Potential application of rain water harvesting technology as an alternative clean water source to mitigate land subsidence

BACKGROUND AND OBJECTIVES: The limited supply of tap water has implications for the massive usage of groundwater in North Jakarta's coastal area, that suffer crucial land subsidence. As a result, it is critical to provide alternate sources of sustainable clean water that can minimize groundwater consumption. Based on climatological aspect, rainwater harvesting technology has potential and has been applied in several unplanned dense residential areas, around the coast. According to that, this study aims to analyze the contribution of rainwater harvesting technology implementation in terms of supply and utilization aspects to reducing groundwater use and meeting clean water needs for mitigating land subsidence in the coastal area of North JakartaMETHODS: This study was conducted in North Jakarta coastal area within a radius of 0—2 kilometers, by conducting survey activities on 148 households who live near the location of the technology installation, as well as collecting the depth wells data, and clean water samples. The survey activity is intended to supporting regression analysis and crosstabulation, regarding the contribution of using Rain Water Harvesting technology in mitigating land subsidence.FINDINGS: Based on its quality, rainwater harvesting has the potential to support the fulfillment of clean water needs in North Jakarta, especially for sanitation purposes. The findings of quality test also explain in more depth that clean water from the rainwater harvesting system was safer for consumption than groundwater, both from dug and drilled wells. The groundwater samples tested showed extremely high levels of Total Dissolved Solids (2829 mlligrams per liter), making it extremely dangerous to use for cooking and drinking, as well as sanitation, such as bathing and washing. In terms of quantity, mathematical calculations estimate that the provision of rainwater harvesting installations can support 0.2 percent of clean water for sanitation purposes in each implementation area. The finding indicates that the belief that rainwater harvesting can effectively meet water needs is a key driver in the decision to utilize rainwater harvesting.CONCLUSION: The expanding rainwater harvesting is very related to the mitigating the land subsidence, through the decreasing depending on extracting groundwater as their source of wáter supply. The difficulty of satisfying clean water needs due to these various factors was the reason why respondents chose to utilize rainwater harvesting ng rainwater harvesting adoption can be accomplished by enhancing the community's perception that the technology can effectively meet their water needs. Strategies such as awareness campaigns, demonstrations, and providing empirical evidence of rainwater harvesting’s effectiveness could help shift community attitudes. Conversely, while perceptions about the benefits, ease of operation, and accessibility of rainwater harvesting are important, even though these factors do not appear to have a direct and significant influence on rainwater harvesting utilization in this study.