Utilization of rainwater harvesting to conserve water in buildings in Semarang City

Abstract

Rainwater harvesting makes a major contribution to sustainable development. The utilization of rainwater for building operations is in line with sustainable development goals for 2030. This research aims to provide an overview of rainwater which can be used as an alternative source of raw water in buildings in Semarang City. This research was carried out purposively on buildings in the city of Semarang that had received function-worthiness certificates. The research results show that the largest rainwater harvesting dimension is the Ciputra building of 372 m3 with rainwater potential that can be utilized in the form of runoff of 0.758 m3/second or 65491.2 m3/day, while the smallest dimension is the Pusatand building of 55 m3 with rainwater potential which can be utilized in the form of runoff of 0.112 m3/second or 9679.8 m3/day. Municipal waterworks (PDAM) tariff costs have decreased after carrying out rainwater harvesting. The largest percentage decline was in the Ciputra building, namely 65.72%, while the smallest was in The Pinnacle at 5.16%. The size of the Municipal waterworks (PDAM) water tariff is determined by the ground floor area of the building since the ground floor area contributes to the dimensions of rainwater harvesting.