The 1990s brought about a change in the mindset, and river administrators started to consider conservation of the natural environment. They developed nationwide policies to implement nature-oriented river works, trying to shift policy from excessive dependence on concrete to the utilization of natural materials. In line with this movement, in 1997 the river administration decided to revise the River Law. The revised act made preservation and conservation of river environments obligatory, and opened up local people’s participation in river planning. These revisions were appraised by the public as fitting the concept of a modern society.