California Surveyors Forums

Paul's BM note reminded me of something I've wanted to ask about for awhile: different conventions for displaying spot elevations. When I started surveying in 1977, the firm I worked for always showed spots with an X where the decimal point would be (e.g., 12X34 would be an elevation of 12.34 feet, with the location marked by the X). I've carried that format forward ever since, but every now and then I get a question from an architect of engineer about it -- either they don't know what "all those numbers and Xs" mean at all, or they think they've figured it out but want to verify their interpretation.

I've occasionally seen others do as Paul does -- put the spot down with the decimal point marking the location -- and I've seen DCA-style point blocks used, with a + at the location and the elevation attribute off to the side.

Is this a regional thing? What's common in your experience, and what are your reasons for favoring one format over another?

carried over from hand drafting (Pre Cadd Days ).

My standard procedure is to avoid showing spot elevations, any.
Except for those on un-mistakeable objects. Period.

Jim: I have done it both ways but using an x and then the elevation "x 32.46" is a format understood by most... (I hate the + symbol, confusing to some)

Clark: spots are essential for hard structures (to calc. conform grades), and in flat areas where the contours do not show the whole picture.

My standard procedure is to avoid showing spot elevations, any.
Except for those on un-mistakeable objects. Period.

The question still pertains: how do you present those elevations?

I've done the same 43x5 etc.

Except with CAD it's simpler to do X 43.5.

In Carlson I draw the points on a plot layer then explode them. Use qselect to select the point numbers and codes, erase them and you are left with the X at the point and the elevations. With them exploded you can move the text as needed at individual points.

one is to show the elevation with a leader line. the leader line will have the elevation above it, the descriptor below(fs, fg, ng) or following the elevation with either a dot or an arrow head at the end of the leader line where the elevation exists.

The leader line on curbs or the edge of flatwork usually does not have the dot or arrow head. It's assumed, I guess, that the elevation is at the end of the leader line that touches the curb or flowline or edge of concrete.

The other way is the way that 4722 presents the elevation i.e. the decimal point is the spot being elevated. The way 4722 presents the elevation uses less space on the drawing, in my opinion, and makes for a cleaner drawing.

there are other times, as in the showing of tc or fl elevations, where the leader line is the more appropriate method.

I learned both of these methods dating back to 1970 when I started working for Wesley Hylen and Associates in Palm Springs. My chief of parties was Pete Billington. Gosh was it hot there! But I was young then and it didn't really matter.

These methods were also used when I worked for Fred Crowe in Elsinore and at Valley Consultants in Fountain Valley. So what I do is a carry over from my days hand drafting, which I still do, except I am a whole lot older.

I have never seen the X in place of the decimal. I have seen the X in front of the value and I have seen just the value and the decimal point is the spot used for the elevation.