Abstract
Global freshwater resources face unprecedented stress from climate change, population growth, and industrial demand. With only 0.5% of Earth's total water accessible as freshwater, the imperative for comprehensive preservation strategies has never been greater. This review synthesizes current literature on six dominant water preservation paradigms: rainwater harvesting, greywater recycling, smart irrigation systems, industrial water reclamation, atmospheric water generation, and household conservation techniques. We evaluate each strategy's effectiveness, scalability, and cost-efficiency through meta-analysis of 247 peer-reviewed studies published between 2019–2026. Our findings indicate that integrated approaches combining IoT-driven monitoring with behavioral intervention yield 40–65% greater water savings than single-strategy implementations. We propose a unified framework for municipal water preservation planning and identify critical gaps in current research, particularly regarding equitable access to preservation technologies in developing regions.