Residents on Alert as La Mesa & Wawa Dams Overflow

Manila, Philippines – July 2025

Residents on alert – Authorities have issued warnings after La Mesa Dam and Wawa Dam overflowed on Monday afternoon due to rising water levels.

This situation has led to concerns about flooding risks in nearby areas, prompting the need for heightened preparedness among affected residents.

La Mesa Dam Reaches Spilling Level

As of 3 p.m., La Mesa Dam‘s water level reached 80.16 meters, surpassing its spilling level of 80.15 meters. PAGASA warned that the overflow from La Mesa Dam could affect low-lying areas along the Tullahan River, including parts of Quezon City, Valenzuela City, Caloocan City, Malabon City, and Navotas.

Residents in these areas, especially those near the riverbanks, have been advised to stay alert for potential flooding.

Wawa Dam Reaches Spilling Level

In addition, Wawa Dam also reached its spilling level of 135 meters, with the water level rising to 135.58 meters.

The watercourses likely to be affected by this overflow include Upper and Lower Marikina River, Pasig River, San Juan River, and the Laguna de Bay Basin. Authorities have warned that flooding is possible in these regions due to the impounding water.

PAGASA Issues Flooding Alert

PAGASA has issued an alert about ongoing heavy rains caused by the southwest monsoon, which is expected to continue affecting areas such as Metro Manila, Zambales, Bataan, Pampanga, Bulacan, Cavite, Batangas, Rizal, Pangasinan, Tarlac, and Occidental Mindoro until Tuesday noon. These rains could worsen the flooding risk in the affected areas.

Monitoring of Low Pressure Areas (LPAs)

In addition to the heavy rains, PAGASA is monitoring two low-pressure areas (LPAs) inside the Philippine Area of Responsibility (PAR).

These LPAs have a medium potential to develop into tropical cyclones in the next 24 hours, which could further exacerbate the weather situation and increase the flooding threat.

Heightened Preparedness and Safety Measures

With the overflow of La Mesa Dam and Wawa Dam and the ongoing heavy rainfall, residents in the affected areas are urged to remain vigilant and prepared for possible evacuations or precautionary measures. Local authorities and PAGASA will continue to monitor the situation and provide updates.

Conclusion

The ongoing situation with dam overflow, heavy rains, and the potential for tropical cyclones requires residents to be alert and take necessary precautions.

The Philippine government, PAGASA, and local authorities are working to ensure the safety of residents and provide necessary updates. Communities should stay informed and follow the advice of local officials to avoid the risks posed by flooding.

References:

1. Residents told to be alert as La Mesa, Wawa dams overflow.
2. Heavy rains forecast in Metro Manila, other parts of PH until Thursday
3. Tullahan River and Marikina River – Waterways that could be impacted by the overflow.
4. LPAs and Tropical Cyclones – Monitoring of low-pressure areas with potential to develop into tropical cyclones.