27/09/2026
Laguna de Bay is already flashing every warning sign - record-high water levels, prolonged flooding, rising pollution, sedimentation and declining fisheries - and government must act now before an ecological crisis becomes a full-blown disaster for our communities, food supply and economy.
🚨LAGUNA DE BAY ON THE BRINK OF TOTAL ECOLOGICAL COLLAPSE
Laguna de Bay is a natural flood basin, a major inland fishery, a water resource, an economic lifeline and one of the country’s most important ecological systems.
And right now, the warning signs are becoming impossible to ignore.
On September 8, 2026, the water level of Laguna de Bay reached 12.73 meters, well above its 12.50-meter critical high-water mark. At least 29 lakeshore barangays in Laguna remained flooded, affecting communities in San Pedro, Biñan, Santa Rosa, Los Baños, Bay, Calamba, Santa Cruz, Pakil and Paete.
In Pansol, Calamba, some communities were still under one to three feet of water. Local officials warned that the flooding could take up to three months to subside because Laguna de Bay itself remained high.
That should concern the entire country.
Because the problem is no longer simply that it rains too much.
The problem is that the lake is being asked to absorb, store and drain an enormous amount of water while its surrounding watershed continues to urbanize, its tributaries carry pollution and sediment into the basin, and its natural drainage system faces increasing pressure.
The numbers tell the story.
Laguna de Bay covers roughly 900 square kilometers. The LLDA has warned that dredging the entire lake by even one meter would mean removing billions of cubic meters of material. More importantly, the sediment at the bottom is not necessarily harmless mud. The LLDA has described it as a reservoir of industrial, agricultural and domestic pollutants.
This is why the solution cannot simply be: dredge everything.
It also cannot be: build another flood-control structure and move on.
We have to deal with what is entering the lake in the first place.
The Philippine Statistics Authority’s Laguna Lake ecosystem accounts found that domestic waste accounted for an estimated 81 percent of the biochemical oxygen demand loading into the lake. The same ecosystem assessment documented rapid urbanization and industrialization around the basin and linked soil erosion and sedimentation to increased flood risks.
And the pollution problem is not merely historical.
PSA data showed that the average nitrate concentration in Laguna de Bay and its major tributaries increased from 0.49 mg/L in 2022 to 0.64 mg/L in 2023, while phosphate increased from 0.54 mg/L to 0.65 mg/L. Average total coliform in the lake also rose by 53.2 percent, from 495.37 to 758.77 most probable number per 100 milliliters.
In June 2026, the LLDA investigated a serious pollution incident in the San Juan River in Calamba after residents reported thick foam, foul odor and a fish kill. The agency has since called on industries, local governments and residents to help identify illegal wastewater discharges before the evidence disappears downstream.
This is what makes Laguna de Bay’s condition particularly dangerous.
The same lake that receives pollution and sediment is also expected to produce food.
The Department of Agriculture estimates that Laguna Lake has historically supplied about 40 percent of Metro Manila’s bangus and tilapia requirements. The lake also supports thousands of fisherfolk and aquaculture operators.
Yet Laguna’s own fisheries data show that total fisheries production in the province fell 7.8 percent year-on-year in the second quarter of 2026, from 4,238.94 metric tons to 3,910.44 metric tons. Inland fisheries production declined 7.3 percent, while aquaculture production dropped 11.5 percent.
So when Laguna de Bay deteriorates, the consequences do not stop at the shoreline.
They reach the dinner table.
They reach fish prices.
They reach the livelihoods of fishing communities.
They reach households and businesses affected by prolonged flooding.
And they increasingly intersect with Metro Manila’s search for additional water sources.
The government itself recognizes that Laguna Lake has to perform several functions simultaneously: food production, fisheries, environmental protection, water security and flood management. In June, the DA called for a whole-of-government strategy involving the DA, DENR, LLDA, MMDA, Philippine Coast Guard and water concessionaires.
That coordination now needs to become operational, measurable and accountable.
First, government needs one integrated Laguna de Bay master plan.
Not another agency-specific plan.
The basin crosses political and administrative boundaries. Its watersheds, tributaries, drainage systems, floodgates and shoreline communities cannot be managed independently by separate agencies and LGUs.
There should be one publicly accessible plan showing the lake’s water levels, tributary flows, pollution sources, drainage bottlenecks, flood-control projects, sedimentation hotspots, wastewater facilities and priority rehabilitation areas.
Second, stop treating dredging as a substitute for watershed management.
Targeted dredging may be necessary. The LLDA itself has identified strategic areas such as the Napindan Channel and mouths of major tributaries as possible priorities, while warning against indiscriminate full-lake dredging.
But if we remove sediment today and allow the same sediment to flow back into the lake tomorrow, we have not solved the problem.
Government needs aggressive erosion control, reforestation and watershed rehabilitation across the tributaries feeding Laguna de Bay.
Third, enforce wastewater laws at the source.
The government should know which facilities discharge into which tributary, whether they have valid discharge permits, whether their treatment systems actually work and whether their effluent meets standards.
And when there is a fish kill, chemical smell, abnormal foaming or sudden discoloration, enforcement cannot begin weeks later.
The LLDA itself has acknowledged the difficulty of tracing pollution across such a vast basin and has asked communities to provide exact locations, photographs, times and other evidence to help identify offenders.
That system should be strengthened with real-time monitoring and publicly reported enforcement results.
Fourth, make floodgate operations science-based and transparent.
The DA reported in June that the Manggahan and Napindan floodgates were being kept open during the dry season to improve water exchange, dissolved oxygen and water quality, while recognizing that closures become necessary during heavy rains.
The public deserves to know the operating criteria. When are the gates opened? When are they closed? What lake level triggers each decision? What rainfall forecast is being used? What is the expected effect on flooding upstream and downstream?
Flood management should not depend on improvisation after the water is already inside people’s homes.
Fifth, protect the people who depend directly on the lake.
A lake rehabilitation program that destroys fisherfolk livelihoods is not sustainable.
But protecting livelihoods cannot mean allowing pollution, uncontrolled aquaculture expansion or ecological degradation to continue indefinitely.
Government has to enforce carrying-capacity limits while ensuring that small fisherfolk receive fair access, livelihood assistance and a meaningful voice in management decisions.
The lake’s future cannot be decided solely from an office in Manila.
And finally, government must publish the numbers. Water levels. Water quality. Pollution violations. Fish kills. Sedimentation. Dredging volumes. Flooded barangays. Drainage projects. Budgets. Contractors. Project completion rates. Before-and-after measurements.
If billions of pesos will be spent to rehabilitate Laguna de Bay, Filipinos should be able to see exactly where the money goes and whether the lake actually improves.
Laguna de Bay has been warning us for years. We already have the ecosystem accounts. We already have the pollution data. We already know about sedimentation. We already know the lake is a critical fishery. We already know its flood-control role. We already have agencies with mandates to protect it. What we have lacked is sustained, integrated ex*****on.
The September 2026 floods should therefore not be treated as another seasonal disaster that disappears when the water does. They should be treated as a national warning. Because when Laguna de Bay loses its capacity to function, the damage will not stay in Laguna.
It will move through our rivers, our roads, our food supply, our water systems, our communities and ultimately our national budget. The government still has the opportunity to act before the lake reaches a point where rehabilitation becomes far more expensive than prevention. But the response has to begin with one basic principle: Do not wait for Laguna de Bay to completely fail before we decide that it was worth saving.
