Brighton ChaMP* for Water Protecting our precious groundwater in the South Downs

Contact: Aimee Felus, ChaMP Project Manager E: [email protected] T: 01730 819282 M: 07887 415149

Wild Park Rainscape Proposal Project Summary and Supporting Statements

Current drainage system for Strategic Road Network (SRN) in project location:

Surface water drainage discharges from the A27 into a balancing pond at Woollards Way, Brighton BN1 9BP. Water and any associated contaminants then pass into a traditional piped system adjacent to Lewes Rd, prior to ultimately discharging to a series of soakaways in Wild Park, Lewes Rd, Moulsecoomb, Brighton, BN1 9JR. The site lies in a Source Protection Zone 1 and 2 (SPZ1 and 2) for drinking water. A recent PhD conducted at the University of Brighton has demonstrated presence of a range of potential contaminants in the balancing pond (heavy metals and hydrocarbons) with zinc and benzo (a) pyrene being of particular concern.

Figure 1: Location of proposed projects - Woollards Way, Brighton, BN1 9BP (TQ 34107 08324), and Wild Park, Lewes Rd, Moulsecoomb, Brighton, BN1 9JR (TQ 33187 07875)

*Chalk Management Partnership Balancing pond at Woollards Way

Series of soakaways in Wild Park

Figure 2: Location of balancing pond and soakaways and SPZ1 and 2 (shown in red and green respectively)

Figure 3: Balancing pond at Woollards Way shows evidence of contamination with hydrocarbons and heavy metals

Figure 4: Balancing pond with water Figure 5: Soakaway in Wild Park with contaminated silts and black water

Summary of Proposed Project:

Proposals are to modify the existing system and create a Sustainable Drainage System (SuDS), or ‘Rainscape’, that prevents pollution of groundwater. Currently the SRN contributes contaminants to groundwater in an SPZ1 and 2. This project would protect groundwater in this location.

Within the catchment area of the balancing pond and soakaways there is an area in Wild Park that could be enhanced with a rainscape. As there are limited pollution control devices on the existing system, groundwater will be protected by discharging surface water through SuDS. Evidence suggests that there is an 80% reduction in typical road run-off contaminants by using SuDS compared with traditional piped drainage (Highway Runoff and Water Quality Impacts, East-West Gateway Coordinating Council, 2000). In addition such a scheme would mitigate flood risk, as these soakaways have flooded on a number of occasions, causing disruption to Lewes Rd. Primary benefits of the scheme will be for flood risk and water quality, with other significant benefits for biodiversity and landscape, as well as social and amenity benefits.

N.B Draft concepts for proposals are shown below as examples only – please see Feasibility Study for further concepts and explanations.

Figure 6: Example DRAFT concept for alterations to existing balancing pond at Woollards Way

Figure 7: Proposed location for rainscape in Wild Park

Figure 8: Example DRAFT concept for rainscape in Wild Park

The Delivery Partnership:

This project was initially proposed by the ChaMP partnership. Brighton ChaMP (Chalk Management Partnership) for Water is a collaborative project to protect and improve the quality of groundwater in the Brighton chalk, to ensure it remains a sustainable resource for public water supply. Additional partners from Brighton and Hove City Council, Highways England and AOne+ have joined the delivery team for this project. The team now comprises professionals with expertise in groundwater protection, highways, flooding and drainage, project management, SuDS creation, parks management and biodiversity. The team has a broad scope of experience to bring to such a project, as well as experience working on similar schemes which can be used as models for a rainscape in Wild Park. The partnership have discussed this scheme and all parties are fully supportive. Each organisation has a slightly different focus in their skills, knowledge and drivers in terms of the primary benefit of the scheme (eg. water quality, flood risk mitigation, biodiversity, landscape character improvements and amenity/social benefits). This has been demonstrated in other projects to be a strength of a partnership to deliver a multi-faceted project such as this.

Supporting Statements:

‘The Falmer public water supply (PWS) abstraction source is operated by Southern Water. This source is within the Brighton Chalk Block groundwater body which was classified as having poor chemical status in 2015 due to diffuse pollution. Wild Park is located close to the abstraction borehole within Source Protection Zone (SPZ) 1 which has a 50 day travel time. Flowsource modelling estimates that the Wild Park area is contributing the highest volume of water to the abstraction at between 150 and 300 m3/day. As such, the proposed Brighton ChaMP Rainscape project at Wild Park has the potential of delivering significant improvements to this drinking water source.’ Leasa Williams, Catchment Management Specialist, Southern Water

Figure 9: Volume from heat map of Falmer abstraction, including area of Wild Park (Amec GW model, 2017)

‘Surface water drainage discharges from the A27 into the Keep drainage pond prior to discharging in to soakaways. These lie in a Source Protection Zone 1 for Falmer public water supply and there is evidence of pollution with a pathway to groundwater via the soakaways. Proposals are to modify the system and create a large rainscape (SuDS) that would reduce pollution of groundwater and meet the Water Framework Directive requirements to prevent deterioration of groundwater quality.’ Simon Deacon, Technical Specialist: Groundwater, Hydrology & Contaminated Land, Environment Agency

‘Wild Park sits on the southern edge of the South Downs National Park and is a potential gateway to the downs for local people. The Wild Park rainscape project can deliver multiple benefits, firstly it will contribute to improving water quality in the Falmer catchment ensuring a sustainable supply. The project will also have landscape and biodiversity benefits by creating a variety of new habitats and associated wildlife in an area of sterile amenity grassland. Finally there are great opportunities for engagement and ownership by the local community, increasing their understanding of water issues and protecting our resources and creating pride in the local landscape.’ Jeremy Burgess, Landscape and Biodiversity Lead (Water), South Downs National Park Authority

‘My involvement and support for this project centres around technical guidance in relation to highway drainage and the benefits this project will bring to the location in preventing flooding of the lower end of the park and onto the footway, cycle lane, north-bound Carriageway and the reduction in pollutants and contaminants on the surface at this location. In just the last 4 years this location has flooded 3 times; in October 2014, August 2015 and June 2016. The positive benefits will be in greater highway safety for all the users, a slower rate of degradation of the highway surfaces and result in a much improved environment for this location in general.’ Stuart Wilson, Highway Asset and Engineering Manager, Brighton & Hove City Council

‘The Parks Projects Team is pleased to be involved in the Rain Gardens proposal and guide its development. Our primary parks focus will be on ensuring that the initiative does not adversely increase the maintenance requirements for Wild Park.

Wild Park is located on the A27 near the wards of Moulsecoomb and Coldean. The nearby destinations of Stanmer Park, the University of Sussex and the Amex Stadium will be increasing their visitor numbers in the next few years, due to planned development.

The Parks Projects Team is delivering the Stanmer Park Restoration Project for the council. This scheme has secured over £10 million pounds of investment over the next 3-5 years (2018-2023). It is estimated that around 300,000 additional visits will be attracted to Stanmer Park alone, following the completion of the restoration project. There are currently 500,000 visits to the park each year.

An increase in visitors to the park and University will also mean greater bus patronage. Buses can provide a bird’s eye view of the surrounding areas such as Wild Park; which would mean that the proposed Rain Garden could become a positive attraction in the area. This will also elevate the profile of Wild Park, increasing its role as a gateway for the city.

The water quality in this area is also important. Stanmer Park was purchased 70 years ago to assist in preserving the drinking water for Brighton that percolates through the chalk substrate in the locality. In recent years, the city has witnessed some extreme localised rain storms which have flooded roads and homes. If such a downpour were to occur in the Wild Park area resulting in flooding impact to this primary road artery could adversely affect traffic flows and the aforementioned destinations. Both issues could have a negative impact on the council; related authorities, residents, visitors and businesses in this area.

Therefore it is important to explore the progression of this scheme as the proposed works could aid in mitigating future flooding in the area.’ Paul Campbell, Parks Projects & Strategy Manager, Brighton and Hove City Council

‘ChaMP is a priority project of The Living Coast Unesco World Biosphere Region programme, our sustainable development initiative that aims to connect people and nature to pioneer a positive future for our local area as part of a global network of world-class areas. The (ground-) water environment is a key priority for proactive action through the Biosphere programme, as is green infrastructure such as sustainable drainage schemes (SuDS) – for which we have already established two pilot rain gardens in Brighton & Hove hence helping to establish this growing local approach. We thus highly commend the proposal for a major SuDS scheme to be created at Wild Park under the ChaMP project.’ Rich Howarth, Programme Manager, The Living Coast