Where adequate on-site infiltration is not possible, flood risks must be mitigated by attenuating stormwater to result in adequate flood storage. The Hydro-Brake® Agile flow control is precision engineered to provide constant discharge, cutting on-site storage to a minimum while ensuring that site discharge is matched to the carrying capacity of the downstream infrastructure.

The Hydro-Brake® Agile flow control delivers effective water management for even the most exacting site conditions.


  • Surface water management and sustainable drainage systems (SuDS)
  • Combined drainage systems and CSOs
  • Sewer network optimisation
  • Flood alleviation, prevention and risk mitigation

Designed for

Low flow
Low storage


Reduce construction costs

Building flood storage leads to land-take and construction costs that are dependent on the rate at which excess water can be controlled and discharged. The Hydro-Brake® Agile flow control minimises the amount of on-site storage required - enabling developers and construction companies to provide flood management while managing construction costs.

Meet stringent discharge consents

The Hydro-Brake® Agile flow control achieves a constant rate of discharge and therefore requires the minimum possible upstream storage. It is ideally suited to sites with stringent discharge consents where the space available for on-site attenuation is at a premium.

Future-proof your flood protection

The Hydro-Brake® Agile can be adjusted easily, enabling operators to change the system to meet differing operating conditions and ensure controlled flow and protection against flooding even if conditions change.

How it works

How it works

Low- and Dry-Weather Flows

During low flows, the water level remains below the float arm and the gate is in its fully open position. The discharge flow rate is controlled by the outlet orifice.

Under these conditions, the unit remains fully open, allowing any waterborne debris to pass forward almost unimpeded.

Attenuating Flows

As the flows increase, the outlet orifice starts to restrict the flows and the water level in the flow control chamber will begin to rise. This will cause the float to rise. Internal components transmits this upward motion and begins to close the gate. As the gate closes, the cross-sectional area of the outlet available for water flow is reduced and a constant discharge rate is maintained even as the water level continues to rise.

The discharge rate will generally be set to the maximum rate that can be accepted without compromising the capacity of the downstream infrastructure.

Extreme Flows

If the upstream water level reaches a pre-determined top water level associated with the design storm event, the internal controls will prevent the gate from closing any further. For further increases in head, the discharge will be limited by the outlet orifice at its closed position.

Drain Down

As the water level subsides, the float will return to its resting position and the gate will return to its fully open position. A high discharge rate will be maintained as the water levels subside, rapidly draining the upstream system in readiness for subsequent rainfall events.

Technical Information

Technical information

Performance Characteristics

Maximum Flow: 100 l/s

Maximum Head: 2.4 m 


The Hydro-Brake® Agile flow control consists of a float arm connected via a series of custom configured components to a sliding gate, placed over an outlet orifice.

Manufactured from high grade stainless steel (typically 304L or 316, as appropriate) with durable internal components under our comprehensive Quality Assurance procedures, the Hydro-Brake® Agile flow control will deliver reliable, repeatable and precise flow rate regulation.

The Hydro-Brake® Agile flow control has been assessed in accordance with all relevant essential Health & Safety requirements and standards and is CE marked under the EU Machinery Directive (2006/42/EC).



Case Studies

Case Studies