Muntinlupa to prohibit all new construction on earthquake fault zones

The Muntinlupa City government will prohibit all new construction on earthquake fault zones in the city. 

Mayor Ruffy Biazon announced this on June 13 as he led the meeting of the Local Disaster Risk Reduction and Management Council. 

The Muntinlupa City government is drafting the implementing rules and regulations (IRR) of City Ordinance 2024-174 or the Fault Zone Ordinance of 2024. 

Muntinlupa Mayor Ruffy Biazon leading the meeting of the local Disaster Risk Reduction and Management Council (Photos from Mayor Biazon's Facebook account)

“Through this ordinance, we aim to ensure the safety of our constituents from earthquake risks by prohibiting construction in areas affected by the West Valley Fault and ground fissures,” said Biazon. 

According to the Philippine Institute of Volcanology and Seismology and Science and Technology Information Institute (STII), “the West Valley Fault system is an imaginary line marking the area where the different fault systems are located underground and are actively moving from where a big earthquake may originate.”

The Valley Fault System “is an active fault system composed of two fault segments: the 10-km long East Valley Fault (EVF) in Rizal and the 100 km long West Valley Fault (WVF) that runs through different cities and towns of Bulacan, Rizal, Metro Manila, Cavite, and Laguna. The WVF can generate a large earthquake with a magnitude of 7.2 or commonly known as ‘The Big One’ which poses threat to people, livelihood, buildings and infrastructures.”

An identified fault zone in Muntinlupa (Jonathan Hicap)

In April, the Muntinlupa City Council passed the ordinance, which was signed by Biazon on April 16. 

Under the ordinance, new construction will be barred on earthquake fault zones transected by the West Valley Fault and Fissure in Muntinlupa 

The identification of the no-build zones will be based on the 2015 Valley Fault Atlas published by the Philippines Institute of Volcanology and Seismology (PHIVOLCS), which “shows an expanded reach and scope of these earthquake fault and fissures in Muntinlupa City.” 

The Muntinlupa City Council passed Ordinance 2024-174 or the Fault Zone Ordinance of 2024, which was signed by Mayor Ruffy Biazon on April 16. 

The Valley Fault System in the country (Photo from PHIVOLCS)

“There are existing faults and fissures zones in City of Muntinlupa, which need to be effectively identified, zoned and delineated to promote the safety and provide guidance to the inhabitants of Muntinlupa City and the general public,” according to the ordinance. 

The ordinance mandates that “permanent fault markers shall be installed for the purpose of awareness and preparedness following national and international standard roadside traffic designs and materials.” 

It added that “buildings, structures, and other properties transected by the West Valley Fault and Fissures, as appearing in the Valley Fault Atlas published by Philippine Institute of Volcanology and Seismology (PHILVOCS), are considered dangerous and unsafe for human occupancy.”

The ordinance was proposed by the Local Disaster Risk Reduction and Management Council. 

An earthquake fault is defined in the ordinance as “a fracture in the Earth's crust accompanied by a displacement relative to the other side of the fracture in a direction parallel to the fracture, For the City of Muntinlupa, the fault has been identified as the West Valley Fault.” 

The danger zone in Muntinlupa is defined as “an area of land five (5) meters in width from and perpendicular to the outer line of one side of the West Valley Fault and Fissures, or a total of ten (10) meters for both sides of the fault trace and fissures or from the edge of deformation form.”

According to the ordinance, a five-meter “easement on both sides of the identified West Valley Fault and Fissures in the City Of Muntinlupa in the Valley Fault Atlas is hereby mandatorily established.” 

“All parcels of land in the City Of Muntinlupa transected by the West Valley Fault and Fissures including the five (5) — meter easement on both sides are hereby designated as Earthquake Faults and Fissures Danger Zones,” it added. 

The ordinance stated that “Earthquake Fault and Fissures Danger Zones shall be considered as No-Build Zones on which no new construction of any kind shall be allowed. Renovations within the said danger zones to mitigate disaster risks shall not be allowed, subject to compliance with the National Building Code of the Philippines and other pertinent laws.” 

It added that “property/owners and/or lawful possessors/occupant who chose to stay or refuse to relocate shall execute a waiver, acknowledging that they were informed of the risks and dangers of the continued occupation of their property within the Earthquake Fault and Fissures Danger Zones, that they opted to stay has refused to vacate their property within the Earthquake Fault and Fissures Danger Zone despite three (3) notices and that they hold the City blameless and free from any liability that they may sustain arising from occupying or continued use of the said property.” 

The only allowed uses for designated Earthquake Fault and Fissures Danger Zones in Muntinlupa are “Parkways, Playgrounds, pocket parks, for vegetables, flowering plants and fruit bearing trees, promenades & play lots.” 

The city government may provide a grant of financial assistance amounting to P30,000 to those who will voluntarily vacate and demolish their property the Earthquake Fault and Fissures Danger Zones.  

“Financial assistance shall only be made available to a property owner with more than 30% of their property or structure within the said danger zones. Tax relief will no longer be granted to an owner of property within Earthquake Faults and Fissures Danger Zones,” the ordinance added. 

PHIVOLCS has developed "The PHIVOLCS FaultFinder" app, which shows fault zones in the country. 

The PHIVOLCS FaultFinder app