Due to the land developments, the hydrological cycle system has been disturbed and has caused floods. From the 1960's, it is obliged to construct the rain regulating reservoir by some local government to recover the declining water retentivity, in case of a land development. Although, it is difficult to construct a regulating reservoir on a low land, and the reservoir is not so comfortable for the new tenants. Therefore, the primary object of this study is to research the actual situation of the constructed or constructing reservoir, and secondary to propose a water way as a reservoir.
