The Fort Royal Primary School redevelopment shows how a variety of SuDS features that create a highly visible ‘management train’ can provide an exciting and legible expression of the ‘water story’ to children of all ages and capabilities.
The Fort Royal School, located in the centre of Worcester, was extended to accommodate additional students and included the provision of a hydropool for children at the school with special needs.
The redevelopment of the school allowed existing flooding issues to be addressed and a new flow route created to deal with runoff in a more controlled manner. Existing playground flows, which used to wash up against the school building, are diverted to a sequence of a wetland and raised viewing pond before reaching a large grass basin and wildlife pond.
Most runoff from new roofs and car parking is collected and cleaned at source in permeable paving with some roof water flowing down rain slides to provide a visual spectacle before trickling along rills to the final basin where the water joins the first flow route. Interesting features include a cup cascade to bring roofwater down to a feature pool by the entrance and a rain chain to carry cleaned car park runoff to the lower rill. The final wildlife pond receives only clean water and shows students how runoff can be managed for wildlife benefits and create beautiful spaces.
The Headteacher in post during the consultation process had seen the our SuDS features at Red Hill Primary School and arranged a visit for special needs children to be mentored by pupils from Red Hill. The children so enjoyed the experience of running around the swale maze and other SuDS features at Red Hill that the Head requested a similar approach at Fort Royal. Therefore all the spaces are accessible under supervision and even the wildlife pond has a bouncy plank crossing for the more adventurous child. It is clear how each SuDS feature connects to the next and the main grass basin is both a teaching and play space. Children are encouraged to touch and experience water whenever possible.
Through careful and imaginative detailing, the Sustainable Drainage System has been used to create a variety of sensory experiences that all children of all abilities can enjoy. Children are encouraged to interact with the water flow and features such as habitat wetland, and windowed pond provide both passive and formal educational opportunity. The lower car park receives and treats roof water and incident rainfall which are collected in a rainharvesting tank which is used to flush toilets. Once a week the water from the hydropool requires replacing and this is also fed to the rainharvesting tank with any surplus making its way through the SuDS train.
This integrated approach to rainfall management, water use and design for place-making is a small but exciting example of what is sometimes referred to as WSUD, Water Sensitive Urban Design, but reflects the approach that has been taken by Robert Bray Associates in all the SuDS projects they undertake.
SuDS Train 1 flow receives treatment through biodiverse conveyance swales and to a limited extent through the large playground storage area.
SuDS Train 2 flow received treatment through two biodiverse raingarden infiltration basins and the final large storage/conveyance swale.
Discharge and Exceedance
The system has a controlled rate of discharge into the existing sewer network for day to day flows (with the first 5-10mm being lost through infiltration) whilst larger storm events will ultimately discharge along a defined overland route to the adjacent road. This strategy was the agreed preferred approach of the client, the Environment Agency, as the only other available discharge point would have been into the existing combined sewer which is prone to surcharge in large storm events.
Flow Route Journeys
Flow Route 1: Overland flow enters the site at a pedestrian access. The path has been re-profiled to shed the water toward a swale and berm that directs the flow down toward the main storage area.
The main storage area is located within an existing hard play area. By creating a timber sleeper wall with sealant layers, along two sides of the play area, the play area can act as storage for larger storm events. For lower flows, a swale alongside the play area carries water toward a flow-controlled outlet. During larger storm events, as the storage area begins to fill, water will begin to pass through a slot weir and along a swale before being allowed to return to the sewer.
Flow route 2: Another point of entry for overland flow into the site is along a second pedestrian entrance to the school. Here the flow is diverted by means of a sine-wave sett channel and raised hump into two raingarden basins. One raingarden flows into the next and each collects rainwater from the adjacent school roof. The lower raingarden discharges into a piped outlet that re-emerges out of the wall of a second hard play area. A sett channel directs this flow, via a cascade, to flow out of this storage swale to enter the sewer via an orifice flow control chamber.
Location : Worcester
Return Period Attenuated : Un-specified due to unknown overland flow inputs from off-site
Techniques : swales, integrated sleeper storage wall, sealed storage gates, slot weir, shallow bridge crossing, raingardens, concrete block channel, flow deflectors integrated
Discharge Destination : Combined sewer
Discharge Flow Rate : 5L/sec/Ha
Client : Worcester County Council