Agriculture Reference
In-Depth Information
Figure 8.7
Aerial view of a Southern California outlining watershed and sub-watershed units
A watershed is simply an area of land that is bounded by a ridge-
line or continuous embankment line of higher elevation; rainwater
that falls within this defined high-ground
boundary flows to a central low point
such as a lake, stream, or catch basin.
Water that falls outside of the ridge bound-
ary flows to an adjacent watershed and
its lowest central point. In Figure 8.9-A,
you can see the outline of a watershed
where all rainwater that falls within the
ridgeline then flows downhill to a river.
In Figure 8.9-B, three additional water-
sheds abut watershed A and are indicated
as B, C, and D, with arrows indicating pri-
mary drainage flows.
Figure 8.8
The catch basin in the center of the walk is the
lowest point in this example of a watershed-like solution
for collecting surface water in a paved area
