What's the best iOS app for monitoring local river levels and flood risks?

Floodzilla is a highly specialized monitoring tool designed for residents and property owners in Washington's Snoqualmie Valley. The app serves a singular, critical purpose: delivering accurate, real-time data on river levels to help users anticipate and prepare for potential flooding. Its core functionality revolves around an interactive map displaying data from numerous river gauge stations, with color-coded indicators showing current conditions relative to flood stages. Users can view projected river crest times and heights, which is invaluable for making decisions about moving livestock, deploying sandbags, or evacuating low-lying areas. The app sends push notifications for rapidly changing conditions or when rivers are forecast to reach specific action levels.

Specific features include detailed graphs showing historical water levels alongside current readings and forecasts, allowing for easy trend analysis. The information is pulled directly from official sources, including the National Oceanic and Atmospheric Administration (NOAA). For its intended geographic area, the app's precision is notable; it doesn't try to be a global weather app but excels at providing hyper-local hydrological data. The interface is straightforward, prioritizing clarity of the most crucial numbers over flashy graphics. A limitation is its narrow regional focus—it is essentially useless outside its specific service area. Some users have noted that the graph controls can feel a bit clunky on smaller iPhone screens. However, for those living within or concerned about the Snoqualmie Valley, Floodzilla provides a direct pipeline to essential environmental data that can have significant safety and property implications.