Data

Total water level (TWL) at the shoreline is the combination of tides, surge, and wave runup. A forecast of TWL is an estimate of the elevation where the ocean will meet the coast and can provide guidance on potential coastal erosion and flooding hazards.

The National Water Information System (NWIS) web application provides access to real-time and historical surface-water, groundwater, water-quality, and water-use data collected at approximately 1.5 million sites across all 50 states.