Posted on November 4, 2026
By Jera C. Sison
PAGASA has warned that a “Super El Niño” will grip the Philippines from late 2026 through the first half of 2027. The forecast carries an uncomfortable double signature: dry spells, wilting farmlands, and above all, water shortage. The reservoirs Metro Manila leans on — Angat, Ipo, and La Mesa — are expected to shed water levels, forcing rationing and exposing how thin the capital’s margin of supply really is. In that looming arithmetic, one asset is routinely overlooked: a 900-square-kilometer inland lake sitting on Manila’s doorstep.
Laguna de Bay is the largest lake in the Philippines and the third-largest inland body of water in Southeast Asia. It is already a water source, not merely a flood basin — Maynilad draws hundreds of millions of liters from it daily to serve the southern portion of its West Zone concession area, including cities and municipalities in southern Metro Manila and Cavite. And the lake is dying from sedimentation. Decades of siltation have driven its average depth from roughly twelve meters to about two and a half. Dredging is therefore double-edged: flood control and, more quietly, water security.
However, dredging will not single-handedly solve the water problem, and full-scale dredging is rightly contested — but a targeted, science-driven, honestly governed deepening of the lake, focused on its outlets and i ntake zones, is among the most underused instruments for keeping taps running through 2027.
A shrinking lake, a thirsty metropolis
The mechanics are simple. The lake drains a vast watershed across Laguna, Rizal, and Metro Manila’s eastern fringe. Industrialization and deforestation have accelerated erosion, and the sediment that washes downstream settles on the lakebed.
That matters because the lake is no longer a marginal source. Maynilad’s Putatan Water Treatment Plants in Muntinlupa draw 300 million liters of raw water per day directly from Laguna de Bay, and the Poblacion Water Treatment Plant, inaugurated in December 2023, added another 150 million liters per day. Together, these supply growing demand in Muntinlupa, Parañaque, Las Piñas, and parts of Cavite. Seasonal algal blooms and turbidity spikes stress the lake-based plants; Maynilad responds tactically with solar-powered ultrasonic algae control, silt curtains, and regular dredging of its own intake zones. The company already treats dredging as an operational necessity. The national conversation is simply about scaling that logic up.
The case for dredging
Deepening the lakebed increases its capacity to retain storm runoff during typhoons, thereby reducing peak water levels that overflow into surrounding lakeshore communities. Desilting choke points — the Napindan Channel and the mouths of major rivers — accelerates drainage toward Manila Bay. The extracted silt is not waste: it can serve as infrastructure fill or garden soil. The MMDA has backed the approach, with Chairman Don Artes framing dredging, alongside the proposed Parañaque Spillway, as a way to increase the lake’s holding capacity.
But where does water shortage come in? A deeper lake is a bigger bank account. During the dry months of Super El Niño, when Angat drops and rationing looms, the lake’s stored volume becomes a drawable reserve—a third reservoir hiding in plain sight. Dredging also protects the intake zones Maynilad depends on, sustaining production as levels fall. El Niño is dry, so the flood rationale may seem mismatched — but the water cycle does not respect that neat division. The wet season recharges; the dry season drains. A lake that has lost four-fifths of its depth recharges less and holds less through drought. Dredging enlarges the vessel that carries water from wet months into dry ones.
The counter-perspective
The Laguna Lake Development Authority cautions that dredging all 900 square kilometers is neither ecologically nor economically practical. Its objections are serious. The silt volume is staggering, the cost prohibitive, the disposal a nightmare. Full-scale dredging risks disturbing buried toxic sediment and the benthic ecosystems beneath it. Instead, the LLDA proposes watershed management, pollution control, and targeted dredging of strategic areas. This is not obstructionism — it is recognition that a lake is an ecosystem before it is an engineering project. Dredging a lake while upstream keeps bleeding sediment is bailing a boat without plugging the hole. However, LLDA must still clamp down on illegal fish-pen infrastructures in Laguna de Bay.
A history of stops and starts
In 2011, President Noynoy Aquino cancelled the P18.7-billion Laguna Lake Rehabilitation Project, reasoning that it merely shifted silt and carried corruption risk. The Belgian contractor sued; a tribunal ruled the cancellation illegal and ordered compensation. A decade and a half later, the lake is shallower and the case stronger — and the country has learned that cancellation has a price too. In 2026, the Philippine Reclamation Authority and DPWH suspended dredging-related work in a Taguig section over potential unauthorized reclamation and missing clearances. The lesson is uncomfortable but clear: the binding constraint on dredging is not hydrology. It is governance.
Toward a workable framework
A credible program would refuse the false choice between everything and nothing: targeted, science-based
dredging of the Napindan Channel, river mouths, and intake zones, with extracted sediment reused as fill — paired with aggressive watershed management and pollution control so the lake stops refilling with mud as fast as it is cleared. It would admit dredging is one leg of a stool; water security also demands leak reduction, wastewater reuse, rainwater harvesting, and diversification away from a single-dam dependency. And it demands institutional discipline: transparent contracts, clear permitting, a standing anti-corruption posture.
The Super El Niño will test the system in ways no contingency plan fully covers. When Angat, Ipo, and La Mesa run low, the country will need every reserve — including the one it spent a century filling with mud. The real question is not whether to dredge, but where, how much, with what safeguards, and who is watching the money. Answered well, dredging becomes more than flood control. It becomes climate adaptation — a modest, hard-won insurance policy against a dry year already on the calendar.
Dredging buys room for the flood; only planning can buy time for the drought
The case for dredging Laguna de Bay is real, but it has been asked to carry more weight than it can bear. Removing decades of accumulated silt is fundamentally a flood-control intervention: it deepens the lake, restores some of its holding capacity, and buys surrounding communities breathing room when heavy rains push water levels toward the banks. What it does not do is manufacture rain. A deeper lake stores more water, but during a prolonged dry spell or a below-normal rainfall season, the volume of water arriving from the watershed matters far more than the depth of the basin waiting to receive it. Expecting dredging to blunt a Super El Niño is therefore a category error — one that confuses a storage fix with a supply fix, and that can lull planners into neglecting the hydrological studies needed to avoid salinity intrusion and ecological damage when flows run low.
The more honest framing is that Laguna de Bay needs two separate strategies aimed at two separate threats. Against flooding and siltation, dredging remains a legitimate and necessary tool. Against drought, heat, and water scarcity, the answers lie elsewhere: harvesting and storing rainwater before the dry season peaks, enforcing serious conservation and rationing across urban and agricultural users, and deploying decentralized infrastructure — solar-powered pumps, deep wells, and tankers — to keep critical facilities supplied when reservoirs and rainfall fail. Treating these as complements rather than substitutes is the only way to make the lake resilient to both ends of an increasingly erratic climate. Dredge for the flood, but plan for the drought.
The dredging of Laguna de Bay will necessarily entail expenditures in the billions of pesos. It nonetheless represents a strategic opportunity for the national government to demonstrate genuine commitment to long-term climate adaptation. While the proposal to store water in household buckets drew criticism on social media, a comprehensive rehabilitation program for Laguna de Bay could constitute the enduring legacy of the Marcos administration.
