Could you flood a sub-irrigated planter (SIP) garden? Of course, but the likelihood of it happening would be much less that what happened here. You can't move a dirt garden. A SIP garden, however, can be moved to higher ground or elevated up on concrete blocks.
SIP garden portability is a major benefit. Also of benefit here is the fact that SIPs are closed systems. You could easily close all the overflow drain holes with duct tape and flood water would not enter the SIPs from the bottom.
The flood this past week raised questions on how to deal with vegetable gardens that have been covered with flood water.
The following information was gathered from the University of Kentucky’s Dr. Sandra Bastin, Extension Food and Nutrition Specialist; Dr. John Strang, UK Extension Fruit and Vegetable Specialist; and from University of Michigan Cooperative Extension.
The first consideration for the gardener would be the source of the flood waters. Rain water or water from a potable water source, or uncontaminated source does not carry the same potential hazards as water from a river, septic field, or other potentially contaminated source.
Water from floods can be contaminated with sewage or industrial pollutants. Raw sewage contains bacteria that can cause illness if contaminated fruit or vegetables are eaten. Flood waters that cover roads, vehicles, dumps, or pass by factories and other manufacturing and business sites can carry heavy metals and other industrial contaminants.
Flood water may be contaminated with sewage, animal waste, heavy metals, pathogenic microorganisms, or other contaminants. These contaminants are deposited not only on the surface of the flooded fruits and vegetables, but may move into plant tissues. These contaminants can also be present and may persist in the soil after flooding.