Rainwater using Plant Started to Dissemination in Earnest at 2000. Based on 2008 Research, 10 has Built in Sports Facilities, 14 in Public Office, 77 in Factory, 72 in Apartment, 39 in School, and Total is 212 in Korea. The Retention Scale for each Plant is 21,439m3 for Factory which is largest. 19,534m3 for Apartment, 5,427m3 for Sports Facility, 4,632m3 for School, 3,013m3 for Public Office. Total Retention Scale is 54,044m3 and Using 652,000m3 of Rainwater Every Year.