How Inflatable Cofferdams Help With Flood Control

1. What Is an Inflatable Cofferdam?

An inflatable cofferdam (also known as a water‑filled or portable cofferdam) is a temporary barrier—typically a long, flexible tube—laid across waterway outlets, around buildings, or along flood-prone areas. Once positioned, it's filled with water (or sometimes air), creating a watertight seal that temporarily diverts or blocks water flow.

2. How They Work: Basic Mechanics

• Self-ballasting via water: Filling the tube with local water adds weight, stabilizing the barrier against flowing floodwaters.

• Internal baffle system: Hidden compartments (baffles) within the dam regulate pressure distribution and prevent the tube from rolling or being displaced.

• Freeboard margin: Designers build in a safety margin (“freeboard”)—commonly ~25% above expected flood height—to accommodate surges or high-velocity flows.

Together, these features create a resilient, flexible flood barrier.

3. Key Advantages Over Traditional Methods