California Surveyors Forums

I was looking at a map yesterday and saw the same old thing on it that really troubles me. It doesn't make sense to me at all yet the County continually approve of it - it is this (for example) ...

"SFN/ SET NOTHING. RE-ESTABLISHED 3.30' S'LY ON C/L PROD PER RSB..."

So this point was "re-established" from a 2-1/4" brass disc 3.30' feet away, then this re-established point is used for a line to establish monuments that get set and measurements are made to. The question is; why isn't the surveyor required to set a point at this initial re-established point? If I were to retrace the measurements and monuments on his map there's nothing there to come off of unless I then re-establish a point 3.30' from the brass disc. I see this all the time on maps and just don't understand how this can be. How can lines and measurements get made from points that are SEARCHED FOUND NOTHING, SET NOTHING? I would set a point there if I were doing it.

The concept is "reference monument" and is quite valid. Why, unless the point 3.3' from the existing brass disk is something other than a POB, something that may be directly significant to an end user (landowner, contractor, etc.) would the surveyor need to monument a point which is already pretty definite due to the fact of a very stable monument being so close and having a well defined record relationship?

I see this a bit different. The 2.25" brass disk 3.30' away is a reference monument to this now re-established location, thus the re-established location is easily re-established at a later date. Setting another monument at the now re-establish location will just create a big pincushion of monuments and in my unqualified opinion could create some ambiguity in the future. Not setting a monument at the now re-establish location helps with clarity in my mind. I have at times seen these pincushion corners where there will be 3 or 4 or even 5 monuments in a very small area. At later dates the tags maybe gone or unreadable and all the monuments maybe of the same relative size and character so its just a big pain in the backside to figure which one is really which. This is why I prefer for clarity sake only to find one monument with all the maps that come after it and if they don't accept it to just use it as a reference monument.

A new monument at the re-established point may be set at 3.34' or 3.25' feet instead of 3.30'. Now what? If 3.30' is a call in a deed, now has that been altered if the new monument was set with small 0.04-0.05' errors.

That's exactly my point. A calculated point is used to establish a line and distances to set new monuments now I go in the field and cannot measure from a calculated point. There's nothing there. Now I have to establish a calculated point to measure from. Is this new calcuated point now no longer an "original" calculated point! Will I be able to establish the same line? If calculated points are going to be accepted on maps perhaps they should be called just that instead of an "established" point with nothing set. If a point is set at the calculated point when the surveyor was out there anyway, then future surveyors have something of record to come off of. Frequently on the maps it's not just a few feet away but 100 or several hundred or more. Now what? Is having a calculated point still OK to use? I feel that if a surveyor is going to establish points on a line then he is obligated to monument, or find the monuments at the end points of that line.
If we as surveyors can't set a point 3.30 feet away and that it might not be on line or might not be at 3.30 feet then I think we may have a problem!

But if you're tieing into the same monuments the previous surveyor has, then, in theory, your calculated point 3.3 feet away is the exact same point as shown in the previous records. Everything is relative to the position of that brass disk.

your description is that the fella didn't reestablish anything from the brass disc cause the brass disc aint there. he found nothing at the corner.

The corner should have been described as " SFN. Reestablished anywhere I see fit. *Set nothing.* Also, Set lead tack and tag or a one inch iron pipe 3.30 feet southerly on CL prod".

I could reestablish the corner and set nothing at the corner. Then I would set a withness or offset thereto if I thought it would make it easier for the landowner or another surveyor to find or use it.

And another thing, if 4 or 5 hundredths is an issue with you, good luck. Granted, I try to set the offset at exactly 3.30 feet southerly of my reestablished point. It's just that I might very well have 4 or 5 hundredths in the true position of the reestablished corner as it exists in the field.

I wish I could do better, but I am limited in how light bends, the accuracy of my tribrachs, the specs on my shooter and a whole bunch of other things. That's why I set things in the ground so that the land owner or other surveyor can touch it and use it. Measurement values are great, but use the monument and throw out the 5 hundreths.

What happens if I take the found monuments set on this new line (with no monumented end point) and project it back to find that it is now 3.6 feet from the brass disc. Wouldn't it have been easier for the original surveyor just to put a point in the ground and save all the problem?
So, if I "re-establish" a centerline point from a corner record (and there's a check box for re-establish on the form) the County will be OK with it if I don't set anything and just use my new re-established point to set other monuments from?

If the brass disk is gone, then by all means, set set set. But from what I read, I did not take from it that the brass disk was gone.

"Wouldn't it have been easier for the original surveyor just to put a point in the ground and save all the problem?"

I suggest that you call him up and ask him. See what he says.

Near as I can tell, I found a monument 3.3 feet away from some postion on a record map. I can either use the other guys numbers or blow it out. I have done both.

pls7809 wrote:If the brass disk is gone, then by all means, set set set. But from what I read, I did not take from it that the brass disk was gone.

In this case the disc was there, however, if it's gone then all I'm left with is a calculated point. A point in the ground would be very beneficial. When I return to survey I find it easier to come of a point in the ground rather than a calculated point. These lines that come off of these re-established points give distances to parcel lines and ROWS on the map. I'm saying I don't have a monument to come off of to check if I wanted to.

saying now. And yes, it would be better and much easier for the following surveyor to have a monument to occupy and measure from, rather than a calculated position out in space somewhere.

It's just the way it is. And there are times when I wished the other guy had set something on some line/corner that he reestablished but set nothing, rather than me having to resurvey the world again.

I personally do not think it should be required, but I do see where you are coming from. It would be easier to have that point, but unfortunately you don't have it and you have to deal with it.

Dont see the big deal really.

It is similar to blocks that I split curbs on. I will set reference marks of the street and then reference them on the ROS. I do not need to return to the site to set a new point at a centerline intersection that will just get taken out again in a few years.

I have had this happen so often I hate to show anything in the streets unless I want to set a cast iron sleeve and cover over my control, which tends not to be very economical.

Ian asked: "What happens if I take the found monuments set on this new line (with no monumented end point) and project it back to find that it is now 3.6 feet from the brass disc[?]"

The answer to that is that you hold the position from the definite object which is an arms length away over the position projected from objects which are several dozen or perhaps several hundred feet away. A common and basic precept of law is that which is more definite will control those things which are less definite. That precept covers our measurements when reconciling disparate positions and/or dimensions when surveying boundaries, and also carries over to the science of measurement, thus applying to almost all survey measurements for any purpose.



Ian later said: "In this case the disc was there, however, if it's gone then all I'm left with is a calculated point."

In this case, if the brass disk is knocked out, at only 3.3' away, there's a very good chance that anything set at the calculated point will also be destroyed or disturbed. This particular discussion would have a little more meat to it if that distance from the brass disk was one that put the calculated point well away. Even then, my opinion would depend upon other specifics.



Aplogies in advance to Bruce for taking one of his statements out of context, but it provides the opportunity to make an additional point.

Bruce said (in part): "your description is that the fella didn't reestablish anything from the brass disc..."

The rest of Bruce's statement was predicated on a belief that the brass disk was gone, but I'm going to use it in the context that "since a monument was not placed, the point wasn't established."

Many surveyors believe that, although it is not true. It is true that it has not been physically established in the field, but publishing the position relative to other fixed objects establishes the point and the line(s) terminating or beginning at that point.

If a line or point not shown on any previous record map is so established although not monumented, it still must be shown on a RS.

But that's getting a little off topic. Back to the issue at hand...


Ian, here's a question for you. If you were surveying a subdivision lot and using the centerline monuments as your control, do you monument the RW points at the PCs, ECs, and intersections anytime they are not already monumented?


Here's another. Whenever you have a POB which is remotely located several courses from a Point of Commencement marked by a monument, if the ends of each of those courses between POC and POB are not monumented, do you monument each one for your survey?


And one more. Where one side of the property being surveyed is bounded by a non-navigable stream, or perhaps a very busy road which makes monumenting the true corner at centerline impractical, do you monument the true point anyway, or do you merely "establish" it on your map and set a witness monument on the sideline at the bank of the stream or at the RW of the road?


Just some cases to think about while forming a complete and well reasoned opinion on the subject.

I'm not going to discuss "what if" senarios -every situation has to be judged on many factors (how deep and wide is that river?) My issue is, if the end of a line I "established" is 3 feet (or 100') from a monument and it is possible for another surveor or me to occupy that established point why would a point not be set. When this point was "established" and used for a line are we really saying that there's not been a "c" nail set there or even a pencil mark? Nothing whatsoever? I don't get it. Setting the terminus of a line I establish makes life for everyone so much easier. It says to the world "Here's what I did -here it is on the ground - you can retrace my footsteps if you need to." Not - "well the points over there, if you want to use it you'll have to figure it out for yourself. You can see it here on my map where it says found and set nothing, but it's not really there. And look at all the measurements you can make from the point I established that not's there." I understand what you guys are saying -I just don't agree with it. It's my pet peeve when I see all these maps with that statement on it.

But, if I had to set stuff at every place or corner that I re-established, I would have all kinds of pipes and spikes set for this "simple lot survey", on top of the ones that I am setting at the corners of the property.

Your point is well taken, and I agree with you in theory, anyway. It would be better. But I sure wouldn't want to have to set all those other monuments if it WASN'T REQUIRED.

The "what ifs" are for you to check your consistency on the issue.

The case where the calculated point is only 3' from an existing monument, lacking any other compelling reason to set a monument there beyond simply being able to set up over an object there as opposed to over the existing monument, really makes it an almost silly issue.

Are there any even marginally competent surveyors who cannot reasonably deal with a 3.3' offset point to a line or reasonably reset a temporary nail to set a sight over 3.3' from the existing monument? At that little distance, I fully expect that if you sent 100 surveyors to physically reestablish that point, you wouldn't get more than +/- 0.02' of variation as far as your line is concerned. In other words, totally insignificant.

That, coupled with the potential confusion someone pointed out earlier, and the additional and unnecessary effort several have pointed out (should your client have to pay for your time and materials to set a point which did not need to be set for purposes of his survey?) lead me to the opinion that unless there is some compelling reason to set this point in such close proximity to the existing brass cap, it is probably better not to.


If the point were far enough away from the brass cap that there may be significant differences in location as re-established by several different surveyors, I might monument the position to propmote consistency in locating boundaries in the immediate vicinity or for someone retracing my survey should other of my monuments get destroyed or disturbed. For instance, if I were re-estblishing a block corner from CL-INT monements, I would likely monument the positions. If I were re-establishing CL-INTs and/or block corners from curb splits or based on other improvements and/or lot corner monuments, I would monument the CL-INTs, the block corners, or maybe both.

The decision would be based upon 1) whether the points would likely be utilized by others and who those others may be, and 2) whether re-establishment of the points by a reasonably competent surveyor might result in a location significantly different from the one I established.


The only real problem I see in the scenario presented in this thread is if a surveyor mistakes the brass cap for being at that position 3.3' away and being on that line. But assuming the brass cap is a record monument, a surveyor would really have to be pretty clueless and/or quite negligent to let that happen.