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GIS again-Stop looking at it
Posted by MightyMoe on August 10, 2023 at 1:55 pmI had a 2.3 Acres that is part of a larger section line survey. This parcel sits north of the section line and my client owns the section to the south along with this small parcel.
So my focus was to place the parcel from the deed which calls for a rectangle a distance from the west section corner the south line on the section line. Simple.
The parcel was cut out from the land owned by the ranch north of the line. I found the section and 1/4 corner, one original, one replaced by DOT.
So, I put the corners in, located the fences, looked for older evidence (no record of any surveys), not worried about the neighbors claiming the land they occupy cause they were the grantor.
So I get back to the office and I clicked on the GIS and I got a bit of a shock as I looked at it. It shows the east line of the parcel to be on the east line of the SW4SW4. This is very typical, call a tie to the section corner, then another distance which puts the line “close” to the 1/16th line. Why didn’t I consider that this time?
So I’m thinking dang, maybe I should have placed the SE corner at the W1/16th corner, the east line along the 1/16th line, then parallel to it for the west line. I started thinking about returning, breaking down the section, 3hrs of driving……….
Then,,,,,,,,,wait a minute, 638′ which is the tie to the section corner, then 498′ which is the east-west length adds up to 1136′. No where near the 1/16th line. The GIS has the property lines shifted 200′ east. If you did that lines will go through the middle of the main building on the property and leave other buildings out.
Eventually I will learn not to pay attention to the GIS.
holy-cow replied 1 year ago 11 Members · 23 Replies -
23 Replies
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I’m lucky, I guess, in that the tax/GIS mapping here in Oregon is fairly reliable – within the limits of accuracy of the underlying aerial photography. That may be part of what recording laws get us. More basic data.
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Did some work with a nearby County that had a problem where two parties decided they owned the same tract of land. A non-navigable stretch of a small river was shown on the 1867 Government survey within the area owned by the two people. Some time later an ox bow was cutoff. The land within the ox bow was being claimed by both parties.
An atlas produced for the county in 1896 showed the cutoff had already occured prior to then. Following back on each set of deeds finally indicated the ox bow area was conveyed to the owner of other land to the south from the owner of other land to the north. The wording of the deeds had been slightly changed over time that made this FUZZY. Both parties had ignored the area for decades, such that neither actively used it for any purpose.
The property to the north sold. A timber harvester approached the new owner about cutting trees on a large portion of his property. He said fine. Then the owner to the south saw trees being cut on what they assumed was their property. The owners went together to the County GIS office to see what they were showing. They debated the issue there and the GIS Tech threw up her hands and said, “We may have this shown wrong or it might be right. I will get some help and let you know.” Then she called me.
It turned out the GIS had been drawn incorrectly based on strict interpretation of historic deeds. The area involved was more than 30 acres.
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That may be part of what recording laws get us. More basic data.
Maybe
However, this is a recording state and there’s no lack of information to place these section lines and that parcel line.
Heck, I was hitting the section corners within 10 feet by using the x on the quad sheet.
Putting in a deed that says go east 638 from the section corner isn’t all that difficult. They simply shifted the figure to place it on the W1/16th, cause it was easier? Hard to say.
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heh Yeah, that would probably make me double check my work.
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I doubt GIS will ever be very precise if they don’t need to be. I only use it to look up deeds other than that I ignore the line work. Seen it of by 50’ or more on occasion.
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So you identified the problem, maybe consider being part of the solution? Slapping state plane coordinates on a couple of boundary corners resolves this issue quite nicely.
When you live and breath plats and deeds, it’s easy to forget how map illiterate the non-surveyor can be. Most of GIS tax folks I’ve met have had only enough training in boundary to allow them to draw out deed calls. Throw them a bone instead of complaining about them.
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I work with my home county GIS crew frequently to assist them as their job is impossible.
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So you identified the problem, maybe consider being part of the solution? Slapping state plane coordinates on a couple of boundary corners resolves this issue quite nicely.
When you live and breath plats and deeds, it’s easy to forget how map illiterate the non-surveyor can be. Most of GIS tax folks I’ve met have had only enough training in boundary to allow them to draw out deed calls. Throw them a bone instead of complaining about them.
Agreed, there were times I would meet with them and give them my deed plots so they could adjust the parcels lines to what is current. Over the many years of updates , things would get dropped or misplaced and become a complete misrepresentation of the area .
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So you identified the problem, maybe consider being part of the solution? Slapping state plane coordinates on a couple of boundary corners resolves this issue quite nicely.
When you live and breath plats and deeds, it’s easy to forget how map illiterate the non-surveyor can be. Most of GIS tax folks I’ve met have had only enough training in boundary to allow them to draw out deed calls. Throw them a bone instead of complaining about them.
Shhhhh, don’t talk so loud, you’ll draw the attention of the “sUrVeYs cAn NevEr sHoW cOORdinAteS” crowd….
I get the impression that many surveyors do not want their county GIS lines to be good (as good as can reasonably be expected from GIS), because they somehow believe it brings them more work…or they just like dumping on GIS.
“…people will come to love their oppression, to adore the technologies that undo their capacities to think.” -Neil Postman -
I always thought the problems with GIS were more the background imagery than the linework, which I assume the county GIS folks have no hand in.
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The OLDTIME surveyors knew their work was probably plus or minus a foot or two. But, that was good enough.
Now we have surveyors reporting to the nearest 0.01 foot and 1.0 arc-seconds. We all know that to be false, but, it sure makes us look good.
When we start providing coordinates to the GIS folks they will soon discover gores and overlaps of miniscule size, but, will view them as problems because they believed a good surveyor would always agree with another good surveyor. BAD assumption.
Hell, we can’t even get people to report identical information for the second survey where they did the first survey.
The absolute fact is that we will never obtain perfection, i.e., absolutely identical boundaries that do not change over time.
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Now we have surveyors reporting to the nearest 0.01 foot and 1.0 arc-seconds. We all know that to be false, but, it sure makes us look good.
I wouldn’t say that it’s not a “now” thing….the bulk of surveys I see from 40+ years ago reported that way.
When we start providing coordinates to the GIS folks they will soon discover gores and overlaps of miniscule size, but, will view them as problems
Eh, they’ve always done that, regardless of whether coordinates are reported, and regardless of what precision things were reported at.
Hell, we can’t even get people to report identical information for the second survey where they did the first survey.
This doesn’t bother me. I report what I measured for this survey, not another survey – whether myself or someone else performed the previous one.
In any case, this is an argument for more engagement with the GIS community, not less. Every time we turn our noses up at becoming involved in something outside of running a boundary line, we lose an opportunity to both maintain (or elevate) our profession’s standing, and to get some more work for ourselves at the same time.
GIS isn’t going to disappear; it’s only going to get more robust and be relied upon more and more. Clients are recognizing the benefits of geospatial deliverables – rather than a black-and-white PDF, or a CSV file with zero metadata and a single cryptic code for identification.
The line between GIS and surveying may have been sharp at one time (I’m not really sure if that were ever true), but now there’s no line, just a big overlap. If we refuse to play in that crossover area, they’re going to be calling the shots rather than us.
“…people will come to love their oppression, to adore the technologies that undo their capacities to think.” -Neil Postman -
As long as the GIS maps serve their intended purpose most of the GIS ppl I know don’t really care if they’re more precise. After all they don’t need the same precision as a boundary survey so why waste the time and dollars to do so?
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Woman called today thinking she needs a survey to know precisely where her boundaries are located because the windstorm a couple of weeks back toppled a tree. No one wants to claim it as their tree now that it will cost money to have it removed.
Wonder what the GIS map shows. Not going to bother to look because I don’t have a clue which tree it is.
She about choked on her spit when I tossed out a very fair range of expected cost of the survey.
p.s.: Her husband is an M.D. One adjoiner is the matriarch of a banking family with about 20 banks.
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Cheaper for her to just pay for the tree removal, or try to get the neighbor to split the cost.
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Woman called today thinking she needs a survey to know precisely where her boundaries are located because the windstorm a couple of weeks back toppled a tree. No one wants to claim it as their tree now that it will cost money to have it removed.
Wonder what the GIS map shows. Not going to bother to look because I don’t have a clue which tree it is.
She about choked on her spit when I tossed out a very fair range of expected cost of the survey.
p.s.: Her husband is an M.D. One adjoiner is the matriarch of a banking family with about 20 banks.
Wait, wait, waitwaitwait…..they thought that paying for a survey and then paying for tree removal would be cheaper than….paying for tree removal???
Something tells me that the M.D. doesn’t do his own billing, and the banking family doesn’t have much to do with day-to-day operations of those twenty banks….
“…people will come to love their oppression, to adore the technologies that undo their capacities to think.” -Neil Postman -
People who live decades having more money than they could ever spend are some of the biggest tightwads I have ever seen.
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@holy-cow i have chainsaw will travel. No survey needed both can pay me and feed me and said tree will be removed or cut up and placed in a smore making area. i will bring the marshmallows and coat hanger.
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People who live decades having more money than they could ever spend are some of the biggest tightwads I have ever seen.
To some extent, they have more money than they could spend BECAUSE they have been tightwads.
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