Hydro-Brake® Flood installation at Northallerton, UK
Flow control and flood protection

Hydro-Brake Flood

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Reliably protect homes, business and infrastructure from flood damage, now and in the future.

The Hydro-Brake® Flood flow control provides consistent, reliable large-scale flood protection at the watercourse level, preventing costly damage and disruption to people, businesses and essential infrastructure and services.

Capable of managing flows of up to 11,500 l/s, the Hydro-Brake® Flood enables engineers and local authorities to design site-specific flood alleviation that meets today’s requirements while also future-proofing against increasing flood risks caused by climate change.

Hydro-Brake® Flood provides large-scale protection at the watercourse level, using precisely engineered vortex flow control technology to manage flood water, preventing costly damage and disruption to downstream residents, businesses and essential services.

Already successfully protecting thousands of properties across the UK, Hydro-Brake® Flood provides reliable flood risk mitigation in a no-power, low-maintenance system with no moving parts.

Only Hydro-Brake® Flood:

  • Has a legacy of more than 30 years
  • Has a proven track record of flood protection
  • Is designed and delivered by the leaders in flow control technology

Design schemes to protect homes, businesses and infrastructure from flood damage

The Hydro-Brake® Flood flow control enables engineers to deliver large-scale flood protection projects at the watercourse level, effectively managing flood waters and preventing floods from reaching homes, business and critical downstream infrastructure such as roads and railways.

Design site-specific flood protection

Each Hydro-Brake® Flood flow control is designed according to the specific requirements of the site, ensuring that each system is precision engineered to deliver exactly the right level of flood protection. Our experts have decades of experience in designing flow control solutions, and will be happy to work with you to understand your requirements and to develop a flow control to provide precisely the level of protection that you need.

Future-proof your flood alleviation

Hydro-Brake® Flood flow controls may be designed to allow for future variances in fluvial flows, meaning that riverine flood alleviation systems can be designed to meet future flood prevention requirements. During the design phase our experts can incorporate a facility for future adjustment to allow for climate change without necessitating new engineering or additional future construction works.

Get low-maintenance flood prevention

With no moving parts and no power requirement, the Hydro-Brake® Flood flow control is designed to ensure consistent, reliable operation with minimal maintenance.

Hydro-Brake® Flood flow controls are often installed in remote locations, however, so for peace of mind we recommend periodic inspection to ensure that the system has not been compromised in any way. We are happy to manage this on your behalf via our inspection services.

Hydro-Brake® Flood flow controls are self-activating, relying on upstream hydraulic head to generate an air-filled vortex within the middle of the casing. This air-filled core occupies the majority of the outlet, restricting the flow.

The Hydro-Brake® Flood flow control moves through three distinct phases of operation:

Low Flow

Under low flow conditions the flow control behaves like an oversized orifice. The flow is gentle, with minimal turbulence inside the volute of the flow control or the outlet pipe. As the water level starts to increase above the soffit of the outlet, air becomes trapped in the volute. This exerts a back pressure against the water and begins to restrict the cross-sectional area available for water flow.

As the water depth continues to increase, a vortex begins to form within the unit and the entrapped air forms the central core.  At first there is not enough energy in the water flow to sustain a stable vortex, so the vortex will continually start to build and collapse.  

The head at the end of this phase is the point at which there is sufficient energy within the flow to sustain a stable vortex.

High Flow

A stable vortex is maintained within the flow control. High peripheral velocities around an aerated core create a back pressure, which effectively chokes the flow through the outlet aperture. Following initiation of the vortex, the flow control restricts the flow in a similar fashion to an orifice, but with clear openings up to 600% larger, significantly reducing the risk of blockage.

Drain Down

As the water level subsides, the energy within the flow reduces and the vortex collapses. Air is drawn into the volute and the flow control returns to operating in a similar manner to an oversized orifice. This drains the system quickly and more effectively, so that the flood storage reservoir is ready for the next event. 

Maximum flow: 11,500 l/s / 182,278 gpm

Maximum head: 11 m / 36 ft

Approximate maximum storage area: 5,750 ha* 

*Assuming 2 l/s  / 31.7 gpm per ha

  • Hydro-Brake® Flood installation as part of the White Cart Water flood prevention scheme in Glasgow
  • Hydro-Brake® Flood installation at Northallerton, UK
  • Hydro-Brake Flood installed in Doha, Qatar
  • Completed Hydro-Brake® Flood Installation at Much Wenlock, UK
  • Hydro-Brake® Flood installation as part of the flood alleviation scheme at Wigan, UK
  • Hydro-Brake® Flood installation with Hydro-Logic® Smart Monitoring to collect data on levels
  • Hydro-Brake Flood during installation in Doha, Qatar

What type of maintenance does the unit require?


Maintenance will be dependent on the site, the size and characteristics of the flow control, the nature of the influent and any physical characteristics of any control chamber.


How many flow control units will I need?


Each site has different existing and future flood alleviation and protection requirements, so the size, design and number of flow controls will depend on site-specific design parameters. We are able to provide design, guidance and advisory support in this area.


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