20. Install Water and Sediment Control Basin |
 |
If
installing a terrace is impractical on your land, you might want to
go with a water and sediment control basin—a short, earthen
dam built across a drainageway. It's commonly referred to as a WASCOB
(pronounced WOSS-COB).
A water and sediment control basin traps sediment and runoff,
reducing flooding and gully erosion and improving the farmability
of a field. However, water and sediment control basins should not
be used as a substitute for terraces in areas where you can use
terraces.
|
 |
The
cross section of the basin's ridge can vary. Both slopes and the top
of the embankment can be suitable for farming; one slope can be steep
and vegetated, while the other is suitable for farming; or both slopes
can be steep and vegetated. |
 |
Build
the basin large enough to control the runoff, without overtopping,
from a 10-year, 24-hour frequency storm (the heaviest 24-hour rainfall
that can be expected, on average, every 10 years). The uncontrolled
area draining into a basin should not exceed 30 acres. |
|