The objective was to enable surface water run-off generated from the site’s refurbished car parks to be managed within a sustainable drainage system that supports a series of visually striking landscaped retention ponds.
1. Allow the car and lorry parking hardstanding to be extended with no increase in discharge to the existing stormwater sewer.
2. Improve pedestrian access to the main services building by eliminating the risk of any standing water.
3. Optimise and value-engineer the drainage solution to the traffic environment in each vehicle zone.
Consulting engineers, BWB, worked with main contractors, Buckingham Group Contracting Ltd, to develop the drainage scheme. “We looked to replace the existing point gully system with one based on a network of more effective, faster draining channels,” says Tristan Tregratha, Senior Project Manager at Buckingham Group Contracting Ltd. “Having worked successfully with ACO on a number of previous sustainable schemes, we were confident that with the help of its Design Services team we could realise an integrated network that could deliver optimum performance in each of the load class environments across the project.”
Surface water intercepted by the drainage channel network is diverted via oil separators and flow controllers to one of three attenuation ponds or the existing stormwater sewer. Clean water held in the ponds can subsequently be released into the main stormwater sewer or a local watercourse.
Three ACO products, each with unique performance and attenuation characteristics, have been utilised in hardstanding zones. Serving the extended HGV parking areas are two sizes of the award-winning channel drainage system, ACO Qmax (ACO Qmax 225 and ACO Qmax 350). Its unique patented inlet allows an unbroken pavement to be cast around the channel which reduces the need for additional reinforcement and minimises installation time. All the runs of ACO Qmax at the site are fitted with ACO’s pedestrian-safe, galvanised steel Heelguard Edge gratings.
Interlinked runs of ACO KerbDrain and ACO RoadDrain, which can be easily tied into the existing sewer connections, provide optimum removal of surface water from the access road and passenger vehicle parking areas. Balanced with ACO Qmax runs fitted with appropriate gratings in the lorry parking and pedestrian pathways, the entire system keeps discharge at a safe level by using attenuation ponds to hold excess storm surges.