Surveying technique question

[Lee Hixson]

You don't state how accurately the nails fit the lot corner monuments.

But, assuming they fit really well, it all comes down to a matter of judgement and the relative risk involved. Personally, I would dig for the pipes.

A key thing in my mind is what you state on the map. Based on what you outlined the note should say: "found 60D nail, flush in A.C., accepted this survey as being in the same position as the iron pipe shown on XX map."

This is stating the facts, plus it highlights the nature of the "evidence" being used to accept the nail instead of digging up the pipe. But it's very risky IMHO. The red flag I see is that I can't help but wonder who/why someone would set nails like that so close to record pipe locations. It smells like the work of someone who was cutting corners, setting those nails for who knows what reason, not documenting them, perhaps as part of an unrecorded survey that should have been filed. Thus, you are hanging your reputation on undocumented nails with no pedigree.

So, yeah, personally it makes me nervous. I would have tried to dig up the pipes.

[bruce hall]

pipes beneath the 60 penny nails prior to locating the other stuff.

But it sounds as though you found the original pipes at the front and rear corners so "why dig for something else" if I found what I want and it all fits something in my brain and on the ground that I like.

What am I gonna do with these pipes(beneath the 60d nails) except to show how "good or bad" it fits with the original corners that I found at the PIQ. And maybe that is enough to have me dig that hole.

[Ken_8699]

I agree with Bruce in regards to finding the original lot corners, but there is one question that I have to ask. Did anyone check for tie notes or corner records to see how they fit the found 60d nails? Just another view.....

[E_Page]

It doesn't seem to me that whoever set the nails did so to cut corners, but rather set something at the surface so that if they ever returned, or if another surveyor followed, they wouldn't have to tear up the road again to access the monumented position.

As a practical matter, it seems that you have verified the positions by their relationships to other monument locations, so there is a good argument to not damage the road surface to be absolutely certain of what you are already reasonably certain of.

On the other hand, if there is no record relating the nails to the original pipes, you cannot say for certain that you have recovered the positions of the pipes. Lacking such a record, had I been in the field, I would have referenced off the 60d nails and then dug them up. Upon verifying the pipes beneath and checking them to the swing ties I just set from the 60d, I would have then buried it again, rockcreted or cold-patched the chunk of pavement I removed with the nail such that the 60d is directly over the pipe, and plan to note it on my map.

Had I sent a crew out and they brought back the info as you've described, being reasonably certain that the 60d positions coincided with the pipe positions, I very likely would just go with it and not send the crew back for what just might be an academic exercise. The corroborative evidence you have supporting the 60d positions, and accepting those positions meets a minimum standard of care, IMO, unless you have any evidence which may tend to contradict those positions as well. Digging the road up in a case where you have good corroborative evidence and no significant contrary evidence isn't wrong, and is more correct from a purely technical perspective, but is unlikely to make any difference in the location of the other points and lines of your survey, will cause damage to the road surface, and will cost either your client or your company a few more hundred dollars.

How likely is it that there will be any controversy in the locations of the lines of your survey? How likely is it that what you find will alter the results of your survey? How likely is it that if you looked with the intention of finding evidence contrary to those positions, that you would find it?

If the answer to each of those questions is "very unlikely", then you probably don't need to dig them up. If the answer to any of those questions is "somewhat likely" or greater, then the answer to whether you should dig them up lies somewhere between "not a bad idea" and "you had better do so before completing your survey".

Weigh the question as a professional, not as a technician. The technician considers only the technical factors and the answer to a question like this will always be to dig it up. The professional needs to consider a wider set of factors including amount of certainty of having recovered the original positions, likelihood of significant effect on survey results, existence of evidence or existent lines not in agreement with your survey, value of effort to client and public, negative effects to client and public, perceptions of the client and the public. Each of those factors is affected by the others and need to be considerd together to make the right call.


Several years ago, the company I was with was working on a boundary & topo of a commercial parcel. We had to survey the sction and breakout the aliquot part that was our client's property. One 1/4 corner fell within the courtyard of a high end professional office complex. The complex had been built so as to preserve some of the natural features. One such feature was a bearing tree of record to the 1/4 corner.

At some point, there was a record of recovery of the original GLO monument and the surveyor had set a RR spike into an oak tree. At some later point, a new monument replaced the original but without benefit of a record. There were a couple of subsequent records accepting that monument and making note of the oak tree.

Our crew found the monument, which fit well with the other corners of the section. They located the oak tree, noting a scar facing the monument direction and having what appeared to be a rust stain coming from it. They got a strong reading on the Schonstedt at the scar. The oak was about the right size to represent the expected amount of growth over the several decades since it had the spike driven in it. The mon and tree location reasonably fit the record bearing and distance from the between the original monument and the oak bearing tree.

Cutting into this 30"+ healthy oak would have left a very visible hole sevral inches across and sevral inches deep and would have exposed the tree to disease or other potential health issues. This tree had been carfully preserved as the professional office complex was built around it and was one of the focal points of the courtyard. And yet we could not be absolutely certain that it was a railroad spike in the oak and not some old piece of fencing or a nail someone might have used to hang a sign from many years ago.

Should we have cut into the tree knowing the risk that would put to its health and th certainty of angering many of the occupants and owners of the professional complex it sat on?

Your case is a little less severe in potential consequences, but the issues are very similar.

[Ric7308]

What if you would have set swing ties to the found nails and upon removal of the found nail, you discovered that the original record 1" pipes didn't exist?

[Propst]

That's the first step.
It may have been due to urgency in getting the results in, or it my be he knows why there are spikes in the surface in lieu of pipes, or maybe both, or neither.
Ask the surveyor.
Also, when you say "a surveyor finds a 60 penny nail", does that mean a licensed surveyor, or just the person in charge of a survey party.

The nails are going to have to have records filed on them if records don't now reflect their existence, which means they will have to be tied out or tagged.

I agree with the previous posters.

[dmi]

I am not sure that absolute certainty is the evidence standard we need to aim to reach.

In my view, Evan demonstrates substantial evidence that the recovered tree is THE TREE, no need to go futher.

I believe that the core question that is being asked is "What is evidence and how do I analyze evidence to form a sound professional opinion?"

What consitutes a diligent search for the original called for monuments ?

What is the basis for accepting a monument?

Does a good math correlation between record and found location of the nails, alone, met the standard of substantial evidence?

[land butcher]

A very prominent surveyor told me years ago "CL mons are just a reference to the real property corners". Fit or not undisturbed original corners hold over any CL mon.
That's the one thing I dislike about maps in LA county - they only set exterior corners, no lot corners. Makes establishing PCs a PITA.

[D Ryan]

I’ll offer some comments on the procedures used here.

You state:

“He then proceeds to use these nails for control and finds lot corners on the stated radial angles of the record map, thus proving that those original nails that he originally found are indeed in the proper location where the 1" pipes were supposed to be.â€￾

First off, if these nails are not of record, they do not rise to the level of being used for “controlâ€￾. I have a problem with the statement that this proves the proper location where the 1â€￾ pipes were supposed to be. The only proper location of the 1â€￾ pipes would be the pipes them selves, if it’s found they are original and undisturbed (or if they had been properly perpetuated at some point in time, and put on record)

Doesn’t finding the lot corners make the use of the nails moot? I guess the nails served to get one close to a search position, but that may have been a stroke of luck. Regarding these supposed “lot cornersâ€￾, have they been subject to the test of whether they are original and undisturbed? Could they have been set by the same person who set the spikes? I’d feel more comfortable having several lot corner pipes that could be reasonably verified as original (which would include age, character according to the record, appearance, other records in the neighborhood giving any history of lot corners from this subdivision being previously found, and analyzing their geometry, i.e. looking for a pattern of consistent measurement among them).

Finally a combination of digging up the 1â€￾ street pipes AND finding lot corners should give one a lot to go on.

What it appears someone may have done, and what thinking went into it could be two different things. I’d want to know what analysis and thinking went through this surveyor’s mind before I second-guess what he did. I’m not ready to take a firm stance they were negligent in not digging up the street pipes if other sufficient evidence is later found to base the survey on. But I would take a firm stance in saying those nails are not controlling (based on the information you provided).

Dave Ryan
Eureka, Ca.

[D Ryan]

Posted same message twice-now removed.

[E_Page]

I agree with Dan on a couple of points. 1st, since the nails are not the original pipes, they cannot be used as control. They may be shown as ties to the probable locations of those pipes if... and I made an assumption here on my original reading... the lot corner monuments are originals of the same survey as the CL pipes. And as Dave and landbutcher stated, if you have original mons at the lot corners, the positions of the CL points, whether to nails or to irons is merely informational anyway. Except for in case of the lot corner mons having been moved or having been set in gross error, the CL points won't control anyway.

If you are dealing with monuments of different vintage/origin, be careful. Without digging up the CL irons, you may perpetuate a mistake made by the surveyor who set lot corners possibly using the nails or otherwise making a measurement mistake from the original CL pipes.

If you have ties to monuments in several directions, it lends more corroborating evidence to the nail positions being the same as those of the pipes.

If you are comfortable with the evidence you have as sufficiently corroborating the nail locations as being the same as the pipe locations, you still have to describe them properly, explaining by what evidence you chose to accept them.

"Fd. 60d accepted as position for 1" I.P. as shown on XX Maps YY" leaves too many questions and does not imply a thorough analysis but rather seems to indicate an unreasoned shortcut.

[Jim Frame]

"Lacking such a record, had I been in the field, I would have referenced off the 60d nails and then dug them up. Upon verifying the pipes beneath and checking them to the swing ties I just set from the 60d, I would have then buried it again, rockcreted or cold-patched the chunk of pavement I removed with the nail such that the 60d is directly over the pipe, and plan to note it on my map."

Straying a bit from the original question: if a surveyor removes an unrecorded and unmarked monument in order to expose another monument below, he's on the hook, in my opinion, for tagging whatever he sets at the surface. Resetting an unmarked monument to reference the lower monument wouldn't comply with the statute.

.

[E_Page]

You're right of course, Jim. Thanks for adding that point.

[Lee Hixson]

""Fd. 60d accepted as position for 1" I.P. as shown on XX Maps YY" leaves too many questions and does not imply a thorough analysis but rather seems to indicate an unreasoned shortcut."

Customs vary.

Personally, next to the monument symbol, I place a brief note giving the physical description of the monument and stating what it represents as well. For situations like the original post, where, obviously, much more needs to be discussed, I don't try to cram my entire analysis into a leadered mon note--I deal with the more complex resolution issues in special, lengthy comments off to the side, together with applicable changes in surrounding annotation.