Rainwater harvesting often involves collecting rainwater from surfaces like rooftops and directing it into storage systems such as tanks made of plastic, reinforced cement concrete (RCC), or masonry. This is a standard and widely practiced method for direct use of rainwater, such as for irrigation or household purposes after basic filtration. Statement (I) is true.
Statement (II) suggests that in a campus with limited space, rainwater can be stored in an open excavated pond. While open ponds can be used for storing water, they are not ideal for rainwater harvesting meant for direct use because open ponds are prone to contamination (e.g., from debris, animals, or algae growth) and significant evaporation losses. For direct use, water is typically stored in closed systems like tanks to maintain quality. Additionally, the statement implies this is a solution for limited space, but an open pond actually requires a significant amount of space to be effective, which contradicts the "limited space" context. Therefore, Statement (II) is false in the context of rainwater collection for direct use.