Guajataca Dam Spillway Failure

Contributed by: Alesandra C. Morales-Vélez (Assistant Professor, Department of Civil Engineering at UPRM).

Hurricanes Irma and María were classified as category 5 hurricanes on the Saffir-Simpson hurricane wind scale before making landfall on the island of Puerto Rico (PR). María left the island of PR totally devastated due to its intense rainfall and strong winds. The National Weather Service recorded maximum sustained winds of 155 miles per hour. Hurricane Maria made landfall just south of Yabucoa, PR on September 20 at approximately 6:15 a.m. In various parts of PR, a total of 30 inches of rain in a period of 24-36 hours were observed. That is equivalent to the total amount that Houston received over a period of 72-hours after the passage of Hurricane Harvey. Winds were strong enough to destroy the National Oceanic and Atmospheric Administration Doppler’s radar located in Barrio Guavate, Cayey, PR, leaving the island with no reliable data about wind speeds and storm’s trajectory.  All the dams in PR performed well but the spillway of Guajataca earthdam's was destroyed due to the extreme intense rainfall, as shown in the pictures. A team of USACOE was deployed to the island on Oct/24 and after inspection they assured the government and the community that the earthdam was in no danger of collapse or failure. Almost 100 days after the hurricane hit PR, there are still communities isolated, with zero to very little access to potable drinking water and electricity services.