The rainy season starts November 1,open sand bag dike construction season too, here's how to build them

This is a properly constructed sandbag dike.

November 1st is the beginning of the rainy season in the Western United States, the rain is the primary driver of most of our Catastrophic natural events. The winter rains soak the ground that was exposed during the past summer's wildfires causing mudslides. Swollen creeks from run-off rushing down steep mountainsides slam into structures, and bridges causing some to collapse. All of that water runs into larger waterways swelling them to flood stage, overflowing their banks and inundating entire cities. Massive amounts of water run off the mountains heading for the flatlands, and the reservoirs.  The large bodies of water are held back by massive dams that were built for flood control and irrigation.

This time of year the dams release water to make room for the incoming deluge. Actually, the amount of water we will be able to store behind them is an unknown, but room must be made. Some years the lost water will not be replaced, other years as occurred during the winter of 2016-2017 more water is collected than the dams can handle. The highest dam in the United States, Oroville nearly experienced a collapsed spillway after an unexpected amount of moisture filled it to overcapacity. During Hurricane Harvey Houston Texas released water from a flood control dam, the spillway directed the water into a densely populated sub-division. Much of the same occurred in San Jose, the Anderson Dam filled to over capacity. Overflowing its banks that overflow spread into a residential area as well. Heavy rains this past summer that took place on the Eastern Seaboard caused flooding of numerous Cities, some repeatedly. One of the most effective methods to deal with the inundation is to construct sandbag dikes, walls, and temporary diversion channels.

Sand in a burlap or polypropylene sack is the basic sandbag. Used for flood control, military bulwarks and temporary traffic diverters they are an excellent choice. Construction of Levees, berms, dikes, and erosion control are all frequent uses of the heavy loaded bags. It takes a lot of them to build a successful structure, experience in building them is a real plus. Many local governments will furnish the bags and the sand, and we supply the labor.  Any soil will work in a sandbag, however a mixture of 1:10 cement to sand if available works best, soil heavy in clay is acceptable as well, however it is difficult to work with. Building a sandbag structure may appear to be a mundane simple task, looks are deceiving. Planning, organization, and leadership are all necessary to construct a berm that is strong and effective.

(Follow this Link to read the Army Corps of Engineers pamphlet on sandbagging techniques.)

The construction usually takes place under stress, a prediction of flooding is broadcast and the location of sandbagging stations are announced and we are off to the races. The amount of time, how much daylight we have left, and how many hours of darkness are just a few of the factors included in the formula for building a diversion. Correctly filled bags and proper stacking of the components are what stands between saving our structures or not.

Notice the plastic sheeting weaving throughout the first course.

A photo of a nicely constructed sandbag dike.

The bags are a standard size, 13 inches x 34 inches, (33 cm x 86.36 cm), it has been established that these dimensions are the most efficient for the use of sand and will not become overly heavy. Filling the sacks 1/2 to 3/4 full will keep them below 50 pounds. Depending upon the moisture content of the sand they should weigh closer to 35 pounds, handling several hundred will get heavy. It takes two people to fill them, one holding the bag and another shoveling, work methodically and carefully. Long pants, gloves, goggles, and boots are the preferred attire, this is not a job for sandals or flip-flops. A 1/2 ton pickup truck is able to carry 33 bags with a weight of 30 pounds each. A team of people building the wall while another team fills bags is part of a successful plan.

Pack the sandbags loosely while filling, do not seal the bags by tying or sewing them shut, they will hold each other closed. Not securing the open end makes placing the bags easier as there is room for the filler to shift and form as it needs to fit tightly. Handle the bags with caution, here are a few tips to remain as safe as possible:

1) Those of us with medical conditions should stay clear, it's not a task for back backs, bum hips, or heart conditions, let the young people do it. I know, I want to help with everything also, but we need to have enough self-awareness to know our limitations.

2) Wear our protective equipment, and take it seriously, fudging will only hurt ourselves.

3) Be sure there are plenty of porta-potties and ample water, regular water breaks should rule the day.

4) Watch for heavy equipment, be aware of our surroundings there are experienced people working around inexperienced people, it's not always a good combination.

5) Flood water is dangerous, it is potentially toxic, it is contaminated with we don't know what, the flow and currents change, beware of the junk being washed downstream. There will be everything from tree trunks to dead animals. It is not only prudent to keep an eye out for debris but it could save someone from injury or worse.

6) Use good lifting methods when handling the sandbags, do not bend more than 20 degrees in any direction. Lift with our knees bent straightening them as we rise with it in our hands. Keep the sandbags close to the body when carrying and hold them below the shoulders. Don't stretch the arms out straight when handing them off, the person receiving it should accept them as close to the body as possible.

Proper lifting technique, don't hurt yourself.

7) When turning or pivoting be aware not to twist the back, it is a better practice to pivot the feet.

8) Don't toss the sandbags, hand them off in a controlled manner. When in line to pass them face one another standing no further than two feet apart; It may be a better plan to use wheelbarrows if they are available.

Taking all of that into account now it's time to start constructing a sandbag wall, dike or berm. 

* Choose a location, a few places not to chose: septic field, swampy soil, loose gravel, or an area covered with snow or ice. It should be located at least 8 feet from a building foundation, we want the room to move between the dike and the house on dry land. A handy rule of thumb is to make the base two feet wider than the estimated height.

* Determine the height of the berm before the first bag is laid down, it will determine the width of the base. The dike needs at least two feet of height above the high water mark. If the water is expected to reach 5 feet, a 7-foot high structure will have to be built. Adding an extra bag to the top will allow for compaction of the sand and bags after they get soaked. A 6-foot high wall would actually need four inches of compaction allowance, it is far easier to merely add one more course of bags.

* The dikes must be at a minimum two feet across at the top of the properly constructed wall. that is the reason for the increase in the width of the base. For a structure higher than six feet, ask for input from a local authority, if none are available building it higher and wider is a proper tact. One cubic yard of water weighs 1700 pounds, almost a ton, it is easily capable of knocking the largest person over and washing them away.

Proper construction aids strength:

First to reduce the leakage of water through the dike polyethylene sheeting six mils thick x ten feet wide is woven between the bags on the waterside. Be careful not to rip or puncture the sheeting, it needs to lay on the ground under the first layer of bags extending to the outside of the stack.

The next task is to lay the first course, or layer parallel to the direction of the water flow, place the open end of the bag towards the center of the berm. Lap the second bag over the empty end of the preceding bag to keep it closed. Tamp down the sandbags to set them in place, make the top level it will aid in keeping the stack neat and orderly. Stagger the sacks in the same manner as laying bricks, it builds strength into the arrangement.

The bag on the left is described in this article, but do not tie them as this view shows. 

Third, the next course of bags must lay perpendicular to the one under it tying them together, the same pattern is used when loading pallets with bags of commodities. Pack this layer in as well, remembering to keep the tops as flat as possible. Alternate each course in this manner, the course above must be perpendicular to the one below. (I am aware I repeated myself, of all the practices that are critical this is the most important.)

Then offset each course 1/4 of the length of the bag, if the bag is 34 inches long back off the edge 8-1/2-9 inches. (22 cm-22.86 cm) the stack will resemble steps like on the Pyramids of Giza. Continue to weave the plastic sheeting as the courses are added, if more sheeting is needed we then need to overlap them by a minimum of 2 feet.

Properly stacked each course must be perpendicular to the one below it.

Completing the wall it is likely water will seep through the levee, how much depends on how high the water is, greater height creates more pressure. Keeping pumps on the "dry" side of the dike with enough fuel and oil available for extended use.

The same precautions should be adhered to when the time comes to take the dike apart, the sand may be used in sandboxes, landscaping or in the garden. The bags may be suitable for trash storing purposes, there is no need to store full sandbags, that defies reasoning.


Don't use bales of straw or hay in the construction, they will merely wash away and water will go right through them. A dike is temporarily constructed for a one time use to direct water, not totally dam it up. It will stop the flow completely for a while, however, they wear out rapidly and need our full-time attention. If a longer lasting dike is needed due to recurring flooding a permanent structure should be built. A permanent structure can be an elaborate cement wall or a hand dug ditch. The intent is to keep the water from the space you want to protect, keeping in mind the basic intent and the direction the water flows a good solid temporary or permanent flood control dike is easily in our future if the need arises.

Thanks for reading and sharing this blog, leave a comment with a story, question, or start a conversation. For some of us, a flood is a real possibility, for others, it isn't, but the knowledge of how to lay sandbags is important in our quest to become as self-reliant as we can possibly be.


Thanks again jacqueslebec  EmergencyKitsPlus.com