There is no way to sugar coat the disastrous events at Montanas de Caldera in Boquete Panama; but we can learn from what happened. This post is about the geology not only of Montanas de Caldera, but of many areas around Boquete Panama.
One house in Montanas de Caldera needed to be destroyed after it’s swimming pool plunged into Caldera river.
Contrary to what I had thought the pool was quite small and many meters back from the cliff edge, not even close to the edge.
After this event and subsequent investigation, the Civil Defense authority, SINAPROC, ordered the other houses on the rim be evacuated until a soil study could be done. Link to information about the order.
The owners of the sub division did commission a study. I have made the English version of the study available for download at this link. LINK . It is a 20 meg PDF file that will download if you click the link.
The engineering study suggested that nothing should be built closer than eighty meters from the edge of the cliff. A subsequent amendment changed that line to exclude some lots along the rim. The amendment is part of the same download and appeared to me to be questionable, at best.
I disclaim expertise, I am neither am engineer nor a geologist. I did however submit the report to a engineer in Boquete and an architect in the US who sent it off to an engineer in the US. I did this because I wanted to know what I and others might learn from the disaster in Montanas de Caldera.
The summary is that both engineers believed the original report was well done and thought the eighty meter rule was minimum. The US based engineer said, “run away as fat as you can”. Do not build, not even as close as the recommended “stay back eighty meters”. He said eighty meters is a safety margin of one, he likes a margin of three, two hundred forty meters back. He said, the river will most likely flood off and on, run into the banks, undermine them again, change directions, undercut and ‘eventually’ the area will cave in. It is not a matter of if, but when, it just time related. The engineer also said that the rock down deep will let water in and undermine the stability of the entire ridge.
After this disaster and the prior slides into Valle Escondido (link), we, the buyers, must beware.
The lesson we can learn is about living on beautiful view or hillside property anyplace. It has special import in Boquete which has many mountains that are really piles of rock and not solid rock. Before investing in property or in building your dream house, have the land checked for geologic issues. The investment in the required studies can allow informed decisions. I am sure if these studies were done and presented to perspective buyers they would never have bought or built on these lots, learn from their experience.
And you can see this on roads too….just see parts of missing roads up towards your own place in Jamarillo….even though no rivers there ,steep inclines with sand,gravel and rocks tend to do the same thing even without river erosion…..
Life is a gamble, study before you bet.
Bjorn.
Some of this problems have some kind of solution with the use of new technologies available for geotechnical engineering with products such as gavions, geosynthetics and geomembranes, anchorings and other products for soil stabilization, erosion control, etc.
Roger, I know, but just pointing out that in these cases (roads) ,none of that was/is done….
But building a house within 20-40-60 feet of any ravine…no way…. on a cliff , yes…not like this.
Lee , everything you wrote there is still correct , IMO, with the exception that you didnt know that they had no soils report or that even without one, most people educated in construction would be very weary about building that close to this kind of ravine
Is the photo at top, with the pool, actually a photo of the home and pool that fell into the canyon?
yes this is the actual house