(PONCE, Puerto Rico) Sept. 25, 2022 -- Puerto Rico's topography varies from the low plains of the southern coast to steep mountain slopes that rise up to 600 above the Portugués River. The proposed plan to build a dam was a response to the wet season and steep mountain slopes that cause runoff from heavy rain and fill the stream quickly, flooding many surrounding areas.
For decades, the people of Ponce have endured considerable human suffering and massive property damage. Portugués Dam mitigates flooding to more than 1,833 acres of urban areas, more than 13,200 residential structures, city hospitals, schools, courts, police, and fire departments, in addition to 5 million square feet of commercial space. The cost of flood impacts can range from $200-$500 million in potential damages based on today's costs.
The fact that Puerto Rico lies in the path of projected annual hurricane activity also adds another significant concern. Atmospheric events such as hurricanes can bring large quantities of rain within a short time, quickly saturating the ground while draining into creeks and rivers.
Since the completion of its construction in 2013, Portugués Portuguese Dam construction has withstood nature's rushing water, floods, and 14 named storms
while protecting the people, communities, and economies of Ponce and its environs.
- August 2–3, 2014 – Tropical Storm Bertha dropped a general 3–5 inches of rain across the territory, with up to 11.11 in. of rain recorded in Adjuntas.
- August 22–24, 2014 – Hurricane Cristobal produced torrential rains, with 13.21 in. (336 mm) of rain recorded near Tibes. Several other areas in Puerto Rico, mostly near Ponce, received at least 10 in. (250 mm) of rain.
- October 14–15, 2014 – Hurricane Gonzalo brought rain but caused no major damage.
- August 25, 2015 – The remnants of Hurricane Danny brought minor rainfall. The rains helped alleviate drought, raising the dam's critically low water levels.
- August 27–28, 2015 – Tropical Storm Erika brought needed rain to the drought-stricken region, with- rainfall peaking at 4.45 in. in Adjuntas.
- September 5–7, 2017 – Hurricane Irma, a Category 5 hurricane, brought tropical storm force winds across much of the main Island. The peak rainfall amount of 13.04 in. was recorded at Bayamón.
- September 19–21, 2017 – Hurricane Maria, a Category 4 hurricane, caused catastrophic damage to the territory. Rainfall amounts totals as high as 37.9 in. were reported in Caguas. High storm surge and heavy rain caused significant flooding, with water levels rising to depths of up to 15 feet.
- July 9–10, 2018 – The remnants of Hurricane Beryl pass south of Puerto Rico, bringing heavy rain, especially to the east side of the main Island. Areas on the island's east side received more than 8 inches of rain.
- August 28–29, 2019 – Hurricane Dorian passed east of Puerto Rico, causing gusty winds and heavy rain. One person died while preparing for the storm.
- September 23–25, 2019 – Tropical Storm Karen closely paralleled the east coast of Puerto Rico, causing flooding.
- July 29–30, 2020 – Tropical Storm Isaias passed south of Puerto Rico, flooding the territory.
- August 22–23, 2020 – Tropical Storm Laura passed south of Puerto Rico, bringing 4.09 in. rain.
- September 18, 2020 – Hurricane Teddy
- Sept 17–19, 2022 – Hurricane Fiona made landfall in Lajas, Puerto Rico, as a slow-moving Category 1 hurricane, bringing heavy rains over to the whole island.
- 1970s: Technical experts began investigations to determine the best location for the dam. The project has brought the Corps and its partner, the Department of Natural and Environmental Resources (DNER) of Puerto Rico, together as one team to, meet its many design and geological challenges.
- 1980s: Technical experts decided the area's many unique challenges would call for creating USACE's first three-centered, double curvature thin arch dam. Final design and approval followed.
- 1990s: Excavation, foundation test grouting, and foundation curtain grouting proceeced with excavation for the left and right abutments, removing 350,000 cubic yards of material. It was during the height of the testing program, which involved grout migration, mapping and extensive lab testing, that a new grouting procedure called "duration grouting" was developed. The innovative procedure formed the basis of the foundation or grout curtain for the original design. However, when the Portugués Thin Arch Dam was advertised for construction in September 2000, only one proposal was received, which was significantly above the government's cost estimate.
- 2000: To reduce costs, a five-year program was started. It included investigation of alternative designs, field explorations, test programs, design finalization and preparation of contract plans and specifications. The Corps of Engineers Computer Aided Structural Engineering Task Group, composed of experts from the Corps and the Bureau of Reclamation, developed arch dam software tools and design criteria. Studies showed that costs could be reduced by redesigning the structure from a double curvature, thin arch dam to a single-centered RCC thick arch dam. Incorporating RCC design also resulted in an overall design change for the left side of the dam, placing it upstream to avoid its foundation resting on weathered rock.
- 2008: Construction began.
- 2010: Concrete installation began.
- 2013: Construction completed.
To promote the training of future engineers, the Corps has used Portugués Dam as part of its "Dam Safety University" program. The program is designed to broaden and deepen the knowledge of dam safety practices across USACE, a new generation of dam safety engineers to follow in the footsteps of those who came before them.
The public can obtain news, updates and information from the U.S. Army Corps of Engineers Jacksonville District on the district’s website at https://www.saj.usace.army.mil/, on Facebook at https://www.facebook.com/JacksonvilleDistrict and on Twitter at www.twitter.com/JaxStrong.