Rainwater Harvesting Using Roof and Wall Catchment with Dual Water Quality Utilization : A Case Study at a Five-Star Hotel in Indonesia

One of the global problems in recent years is shortage of appropriate water resources due to increasing demand, seasonal rainfall, and depletion of groundwater reserves, leading to water scarcity. Indonesia, especially Jakarta, is often affected by flooding and waterlogging due to high rainfall and poor water management. High population, urban area density and both of commercial as well as industrial water consumption, such as hotel industry, have increased the demand for clean water. Rainwater management through rainwater harvesting is an alternative of solution to overcome water scarcity. The purpose of this study focuses on the application of rainwater harvesting at a five-star hotel in East Jakarta, namely to determine the characteristics of rainwater quality and quantity from the roof and walls of the hotel building, determine the water savings obtained, and estimates the benefits of implementation a rainwater harvesting system with dual water quality utilization. It was revealed that the water quality of the rainwater reservoir could not be used for food grade purposes because it was contaminated with coliform bacteria, but it will be feasible for lower standards of water consumption, for examples as toilet flushing, outdoor cleaning and gardening, then the rest of rainwater harvesting results will be treated as food grade of water. This scheme will save the investment and operational costs for water treatment rather than processing the whole amount of rainwater harvesting. Annual water savings obtained from the implementation of rainwater harvesting at the hotel reached 12% with the required investment and installation costs of Rp. 105.27 million