Thursday, April 2, 2009

Survey Markers

The people who waymark have a variety of categories, and one of them is U.S. Benchmarks. I have found three of them around Rensselaer. Two of them are on the Saint Joseph's College sidewalk a bit south of the bowling alley. They are in bad shape, probably because it has been run over too many times by snow plows.
I do not know why there are two of them here, but they drove me crazy. I have walked on this sidewalk literally thousands of times, but for some reason I only remembered one of them. So as I was starting to put this post together, I kept seeing the marker first on the east side of the sidewalk and then on the west side, and I was worried senility had set in early. So finally I looked very carefully and saw that there were two of them. If I ever knew that in the past, I had totally forgotten it.
Another that is in much better shape is on the north side of Clark Street, very near the creek. Do you know of any others?
A very similar looking marker is near the Melville Street Bridge over the Iroquois River.
Below is a wider view, with a sign that says that in times of flood, raw sewage will be dumped into the river.
I am not sure what the point of USGS markers are. I suppose they are sort of like the county survey markers, which are all over the place out in the county. If you ever run, walk, or bike on the county roads, you will encounter them. Look for the little triangular signs like the one below.
The sign is not the marker. When you see the sign, look on the road for something metallic. This one is on Mt. Calvary Road and is an older one.
Many of them look like the marker in the picture below. They are important because they form the basis for measuring property boundaries. If you ever have a dispute with a neighbor about where the boundary is, markers of this sort will settle the matter.
Here is the same kind of marker, but it has lost its cover. Sometimes they also get covered by the road surface. During the summer the surveyor's office will go out and repair them. A couple of my sons worked summers for the surveyor and know vastly more about this than I do.
(The one above is in the middle of 114 at the intersection of airport road. Just in case anyone from the surveyor's office reads this.)

3 comments:

  1. i am familiar with waymarking and benchmarks thanks to my knowledge of geocaching. in the twin cities i can find billions of geocaches within 10 miles of my house. in rensselaer i have found, based upon past searches, that there's a finite number of caches hidden in the area....which is not the least bit surprising. i like to geocache when i travel, and spent a brief period of time finding geocaches in alabama and mexico when i traveled there this winter. my thursday evening cameo in rensselaer didn't lend itself to such activity.

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  2. Thank you for keeping your eyes wide open.

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  3. Benchmarks are important for tying in local surveys to a known hard point - this allows you to compare multiple sites or to track elevation changes at the same site over time. The USGS doesn't actually maintain most benchmarks anymore, it's done through the Geodetic Survey who I believe is under Commerce. Most new USGS benchmarks are near streamgages for maintaining cross-sections for stage-discharge relationships (totally irrelevant to this post ;)

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