Recent typhoons, though packing powerful winds, did not bring as much rainfall as “Ondoy” or “Pepeng.” But the rainfall was enough to bring back flooding in areas where the water had already receded, such as communities around Laguna de Bay.
The flooding problem in those communities is a story of inaction, lack of foresight and political will.
A comprehensive study of the lake had been undertaken several years ago, with the cost underwritten by the Dutch government. But the study and recommendations, which were presented to President Arroyo herself, were soon forgotten.
This time, among those that were flooded again were barangays in Muntinlupa, though this is hardly surprising, since this is a city where a sports center and an elementary school have been constructed right on the lake.
As those government structures illustrate, the 60,000 families relocated from the slums of Metro Manila to reclaimed land that is now called Lupang Arenda aren’t the only ones encroaching on Laguna de Bay.
Way back in 2000, the Dutch government financed a three-year study at a cost of 2.5 million guilders (about P70 million at the time). Those who undertook the study warned that encroachments on the lake, combined with its natural deterioration, constituted a ticking time bomb.
Even further back in the 1970s, in fact, water management experts had already foreseen problems in the Laguna de Bay floodplain and had proposed the construction of a seven-kilometer-long spillway that would allow excess water from the lake to wash out to Manila Bay during the monsoon season. The spillway would cut through Parañaque.
Since then the South Luzon Tollway and Sucat Road have been built, Parañaque’s salt beds have disappeared, and homes, commercial and industrial structures have been constructed along the proposed path of the spillway. The cost of paying for right of way and building the spillway, as originally envisioned, would now be prohibitive. The alternative, a tunnel running from the lake to the bay, would be even more expensive.
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The 2000-2003 study was conducted by an international consortium under a bilateral agreement between the Philippines and the Netherlands. It came up with detailed proposals for the sustainable development of the Laguna de Bay environment.
Among the government agencies that were part of the project were the Laguna Lake Development Authority, the Local Water Utilities Administration, Metropolitan Waterworks and Sewerage System, the Department of Public Works and Highways, the Metro Manila Development Authority (MMDA), National Housing Authority and local government units.
Officials and personnel of these agencies were brought to the Netherlands to see for themselves what could be done for Laguna de Bay.
The MMDA chairman at the time, Benjamin Abalos, was in the Netherlands on such a trip when he was informed that he would head the Commission on Elections. That could have been among the reasons why the study was soon forgotten.
About 60 percent of the Netherlands lies below sea level, with the lowest point 6.74 meters below sea level, so the Dutch built “polders” to prevent flooding.
A polder is a lowland area separated from water through dikes, in which water levels can be controlled artificially through pumps and similar devices. It can be land reclaimed from a lake or the sea, or a marsh or floodplain separated from surrounding water through dikes and then drained.
The Netherlands’ principal airport and one of the world’s busiest, Amsterdam Airport Schiphol, is built on a polder. “Schiphol” translates into “ship hole.” The airport started as a military air base in 1916 on land reclaimed from a lake where many ships were lost during storms. The airport is now the world’s lowest lying major commercial hub, sitting 3.4 meters below sea level.
Europe has had polders since the 11th century, with windmills powering the earlier versions in the Netherlands.
The polder dikes were not strong enough to withstand a storm tide that spawned the North Sea Flood of 1953, which killed 1,835 people in the Netherlands, 307 in the UK and 28 in Belgium, plus 230 more on various ships in the North Sea. The flood led to a redesign of the dikes, and there has been no repeat of the flooding for the past half-century. Today two-thirds of the Netherlands would experience regular flooding without thousands of polders scattered across the country. Polders are now used even in Singapore.
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Can polders work for Laguna de Bay and the surrounding floodplain? We have to think of ways to mitigate flooding around the lake, because the problem is likely to worsen.
The Netherlands-sponsored project comes to mind because Tjitte Nouta, the Dutch engineer who headed the study in 2000, is back in Manila for a week until today on the invitation of the United Nations Children’s Fund.
Unicef is alarmed by the rising cases of leptospirosis and other health problems in evacuation centers and communities around the lake that are still flooded, and is inviting international experts to assess what can be done.
Covering an area of about 900 square kilometers, Laguna de Bay is one of the largest lakes in Southeast Asia. The watershed occupies about 3,820 square kilometers, but it has steadily shrunk from deforestation, quarrying, land conversion and population expansion. About 100 streams drain into the lake, where the salinity rises during the dry season, which is good for algae that serves as natural food for fish. About four million tons of suspended solids enter the lake every year, and the lake now averages just 2.5 meters deep.
Among the findings of the study was that while dredging the Pasig River by about two meters would ease flooding, dredging the lake would not, since excess water would simply wash over into the surrounding floodplain. The lake, whose bed is not flat, is susceptible to storm surges.
Ridding the Pasig, the Napindan Channel and Manggahan Floodway of obstructions, including water hyacinths, would help.
The study proposed the construction of four polder islands, occupying 30 square kilometers, on the northern part of the lake. One polder would serve as a drinking water reservoir, with wastewater treatment facilities. Another would be a sanitary landfill for Metro Manila and containment for industrial sludge, which could later be converted into a recreational area.
The two other islands would be for social housing, parks, a light industrial zone and a commercial fishing village.
The project also proposed the construction of the C-6 road linking the north and south expressways.
Those proposals were made seven years ago and quickly forgotten. Amid the continuing flooding, perhaps someone would now give the proposals a second look.