日本是个水资源的比较缺乏的国家，目前全国水资源利用率已经达到20％左右，新辟水源所需的投入越来越大．为此，日本政府除了采取开源措施和提高水利用率、鼓励全社会利用循环水外，还十分重视对雨水的利用．早在1980年，日本建设省就开始推行雨水贮留渗透计划．采用雨水贮留 Japan is a country that lacks water resources. At present, the utilization rate of water resources in the country has reached about 20%, and the investment required for new water sources is getting bigger and bigger. To this end, apart from adopting open-source measures and improving water utilization rate, the Japanese government encourages the whole society to make use of circulating water and attaches great importance to the utilization of rainwater. As early as 1980, Japan’s Ministry of Construction began to promote rainwater retention infiltration plan. Rainwater storage