Is there really a fault line in Sta. Rosa, Laguna?

October of last year, upon a tip of a friend, I wrote in this site that there may be an active fault line that traverses part of Sta. Rosa. The image on the left below was released by the online version of ABS-CBN News showing the so-called Valley Fault System.

To see the full image click here to see the various active fault lines and trenches in the Philippines as lifted from Phivolcs’ website, then click on Region IV-A or CALABARZON.

By comparing the two images above, it’s apparent that at least the southern part of Sta. Rosa is traversed by this fault line. Everyone who saw these images came to the same conclusion.

The veracity of this issue has bothered me for a long time. This fault line has been discussed in at least one forum and has caused anxiety among some who have invested in real estate properties in the area. Most often mentioned is Nuvali.

Just this Tuesday, June 15, I received a question from a reader asking if Venare in Nuvali is traversed by this fault line.

To settle the matter ones and for all, I went to Phivolcs (Philippine Institute of Volcanology and Seismology) yesterday and tried to find out what I could about the Valley Fault System. I was directed to go to the Geology, Geophysics, Research and Development Division. There, I was told that anyone can apply for a “fault certification” for any property or project that he suspects might be near or lies along a fault line. Such certification will either confirm or dispel such suspicion.

image of receipt for fault certification relative to NuvaliSo for 500 pesos, I requested that they plot the Valley Fault System relative to the location of Nuvali. I also submitted three satellite images of Sta. Rosa that was given to me last year by Mrs. Nelly Gomez, Sta. Rosa’s City Assessor.

When told that they also needed a vicinity map of Nuvali, a staff helped me get online to secure this map.

Place your cursor on the cross hair in the middle of your screen to make the Nuvali map light up in yellow. Play around with it, zoom in and out, to examine the area. Note that places in Wikimapia are tagged by its users, including myself, to the best of our knowledge and we do not claim that our tags are 100% accurate. If anyone among you feel that the map of Nuvali is incorrect, I cordially invite you to join Wikimapia and edit it. Click on the Nuvali map then click “Menu” and choose “Resize outline (polygon).”

Be informed that serious users of Wikimapia do not take “vandalism” lightly; members have the responsibility to improve the maps, not make them worse.

Back to Phivolcs, I took pictures of a larger (3 feet by 2 feet) and more detailed map that shows the active fault lines in Region IVA or CALABARZON. Below is the map showing the Valley Fault System relative to the location of Sta. Rosa.

map indicating the Valley Fault System in parts of Laguna

The slightly curving vertical broken lines inside the upright rectangle represent part of this fault line.

I will not make any conclusion based on this picture but I can’t help noticing that the fault line “appears” distant. What do you think?

I was told to call Philvolcs on Monday to see if the certification is ready for pick up. I will post the findings of Phivolcs as soon as I get my hands on it.

Update: I called up Phivolcs today, June 21, and was told that they are not yet done with the fault certification. I was told to call again on Wednesday for possible pick up the same day.

Thank you so much.

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  1. Pablo Primero says:

    [Theresa Rosin says:
    March 6, 2012 at 10:36 am

    yes,there is a faultline in Binan,Laguna..ang alam ko Rosario if you are aware of the Villages inside Pacita..Juan 3 is the most affected actually sira na ang ibang bahay dyan,if you want you can check it,may project nga din dyan na Ecocentrum i don’t if itutuloy pa yan kasi sa may area na yan ang fault..]

    I cannot help but notice a post that I repeated above. I found these posts that tell JUANA 3 is traversed by a fault line, here: <—— where Villa Olympia 6 and Juana 3 are shown affected. <—— where Brgy. San Jose, Juana 3 and Southbreeze are affected.

  2. for a fairly thorough if not complete list of subdivisions and communities, including the visual identification of houses and buildings directly on top of the MARIKINA VALLEY FAULT LINE SYSTEM, pls. visit my blog at:

    as you will not be disappointed, pls. pass on this information to others, too …while there is still time. thank you!

  3. Hello Roy,

    Sorry for this late reply as I was hospitalized for more than a week.

    I have not done any further study on active faults since after this article. First, I am not an authority on the subject and whatever I say about it may either create undue fear on one extreme or complacency on another.

    The study of earthquake is not an exact science. No matter how good the people who are involved in its study are, much uncertainty remains. The first and last time I went to Phivolcs, I was told that the active faults that they have mapped are based on what they see on the surface. Problem with this is, because of too much urban sprawl, they think that many of the active faults have already been covered and can only be discovered if they actually move. And when that happens, it’s too late.

    Also, much of the recent major earthquakes, including the one in Bohol (I think) happened in places where active faults were previously thought of as absent.

    In short, no one is totally safe from an earthquake whether one lives near or far from a known active fault.

  4. As i see it certifications are supposed to give us a feeling of security… no doubt these guys know what they are doing, but i prefer to see more in-depth studies about faults aside from certifications – like the one made by Punongbayan and a team from the US geological group. As of now i am concerned with the correlation of the frequency and effects of an earthquake to their distances from the fault lines. Kindly share if you have found one. As of this article, you are kind to share it. God bless you. (written after about 24 hrs an a major quake hit Bohol – mag 7.+).

  5. Hello Jon,

    When I applied for the certification for Nuvali, Philvocs couldn’t come up with a definitive certification based on the map that we used. They wanted me to come up with an accurate map of Nuvali and its vicinity drawn by a reputable map maker. Given the size of Nuvali, that map will definitley cost a fortune that I, aboviously, cannot afford. If there is one company that has that map, I guess it is Ayala Land. But knowing how said map will be used, asking for such map from them will be futile

    The next step I did was to ask for an audience with the Mayor of Sta. Rosa, Laguna, Mayor Arlene Arcillas-Nazareno. She neither confirmed nor denied the existence of the fault in Sta. Rosa or in Nuvali.

    To ease the apprehension of those who have acquired or about to acquire properties in Nuvali, although the map we used was little less than ideal, it showed the West valley fault passing through several meters due west of the westernmost part of Nuvali. I reckon it’s a few hundred meters west off the bird sanctuary. Maybe that’s the reason why Ayala land has chosen it as the place for the Bird Sanctuary where no development will be put up.

    Sometimes we should make do with the little available resources that we have. And given what we have, my best guest is Nuval is not traversed by the active fault.

    Remember also that the last 2 major earthquakes in the Philippines ( I can’t recall exactly where), the earthquakes took place in areas where there were no known active faults. So to say that an area is safe because it has no known fault and an area is unsafe because there is a discovered fault there, seems askewed.


    Always think that in a worst case scenario, in an Act of God, nobody is safe whether you live near of far from an active fault. But should we dwell on that thought? Of course not. If we do, it will all lead us to immobility and inaction. So forget the active fault and let’s all go on with our own respective lives.

    Thank you so much

  6. sir, what happened to this? did you ever get the certification from Phivolcs?

  7. Hi Jun, greatly appreciated your reply on my query regarding the fault line in Wedgewood (San Miguel Property). How did your meeting with Mr. Jalandoni turn out ? Again, thank you very much. Terry

  8. llerym says:

    hi. we are planning to buy a house in pulo, cabuyao, laguna. is there any fault line within the vicinity. your quick response on this will be appreciated. you can also inform me through my email address. thanks.

  9. As far as I can tell, Wedgewood is not traversed by the West Valley Fault.

    In order to be certain, I have set an appointment with the Sales Head of San Miguel Properties, Inc. (or SMPI), Mr. Julio Jalandoni. We shall have a meeting on May 9, Wednesday.

    Please do watch out for my follow up comment.

    Thank you

  10. I am planning to buy a lot in Wedgewood Subd. (San Miguel Properties) in Sta. Rosa, Laguna. Is there a fault line within the vicinity. If there is, where is it located ?

    Any infos would be greatly appreciated.

  11. Theresa Rosin says:

    yes,there is a faultline in Binan,Laguna..ang alam ko Rosario if you are aware of the Villages inside Pacita..Juan 3 is the most affected actually sira na ang ibang bahay dyan,if you want you can check it,may project nga din dyan na Ecocentrum i don’t if itutuloy pa yan kasi sa may area na yan ang fault..

  12. jaz want to ask if villa de toledo subd. infront of enchanted kingdom is near to the fault line.. we have a housing project kc po dito.

  13. Hello Ronald;

    All indications point to Westgrove being traversed by the west valley fault.

    Thanks for dropping by.

  14. Is WESTGROVE AYALA HEIGHTS in Silang Cavite near the fault line? If not, how far it is?

  15. Thanks a lot, Tulisanes

    It’s very helpful what you’re doing here.

    I’ll be the first in line to ask for that information

    My best regards

  16. says:

    hi, simply on the topic of marikina faultline, i assembled maps (google map circa 2011) that can help people locate/determine which subdivisions/barangays/streets (yes, streets are identified) that have the marikina valley faultline running through them from EAST to WEST of the faultline system.

    pls ask and i’ll give the info free.

    e-mail me at

    (in return, i just ask that you pass forward the information to other people whose lives you could be saving someday).

    my many thanks! – tulisanes

  17. Hello Mons;

    You obviously know a lot more than we do and we love to hear more from you.

    If you don’t mind, can you share with us the nature of your work. If appropriate, I can include you in my Directory.

    I agree with you 101% that developers have the obligation to make full public disclosures about their projects including geological hazard reports. In fact, I believe that both the Senate and Congress should make this a law.

    Thanks a lot for dropping by, Mons.

  18. Hello Mari, as usual, pardon me for this late reply.

    I was basically told by Phivolcs that if I want an accurate mapping of the subject active fault, I will have to hire an expert geodetic engineer to have the whole area “mapped.” That obviously will cost me a fortune. I had our small property surveyed to make certain of its exact location as specified in its TCT and I paid P15,000.

    The best thing is to ask Ayala Land for the map of Nuvali. But if they know the purpose for which it shall be used, obviously they will not give me one.

    Perhaps we should ask mons cruz how this should be done.

    Thanks a lot, Mari; again my apologies.

  19. input lang po ng ideas. i think kaya mukhang malapit yung fault line dun sa map from abs-cbn dahil po maliit yung map. i mean yung scale nya is mallit like mga 1:250,000 (this means 1 centimeter represent 2.5 kilometers.)po cguro. unlike yung from Phivolcs, malaki yung scale, like 1: 25,000 or mas malaki pa po.

    also, dapat po yung mga nagpapatayo po ng mga buildings and nagpapagawa na subdivision ay required po na magsubmit ng engineering and geological hazard assessment report. geologist po gumagawa. i don’t know po bakit yung iba nakakalusot. dapat yung mga bumibili ng properties hinihingi po yang mga ganyang reports.para aware po tayo sa geological situtaion ng bibilhin nating property.

    kung me tanong po kayo regarding sa mga ganyang stuff, you can contact me po.

  20. Hello! Any update with your Fault Certification for Nuvali? The topic came up again after what happened in Negros. Thank you for your reply…


    Check this site and type Sta. Rosa on the googlemap.. You can the faultline passes thru De Lasalle up to Ayala Westgrove area only… but still..

  22. It did not pass Nuvali but it De Lasalle canlubang is right top of it, mostly westgrove area.

    You can check the googlemaps and type Sta.Rosa on the link below

  23. Is Wedgewood Subd. (San Miguel Properties) near Westgrove and South Forbes Subds. Sta. Rosa, Laguna within the path of the Valley earthquake faultline ?

  24. ricardo says:

    dont worry about the fault unless GODZILLA comes out and destroys Nuvali!!

  25. According to the Phivolcs people, the fault in Binan, Laguna is in San Francisco Halang.

  26. villamor says:

    saan po may fault line sa binan?

  27. Hello Nanette,

    I hope to answer your question when I get the certification. I hope that’s okay with you.

    Thanks a lot

    Hello Robert,

    I called Phivolcs yesterday afternoon and I was told that they haven’t even started working on my request yet. I was told to follow up tomorrow. What a great way to deal with government red tapes : (

    Thanks for dropping by, Robert

  28. Hi Jun, any update about the result from Phivolcs?


  29. Nanette says:

    Hi Jun,

    Is it not a protocol for the land developers to get the Fault Certification from Phivolcs? Or maybe other government agency should be the one doing this e.g. HLURB.

    I am still optimistic of the result.

  30. Hello Nanette,

    You’re the first person I thought about when I posted this. What I regret is I should have done this a long time ago.

    Thanks for dropping by, Nanette.

    Hello Josee,

    I agree with you 100%. But what really bothers me is why developers in the area, Particularly Ayala Land chose to be silent on this matter. With thousands of people under its employ, I’m sure some of them have known about this issue or seen it discussed in at least one forum that I mentioned above. There are several Ayala Land agents and brokers participating in that forum but none went the extra mile to dig deeper into it.

    Thanks a lot for dropping by, Josee.

  31. Hi Jun,

    I’m a bit anxious also to find out if Nuvali is indeed traversing a faultline. I was just wondering why the developers of Nuvali didn’t apply, in the first place, for a “Fault Certification” from Philvolcs prior to their development of the area, and that should apply as well to other developments around Sta Rosa lying on a faultline. With the occurrences of the sinkhole phenomenon in Guatemala and across China, it becomes kinda worrying, isn’t it?

  32. nanette says:

    I can’t wait for the result Jun. I am very sure that Nuvali is far from the faultline.


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