Feasibility Analysis of Rainwater Harvesting System Implementation for Public Facilities in Palembang

Rainwater is one potential source of water that is often overlooked. Potential rainfall is often left discarded into runoff whereas with rainwater harvesting (RWH) system it could be harvested and used to meet the need for clean water and minimize the risk of flood by detaining the runoff. This study aims to analyze the feasibility of RWH systems implementation to meet the water need of public facilities in Palembang based on water balance concept. The behavioral model is used to simulate and mimic the RWH tank behavior. The analysis conducted on various scenarios based on RWH tank capacity and water demand. Two public facilities in the same area are analyzed, the office of Pengadilan Tinggi Agama (PTA) and SMAN 3 Palembang, along with 28 years of daily rainfall data. The financial analysis conducted using present worth analysis and payback period. For PTA, with 1050 L tank capacity, RWH is applicable and feasible. It can save the water up to 58% with an estimated payback period in 7, 5 years. Nonetheless, although SMAN 3 has a bigger catchment area, because of the higher demand (21 times than PTA), RWH is not feasible to implement. The water saving efficiency is just 29% for a system with 4 tanks of 5100 L. These results are expected to be used as the initial analysis to find the typology of RWH systems implementation in Indonesia.