Here is the scenario. Your small firm has performed many surveys in the rural area of a specific county over decades. This is a PLSS State. Once the firm adopted the technology to determine the State Plane Coordinates of every point they use, they began a cyber library of the various monuments found at PLSS corners and aliquot corners. A fairly typical survey plat turned out by said firm will show the boundaries of the subject survey, any adjacent or nearby surveys in the same section they have produced and will label some or all of the PLSS corners involved as "Not uncovered this survey"
Thus, they are holding all "old" information of theirs as perfect (without re-verification). Descriptions are written based on grid coordinates wtih no conversion to ground coordinates. Applicable section corner reports are identical to the ones produced at the time the monument was first found or set.
Is this procedure appropriate for surveys in your backyard?
Nope. It is common in a few States I work in, but I won't do it.
We have a large data base dating back to the 1960's with many points and maps tied into the state NAD83 network including PLSS points. Whenever a new job falls within surveys we have done I check a few easy points on our map and look for any other points that tie directly to the new job to make sure they are still in but I do not re-survey everything. Are you saying that you would not trust your own work after checking a few points?
As surveyor for a mid-sized city - about 20 square miles in area - I am in the process of building and maintaining a StarNet job of measurements including a network of passive control marks with ties to PLSS monuments. This allows me to readjust the network as new measurements become available. Once a good measurement is made, redundantly, to a stable monument I can't see any virtue in continuously remeasuring it again and again ad infinitum. If I was going to use these monuments in a local boundary resolution I'd want to visit them to confirm that they still exist, and that their surroundings remained unchanged. If I'm going to set new monuments in reliance upon these old ties I'd be making check shots to the old, but generally that's how I roll.
I'd be nervous about just using old coordinates due to the ever changing flavors of NAD83 we have experienced. But the measurements are mine to keep and use forever.
Is this procedure appropriate for surveys in your backyard?
Nope, I would consider it negligent. I wouldn't expect the measurement to change, but you at least need to drive by and verify the monument is still there and seemingly undisturbed.
All surveys in my states must be completed on ground, not grid. In Idaho, you cannot show calculated corners at all. All mons must be visited and tied and/or set. So no, this exact scenario wouldn't work. A modified version would, which is what we do.
@landbutcher464mhz Monuments, possession, agreements, etc. are dynamic. Laws (and my understanding of them) change.
I'm not saying a database has no value, just that visiting lines and corners can't be a one and done.
Here's a thought exercise: You tied a section corner monument into a tight control network (solid equipment and procedures, redundant ties, least squares adjustment) and file a map showing same. A couple of years later you get a call that the section corner monument has been obliterated. The rest of your control network is still in place, undisturbed. Do you reset the section corner monument based on measurements from your control network?
If you answered "Yes," what's the difference between replacing the section corner monument and showing its calculated position on a different survey that relies on the section corner location?
I'm not advocating anything here, just thinking out loud.
Yes and in Idaho its the law to set it, calculated PLSS corners are not allowed on surveys/plats. WA allows it, not sure outside of those two.
@jim-frame As usual, it depends..
Is there better information in the record? What has happened since I was there?
No matter the answer I'll put in the research time and look at the evidence as it sits today. My new corner record will tell the story so the next person understands why I put it where I did, and gives them a reasonable chance of putting it back where it was (assuming I was correct).
If you answered "Yes," what's the difference between replacing the section corner monument and showing its calculated position on a different survey that relies on the section corner location?
It doesn't make sense to me to show ties to calculated corners. That's fantasy. Even if I was allowed to do that I wouldn't even bother. To me the point of showing the tie is so you can say that at the time of this survey this monument was here and this (description) is what I found. The measurement is mostly just along for the ride.
Do you reset the section corner monument based on measurements from your control network?
In the absence of any other information indicating where to set it, Yes.
To me the point of showing the tie is so you can say that at the time of this survey this monument was here and this (description) is what I found.
What if you need that corner for your survey and there isn't a monument there anymore? Is it okay to reset it at your calculated position, showing your control ties and documenting your prior work?
What I'm suggesting is that sometimes a coordinate position is the best available evidence of a corner location. I'm not endorsing blind reliance on it, and I'm not suggesting that the corner shouldn't be revisited to ensure that it's marked in harmony with the calculated position (and adapting accordingly if it's marked elsewhere). But the difference between that and the "hope it's still good" approach described by the OP isn't all that large. It's ethically significant, but the result will be the same most of the time.
It's not what I would do, but I'm the type of person that'll check that the garage door is shut at least three times before bed, even when I'm the only one at home. If they clearly labeled the monuments that were and were not surveyed, I'm not going to call foul. As long as they tell me what they did or did not do, then I can make an informed decision for my survey. Even with the NAD83 shifts, their survey will get me close enough to find the monuments and that's ninety percent of the game.
What's the maximum amount of time a PLS can reasonably go without reverifying a monument he has previously located? A day, a week, a month, a year, ten years? If you're surveying a large tract or a long easement that takes many months of fieldwork, should you circle back and verify that the first few monuments you located are still undisturbed before sealing the final plat?
While taking a boundary law class at the local community college, and working in the field and office full time, I had the bright idea of putting the specific date each monument was set or found on a plat I was drawing. I thought it could be a valuable bit of data. My PLS strongly disagreed. Do you, and if so, why?
To me the point of showing the tie is so you can say that at the time of this survey this monument was here and this (description) is what I found.
The survey can also say that the monument is not there right now, but it was at exactly such and such a spot at some specific previous time. That information is, in some ways, even more valuable than a report on an existing monument that anybody with working eyes can see.
Surveys are dated, so as to show the circumstances that exist as of that date. The surveyor should visit the ground at or near the date of the survey, and make a report on the current findings. That I agree with. If he/she shows the location of a monument that no longer exists, that fact must be clearly stated, along with the date of its last known existence. If the client wants the monument set it can be set, but clients don't always want that - perhaps, for example, when such a monument in question doesn't fall on the client's boundary.
The only way you can know for certain a monument was there when you signed the survey is to re-survey the entire project after you sign.
And don't forget that there can be a difference between monuments and corners. A set stone marks the corner of a PLSS Section, if the stone is somehow disturbed the corner doesn't shift with the stone. The coordinates in a system can help identify shifting disturbed monuments. So even if the monument is gone that coordinate can be the best location of the corner. We have two kinda survey famous corners where the monuments are moving fairly rapidly (8" to a 1' per decade). There is even an often presented seminar topic that tries to address the issue even though they get it wrong.
Surveys often take months or even years before they are filed after the survey, it's something we've discussed for many years, however, having a good sectional data base is an excellent resource, but it doesn't preclude re-visiting the corners when a new survey is being surveyed connected to them, how long before that is necessary is the question, you know you won't survey it after your signature.
So, what's the time or situation limit?
Clearly dragging coordinates out from a data base that were surveyed years ago is a no-no.
As far as having state plane coordinates precluding ground surveys. What?
I don't understand that at all, I have a massive data base of state plane section monuments, I use ground distances using them on every survey. I filed a half dozen of them last month.
What if you need that corner for your survey and there isn't a monument there anymore? Is it okay to reset it at your calculated position, showing your control ties and documenting your prior work?
Sure, in that case it's fine because you're essentially relying on bearing and distance calls from your previous work to reset it; which is the next best evidence according to the priority of calls.
The difference between that and showing a calculated position on a subsequent ROS is the monument isn't missing, so you're running afoul of the priority of calls by showing a bearing and distance tie (based on previous work) over the monument's actual position that day.
Would the difference be big? Probably not assuming your network is as tight and you say it is, but I think we should try to stay in the business of perpetuating corners rather than perpetuating dimensions.
Surveys are dated, so as to show the circumstances that exist as of that date.
Yep. I listened a youtube video during a long drive once where the speaker (geodesist I think) was talking about how people commonly recognize how surveys track the 3 dimensions of X and Y, and sometimes Z but they also track the 4th dimension of time. Modern recordkeeping hasn't really existed long enough for it to be noticeable now, but if humans hang around long enough for surveys to show the movement of tectonic plates or other changes in the planet then the data becomes that much more useful.
The talk was somewhat dry but fairly interesting if anyone cares to do a search for it.
While taking a boundary law class at the local community college, and working in the field and office full time, I had the bright idea of putting the specific date each monument was set or found on a plat I was drawing. I thought it could be a valuable bit of data. My PLS strongly disagreed. Do you, and if so, why?
I'd probably agree with the PLS though not strongly. If you have that data then sure, throw it on your survey or corner record. In Idaho we're required to record our stuff within 90 days of the conclusion of the fieldwork anyway, so all a date will do is potentially shave off 90 days. I don't see that making a big difference in the grand scheme of things, but it's not like it'll hurt anything either so...
EDIT: Oh, I see how it could be impactful for projects that span multiple years. With that in mind I might not be opposed to having a requirement that said you had to date monuments found more than 180 days before the date the survey was recorded or something (though there'd be no way to verify this).
I had the bright idea of putting the specific date each monument was set or found on a plat I was drawing.
Off topic but...
I once worked for a firm that owned the records of an older, well-established, surveyor who working in the area for decades and mentored a lot of future surveyors. A friend called one day and asked if I could pull the records from an old job because they were retracing the property and couldn't find one corner. I made a copy of the older surveyor's worksheet and sent it to him pointing out that, according to the worksheet notes, in March of 1974 his father set the corner is question. So, it's a family legacy issue if it's not there.