Supplemental Appropriations for Disaster Recovery Activities

Assessment of Landslide and Debris Flow Impacts in Puerto Rico

Hurricane Maria generated more than 40,000 landslides in Puerto Rico, devastating infrastructure and property.


landside by Lago Caonillas in Utuado Municipality

Landslides along the banks and turbid waters of Lago Caonillas in Utuado Municipality.

(Public domain.)

Landslides are a frequent hazard to life and property in Puerto Rico, owing to the steep terrain and heavy rainfall from hurricanes and other tropical weather systems. In 2017, Hurricane Maria generated more than 40,000 landslides in Puerto Rico, devastating infrastructure and property. Along with the initial damage, sediment moved by landslides from hillsides and deposited in stream channels has changed drainage systems hampering rebuilding and recovery efforts and increasing risks from future storms to crews on the ground. Supplemental funds are being used by the USGS Landslide Hazards Program to work with partners in Puerto Rico to assess post-storm landslides conditions and impacts, identify ongoing and potential threats, and deliver landslide hazard assessments to guide decisions on recovery and rebuilding in areas with the greatest landslide risk.




  • Map and characterize landslides generated by Hurricane Maria in areas of greatest social and economic vulnerability to deliver geospatial data on landslide location, volume, and mobility for the populations and infrastructure most threatened by these hazards. These data can be used to assess impacts on existing and planned infrastructure, and identify areas where infrastructure should be designed considering landslide impacts or avoided when rebuilding or siting new development. 


landslide map Puerto Rico

Map showing concentration and distribution of landslides generated by rainfall associated with Hurricane Maria in Puerto Rico.

(Public domain.)

  • Deliver digital geospatial products derived from planned lidar data acquisition that define the landslide threat for high-priority areas at a scale and resolution appropriate for land-use decision making and emergency planning. Products will define areas potentially impacted by landslides and provide estimates of the magnitude of the impact. This information can be used to guide loss reduction strategies and direct decisions regarding site-specific investigations or requirements in communities where evacuation and relocation options are limited due to the the constraints of the island geography.


  • Hazard assessments delivered by the USGS will support longer-term decisions by FEMA and Puerto Rico governmental agencies such as the Planning Board to plan and rebuild in such a way as to reduce future landslide losses. Providing this information will represent a significant step forward for the Planning Board whose decisions relating to landslides are currently informed by landslide susceptibility maps published in the late 1970s.



Additional Resources

Puerto Rico Landslide Hazard Mitigation Project

Two hydrologic monitoring sites (Utuado and Toro Negro) for the Landslides/Debris flow impact assessment provide real-time data.

Geologic Hazards Science Center 

Geology Minerals Energy and Geophysics Science Center 

Bessette-Kirton, E.K., Coe, J.A., Godt, J.W., Kean, J.W., Rengers, F.K., Schulz, W.H., Baum, R.L., Jones, E.S., and Staley, D.M., 2017, Map data showing concentration of landslides caused by Hurricane Maria in Puerto Rico: U.S. Geological Survey data release.

Smith, J.B., Thomas, M.A., Ashland, F., Michel, A.R., Wayllace, A., and Mirus, B.B., 2020, Hillslope hydrologic monitoring data following Hurricane Maria in 2017, Puerto Rico, July 2018 to June 2020: U.S. Geological Survey data release.

Baxstrom, K.W., Einbund, M.M., Schulz, W.H., 2021, Map data from landslides triggered by Hurricane Maria in the greater karst region of northwest Puerto Rico Summary: U.S. Geological Survey data release.

Einbund, M.M., Baxstrom, K.S., and Schulz, W.H., 2021, Map data from landslides triggered by Hurricane Maria in four study areas in the Lares Municipality, Puerto Rico: U.S. Geological Survey data release.


Jonathan Godt

Program Coordinator
Landslide Hazards
Phone: 303-273-8626