Manila Bay reclamation project raises specter of storm surge

The risk of storm surges, ground subsidence, and liquefaction make any reclamation project in Manila Bay a bad idea, according to marine geologist Kelvin Rodolfo.

 

This, in response the Manila Goldcoast Reclamation Project, which proposes to reclaim 148 hectares in the waters of Manila Bay along the coast of the City of Manila.

 

The project will create three islands of reclaimed land plans adjacent to Roxas Boulevard.

 

A map in an Environmental Management Bureau report shows one island will be adjacent to the Cultural Center of the Philippines, the Philippine Navy headquarters, the Manila Yacht Club, the Embassy of the United States of America, the World Trade Center, and the Manila Hospital.

 

The other two will be west of it, toward Manila Bay.

 

In his critique of “An Environmental Impact Statement (EIS) for the Proposed 148-Hectare Manila Goldcoast Reclamation Project Along Coast of the City”, Rodolfo said that these areas will be vulnerable to storm surges, ground shaking, and liquefaction.

 

He also said that the EIS “does not discuss (the) site's vulnerability to natural hazards (seismic, volcanic, meteorological), but only tells the reader (to) go to NDRRMC, NAMRIA, and other agencies for information.”

 

Manila Goldcoast is one of the projects under the National Reclamation Plan of the Philippine Reclamation Authority (PRA). The NRP includes 38 other proposed reclamation sites stretching from Cavite to Bataan.

 

Manila Goldcoast is meant to be an upscale business district with high-rise office and commercial buildings with space for casinos and a mall.

The proposed development is expected to rival smaller commercial hubs like Eastwood in Quezon City and The Fort in Makati.

 

At a people's forum held on November 22, Rodolfo explained why the shores of Manila Bay are not suitable for reclamation. He pointed out the same items in his critique of PRA's EIC of the Manila Goldcoast.

 

Liquefaction: “The greatest hazard that threatens coastal areas”

 

“By far the greatest hazard that threatens coastal areas, whether underlain by natural deposits like those of the Pasig River Delta or artificial reclamations, is seismically-induced liquefaction.”

 

The critique explains all bay-fill materials, natural or man-made, are masses made up of pieces of rock ranging in size from tiny particles of clay to large boulders. Spaces between the solid pieces are occupied by water.

 

Under normal conditions, these grains of sediment rest on top of each other, with water filling the spaces in between. But, in an earthquake, the sediments shake as well, and no longer rest on top of each other.

 

“Shaking mixture of sediment and water behaves as a “slurry” like freshly mixed concrete, a liquid without strength.”

 

This effect causes buildings to sink, topple over, or fall. “Reclaimed areas in Manila Bay would not require an earthquake to occur nearby to suffer serious damage.”

 

Rodolfo cited the 7.3-magnitude earthquake in 1968 that hit Casiguran, Quezon, an area 225 kilometers away from Manila. Although far from the epicenter, many structures on river deposits near the mouth of Pasig River were destroyed. The six-story Ruby Tower in Binondo also collapsed from liquefaction, groundshaking, or both, killing 260 people, he said.

 

Storm surges and waves

 

“The most susceptible area is the shoreline and what they're doing is they're advancing the shoreline seaward. So, they're the ones that are going to be more susceptible. It's that simple,” Rodolfo said in a separate interview on the sidelines of the people's forum.

 

According to a PAGASA hazard map, the area where the Manila Goldcoast will be built had had storm surge occurences in the past.

 

But the Goldcoast proposal specifies no adequate way to defend itself from storm surges and storm waves. Anecdotal evidence shows that storm surges are becoming higher as the typhoons that bring them become stronger and more frequent.

 

Ground subsidence

 

The area is also prone to ground subsidence, or the “sinking” of the ground due to excessive pumping of water from the natural aquifers underneath the surface. Since the densely-populated capital region requires more water to support its population, coastal areas continue to subside, worsening both flood and high-tide invasions.

 

Among the areas sinking up to five centimeters per year are Obando in Bulacan, the cities of Caloocan, Valenzuela, Navotas, Malabon and Manila, and Rosario in Cavite among others.

 

Goldcoast islands, fundamentally unsound?

 

Rodolfo's critique also says that “nature works unceasingly to render shorelines straight.”

 

Because of the behavior of waves, sediments are deposited gentler at bayshores, while other areas are eroded, which is likely to happen in the artificial peninsula that will be the Goldcoast.

 

“The problem is that all the shore areas have the wrong geology. If you can find a place where there are rocky ledges, and very rigid rock, you might be able to do something. But this whole thing is nothing but soft sediment here in Manila Bay. There may be (places) in other areas of the country. But I don't know of them. I'm not saying that there are none, but I don't know of any.”

 

Rodolfo said reclaimed land that has been around for decades is also susceptible to liquifaction and to storm surge. These areas also contribute to subsidence.

 

"Until the next big earthquake happens, or until a really bad storm surge happens, that's going to be valuable real estate. Nobody is going to abandon valuable real estate voluntarily," he said in a separate interview.

 

"I don't want reclamation to happen at all, as far as I'm concerned."

Gonzales added that they have yet to review the Manila Goldcoast Project.

 

The EIS still has to be reviewed by the DENR, which has the power to give the project an Environmental Compliance Certificate (ECC), a requirement for its approval.

 

Acquiring the ECC is only one step in the five-stage approval process imposed by the PRA.

 

Aside from the ECC, project proponent Manila Goldcoast Corp. also has to submit a detailed engineering design, a detailed feasibility study, flooding and flushing impact study, and a social impact assessment (where public consultation is included, according to Gonzales).

 

The PRA will also require a climate change adaptation strategy and a geohazard study, where liquefaction and earthquakes will be taken into consideration, Gonzales said.

 

Gonzales also said Goldcoast is subject to a suspension order from Malacañang since 1992 and that the PRA "will only continue processing of Goldcoast (applications) once they are able to secure lifting of the suspension order."

 

"What Goldcoast is trying to do right now is get all the approvals that they can," he said.
 

On Wednesday, President Benigno Aquino III transferred the power to approve reclamation projects to the National Economic and Development Authority (NEDA). 

 

The move comes at a time of rising opposition to the plan. In January, a citizens' coalition mobilized to stop a reclamation plan by the City of Manila and Manila Goldcoast Corp. 

 

Despite opposition, Manila Mayor Joseph Estrada, elected in May, supports reclamation along Manila Bay. — JDS/TJD, GMA News