Puerto Rico Seeking U.S. Funds for Emergency Dredging
Along the Caño Martín Peña, a six-kilometer (about 3.7-mile) estuarial channel that connects San Juan Bay to San Jose Lagoon, densely populated communities have built neighborhoods atop trash built up in the channel. A dredging project to clear the waterway is high priority for the Puerto Rican government.
The Caño Martín Peña is filled with trash and debris including sewage, which poses serious human health issues.
The governor of Puerto Rico has asked the U.S. federal government to spend $600 million to dredge San Juan’s polluted Martín Peña Channel.
The Puerto Rican government has already spent more than $100 million in rehabilitating the channel and the neighborhoods around it, which have contended with flooding for many years. The $600 million would pay for the relocation of some 26,000 people who live on homes built on trash in the channel, and the dredging of the obstructed waterway.
Puerto Rican Governor Alejandro Garcia Padilla said the dredging project is one of his administration’s highest environmental priorities. Local newspapers and community groups have been describing the situation as “subhuman” and are calling for the country to pay for emergency environmental dredging.
As IDR has previously reported, the Caño Martín Peña is a six-kilometer (about 9.66-mile) estuarial channel that connects San Juan Bay to San Jose Lagoon. It once stretched 200 feet across and had a natural depth of 10 feet, and was used by fishermen, ferries and shippers to move between the two bodies of water. (See the September/October 2012 issue.) But over the course of the last century the channel has been filled with trash, and as the city’s population grew, whole neighborhoods have been built on that trash.
The aerial from the 1930s (top photo) shows a much wider channel than the current aerial shot.
While this seemed practical during San Juan’s economic booms, it has devolved into an environmental disaster. The estuary’s ecosystem has been stymied by raw sewage, garbage, and chemical pollution. The channel is lined with illegal dumps, and the pollution in the waterway and the dumps frequently flood into nearby low-income neighborhoods during heavy rains. Mangrove forests that once flourished in the estuary have disappeared, and the channel no longer serves the purpose it once did, circulating water through the bay and nearby lagoons. Water quality throughout the region has suffered. Last June, news outlets in Puerto Rico reported that thousands of fish were dying because of a lack of oxygen in the water, due to poor water circulation. Publication Noticel quoted Melba E. Ayala Nieves of tour agency Excursiones Eco as saying this massive fish death occurs every couple of years when something large obstructs the already-congested waterway. “When you go over the Teodoro Moscoso Bridge, you observe this beautiful lagoon that might appear to be very healthy, but many know the reality of the ecosystem,” Ayala Nieves said.
The clogged waterway has had an effect on human health as well: Because untreated sewage flows into the waterway and there is little circulation, the area has turned into a breeding ground for mosquitos that then infect residents with the Chikungunya virus and dengue fever. The sewage is also responsible for the channel recording some 10,000 times the accepted fecal coliform levels. A study by the Ponce School of Medicine revealed that people living above the channel have nearly a 50 percent greater greater incidence of gastrointestinal problems than the rest of the population. Small children living above the channel are more than twice as likely to suffer from bronchial asthma than the rest of the country.
Dredging the channel has long been advocated by government and community leaders as the best way to restore the once-vibrant waterway, but this would require finding new homes for 26,000 people who live in eight different neighborhoods on the estuary. The proposal would restore the channel to 100 feet wide and 10 feet deep. About 500 people have been removed in smaller projects in recent years and some new sewage systems have been installed, largely thanks to the advocacy of community group Proyecto Enlace del Caño. But a much more ambitious and costly project would be necessary to restore the channel to health.
Such a project was conducted on the western half of the channel some 30 years ago with mixed results. In the 1980s, the government spent $125 million to relocate thousands of people out of the western half of the channel. In that case, the motivation wasn’t environmental but economic: The government had found federal dollars to fund a public transit project called the Agua-Guagua, which would ferry people between the financial district and the old San Juan neighborhood. This required relocating thousands of people; however, the relocation was not handled well and the people who were removed wound up poorer than they had started. The $20 million dredging and construction project that followed removed 1.3 million cubic yards of sediment and created a 200-foot wide, 10-foot deep channel. Although the ferries have never been very popular, the dredging did have positive environmental effects on the estuary.
Community leaders promise that the proposal to dredge the eastern half of the channel will be handled radically differently, and will not have the deleterious effect on the community that its predecessor project did. Community group Enlace held hundreds of public meetings to gain public support. Now, many members of the neighborhoods are cautiously backing the project, but the problem is funding. It will cost hundreds of millions of dollars and take years to remove 26,000 people from their homes and find them new ones.
The Puerto Rican government has already detailed a plan for the dredging. As the IDR reported in 2012, the project would remove 825,000 cubic yards of material. An environmental study concluded that the material to be removed is contaminated, so a dredging project would have to be conducted sensitive to that. The contaminated material could be deposited in “artificial depressions” in the lagoons and channels that were dug decades ago for never-finished development projects, and which create unhealthy anaerobic conditions in the lagoon. The areas would be used like a landfill – first lined, then the contaminated material would be deposited, Jose Soto, a life scientist with the U.S. Environmental Protection Agency, told IDR in 2012. The pits would then be capped and covered, then planted with mangrove forests. This would get rid of contaminated material and fill the anaerobic pits.
“We’d take care of two problems at the same time,” Soto told IDR.
Katia Avilés-Vasquez, environmental affairs officer for Proyecto Enlace, outlined some of the dredging specifics in an email to IDR. If the project is funded, Avilés-Vasquez wrote, the design would use sheet piles with a concrete cap and gaps in between for certain areas to promote good water exchange. Given the restricted physical environment within the channel – shallow water and low bridge clearances – as well as the nature of the material to be dredged, the job will most likely require a small clamshell mechanical dredge, which could switch between an open bucket to excavate trash and debris, and an environmental bucket, to excavate unconsolidated contaminated sediments. Appropriate dredged material would be placed within shallow-water dump scows and transported to disposal sites at underwater artificial pits in the San José Lagoon. The dump scows would be outfitted with metal sieves, to separate trash and debris from the dredged material. That trash and debris would be taken to a municipal landfill.
“The preferred bulkhead is a sheet pile cantilevered wall with no tie-backs and a concrete cap. That sheet pile could be installed with a vibratory hammer and a diesel, steam or hydraulic pile hammer for sections of sheet pile that may not be able to be driven completely to the required tip elevation,’ she stated. “During dredging operations, temporary slope angles would be maintained until the installation of the sheet pile. In support of the project’s goal of wetland (mangrove) restoration, the channel cross section includes grading both the sides of the channel to permit the creation of habitat for mangrove planting.”
That grading would be performed using the dredge equipment as well as land-based excavation equipment.
Governor Garcia Padilla said that the Puerto Rican government has already spent $100 million over the last decade to restore the channel and now the federal government should come up with the rest.
A recent editorial by Puerto Rican newspaper El Nuevo Dia said Martín Peña’s “subhuman conditions still affect thousands of residents,” and that “we should all, as a nation, commit to dredging the silted and polluted channel.” The commonwealth government has attempted to enlist the help of congressmembers and its large diaspora off the island to pressure the federal government to find funding for the project. Several congressmembers, as well as New York Mayor Bill de Blasio, recently visited the island in and stated some commitment to pushing the federal government and the Army Corps of Engineers to prioritize the project.
Lyvia Rodriguez, executive director of community group Proyecto Enlace del Caño, told IDR in 2012 that dredging the Martín Peña is key to the economic revitalization of the city. “The caño is the heart of the city,” she said. “Its rehabilitation will allow for the reconnection of a series of waterways, and at the same time would provoke the possibility of real urban development.”
Puerto Rico Federal Affairs Administration (PRFAA) Director Juan E. Hernández, in a press release about these efforts, described the issue as “one of social and environmental justice.”’
“It also has a huge impact on Puerto Rico’s economic activity, as this channel is part of the San Juan Bay National Estuary in the metropolitan area, which operates as one of the most important ports in the Caribbean. On the other hand, flooding caused by the channel’s blockage frequently impacts operations in the Luis Muñóz Marín International Airport, which receives around 5,000 cargo flights per month and 2,200 commercial flights of more than 20 airlines, with an estimated flow of 425,000 visitors each month. According to estimates from a feasibility studies of the CMP Restoration Project, channel degradation costs to the government fluctuate in around $7.5 billion annually in damages to public health and property,” he stated.Edit Module