Agriculture Reference
In-Depth Information
coming from the level area and from the 31 contour would flow to the
3.25 elevation (not into the building site), and then the water would flow
following the arrows (labeled B on both sides of the area E) around the
level area to the lower slopes of contours 31, 30, 29, and so on. Notice
that the new contours in the area labeled C have been realigned toward
the uphill, which in effect is producing cut or removal of earth material.
The contours noted in the D area have been moved downhill, which in
effect is filling the lower slope in order to create a level area shown in E.
By realigning some contours uphill (cut) and downhill (fill) we are working
towards balancing cut and fill.
Also notice that in this example the area where cut will take place,
the 32-contour is the last contour to be moved. Contours 33 and higher
will not have to be moved, as we have not shifted any lower elevation con-
tours on top or pass the 33. Likewise, contour 27 is the last contour moved
in the downhill area as the 27 does not overlay past the 26-contour.
Figure 11.26 is an example of what a grading plan might look like,
applying this contour signature with drainage swales. Note that in this
figure the finish floor elevation (FFE) is shown as 80.25ยด on the build-
ing pad. It is customary to assign a finished floor elevation in grading
plans. The contours that form the pad are at elevations decreasing as
they move away from the building area. This configuration of contours
ensures that surface water flows away from the pad and down-slope.
D
28
26
29
E
30
B
31
B
A
32
C
33
34
35
Figure 11.26
Preliminary grading plan showing signature swale
solution
Courtesy of sAdik ArtunC
Figure 11.25
Diagram of how contours are used to
create a level area
