02/06/2026
REGIONAL GEOHAZARD THREAT ADVISORY
Reiteration of Preparations and Recommendations prior to the Onset of Rainy Season
This is a Geohazard Threat Advisory reiterating the preparations of LGUs and Mining/Quarrying Companies regarding rain-induced landslide and flooding hazard occurrences, as well as this Office's recommendations on the matter prior to the onset of the rainy season for the year 2026.
Based on the press release issued by DOST-PAGASA at 7:45 AM on 30 May 2026, the Southwest Monsoon (Habagat) has become the dominant weather system in the country, which is one of the precursors of the onset of the rainy season. Occasional to frequent rains and thunderstorms are expected, particularly over the western sections of the country.
The LGUs and Mining/Quarrying Companies may refer to the MGB-issued list of barangays that are most likely to experience various levels of flooding and landslides due to severe rain showers or thunderstorms. The said listing is available online, accessible via the following link: (https://tinyurl.com/MGB3-Hazlist-2026). In connection to this, our Office reiterates the following:
RECOMMENDATIONS
1. Residents living in areas with high susceptibility to landslides (adjacent or along mountainous slopes or generally steep slopes) should be notified by the concerned LDRRMOs that continuous heavy and prolonged rainfall could trigger landslides caused by the water saturated condition of the soils and slopes. For guidance, you may access the list of barangays that may experience flooding and/or landslide via the link provided above.
2. Residents and assets situated in the following areas are also at threat to landslides even if their barangays are NOT included in the listing shown in the above link.
a. At the foot of hillslopes with previously noted/reported ground cracks,
b. At the foot or near the crown of old and/or active landslides,
c. Along road cuts and road easements where slopes had been modified and oversteepened due to road developments,
d. At the mouth of rivers/creeks/gullies coming from mountains that are landslide prone, and,
e. Areas that fall within moderately susceptible to very highly susceptible to landslides based on the MGB landslide susceptibility maps.
3. Areas not included in the list but are located in close proximity to or downstream of the areas in the list may also be affected by flooding events.
4. The DENR-MGB strongly advises the LGUs through the Provincial/Municipal/City Disaster Risk Reduction and Management Councils (LDRRMCs) to monitor for possible occurrence of landslides, flood/flash flood and/or debris flow in their respective Areas of Responsibility.
5. If the situation warrants, pre-emptive evacuation protocols for residents and relevant assets should be implemented by the concerned Local Government Units through the MDRRMOs, particularly in areas identified by the DENR-MGB as highly to very highly susceptible to flooding. A pre-emptive evacuation is also strongly recommended to be enforced by the LGU for those residents and relevant assets living in the vicinity of areas categorized as having high to very high landslide susceptibility or those demonstrating slope instability. This Emergency Preparedness and Response Protocol is also advised for those areas previously hit by debris flow and flash flood. When NDRRMC EPR protocols have been downgraded, the LGU should continue checking the area for safety (e.g. no signs of slope instability, no artificial damming of rivers) before allowing people to return to their dwellings.
6. The LGUs should ensure that all evacuation centers are safe from landslides, flood/flash flood and/or debris flow.
7. Monitoring of Early Warning Systems available within the communities, such as; flood markers to monitor any significant river water level changes, and rain gauges to monitor rainfalls within the community are also recommended.
8. LGUs are directed to monitor vulnerable shorelines and notify coastal residents of the potential threat. The public is urged to exercise caution, avoid coastal areas, and heed all instructions from local authorities. Monitor official channels for updates.
9. The mining/quarrying companies within the jurisdiction of the Mines and Geosciences Bureau RO3 are directed to implement the following measures:
a. Continuously monitor their respective AOR vicinities and host community/ies for any rainยญinduced landslides, Hooding, or any disturbances to critical lifelines.
b. Daily reporting to this Office of mine area activities and statuses should be strictly observed during this OPCEN reporting period.
c. Ensure that the environmental mitigating measures and structures such as settling ponds, mill waste/ tailings storage facilities, water reservoirs etc. are in place and being closely monitored. Furthermore, expedite all ongoing maintenance and/or enhancement activities to ensure their integrity and effectiveness
10. As part of the NDRRMC Operation LISTO Protocol, your Office is required to provide threat advisories to all municipalities under your jurisdiction.
11. This advisory is valid for broadcast until a following geohazard advisory is issued.
See the full document here:
https://drive.google.com/open?id=1bKIc6NVngNfoZ5uJuf7rS0rKmfhi1kxu&usp=drive_fs
