FlexiBaffle

FlexiBaffles have been designed to assist with upstream fish passage by altering water flow through culverts and providing areas for fish to rest. The baffles can be fitted before the installation of the culvert or retrofitted to existing structures.

FlexiBaffle Data Sheet

Great for Round or Box Culverts

Standard FlexiBaffles are 100mm and 150mm high but can be trimmed if required. Lengths up to 1800mm but can be placed end on end to suit any width structure. If you need any help determining the baffle size, don’t hesitate to contact us directly.

FlexiBaffles placed inside culvert pipe can:

  • Reduce velocity
  • Increase depth
  • Create nature-like complex flows
  • Extend the range of flow characteristics including wetted margins for climbing species
  • Retain stream bed material
  • Create high and low flow passage

FlexiBaffles are designed with sustainability in mind — they can be manufactured using recycled materials and are fully recyclable at the end of their service life. This ensures minimal environmental impact while supporting circular economy principles.

ATS Environmental FlexiBaffles are made in NZ, Australia, Norway, the U.S.A and the U.K. Our culvert baffles are suitable for round or square culverts and can be modified on-site to fit any particular requirements.

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Performance Under Pressure

The graph demonstrates the performance of the FlexiBaffle under varying levels of applied force. As force increases (measured in N/m²), the baffle height responds dynamically, gradually reducing to accommodate the pressure. This characteristic curve highlights the product’s ability to maintain a reliable seal while flexing to suit different operational conditions.

Overlayed on the graph is a cross-sectional illustration of the baffle in multiple stages of deflection, visually representing how the baffle adapts as force increases.

Fish are unlikley to be migrating upstream during very high flow events when the FlexiBaffle is bent to maximum extent.

Engineered for resilience and flexibility, the FlexiBaffle delivers optimum fish passage without compromising culvert performance

FlexiBaffle Installation Detail

The FlexiBaffle system is designed for secure and adaptable installation across a range of culvert and channel environments. The illustration outlines a standard mounting configuration using stainless steel components to ensure long-term durability and corrosion resistance.

Installation Features:

  • Typical Fixing Methods:
    Culvert Material:
    Concrete –     M6 x 50mm or M6 x 60mm 316 stainless steel wedge anchors with cleats/washers.
    Plastic – 14g (7mm) x 35mm hex screws with cleats/washers.
    Steel –     Self drilling self tapping hex drive tek screws with cleats/washers
    Fiberglass –     Pre-drill 6mm hole Self drilling self tapping hex drive tek screws with cleats/washers 

  • Typical Fixing Spacing: 100 mm

With modular spacing and straightforward installation, the FlexiBaffle offers a reliable solution for flow control and sediment retention applications in both new and retrofit scenarios. The longevity of the flexi baffle installtion is dependant on the stability of the culvert material and the care of the installer.