If you choose to build a sandbag dike to protect your property during a flood, the following tips and video may be helpful.
Regular sandbags for this purpose are a specific size, 13 inches by 34 inches. The advantages of this size bag as opposed to a turnip or potato sack are that the sandbag is smaller, thus economizing on sand, and are lighter to handle and easier to put in place.
Use a proper size sandbag. Either stockpile bags or determine where a ready supply is available.
- Fill bag two-thirds full. (roughly 24"). Do not tie.
- Fold top of bag over loosely to allow sand to settle for best results.
- Lay the top of the bag against the bottom of the previously-laid bag.
- A plastic membrane, if desired, can be used in conjunction with the sandbags to reduce leakage.
- If time permits, a more efficient result can be acquired by tapping the bags flat after laying. This will prevent holes between bags and prepare a flat surface for the next row of bags.
- The subsequent layers of bags should be staggered like bricks so that each row will cover the joint of the bag below.
- Do not use sandbags as an erosion protection system or where bags are subject to direct wave attack. If this cannot be avoided then support sandbags against a structure.
- If possible, do not place bags or construct a sandbag dike bearing directly against a home with an old or questionable foundation system as the weight of the dike could affect the structural integrity of the home.
- The number of sandbags needed for 100 linear feet of dike is:
- 800 bags for 1 foot high dike
- 2,000 bags for 2 foot high dike
- 3,400 bags for 3 foot high dike
Remove all ice and snow from a strip of land at least as wide as the base of the dike. If the dike is to be more than 3 feet high, remove a strip of sod to provide better anchorage for the dike.
Common errors in sandbagging are:
- Attempting to build, fill bags or construct a dyke too quickly or with inadequate help thus causing personal fatigue, possible injury, and/or construction of an inferior dyke.
- Filling the bag too full, making the bag like a sausage, and requiring an additional bag to plug the hole left between bags.
- Letting edges of bags overlap, thus again leaving a hole and spoiling the level for the next row of bags.
- Bags are placed where they are easily destroyed by wave attack.
- Thinking sandbags are a permanent means of shoreline and/or protection.