counter map and sewer invert elevation

[rmusa]

How to read counter map?

See attached image

Are A and B invert elevations or rim elevations? Can both be determined by this number?
How can we find the elevation of the house? C
Is E and F the elevation of street or house? Generally there are 4-5 steps up to first floor of house in front yard on this street.
For D it is a 10” sewer main. What is meaning of 23-83?
For G is R=4.77 the slope of ground?

http://files.engineering.com/getfil...-8403-df79e117c184&file=COUNTER_MAP_SEWER.JPG

 

[bimr]

Regarding: Are A and B invert elevations or rim elevations? Can both be determined by this number?

Would appear that A & B are sewer inverts. Rim elevations normally are put on the drawing, but not in this case. Rim elevations are unkwown.

Regarding: How can we find the elevation of the house? C

Do a survey.

Regarding: Is E and F the elevation of street or house? Generally there are 4-5 steps up to first floor of house in front yard on this street.

I would think that E & F are the elevations of the lot corners.

Regarding: For D it is a 10” sewer main. What is meaning of 23-83?

Unknown, but may be evident if more of the plan is shown. May be manhole numbers.

Regarding: For G is R=4.77 the slope of ground?

I would think that is correct.

 

[rmusa]

Thanks for the information. Attached is the full file. Is there any more information about manholes that can be obtained by this map?

 

[dbill74]

Where did you get the map from? Best bet is going to be to ask your source.

My guess would be that the 2-line numbers formatted 15" over 20-70' for example is the sewer size and line identification.
5 digit numbers near circles/manholes appear to be inverts inlets and outlets.

Again, I'm just guessing here, go back to the source of your map and ask there.