Representatives from the U.S. Corps of Engineers officially handed back a repaired Guajataca dam to the Puerto Rico Electric Power Authority, after completing work at a cost of $50 million from the Federal Emergency Management Agency.
After the impact of Hurricane María in 2017, the reservoir — which is operated by PREPA — suffered serious damage as a result of the rains that exceeded 24 inches and caused several deficiencies in the dam. The water flow damaged the emergency discharge channel or spillway and the water supply line that connects the dam to the canal.
A failure of this magnitude would have affected approximately 1,000 people residing downstream and the suspension of the supply of drinking water to more than 250,000 people, the local government said.
On hand for the transfer ceremony were Gov. Wanda Vázquez-Garced along with Puerto Rico Electric Power Authority Executive Director José F. Ortiz and Diana Holland, Major General of the USACE.
“The magnitude of the works carried out by the Corps of Engineers in this critical installation, represent significant improvements in safety, and the capacity for long-term supply of drinking water, for thousands of people in this region,” Vázquez said.
“We’re grateful and confident in continuing the work that will take the dam to the height of the established standards, for the benefit of the people of Puerto Rico,” she said.
This scenario required an integrated work plan among the local government’s emergency component, and the USACE’s Jacksonville District, under the supervision of the FEMA team that prevented flooding of the sectors downstream before the imminent danger of the collapse of part of the infrastructure of this reservoir, the government stated.
“We’re honored and excited to return this very special project to the Puerto Rico Electric Power Authority, after having implemented measures that reduce the risk for communities near the dam, communities that have lasted so long and in many cases are still recovering because of Hurricane Maria, every aspect of the work in Guajataca has been a team effort and we are very grateful to each one of our partners who have participated in this journey,” Holland said.
The works were divided into three phases according to the risk presented, such as: danger of imminent flooding, implementation of temporary measures to reduce irrigation and carry out permanent works.
As part of the first phase, USACE completed certain emergency stabilization measures to prevent dam failure. However, the spillway continued to present an unacceptable risk of collapse.
To do this, the USACE focused on lowering the level of water in the lake to a safe one and stabilizing the damage to the spillway to ensure the residents of the area and the workers, the local government confirmed.
USACE placed 10 water pumps to lower the level of the lake, and these, in turn, were used to provide water to the Guajataca canal, after damage to the water distribution pipeline by the Puerto Rico Aqueduct and Sewer Authority.
With the assistance of various branches of the U.S. Army, including the Puerto Rico National Guard, the spillway was stabilized with the placement of more than 500 concrete barriers, stone fill and 1,300 sandbags in the canal.
At the moment, FEMA is negotiating to proceed with the first stage of a study and risk assessment that will serve as a guide for the realization of permanent works at the height of the standards established in projection to future weather events.
“The completed work demonstrates that the well-planned interaction and clear communication will lead us to the development of the permanent works of a more reliable electrical system, always in team with the federal government,” PREPA’s Ortiz said.
The repair work will benefit residents of Isabela, Aguada, Aguadilla, Rincón, Moca and San Sebastián who saw their service interrupted after the passage of Hurricane María and the rupture of the pipeline that led to a plan for scheduled interruptions.