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Home arrow Archives   The American Surveyor     

Point to Point: Caste-less Retracement Print E-mail
Written by Joel Leininger, LS   
Wednesday, 29 August 2007

A 86Kb PDF of this article as it appeared in the magazine—complete with images—is available by clicking HERE

Regulations come and go over time. Gone in many areas, for now, is the concept of "classes of survey." This refers to heightened or relaxed precision depending either on where the land lies or how valuable its proposed use. I write this essay not to mourn its passing, but to give aid and comfort to those who may have to fight in the future to keep it dead. As important, it may still live in some jurisdictions in the form of state minimum surveying standards, and this might assist would-be executioners. (Although it was a staple of ALTA/ACSM standards for many years, I don't think it is fair to blame ACSM for the original idea, only for how long it took to correct the mistake.) As far as I can tell, most regulations separating surveys into classes do so on the basis of the perceived value of the property, and only concern the mechanics of field measurements.

In 20 words or less, classes of survey require more precise field measurements for properties deemed more valuable, and vice versa. At first, that seems appropriate. After all, why expend extra effort on something not worth it? Classes of control surveys have been around for a century or more, and it is likely that classes of retracement surveys were an attempt to mimic the usefulness of the control division. In all but the rarest of cases, however, control surveys are an interim product. Important as they have become, they are a means to an end, not the end themselves. Thus, when higher-order control is required, there is no residue of the earlier work with which to contend. One simply voids the old work, and moves on. Not so with boundary surveys.

There are three reasons, in my opinion, that argue against any classes of retracement: present versus future value of the land, inadequate notice to future surveyors, and inconsistent retracement doctrine.

Farm Surveys
I once worked in an area where previously a surveyor had offered both "boundary surveys" and "farm surveys." His theory, I presume, was that out in the hinterlands no one cared about a foot or two (or ten), so forcing the landowners to pay for higher precision work forced a product on his public that it neither wanted nor needed. Hence, his "farm surveys" were a service in which he identified approximate property lines, but without going into the detailed examination he would otherwise have done on a normal survey. Worse, this surveyor had a reputation for always setting markers at property corners. As a result, you can find the results of his approximate work all over that county today. Since it is an outlying suburb of Washington, D.C., the farms he treated thusly eventually became multi-milliondollar subdivisions, the owners of which, as it happens, do care about a foot or two (or ten). Go figure!

It is silly to presume that the relative value of property today will extend unchanged into the future. None of us knows what areas will explode into the next hot market. How are we to predict land use three years from now, not to mention 25, 50 or even 100 years from now? And yet, the surveys we launch into the stream of commerce take on a life of their own, being used and relied on by persons and organizations completely unaware of the caveats surrounding and built into those efforts. Some will argue that when land values increase or when the proposed use warrants it, new, more precise surveys can be conducted, replacing the earlier, sloppier work. Only one scenario gets fixed by this method: a survey producing no writings and no monuments. (I doubt that the primary focus of the classes of survey was on such a rare situation.) For all other scenarios, the writings produced and the monuments placed have the potential to cloud the judgment of future surveyors who encounter the earlier survey and do not know its idiosyncrasies. How is one to determine the original location of monuments that existed at the time of the sloppy survey but have since been lost?

See No Evil
It is useful to consider our potential products when we conduct retracements. We can draw plats, place markers on the boundaries, and write descriptions. Of the three products, the plats are the only ones able to alert subsequent surveyors to the relaxed nature of our field procedures, but the plat is the least likely to fall into the hands of subsequent surveyors.

The most telling thing (in my mind, at least) with the notion of classes of survey, is that by focusing solely on field measurement precision, subsequent retracement decisions are ignored. For example, say a boundary was described as having four sides 200 feet long, and, during a survey of "relaxed precision," we found a marker at each end of one of the lines. If we conclude that the found markers are the ones called-for and are undisturbed, they define the location of those two corners. Now let's say that we found them 199.60 feet apart. It is likely that if I have religiously applied the relaxed traverse standards in my work (huh?), some of the variance between the called-for distance and my field measurements is, in fact, due to my using those relaxed standards. Fair enough. But how do I then incorporate that relaxation into the mathematics of placing the remaining corners or in computing an area? Do I pro-rate? Certainly not; I have no way of determining how much of the variance is due to my work and how much is due to the original work. Of course, there is no attention given those issues in the standards. Apparently the classes of survey concept only lasts until the initial traverse is complete, and thereafter is ignored. If that makes sense to you, your thinking is more advanced than mine.

Retracement is the result of research, measurement and analysis. Water down any one of the three, and you have something short of retracement, and perhaps long on making the lives of later surveyors miserable. What's up with that?

Joel Leininger is a principal of S.J. Martenet & Co. in Baltimore and Associate Editor of the magazine.

A 86Kb PDF of this article as it appeared in the magazine—complete with images—is available by clicking HERE

 
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