2022 Snapshot:
Surveying the Aftermath of Hurricane Fiona
Some projects are planned months in advance and begin with a set of plans. This one began in the aftermath of a disaster.
In September 2022, Hurricane Fiona made landfall in Puerto Rico, bringing catastrophic flooding, landslides, widespread power outages, and extensive damage across the island. In some areas, more than 30” of rain fell, causing rivers to overflow their banks, roads to wash out, and entire communities left without electricity or reliable access to water.
Long after the storm passed, its impact remained visible. The ongoing flooding was imposing critical threats to the island’s habitat through erosion and loss of wetlands. As recovery efforts shifted toward understanding the extent of the damage and preparing for future storms, the St. Louis District of the U.S. Army Corps of Engineers needed teams to collect accurate, on-the-ground data to guide and support flood mitigation efforts. TWM was mobilized as part of that response.
Working in challenging post-storm conditions, TWM’s geospatial team traveled across multiple regions of Puerto Rico to collect critical data in areas heavily impacted by flooding. High-water marks etched into buildings and vegetation revealed how far the water had risen. Altered shoreline conditions and newly formed sandbars showed where rivers had been affected and reshaped by the force of the storm.
For communities that regularly face the threat of hurricanes, flooding, and erosion, access to accurate data is a critical first step toward building safer and more resilient infrastructure. Using a combination of GNSS surveying, mobile LiDAR, terrestrial LiDAR, hydrographic surveying, and multi-beam bathymetric technology, TWM documented conditions across Arecibo, Guanajibo, and Nigua. Crews collected high-water elevations, mapped flood-affected corridors, and surveyed waterways. In Arecibo, terrestrial LiDAR was used to scan a large sandbar created by changing hydraulic conditions, while multi-beam sonar mapped river and channel bottoms to provide a complete picture of existing conditions both above and below the waterline.
Every survey point, scan, and bathymetric measurement captured a different piece of the storm’s impact and contributed to a larger effort to understand how Hurricane Fiona affected the island’s waterways and surrounding communities. The resulting data provided engineers and planners with the foundation needed to evaluate future flood protection improvements, including the design of flood barrier walls throughout the island and other resilience measures that could minimize the threat of flash flood damage and other storm-related impacts.
For TWM, the project represented more than the application of advanced surveying technology or a technical assignment. It was an opportunity to support communities during a critical time of recovery, better understand the impacts of a historic hurricane, and help transform the lessons learned from one storm into solutions that can better protect lives, property, and infrastructure from the unpredictability of severe weather events.
