PEMANFAATAN AIR HUJAN DARI ATAP BANGUNAN SEBAGAI SOLUSI MENGHEMAT PEMAKAIAN AIR PDAM PADA GEDUNG PERKANTORAN DI KECAMATAN MEDAN BELAWAN

Abstract

The increasing urban water demand due to the increase of population and the change of land function caused the absence of land for rain water absorption so that rainwater runoff increased. Therefore, it is necessary to do water conservation with rain water harvesting efforts, where rain water in harvest can be utilized for the need of raw water in Medan Belawan district one of them in office building in the area. The data collected in the form of roof area of office building from building modeling using Autocad software, maximum daily rainfall data from BMKG Sampali and needed water requirement. From the analysis results obtained the capacity of a container in an office building of 100m, can save water usage PDAM for 12 months. From the results of the analysis, it can be concluded that the use of rain water can save water from PDAM by 78% cost which can be saving Rp 7.093,655 in 12 months, from the normal paying cost of PDAM issued by Rp 8,378,424 within 12 months.