Green-Infrastructures: Beyond the flood control function of the Kameoka basin

: Because of a natural monument fish species, Kissing loach (Parabotia curtus), and other endangered species of Satochi-Satoyama are still inhabited, the flood plain of Kameoka Basin was selected as one of the 500 sites of Ecologically Significant Satochi-Satoyama (Ministry of the Environment 2015). The significance is deeply related to the fact that the basin is prone to flooding by the existence of the narrow Hozu-kyo gorge, which provides tourists the impressive beautiful scenery while boating down the stream to the national registered scenic beauty of Arashiyama in Kyoto. The sports stadium project at the habitat of the fish is not a simple controversy between developments vs. conservation, because the current habitat of the species is a human-controlled river for the purpose of irrigation for rice paddies. The local farmers, who are willing to develop the stadium, have been taking part in the conservation activities by damming up the river water to facilitate egg laying of the fish. Therefore, not only to preserve the habitat, but also a comprehensive solution that enables to continue the traditional agricultural environment is needed for the conservation. More important issue is to take this opportunity to change our course from the “ Grey Infrastructure ” policy adopted in the age of urbanization, such as closing the existing open levees with river and gorge excavation, to the “ Green Infrastructure ” policy, inheriting the traditional Eco-DRR to ensure rich biodiversity and ecosystem services. The Kameoka basin could be a leading model case of “ Green Infrastructure ” in the era of population decline, following the promotions by MOE and MLIT of Japan. Several green-infrastructure solutions of rain gardens for urban areas are also proposed.