New King’s Moat school has a space-saving stormwater system by GRAF UK.
A state-of-the-art primary school is now set to be the heart of a brand-new community, thanks to GRAF UK.
King’s Moat Community Primary School is due to open in September 2026 when it will provide places for more than 300 pupils, as well as a 26-place nursery, 3G multi-use games area, and outdoor play and teaching areas.
It is located at the heart of the new, award-winning 1,300-home King’s Moat Garden Village two miles from Chester which is being built by Taylor Wimpey around a medieval moated site that is now a Scheduled Ancient Monument.
While there may be no water left in the moat nowadays, water – or stormwater to be precise – was a consideration for the new school which required an attenuation tank to capture, store, and gradually release excess rainwater to prevent flooding.
The tank supplied through civils and drainage products distributors JD Pipes comprised 500m3 of GRAF UK’s EcoBloc Maxx recycled plastic crates which feature a space-saving stackable design and a high 96% void ratio.
And just as the two to five-bedroomed homes at King’s Moat are being built with energy efficiency in mind, with solar panels, EV chargers, wastewater heat recovery, thermal lintels and triple glazing, so too was the stormwater attenuation tank.
GRAF UK business development manager Lawrence Finch explained: “When we received the drawings for this project, we had to decide on the most suitable crate and we decided on our EcoBloc Maxx crate which allows more crates per delivery, less time taken to offload on site, and less space taken on site as our crates are stackable and modular.”
The tank system – the crates and membrane – was installed in three days by GRAF UK’s installation team, into an excavation dug and lined with shingle by main contractor AJC Construction, with whom GRAF UK has worked several times.
AJC also offloaded the already delivered, crates, and base and end plates, to the GRAF UK installation team in the excavation while they put the crates together, the end plates on, and then brought up the membrane and textile around the sides. They then cut holes for inlet and outlet pipes, and any other vent pipes required.
They then brought the membrane up over the top and heat welded it to ensure the complete system is waterproof, before the tank surrounds were filled with pea shingle, and the entire system was back filled with the dug material.
Lawrence explained: “Overall, the installation was a success, as we had expected this to take up to five days to install, but the team were very efficient and managed to complete it in three days. This was despite there being bad weather which posed some problems throughout.
“Upon arrival, the sides of the excavation had fallen in due to the ongoing downpour of rain and the excavation had also started to fill with rainwater which prevents our team from installing the tank. This was sorted out very quickly by AJC and allowed us to begin installing the crates as planned. As I say, the team did this efficiently whilst maintaining our quality standards.
“However, the weather was a challenge again when it came to heat-welding the tank to seal it and make it watertight. This was due to 37mph winds. Despite this, the team found a way to get the job done successfully.”
Lawrence added: “We managed to achieve the net storage volume required, whilst actually reducing the gross overall volume of the tank. This enables less of an excavation to be dug and also less time spent on site, and makes the tank more cost effective.”
To see the installation in action, watch the full video here.
Posted by Callum Vallance-Poole, on December 1, 2025.
