Sandbags: An Essential Tool for Flood Mitigation
Overview
Properly filled and strategically placed sandbags are an effective method for redirecting stormwater and debris flows away from property improvements. This simple yet vital tool can help protect your home and surroundings during flooding events.
Filling Sandbags
Fill Level: Sandbags should be filled to approximately half their capacity. While sand is the recommended filling material, any local soil can also be used if sand is not readily available.
Enhanced Durability: For a more resilient sandbag, consider mixing 10 parts of sand or soil with 1 part of cement. This mixture can be applied dry. Once all bags are in position, a light sprinkling of water is advisable. Please note that this technique is effective only with burlap sandbags; it is not suitable for plastic sandbags.
Placing Sandbags
Orientation: When placing sandbags, fold the top down and position the bag on its folded edge. It is crucial to orient the folded top toward the upstream or uphill direction to prevent the bags from opening when water flows by.
Stacking Guidelines: Stack sandbags according to the provided illustrations. Ensure that each layer is completed before starting the next. Limit stacking to two layers unless a building provides support or the bags are pyramided for stability.
Limitations
Water Seepage: It is important to note that sandbags do not create a watertight seal.
Material Deterioration: Burlap sandbags filled with sand or soil may deteriorate if exposed to prolonged wetting and drying. If placed too early, they may lose effectiveness when needed most. Sandbags are best suited for low-flow protection (up to 2 feet); for higher flows, a more permanent structure is recommended.
Caution
Avoid using straw or hay bales as substitutes for sandbags, as they perform inadequately and may be washed away in flood conditions.
For effective flood mitigation, proper filling and placement of sandbags are crucial. By following these guidelines, you can help protect your property and enhance your preparedness for potential flooding events.