An Integrative Rainwater Harvesting–Artificial Recharge Model for Drought Adaptation in East Nusa Tenggara

Abstract

East Nusa Tenggara (Nusa Tenggara Timur, NTT) is recurrently exposed to drought because rainfall is strongly seasonal, the dry season is prolonged, storage is limited in many settlements, and a substantial share of wet-season runoff is not retained for later use. This study formulates an integrative rainwater harvesting (RWH)–artificial recharge model as a context-sensitive drought adaptation strategy for NTT. A qualitative applied-conceptual review was undertaken through thematic synthesis of peer-reviewed studies, technical standards, institutional reports, and established guidance on drought, RWH, groundwater conservation, infiltration structures, and managed aquifer recharge (MAR). The synthesis distinguishes two complementary functions: RWH provides a decentralized short-term water buffer, whereas artificial recharge converts controlled overflow into medium- to long-term subsurface storage. The resulting model comprises five linked stages—capture, store, use, recharge, and govern—and is organized across household, institutional, and area-wide implementation scales. To improve engineering applicability, the model is supplemented with a screening framework covering rainfall and demand, runoff coefficient, infiltration capacity, groundwater depth, vadose-zone thickness, source-water quality, contamination risk, and operation-and-maintenance capacity. The study argues that integration is preferable to stand-alone storage or recharge because it couples immediate demand reduction with groundwater conservation and runoff attenuation. However, implementation requires site-specific hydrologic and hydrogeologic assessment, water-quality safeguards, and monitoring before structural design. The model provides a practical conceptual basis for pilot projects, feasibility studies, and drought-resilience planning in semi-arid island settings such as NTT.