Water, water everywhere
SWIG event and competition showcase sustainable water management
The Sustainable Water Industry Group (SWIG) recently held an event which highlighted ways that landscape design can impact water management. The working lunch attracted an audience of about 100 to The Roof Gardens, an impressive 1930s roof garden (open to the public and well worth a look) located above the former Derry and Tom’s department store in Kensington.
Chair Neal Landsberg of SWIG & Watermatic Ltd introduced two speakers:
Peter Wilder, whose landscape and environmental design practice specialises in surface water management, explained that water encapsulates a large amount of energy. Water should therefore be seen as an asset and future water systems are likely to be low maintenance light infrastructure. Wilder discussed a plethora of large-scale, high budget projects, including Dalton Park in Newcastle. A contaminated colliery tip site was transformed into a green oasis in just six months using a seven stage ‘bio-filtration network’ that incorporates ephemeral stream beds, attenuation ponds and filter strips.
At Innovation Park Scotland, the siting of the buildings was determined by the landscaping rather than it being dealt with as ‘left over space’. Had it not been informed by landscaping, the housing development would have failed to achieve Code Level 6 for Sustainable Homes.
Wilder says SuDs need to be integrated into urban environments to create adaptable spaces, though concerns over ownership and maintenance responsibility need to be addressed. The concept of waste is redundant; everything is re-usable and creates opportunity, as demonstrated at King Edward Memorial Hospital in Bermuda. The hospital treats its own sewage and is efficient in energy and water use with re-use of hot water, collection of grey-water and green roofs.
Wilder says increasing awareness of water management issues and sustainable landscaping via policy and statutory legislation is encouraging. BRE Watford achieves 61% site water attenuation by using many prototyping systems ranging from vortex flow controls to geothermal paving. BRE are promoting an international network of sustainable communities through knowledge sharing; the campus design is intended to generate awareness of the positive impacts of sustainable water management.
Public opposition to planned changes to Hampstead Heath Ponds highlights the negative perceptions which often accompany an approach which seeks to ‘control natural resources’. Wilder says many people are not familiar with sustainable water management, and it is often difficult to convince developers and clients of the benefits.
All projects showcased a ‘celebration of water’ in cities, allowing infrastructure to become landscaping and simultaneously create more attractive adaptable spaces.
Landscape and garden designer John Wyer approached the issue from a different angle, focusing on retrofitting existing developments and affordable community projects with examples of how green roofs and walls help mitigate water run-off. Other positive impacts include:
- Mitigating urban heat island effect
- Pollution reduction
- Increased biodiversity
- Thermal and sound insulation
- Sequestered carbon in soils.
Wyer presented a 12,000m2 intensive green roof garden in St Johnswood, explaining that the project required careful detailing in order to achieve soil depths greater than one meter to avoid anaerobic decomposition and aid natural bio-filtration of water. Recycled crushed type 3 material was used rather than expanded polystyrene [EPS] which is lighter than conventional top soil and important for the success of such a large roof garden.
A 180m2 green wall installed at Edgware Road tube station primarily tackles air pollution by trapping harmful particles PM10 but also brings biodiversity to the site. The choice of planting includes pollution-absorbing species which tend to be hairy varieties. Wyder noted that many high end residential projects choose to squeeze in living walls but light levels must be carefully considered when siting green walls.
Food production and biodiversity are increasingly on people’s agendas. Wyder noted a trend towards living wall food production, explaining that various crops can be replaced quickly. The Triangle Community Garden provides sustainable landscaping in a public park based upon permaculture principles and features a sensory garden, orchard and insect attracting wildlife area. The focus is on empowering communities by finding affordable solutions which bring the additional challenges of co-ordinating volunteers but also reap strong social rewards.
According to Wyer, rain gardens are becoming increasingly popular in commercial buildings as they are relatively low cost when drainage is too expensive to fix. A rain garden can double as a solution to drainage issues and create breakout areas for staff, echoing Wilder’s examples of infrastructure becoming the adaptable recreation space.
Wilder says planning restrictions and weak policy in promoting SuDs are to blame for lack of awareness. The UK is risk adverse, and everyone must be consulted before any developments can take place resulting in too many restrictions. Noting the leadership of Marks & Spencer, Wyer suggested that implementing sustainable infrastructure in supermarkets would promote awareness of these issues.
SWIG has launched a competition to showcase sustainable water management. Deadline for entries is 30 September 2013, more details on how to enter can be found here.
Subscribe to AJ for £3 per week
Subscribe today and receive 47 issues of the magazine, 12 issues of AJ Specification and full access to TheAJ.co.uk and the AJ Buildings Library
Are you a student?
Students can subscribe to the AJ for £8 per month or £1.60 per week! Click here to start receiving the most recommended magazine for architecture students