Testing Requirements
To build an independent evidence base for highway use, the Rosehill Drainage System was put through a full-scale trial at the National Highways Moreton-in-Marsh Test Centre. The programme set out to demonstrate hydraulic capacity across a range of storm return periods and to generate data for extrapolation into National Highways CG 501 and MCHW 500 Series calculations.
Testing Protocol
A full-scale test installation was constructed to replicate real-world highway conditions. The programme included simulated extreme rainfall events exceeding design storm intensities, comprehensive flow measurement to validate hydraulic performance claims, and structural stress analysis under representative loading scenarios. An extended monitoring period assessed performance consistency over time.
Trial Results
The 60 m installation passed every simulated storm return period — up to 1 in 1000+ — with zero surcharging, flooding or damage. The maximum flow tested was limited by the water-tanker pump, not by the drain, indicating further headroom. The results provide an independent evidence base for extrapolation into CG 501 and MCHW 500 Series highway drainage calculations.
- 11,000 L discharged in under 22 minutes
- Storm returns to 1 in 1000+ — all passed
- 60 m full-scale test installation
- Zero surcharge, flooding or damage
- CG 501 / MCHW 500 Series data basis
- Moreton-in-Marsh Test Centre
