Contour Barriers 293
Different types of contour barriers
Use the contour barrier that is easiest to build and works best for your land.
Live barriers made of
trees, shrubs, grasses,
or other plants grown
on contour lines hold
water and soil.
Check dams of brush, rock, or straw
bales placed across gullies and eroded
areas where water flows let the water
through, but slow it down.
Trenches direct the flow
of water to a certain area.
To help water sink into the
soil, make small barriers
every 8 to 10 meters
inside the trench.
Walls 30 cm wide and at least 25 cm
high, made of stone, earth, straw bales,
or other materials will slow the water
and help it sink into the ground.
Gabions are wire cages fixed to
the sides of a gully and filled with
stones that catch and hold soil.
Swales are small earthen barriers with
a trench on the uphill side. Soil dug out
to make the trench is piled below it
to make the swale. Make the trench 3
times as wide as it is deep so the sides
will not collapse. Trees or shrubs
may be planted in the trench to
take advantage of the water,
and on the swale to hold
it in place.
A Community Guide to Environmental Health 2012