Owner`s manual

Building Dikes to Prevent Flooding
HOW TO FILL AND POSITION SANDBAGS
Standing water from melting
snow or heavy rains can flood
basements and damage yards,
wells, feed supplies, machinery
and other property. Flooding is
more apt to occur in areas with
poor surface drainage,
malfunctioning drainage systems
or ice dams.
A 1- to 3-foot-high sandbag or
earth dike offers protection from
shallow flooding (water depth
less than 3 feet). Contact a
construction firm, lumberyard or
your county emergency
government office for
information on where to obtain
sandbags.
SITE SELECTION
Select the site for the dike, making the best use of natural land features to
keep it as short and low as possible. Avoid trees or other obstructions
which would weaken the structure. Do not build the dike against a
basement wall. Leave about 8 feet of space to maneuver between the dike
and buildings. Remove ice and snow, down to the bare ground if possible,
from the strip of land you've selected.
SANDBAG NEEDS
The number of bags required for 100 linear feet of dike is as follows:
♦ 800 bags for 1-foot-high dike
♦ 2,000 bags for 2-foot-high dike
♦ 3,400 bags for 3- foot-high dike
FILLING AND POSITIONING SANDBAGS
See diagrams on the back side. If you are building the dike on a lawn you
may omit the bonding trench shown in the diagram on Stacking Sandbags.
♦ Fill bags approximately half full of clay, silt or sand. Do not tie.
♦ Alternate direction of bags with bottom layer lengthwise of dike. Lap
unfilled portion under next bag.
♦ Tamp thoroughly in place.
♦ Build the dike three times as wide as high. For example, if the height
is 3 feet, make the base 9 feet.
SEALING THE DIKE
Seal the finished dike to increase its watertightness. To seal the dike:
♦ Spread a layer of earth or sand 1 inch deep and about 1 foot wide
along the bottom of the dike on the water side.
♦ Lay polyethylene plastic sheeting so the bottom edge extends 1 foot
beyond the bottom edge of the dike over the loose dirt. The upper
edge should extend over the top of the dike. This sheeting is available
from construction supply firms, lumberyards and farm stores. It
should be about 6 mils thick. It comes in 100-foot rolls and is 8 or 10
feet wide.
University of Wisconsin-Extension • Cooperative Extension FLOOD-FARM PREPARATION
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