Our AH4C Headwalls are two part precast concrete headwalls that allow water to discharge at a 45 Degree angle. This is the Environment Agency’s preferred method when discharging into a watercourse.
AH4C precast headwalls fully meet the Environment Agency’s ‘Standard rules SR2015 No 27 – Constructing an outfall pipe of 300mm diameter through a headwall into a main river’ and exempt flood risk activities: environmental permits section FRA12 ‘Outfall pipes less than 300mm diameter through a headwall’.
The AH4C is available with three different back wall heights and three different toe depths for plastic or clay pipes up to and including 300mm. We provide separate toe extensions to make the headwall easier to handle and more importantly ensures the foundation around the toe and beneath the headwall structure can be well compacted.
AH4C angled precast headwall units can be pre-fitted with a range of accessories such as Kee Klamp® handrails, gratings, flap valves, penstocks and other flow control devices.