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We talked to a UP scientist to understand why Laguna Lake keeps on flooding its shore communities

Apparently, it’s an environmental tragedy much bigger than we think.

Three months after Typhoon Ulysses devastated Metro Manila and several areas in Luzon, some shoreline communities along Laguna de Bay are still submerged in flood.

In a November 24 Inquirer report, the Regional Disaster Risk Reduction and Management Council in the CALABARZON region identified several lakeshore barangays in Laguna cities including Calamba, San Pedro, Biñan, and the municipalities of Santa Cruz and Pila to be among those still in “under-knee to waist-deep floodwater.” 

The water is receding in many areas, but not totally. 

When Ulysses hit on November 11, Brgy. Dela Paz, Biñan, Laguna resident James Marzon took refuge on the second floor of his family’s home. With at least four steps of their staircase submerged in flood, he says it was a frightening experience because they felt like they had no control.

Yung pagtaas, ambilis talaga niya […] so nag-start siya ng madaling araw, alas-kwatro […] talampakan pa lang yun and pagggising po hanggang alas-otso […] sa loob palang ng bahay namin yun, dibdib na siya,” he recounts.

For the residents of Brgy. Dela Paz, where streets remain in under-knee water, something of the sort has become so “normal” that almost every household has its own wooden or improvised boat as the main mode of transportation.

Taon-taon, as in [k]onting malakas na ulan lang sa gabi […] ‘tas tuloy-tuloy hanggang umaga. Expected na po talaga na [babaha],” says Marzon. 

Marzon is fortunate that his family’s home is located in the central part of the barangay where elevation is a bit higher. But for the families in areas they call “laylayan” — which literally means ‘edge’ — the situation is much worse because of their proximity to the lake.

Meanwhile, the scene of flooded streets in Dela Paz is not exactly new to the residents; but in the aftermath of Ulysses, it felt different. This time around, floodwater is murkier than ever. Streets are overwhelmed with floating garbage producing a foul odor. They say this has not always been the case.

Ngayon kasi, may burak — kulay kanal ganun, kulay black. Tapos yung mga basura, sobrang dami na talaga. Yung mga tao din kasi, irresponsible din kasi sa basura, kaya rin siguro ganun yung nangyayari ngayon. Dahil dun sa mga basurang natatapon din ng mga tao dito,” Marzon describes.

Dean Valmeo’s special report from the February 13 episode of [P] Live

Where is the floodwater coming from? Decades of neglect

Dr. Decibel V. Faustino-Eslava, a geologist and dean of the School of Environmental Science and Management (SESAM) at the University of the Philippines Los Baños (UPLB), explains that there are several contributing factors as to why Laguna de Bay is overflowing to the communities even during light rainfall.

Ang malaking problema natin sa Laguna de [Bay], is the amount of sediments going into the lake. And that has been caused yung several decades of […] uncontrolled or unregulated upland development na nagde-deliver ng too much sediments and of course, garbage into the rivers and the lakes of Laguna de [Bay],” the SESAM dean says in an exclusive interview with the Perspective.

Faustino-Eslava, who is a part of a group of UP scientists conducting a study on the ecological status of the lake, compares it with a cauldron, saying “when it rains, tumatanggap ng tubig yung watersheds and they all go to the streams and to the river and into the lake. And the lake itself is also an open area that receives water from the skies. So dalawang pathways ng rainwater diba from the watersheds and directly into the lake.”

She also notes, the lake has been experiencing “heavier sedimentation or siltation,” which made it much more shallow through the years — failing to accommodate more water.

Sedimentation happens when eroded soil, sand, clay, silt, and other solid materials settle at the bedrock of a body of water. Faustino-Eslava identifies waterways such as Pasig-Marikina river systems and the Pagsanjan river as among the highest suppliers of sediments to the lake.

Ngayon na mas marami nang sediments na kasama ang basura na pumapasok sa kanya, just a little bit of rainwater kaagad nang tumataas yung tubig ng lake. So mas mabilis ngayon ma-flood ang mga coastal communities. And that’s the reason why, for example, yung Dela Paz na barangay is now flooded, and is still probably flooded kasi […] mas mababaw yung lake, mas matagal pati siyang mag-flow out of the lake. And it’s not just Dela Paz. All around the lake, ganyan yung sitwasyon ng coastal communities,” she explains further.

The geologist’s group is recommending regular but “pinpointed” dredging in the lake to maintain or even improve its water levels. However, because of the size of Laguna de Bay, the negative environmental impacts it would bring as it would “disturb the sediments,” and how expensive it is to push through, she says it would be “not practical” to desilt the entire lake.

“[…] una, magastos mag-dredge, pangalawa, marami siyang negative environmental impacts, especially because you disturb the sediments. So those suggestions that we have in the book are meant to minimize the negative impacts and then maximize the benefits from dredging,” she adds.

Polluted and contaminated water 

Another concern for Laguna de Bay is the presence of fecal coliform or the bacteria that come from animal and human waste or sewage. Aside from supplying sediment, the 21 major tributary river systems and small streams connected to the lake also bring polluted water. 

For Faustino-Eslava, this could only be addressed through the construction of wastewater treatment facilities in the country, especially in Metro Manila. 

Importante na bawat munisipyo merong sariling wastewater treatment plant […] ’wag nating gawing basurahan yung lake, kasi yun yung nangyayari eh, diba? Lahat ng drainage, they go into the streams and then they go into the lake. And there’s no effort in cleaning up the water before they enter the lake […] the establishment of wastewater treatment plants is  — should become a national priority.”

It gets worse

For the Global Environment Facility (GEF), another major problem is nutrient pollution, or the increase of nitrogen and phosphorus in a body of water that comes from household, industrial, and agricultural waste. This is detrimental to Laguna de Bay because it leads to excessive plant and algae growth and could also result in fish kills due to lack of oxygen.

“Key sources of nutrients include run-off from farmland treated with fertilizers as well as detergents and untreated sewage in domestic wastewater,” GEF wrote in 2017.

In fact, this is consistent with Dr. Faustino-Eslava’s claim that farming businesses in Rizal and Laguna have also become the “emerging pollutants” in the watersheds. She says that farmlands are recklessly draining hormones used for raising livestock directly into the lake.

The Philippines has existing environmental laws such as the Republic Act (R.A.) 9003, or the Ecological Solid Waste Management Act of 2000 and the R.A. 9275, or the Philippine Clean Water Act of 2004, but for her, legislation is not the issue. It’s proper implementation.

May mga batas na tayo na nagsasabi kung paano natin dapat i-handle ang ating solid and liquid waste and kailangan lang ng matinding suporta para ma-implement yung mga yun,” she points out.

What now?

In the aftermath of Typhoon Ulysses, the Laguna Lake Development Authority announced in November 2020 that they have approved a P609-billion Build-Own-Operate (BOO) proposal for the rehabilitation and development of the Laguna de Bay. This is now under review by the National Economic and Development Authority, which will determine its fate. This means that  it remains uncertain whether or not it will materialize. Not to mention, it needs to survive the national government’s years and years of bureaucracy.

For the affected residents, all they can do for now is wait. After all, relocating is not an option they could afford. 

Tanggalin mo man yung mga communities sa coastal areas, kailangan ma-relocate mo sila within the same city. ‘Wag n’yo silang itapon sa kabundukan, kung saan walang tubig, walang kuryente, walang trabaho. Because they will keep coming back,” says Faustino-Eslava, who called on the government to address the socio-economic concerns of the communities affected.

Until then, the residents of Brgy. Dela Paz and other flooded communities will have to keep on paddling their boats and go on with their daily lives. 
“Wala na po talagang magagawa yun pong mga kabahayan,” Marzon told the Perspective. [P]

Photo by James Marzon

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