Waterfront is better than waterlogged, reasoned residents facing floodwaters along a smaller tributary of the Mississippi river, many of whom went to great lengths in protecting their properties from rising tides.

Inverted DIY moats of muddied sand and dirt stand guard, ringing yards or simply houses themselves – support structures, driveways and such were simply not worth saving to some, while others broadened their boundaries to accommodate these extras.

Some of these improvised barriers reach as high as the Vicksburg home they guard, while walls of this kind generally mean boat-only access to get in or out.

And there are no guarantees, either: if water levels rise high enough there is no retreat for vulnerable first floors and basements, perhaps whole houses if sufficiently weakened from the ordeal.
Planning is important, but luck plays a (sometimes unfortunate) roll as well. In most cases, there is no second line of defense.

If you want to learn how to build a DIY levee or temporary moat, the best time to start is well before flooding starts. Popular Mechanics consulted the levee experts at the U.S. Army Corps of Engineers for the best tips that might actually work. You start by gathering materials like shovels, sand bags, sheets of polyethylene plastic and wheelbarrows, determine the best place to lay out your earthen barrier and then dig a trench. From there you’ll start building your mounds, making sure they’re high enough to not be breached but still topple-proof. Next comes covering the levees with plastic tarps and performing some maintenance when disaster strikes.
“George Riedel, deputy executive director of the Association of State Floodplain Managers, says that even the best-built levee may not hold up to the emergency at hand, and there will always be a bigger flood. ‘Levees are one tool in the toolbox for fighting floods,’ he says. ‘But to my mind they come in two varieties: ones that have failed or been breached, and ones that will fail or be breached.” And as Led Zeppelin famously said, ‘When the levee breaks, mama, you got to move.'”
Get the details of these tips for building DIY moats for flooding at Popular Mechanics.