How will Google Maps Parcel Lines affect the Land Surveyor?

I see a whole lot of problems and court cases over land disputes, people will be fighting over a fence or building that is 5 to 10' encroaching....should be a lot of work for surveyors with a lot of angry property owners.....I'm always having someone say, "That ain't how my property goes, here, look at the tax map, the line is over there", yeh right.....

With the "line" being 2-5 feet in width to start with, I would expect google earth to have a huge disclaimer  to be acknowledged by the user anytime you use the feature.

(and we've already been involved in lawsuits where the GIS people have been devining what is or isn't encroaching, including at least one case where a 10 ft gap was created (a 50 year old no-mans-land blunder with a ditch in it resulted - and then a 6 ft diameter cottonwood in the gap fell over on a house) 

The trail organization I volunteer for uses GIS to make maps. They print a map showing the trail location through several towns in our state. The trail shows as a very thick line on a page size map. The trouble begins when they zoom in to the parcel level to identify which properties the trail traverses.
 
When I checked the status of the trail in my town through land records most of the parcels they had identified were wrong by hundreds of feet. I found that deeds of properties had mentioned easements for the trail and some had surveyed maps that showed its location to verify my conclusions. I do not think that any of them had even bothered to read deeds or look at land records.
 
The popular opinion is that using some recreational GPS solutions and a computer image of a tax map is the best and least expensive way to secure the trail location. They also think that survey methods are too expensive. They are very hard to convince otherwise.
 
Tax maps do have statements to the effect that they are not to be used for determining parcel boundaries. In fact I have seen tax maps with the parcel shown on the wrong side of the road. They are simply to determine area for tax purposes. A parcel layer that does not have a basis in precise survey information is simply an expensive waste of time.
 

Tax parcel boundaries have never been authoritative for anything.  The part that's supposed to be authoritative is the ownership and assessment data, not the graphical depiction of boundaries.  Tax parcel boundaries should never be allowed to hold precedent over an actual survey.

If anything, it should expose how bad they are.

Since the advent of Google Earth and a few others systems, land sellers have been using these systems to produce a map depicting boundaries with lat -long notations to give their clients.  No survey is mentioned.  I see a large problem in the future.  These new land owners seek out and find un-license individuals to establish their boudaries. 


Tax maps, sometimes they are the onlysource of filed info.  I have seen plats that where signed and sealed filed with the Central Apppraisal District  Office stamped as a tax map and to used for survey use. 

Have a nice day

jdw

When people rely on bad information like tax maps and when they don't bother with due dilligence like understanding the method, accuracy and purpose of the map that they are looking at, they expose themselves to liability and lawsuits - in which case surveyors benefit by getting the work to help sort out the mess.  

Anyone using a tax parcel boundary for anything with legal ramifications (such as land transfers, determining setback compliance and so on) is irresponsible and foolish and is setting themselves up for a lawsuit - which they are likely to lose.

That's not to say that surveyors shouldn't already be out there explaining the differences between a tax map or Google parcel depiction (which is just a rough schematic depiction) versus the actual boundary information based on deeds and evidence in the field - to avoid the litigation in the first place.

I live and do land surveying and GIS mapping in a county with only 8,000 privately owned land parcels.  To adjust every parcel to an actual land survey will take years.  And even then I would still include the following statement on any GIS map:

This map is for administrative purposes only, and may not be accurate by surveying standards.  Do not use for legal conveyance.

Gunter Chain:
Tax parcel boundaries have never been authoritative for anything.  The part that's supposed to be authoritative is the ownership and assessment data, not the graphical depiction of boundaries.  Tax parcel boundaries should never be allowed to hold precedent over an actual survey.

If anything, it should expose how bad they are.

Tell that to the judge down here that told a member of the surveyor's board to stake a parcel based on the tax map.  This parcel was 60 acres, and sat in the middle of a 1500 acre tract.  The deed to the 60 acres did not trace back to the 1500 acre tract, and no tract had ever been sold out of the 1500 acres.

That being said, I think the tax map data being more widespread will only lead to more work. 

Surveyors do not use tax parcel maps as source for the boundary survey. We rely on the technical description from the deed or cadastral survey data for boundary corner settings. The tax parcel maps are usually digitized from paper maps and as such have inherent errors in them. The shape may be correct but the coordinates of the corners are never used for setting out of corners.
Tax parcel maps' accuracy will always lead to the debate of which is more accurate - survey or GIS data?

Surveyors should probably look at the tax maps/GIS even though they expect them to have inaccuracies, because that could alert them to things that get missed in other searches.

For instance, my brother-in-law bought a parcel and was surprised when I showed him the tax map with a county road (easement or fee?) across it.  No road has ever been there and the abutters do not have such an easement, nor do they need his for access.  Would a careful search of the deed books find it?  Probably, if it is real and not an office error, but you wouldn't be expecting it and so it would be easy to miss.

I am not sure of your land titling system Bill but we are based on the Torrens system. Anything that is not appearng on the title is not valid. The title itself and everything that is written on it has the last say when it comes to legal matters. I am not sure that I understood your post regarding a road on the tax map but not on the title but for me if it is not mentioned on the title regarding the road then the owner can fence the entire lot andclose the road legally. A road can traverse the property but the original boundary or title has to be subdivided to reflect the road on it after the government or adjoining lot owners paid for the right of way.