Wet floodproofing is a flood protection option that allows floodwaters to enter the building. The spaces in which water will enter, such as the basement or ground floor, are modified to minimize damage. Modifications may include water-proofing building materials and creating or modifying openings in the exterior walls to allow water to enter. By allowing floodwaters to enter the building, you don’t have to worry about the excessive build-up of pressure caused by the floodwaters on the building’s exterior walls (hydrostatic pressure). Wet floodproofing is best suited for infrequent flooding and shorter duration floods, and it is typically the cheapest flood protection option.


One of the main advantages of wet floodproofing is that it is a minimal cost and minimal effort solution.


The main disadvantage of wet floodproofing is that it is a short-term solution and will, therefore, result in the deterioration of building materials due to repeated exposure to floodwaters.


  • Some aspects of the building’s architecture will be modified, although these modifications are minimal.
  • If there are important collection items in the spaces that may get wet during a flood, these items either need to be temporarily moved before the flood or permanently moved to avoid damage.
  • Because wet floodproofing allows floodwaters to enter the building, clean-up after flood events can be substantial and may require that the building stay closed for an extended period of time.
  • Utilities may need to be relocated or waterproofed if they are located in spaces that may be submerged during a flood event.


Flood vents allow water to enter the basement, preventing excessive pressure from developing on the basement walls. (Image source: floodflaps.com/new-construction/)

To protect outdoor utilities, such as air conditioning units, they should be elevated above the flood level. (Image source: floodsavvy.com/options-in-flood-proofing-3/)