Landscape design is an important integrated process for residential schemes, particularly where a site has complex geological and hydrological issues.
Many brownfield schemes which have contaminated soil require a sensitive scheme of planting which can tolerate poor soil conditions and in instances harsh climatic environments such as extreme rainfall (or lack of) and steep gradients which increases run-off and reduces available nutrients to the root structure within the soil below. Often within residential schemes trees can be seen suffering from poor planting conditions and lack of maintenance, combined with poor species selection these trees will continue to struggle and can eventually fail.
If brownfield sites were left to establish naturally, colonisation would take place, this process of succession would happen slowly over time and planting would need to overcome the often extreme pH values, ranging from 2.5-4.0 for some former colliery spoils, to much higher pH values in brownfield sites. Many of these sites consist of brick rubble, crushed concrete and stone with generally infertile, contaminated soils, as mentioned these brownfield sites would be colonised in a successional nature with immediate weed species such as rosebay, willow herb and coltsfoot with common grasses dependent on the area the site is located. If colonized by Clover this would raise the nitrogen and therefore fertility, eventually resulting in a coarse grass cover. Following this, scrub would establish usually by native willow species which can root into the consolidated soil. Other good pioneer plants include birch, hawthorn and alder.
Landscape proposals have dual purpose, appeasing planning concerns and comments whilst ultimately providing a pleasant environment for residents. Often larger infrastructure schemes such as Littlecombe include existing water courses and large open spaces which often need to contain play elements for several age groups. By retaining and enhancing these natural features the site can become more accessible and create open spaces of varied character and interest. The planting design needs to provide year round interest, where possible this planting will consist of indigenous species, these species increase wildlife habitats and if planted correctly will establish with less failures. The planting also needs to provide a contemporary aesthetic to match the modern architectural design and façade style to each individual plot.
Ultimately the external landscape design needs to be multi-faceted and draw on the rich heritage, varied geographical features and the vibrant social context within the context of each site. The landscape design emphasises these elements through carefully designed and specified materials, including hard surfacing and street furniture to create a contextually appropriate scheme. Once the planting design has been developed a detailed maintenance strategy for the site will be outlined within the Landscape Management Plan. This provides a cohesive and sustainable approach to managing all aspects of landscape, for example reducing the use of chemicals due to the proximity of the watercourse, with permeable paving used at the ground levels to provide sustainable drainage across the site and reduce run-off into the surrounding water course and therefore reduce the risk of flash-floods.
Overall, the landscape design proposals will be developed focusing on the historical and contextual influences within and surrounding the site, whilst applying contemporary elements to create an interesting, experiential landscape. This can be demonstrated through the general design layout, the materials and planting, providing historical references, social spaces, dynamic planting, and a varied and interesting aesthetic.
Liz Lake Associates have worked on many brownfield sites such as the former MG Rover site at Longbridge in Birmingham, read about our involvement in the project here