Wild Park Rainscape - the details
The Aquifer Partnership has won funding to improve a small part of Wild Park in Brighton, creating an attractive area for people and wildlife. It will be designed around several shallow planted basins that can hold water during heavy rainfall, and which help to reduce pollution and improve the area for people and nature. This will be the Wild Park Rainscape.
This project takes surface water from a section the A27 at the junction with the Lewes Road by The Keep. The detention pond there currently stores water before piping it to soakaways next to Wild Park, where it goes directly in to the aquifer without any treatment – presenting a pollution risk to the groundwater. The Wild Park Rainscape is designed to manage that surface water in a more natural and sustainable way that brings extra benefits for water quality, people and nature.
What will it look like?
There will be four linked basins, dug or scraped out and planted as shallow wetlands (we’ve done lots of work to test the soil, the chalk and how the water flows). These linked basins will be in the grassed area between the park entrance and the end of the turning circle, next to the road – it’s a relatively small part of the overall park area.
There will be attractive wildlife-friendly planting, and it will be wet or damp for some of the time. It will be designed to accommodate most current park use, and with safety in mind. There will be space for interpretation and seating.
How will it work?
The new scheme is designed to reduce the risk of groundwater contamination. It introduces a new system to prevent polluted highway runoff going directly into the underlying groundwater through the soakaways. It will improve the layout and function of the existing highway drainage and detention pond next to The Keep, which forms the first element of an innovative treatment train, linked to new wetland elements in Wild Park.
The new system will slow down the water and hold it closer to the surface – in the park – copying natural processes. Pollution is broken down through a variety of processes, helped by time, plants, microbes in the soil and sunlight, before cleaner water is filtered into the aquifer.
Will it help with flooding too?
Rainscapes are designed to manage water in better ways, which includes slowing the flow and providing capacity to store, treat and filter water into the soil.
Why did you decide on this area?
We looked at the whole of the Brighton & Hove area using walkover and mapping techniques, where we focused on areas that are most vulnerable to groundwater pollution, as well as good visibility so that people could easily see the benefits. Sites were selected and short-listed by specialists in the partnership with local and technical knowledge.
What is the problem?
When it rains, water is stored in the Brighton Chalk aquifer, which provides drinking water supplies for around 365,000 people in Brighton & Hove and beyond. Over the years, nitrate pollution from farming and sewage leaks, chemicals, pollution from vehicles and urban development have caused increasing pressure on the Brighton Chalk, which means that water quality is at risk. This project focuses on pollution from roads – we want to use this project to demonstrate the benefits of a nature-based solution. This is to reduce the risk of contaminating drinking water
What is a rainscape?
Rainscapes (also known as sustainable drainage or SuDS) are specially designed, engineered and landscaped solutions to manage surface water, reducing flood risk, improving water quality, and providing better biodiversity and community benefits.
Shallow landscaped and specially planted basins and other features capture water runoff from the roads. Rainscapes help to manage water flow and quality, copying natural processes. They can capture water from roofs, roads and car parks, slowing and holding it to reduce the risk of flooding. They help to remove pollutants from road and car park run-off through natural processes including time, sunlight, microbes in the soil and vegetation.
The Wild Park Rainscape is designed to highlight this type of solution and stimulate further projects in the city to address pollution risk to the aquifer. We’re linking the Wild Park Rainscape with a rainscape project in Moulsecoomb Primary School.
What pollution comes off our roads?
Runoff water from the construction and operation of roads contains a multitude of chemicals including nutrients, salts, metals, persistent organic pollutants (POPs) – as well as plastic particles. Road run-off is the third highest cause of water pollution in UK today, and accounts for 13% of failures under Water Framework Directive are due to road run-off.
What are the main pollutants?
- Fuel and oil
- Hydrocarbons – Persistent Organic Pollutants (POPs)
- Tiny plastic particles from brake pads and tyres
- Heavy metals – lead, copper, zinc
- Poor air quality can affect pollution on the ground, emissions such as oxides of nitrogen from vehicles can be deposited on the ground
Where will the money come from?
TAP has secured funding from National Highways, from a fund that’s specifically designated for environment and well-being. We had to apply for the funding and meet some tough criteria to demonstrate that the scheme would work – meeting water quality, flood management, biodiversity and other criteria.
Find out more here.
Are there any other rainscapes in Brighton?
There is a small project in Darcey Drive, off Carden Avenue, which is Phase 1 of a two-stage project, with Phase 2 now underway, and an additional rainscape planned at Carden School.
How long will it take?
We are commissioning specialist designers who are very experienced in rainscapes, including community involvement and planning. We expect the design to take until autumn 2022, with expected completion around July 2023. We’ll keep people up to date as the project progresses and timescales become clearer.
Find out more about the timescales here.
Will it create a mess/noise?
During the construction stage there will be some heavy machinery on site, and we will consult with local people about ways to minimise any disturbance.
Will there be more litter?
It’s unlikely that a project like this will increase the amount of litter in an area, and there is some evidence that investment helps to promote greater care, combined with well-designed and maintained bins and regular litter picking.
What will happen if travellers park in Wild Park?
The council has established a Travellers site at Horsdean that has areas of permanent residential and temporary pitches, which the travelling community are encouraged to use. The Police are able to direct Travellers from an unauthorised encampment to the council’s Transit Traveller site. The incidence of travellers using Wild Park has decreased over the past few years, and travellers setting up at Wild Park will be required to move.
What about water quality and flooding on the Lewes Road?
This project is designed around the existing drainage system, which takes polluted water from the A27 and pipes it to the soakaways next to Wild Park. When we were looking at possible locations to demonstrate the benefits of SuDS or Rainscape, we identified this area because we wanted to change the way the current system works, taking the soakaways out of action and creating an attractive landscaped area in the park.
What is a soakaway?
Soakaways are square or circular excavations either filled with rubble or lined with brickwork, or other material. They help to manage storm water by letting it drain back into the ground, but this can present a risk if polluted water comes from the road directly into our aquifer.
Why aren’t there more projects like this in Brighton?
All new developments are encouraged to include sustainable drainage in their plans, and there is very good guidance available, however because it isn’t a legal requirement (as it is in Wales) it’s not enforceable. We are designing this project to be a good example to encourage others to follow.
The Wild Park Rainscape is an opportunity to show how we can adapt to the risks of climate change by managing our water in better ways, and in a way that benefits people and nature.
Why is the council spending money on this and not on other things?
The Aquifer Partnership bid for and won the funding from a designated Environment and Well-being Fund from National Highways, so the partnership can only spend it on this project. It’s an additional investment in the area that we wouldn’t otherwise have had.
Will the wetter areas attract mosquitos?
Mosquitoes are more likely to be attracted to features like open water butts, blocked roof drainage gullies or other small stagnant water-containing features occurring in or around the garden.
We are designing this area to promote a greater biodiversity and a balanced habitat. Mosquitos are a natural part of the ecosystem and many species such as bats, birds, other invertebrates and amphibians, plus dragon fly nymphs predate on them. Their larvae are often eaten by other living things within a balanced habitat, and this will be the objective of any permanent or temporary waterbody design.
Safety by design
In a park setting such as this, it is appropriate to design for the assumption that children will be supervised, and the risk of running onto the road is likely to present a greater risk here than the introduction of wetlands and predominantly dry meadow basins. We will be looking at a strategy of safe access and egress appropriate for adults and children above toddler age.
Best practice includes:
- Shallow side slopes to allow ease of, and controlled access and egress.
- A dry strip around the feature to allow surveillance and awareness, without being physically drawn into the wetland.
- A level damp area where the vegetation type changes to marginal planting. Anyone standing here will have both visual and tactile cues about the presence of water and can choose to egress via the gentle side slopes up to the dry area and beyond.
- A level wet area around the basin with further physical cues, including wet feet and thicker aquatic vegetation, to warn against travelling further into the wetland.
If these design measures are carried out, access into the wetland is more likely to be through determined effort. Designs such as fencing and barriers can create greater danger by preventing natural surveillance of the wetland, and preventing rescue access in case of a person becoming in distress. A far better approach where small children toddlers are supervised is to provide safe and controlled access and egress. This approach is supported by RoSPA and has been employed in a number of similar projects