The Aquifer Partnership (TAP) is a partnership between the South Downs National Park, Brighton and Hove City Council, the Environment Agency, and Southern Water. Its core ambition is to protect the chalk aquifer that exists beneath Brighton and the immediate region. The aquifer is a key source of fresh drinking water for the area, but is currently seeing higher levels of pollution, above the drinking water accepted standards.
As part of this partnership, TAP instigated a number of key pilot projects to develop Sustainable Drainage Systems (SuDS) with an aim to:
· Reduce surface water pollution
· Manage surface water volume
· Promote biodiversity and habitat value
· Improve amenity value
Moulsecoomb Primary School was one of these pilot projects. Its central courtyard is highly visible as you pass through the school, as many of its internal walkways face into it. However, despite having such a prominent position, it was under used, overgrown and lacked usable space for the school’s students. TAP’s aim therefore was to not only incorporate SuDS into its development, but transform the space into a multi-use, inspirational and informative environment for all who used it – a ‘rainscape’.
A multi-functional, biodiverse, beautiful, SuDS-focused, educational space.
The SuDS design consists of a number of key attenuation, infiltration and runoff cleaning features integrated into the educational landscape:
· Rainplanters (raised raingardens)
· Central wildlife pond
· Raised accessible pond
· Permeable paving
The scheme primarily manages roof run-off from the adjoining school buildings, along with rainfall that lands directly in the courtyard. Rather than allowing rainwater to enter the sewer system, the scheme intercepts rainwater at the downpipes and manages it through a “management train”. Utilising nature-based SuDS, rainwater is kept at, or near, the surface which allows for natural losses of the water along with providing a more interesting and dynamic space. It also allows the drainage scheme to be more easily recognisable and easier to maintain.
Much of the intercepted rainfall is directed to raised rainplanters, through artistic “watering can” inlets. These vegetated features help attenuate and clean roof runoff, whilst providing natural irrigation to the planting which helps them be more self-sufficient and resilient to drought during hot summer months. Water discharges from the rainplanters into surface channels. These convey water through attractive letterbox spouts into the central pond, which provide the focal feature of the courtyard.
A composite deck dipping platform on the edge of this pond provides the basis for wildlife and ecosystem education, where students can observe aquatic life during their seasonal change. The pond has been designed with a series of ledges and “benches” that promote a range of wildlife life to thrive whilst maintaining a safe space for children.
There are other artistic features, such as the overhead “trickle” channel that conveys rainwater into the raised ornamental pond. This pond contains a range of surface plants that bob around as the pond level fluctuates, and overflow into the central pond. Another overhead channel creates a cascade feature down a metalwork umbellifer sculpture by a local artist, onto the permeable paving surface below. This paved area provides the main seating space for the courtyard, allowing for external classroom learning and one-to-one sessions in the quieter, more peaceful, surrounding of the courtyard.
The SuDS features provide a key learning opportunity for anyone using or entering the courtyard, particularly the children who are taught both the importance of water in our environment, and how it can move and be experienced in a hands-on way. However, there are several other educational experiences that the courtyard provides. The chickens within the newly built pen provide a key attraction. Again, SuDS plays a key role here as the grit joints of the permeable paving of the pen provides at-source cleaning of chicken waste, which is broken down further by the biofilm growing on the grit and the soil layers installed beneath.
Above he chicken run is a partially covered timber pergola, designed to provide covered external seating for users as well as adding verticality to the courtyard. A variety of climbing plants have been installed on its structural uprights that extend into the planted gabions of the central pond. Over time it is envisaged that the pergola and gabions on this side of the courtyard will be enveloped in a flowering mass of colours and textures, that will provide visual and habitat benefits to the space.
A series of small, raised planters were provided to assist in horticultural after-school clubs. These were installed at different heights and sizes to enhance accessibility. The existing courtyard was inaccessible for many of these students, and so this became a key aspect in the new development – making it accessible despite a slope in the surface and different building thresholds levels.
Wherever possible, material was kept and re-used from the existing courtyard, including the extensive cleaning and relaying of paving blocks, reusing stone rocks and boulders, and repairing old structures such as a raised planter into a new raised ornamental pond. Even the metal clasps of the removed downpipes now provide a holding structure for suspended plant pots and drilled timber posts for solitary bees. A new focal tree has been installed to replace the previous, which was becoming unsafe and nearing the end of its life. Its wood however was used to create habitat features surrounding the pond, allowing for natural process to take place.
Additional artistic elements were incorporated into the design including engraved coping stones surround the raised pond, with a poem from a book which formed part of the school’s curriculum. The students have also added artistic elements of their own, including toy tigers and dinosaurs, nestled into the vegetation.
The result is an intensively designed, charming, multi-use space that has been highly celebrated by the school, its students and their parents and guardians that visit the school.
Robert Bray Associates (RBA) were involved with the early feasibility study of the school, exploring what was possible within the confines of the courtyard. Following the recommendations of this study, funding was raised for the works and a competitive tender was released for the RIBA stage 3 through to 6 design works. RBA were successful tenderers and the design process began in early 2021, with the school and client team being integral partners in the design process.
A competitive tender was released for the construction works in June 2021, and the successful contractors – Vu Garden Design – were appointed. Works started in July and completed in October 2021.
TAP, along with input from RBA, engaged with the school and its students multiple times throughout its development. First engagements focused on learning about runoff and its impacts on the natural world and the vulnerable aquifer as well as the role of SuDS, its importance, and how it could be established within the courtyard. Further “art and creative workshops” gave the students opportunities to design aspects of the scheme, including the ornamental pond engravings, and to discuss how the scheme was to be used once built. Opportunities to provide updates of the building works during construction was difficult due to Covid but was still possible within governmental guidelines at the time. This was facilitated by the ongoing visibility of the scheme from the many classrooms and walkways that faced out onto the courtyard.
Continual engagement with the school’s groundskeeper also helped form the design into a space that they could comfortably use, manage and maintain.
The incorporation of SuDS meant that a total volume of 22.27m3 of rainfall from the 637m2 of surrounding impermeable catchment can be stored and infiltrated. This is equivalent to approximately the 1 in 100 rainfall event, providing a huge reduction in water leaving the school grounds and entering the sewer system. This is particularly important during storm events as it helps reduce the risk of flooding and, in places, reduces pressure on the sewage treatment network.
The range of different vegetation types, including those in and surrounding the central pond, provide a rich biodiverse lattice benefiting a wide range of invertebrates. Identified invasive species were removed and identified for removal as part of the long-term maintenance to uphold diverse plant species. The focus on flowering species within the horticultural beds also provide benefit to pollinators.
The newts and frogs first discovered in the existing pond, along with the rich ecological material at its base, were translocated into the new pond helping to promote quick establishment.
As well as school-time learning opportunities, the courtyard has been used to house after-school events, including horticultural lessons and environmental learning, run by local residents. It has also held evening gatherings with parents and guardians, as well as a place of focus for the school’s promotion to new students.
Location: Moulsecoomb Primary School, The Highway, Lewes Road, Brighton and Hove, Brighton BN2 4PA
Design year: 2021
Year Completed: 2021
Project Description: Moulsecoomb Primary School SuDS Rainscape
Client: The Aquifer Partnership (TAP)
Location: Moulsecoomb, Brighton, UK
Construction Cost: £101,603.00