective areas for infiltration facilities in Takamatsu city are discussed.