What evidence suggests active water infiltration in a crawl space?

The presence of liquid water and wet soil in a crawl space is a direct and clear indication of active water infiltration. When water accumulates in the form of puddles or saturates the soil, it signifies that water is entering the space rather than simply condensing or being present due to previous moisture events. This active infiltration can lead to a range of issues, including structural damage, mold growth, and compromised air quality.

While high humidity levels can suggest moisture issues and potentially stem from water infiltration, they do not provide concrete evidence of active water movement into the space. Mold presence is often a result of ongoing moisture problems but doesn't specify the source of water infiltration. Cracked foundations may indicate structural issues that could allow for water seepage but do not represent active water entry on their own. Therefore, observing liquid water and wet soil serves as the most definitive evidence of current water infiltration in a crawl space.