Performance Analysis of Rainwater Management using Rainwater Harvesting System and Infiltration Trench in Perumahan Dosen UNSRI Palembang)

Changes in land use affect the amount of runoff that can seep into the soil. This problem can be found in Perumahan Dosen's UNSRI. This can be overcome by rainwater management such as infiltration trench and rainwater harvesting (RWH). This study aims to analyze the best scenario for rainwater treatment in the research area to reduce excess runoff that occurs. Daily rainfall data, land use, soil permeability, land measurements, and existing drainage dimensions are used in the algorithm analysis. Determining the effective scenario is done by analyzing the algorithm and taking into account the budget estimate plan (BEP). The scenario which includes an infiltration trench with a depth of 1 m and an RWH system with a tank volume of 2 m3 has the greatest average effectiveness of 55,33%, when compared to the scenario with an infiltration trench with a depth of only 1 m. Furthermore, the RWH system brings an additional effectiveness of 23,94%. Compared to the contrary, the addition of an infiltration trench only increased the effectiveness by 18.4%. The total cost of implementing the infiltration trench is 2 times that of the RWH system based on the calculation of the budget estimate plan. Accordingly, the best scenario is determined, namely the implementation of a RWH system with a tank of 2 m3 in volume. This scenario has an average runoff reduction effectiveness value of 37,05% and a total cost of 1.8 billion Rupiah for all 194 houses.