Even with new flood protection products, sandbags are still useful for defending against floods. However, they must be used properly to be effective.

This guide will walk you through the process of building a sturdy levee using large sandbags, ensuring your property is well-protected from rising waters.

Planning Ahead

Before you start building your sandbag levee, it’s crucial to plan the construction carefully. Consider the natural flow of water and how it will interact with your property. Your goal should be to redirect water away from buildings and towards drains or gutters.

Key Points to Remember:

Placement:

Do not build the levee directly against the wall of a building unless that wall is specifically designed to withstand flood pressure. Instead, leave at least 8 feet of space between the levee and any structures. This gap will allow you to monitor and reinforce the levee if necessary.

Stability:

Make the levee as low and wide as possible. A broader base provides better stability.

Materials Needed:

To construct a sandbag levee, you will need:

• Large sandbags (traditional or alternative)
• Sand (for traditional sandbags)
• A pointed shovel
• Water source (for alternative sandbags)
• Polyethylene plastic sheeting (6 mil thickness)
• Gloves and protective gear

Building the Levee: Step-by-Step Instructions

Preparing the Sandbags:

Traditional Sandbags:

Fill each sandbag halfway with sand using a pointed shovel. This is a two-person job: one person holds the bag open while the other shovels sand in. Ideally, a third person should stack the filled bags.

Alternative Sandbags:

Soak these bags in water for 3 to 5 minutes until they “inflate” to their full size.

Constructing the Base:

• Dig a ditch approximately one bag deep and two bags wide. This trench, known as a “bonding trench,” provides a solid foundation for your levee. Remove any sod or debris from this area.
• Place the first layer of sandbags into the trench, ensuring they lie flat and snug against one another.

Stacking the Sandbags:

• Position the first layer of sandbags lengthwise, with the open ends facing downstream. Flatten the unfilled portion of each bag.
• Stack the bags in a staggered manner, similar to laying bricks. Alternate the direction of each layer of bags (parallel and then perpendicular to the water flow) to enhance stability and close up gaps.
• Tamping: After placing each layer, tamp down the bags with your foot to ensure they are stable and gaps are filled.

Ensuring Stability:

• The base of the levee should be three times as wide as its height. This triangular profile provides the best stability.
• Continue adding layers of sandbags until the levee reaches the desired height, making sure to overlap the bags to close gaps and reinforce the structure.

Sealing the Levee:

• Lay a sheet of 6-mil polyethylene plastic under the first layer of sandbags. This plastic will act as a barrier against water seepage.
• Once the sandbags are stacked, wrap the plastic over the entire levee. Start by covering the water-facing side, then wrap over the top and down the dry side.
• Secure the plastic sheeting by placing additional sandbags on the bottom edges and the top of the levee.

Additional Tips for Effective Levee Construction

Preparation:

If you live in a flood-prone area, keep a supply of sandbags ready. This will save valuable time during an emergency.

Weight Management:

Traditional sandbags can weigh up to 40 pounds each when filled. Try to fill and stack them close to where they will be used.

Disposal:

Do not reuse sand that has been contaminated by floodwaters. Sandbags that have absorbed flood water should be treated as hazardous waste and disposed of properly. For alternative sandbags, check with the manufacturer for specific disposal instructions.

Estimating Sandbag Requirements

The number of sandbags you need depends on the length and height of your levee. Here is a quick reference to help you estimate:

1-foot high level:

• 50 feet: 250 bags
• 100 feet: 500 bags
• 200 feet: 1,000 bags

2-foot high level:

• 50 feet: 850 bags
• 100 feet: 1,700 bags
• 200 feet: 3,400 bags

3-foot high level:

• 50 feet: 1,800 bags
• 100 feet: 3,600 bags
• 200 feet: 7,200 bags

4-foot high level:

• 50 feet: 3,100 bags
• 100 feet: 6,200 bags
• 200 feet: 12,400 bags

How to Buy Large Sandbags for Making a Levee

Understand Your Needs

First, determine how many sandbags you need and their size. This depends on the length and height of the levee you’re planning to build. Large sandbags, typically holding 1 to 2 tons of sand each, are usually more effective for creating a solid, long-lasting structure.

Choose the Right Material

Sandbags come in various materials, such as polypropylene, burlap, and polyethylene. Polypropylene is the most common for levee construction due to its durability and resistance to water and UV rays. Ensure the bags you choose are heavy-duty to withstand the pressure and weight of the sand.

Find a Reliable Supplier

Look for suppliers specializing in flood control products. Whether you are buying large sandbags online or at any sandbag store, make sure to check the ratings and reviews of your supplier. It will help you determine the quality of the product.

Compare Prices

Prices can vary significantly, so it’s wise to compare different suppliers. Some suppliers will give discounts for bulk purchases. However, make sure to consider the shipping costs for your large order.

Check for Extras

Some suppliers offer additional features like UV protection or built-in ties. These extras can add to the durability and ease of use of the sandbags. While they might cost a bit more, they can be worth the investment in the long run.

Consider Delivery and Handling

Large sandbags are heavy, so consider how you’ll transport them to your site. You may get delivery services from some suppliers. However, it is important to have the necessary equipment such as forklifts or cranes to move the sandbags.

Plan for Storage

You can store your sandbags if they are not in use. Keep them in a dry, shaded area to prevent deterioration from sun and moisture exposure. This will ensure they are in good condition when you’re ready to use them.

Conclusion

Constructing a sandbag levee is a practical and effective way to protect your property from flooding. By carefully planning and following these step-by-step instructions, you can build a sturdy barrier that will redirect water and minimize flood damage.

Remember to keep safety in mind, work with a team for efficiency, and ensure proper disposal of used sandbags. With the right preparation and effort, you can safeguard your home or business against the devastating effects of floodwaters.