NWDTW 2024

In addition to USGS products such as the USGS Water Watch and the National Water Dashboard, the presenters will provide an update on other “Event Monitoring” resources such as the Flood Event Viewer, Flood Inundation Mapper, Hydrologic Imagery Visualization and Information System and the Real-time Flood Impact Map.

During large, short-term events, the USGS collects streamflow and additional data (including storm tide, wave height, high-water marks, and additional data) to aid in documenting flood events. The USGS Flood Event Viewer provides convenient, map-based access to downloadable event-based data. In 2022, the USGS Flood Event Viewer is available for the following events: During the 2022 Hurricane Season, the Flood Event Viewer is available for several notable flood events such July Kentucky Flood, September Alaska Extratropical Cyclone, and Hurricane Ian.

USGS Flood Inundation Maps, along with Internet information regarding current stage from the USGS streamgage, provide emergency management personnel and residents with information that is critical for flood-response activities, such as evacuations and road closures, as well as for post-flood recovery efforts. The Flood Inundation Mapper allows users to explore the full set of inundation maps that shows where flooding would occur given a selected stream condition. Users can also access historical flood information and potential loss estimates based on the severity of the flood. The FIM Mapper helps communities visualize potential flood scenarios, identify areas and resources that may be at risk, and enhance their local response effort during a flooding event.

Many USGS water-resource monitoring sites have webcams installed to allow remote visibility of current water and environmental conditions, identify technical issues, verify remote measurements, and gather data for visual analyses. The Hydrologic Imagery Visualization and Information System (HIVIS) provides access to still-frame images and timelapse videos from our active webcams. Many sites also pair recent still-frame images to an interactive hydrograph.

USGS Real-time Flood Impact map displays “Flood Impact Locations” where the USGS has measured the height of critical safety or infrastructure features that may be vulnerable to flood impacts. Some examples of Flood Impact Locations include stream and river embankments; roads and bridges; pedestrian paths; buildings; and more. Flood Impact Locations are surveyed and associated with a nearby USGS real-time streamgage. When the streamgage water level (gage height) exceeds the Flood Impact Location’s surveyed height, its icon will display on the map, showing that this location may be currently flooded. When the user clicks on the icon, a pop-up will display the current gage height and the Flood Impact Location height, so that the user can compare how close that location is to the current water level. Some Flood Impact Locations may be measured below the level of actual flooding to provide an early warning that flooding may be imminent. Although the mapper is not a flood warning system, it can be used to convey immediate flood risks by showing the locations where flooding may be currently or soon occurring. The USGS has over 10,000 streamgages nationwide in the continental U.S. and U.S. territories. Please note that flood impacts have not been collected at all USGS streamgages. Additional Flood Impact Locations will continue to be added. If you would like to add Flood Impact Locations at or near existing USGS streamgages in your Water Science Center, please refer to Alternative Way of Delivering USGS Streamgage Data (Ver 6).pdf or contact Julia Prokopec, Lauren Privette, or Athena Clark.