Agriculture Reference
In-Depth Information
D
B
B
A
A
C
A
Figure 10.14
The existing tree trunk had a partial tree well
installed to protect existing roots
Figure 10.15
Retention pond on an old dairy farm in
Costa Rica
overvieW for the GradinG conditionS
diScuSSion
The list of typical site design elements just reviewed is provided to
give the grading designer an idea where spot elevations are needed
in site-grading plans. It is possible to have too many spot elevations;
however, their use should be considered wherever the grading designer
wishes to provide specific elevation instructions and to clarify where
confusion may be possible. The goal is to provide the contractor with a
clear road map of what is expected. As a general rule of thumb: Use spot
elevations to direct the contractor in the construction of all hard sur-
faces and constructed elements. Contours are primarily used to direct
the contractor in grading all softscape areas, with spot elevations placed
at critical high and low points. Provide spot elevations where changes
of grade occur and for critical elements such as rim elevation of catch
basins, tops of created landforms, or bottoms of ponds and depres-
sions. Provide spot elevations at the beginning and end of sloping sur-
faces such as swales and ramps, and to control the heights of walls and
fences. When in doubt, provide a spot elevation.
