Self-activating passive flood barrier raised across an underground parking entrance, with a flood alarm beacon on the wall

Passive automaticCustom engineered

Hydrodynamic Passive Flood Barrier

Automatic flood protection powered by the floodwater itself. No power supply, no operator and no deployment time.

Pricing

Quoted per opening

The Hydrodynamic Passive Flood Barrier is a self-activating flood barrier for underground parking entrances, driveways, ramps and loading docks. On a new build it sits in a recess and lies flush with the finished surface, so vehicles and pedestrians cross it as normal. On an existing site it can be fixed onto the slab instead, with a ramp on each side. When floodwater arrives it flows in beneath the panel, and buoyancy lifts the panel upright to close the opening. As the water recedes the panel lowers under its own weight, ready for the next event. Nothing has to be switched on and nobody has to be on site.

Request a Quote →Email Us

🌍 Shipped worldwide

⚙️ Sized to your site

🛠️ Engineering support

⏱️ Reply in 1 business day

Why this product

Key features

Raised by the floodwater itself, so a blackout during a storm cannot stop it
Deploys on its own at night, on weekends and on unattended sites
No external power, motors, pumps or electronics to raise the barrier
Trafficable to 20 tonnes GVM (about 44,000 lb) when fully lowered
Recessed flush with the slab on a new build, or surface-mounted with a ramp each side on an existing site
Sits in a shallow recess rather than a deep pit, which keeps excavation and site preparation costs low and leaves every part reachable at ground level for maintenance
Lowers under its own weight as the water recedes, with nothing to reset
304 stainless-steel base frame and a buoyant composite panel under a patterned steel top plate
Optional aluminum checker-plate top or anti-slip coating for extra grip
Optional alarm with a water-level detector that flashes and sounds when floodwater reaches the barrier

Technical detail

Specifications

Activation	Buoyancy, as floodwater flows in beneath the panel
Reset	Gravity return as the water level recedes
Power required	None for barrier operation
Protection height	From 0.6 m up to 1.2 m (about 2 ft to 4 ft)
Width	Made to the measured opening
Traffic rating	20 tonnes GVM (about 44,000 lb) to AS 1170.1 when fully lowered
Installation	Recessed flush with the slab, or surface-mounted with a ramp each side
Base frame	304 stainless steel
Panel	Buoyant polymer composite under a patterned steel top plate
Options	Aluminum checker-plate top, anti-slip coating, flood alarm with water-level detector
Designed to	Australian Standards AS 4100, AS 1163, AS/NZS 1554.6 and AS 1170.1
Manufacturing	ISO 9001, ISO 14001 and ISO 45001 certified factory
Pricing	Quoted per opening

What our products do and don't do

How it works

Raised by the water, lowered by its own weight.

Floodwater flows in beneath the panel and buoyancy lifts it upright across the opening. As the water recedes the panel settles back flush with the surface, ready for the next event.

1. Standby. The barrier lies flush with the driveway. Cars and pedestrians cross it as normal.
2. Flood arrives. Rising floodwater flows through the inlet into the recess beneath the panel.
3. Rises automatically. Buoyancy lifts the panel into its upright position and closes the opening.
4. Resets itself. As the water recedes, the panel lowers under its own weight back to flush.