Holland Park
This Sustainable Drainage System within one of the major London Parks will solve existing erosion and flooding issues whilst enhancing the natural character of the Park. We will be introducing a series of dynamic and biodiverse features such as micropools, swales, basins and wetland areas to delight visitors – especially when it rains.
Design Objectives
Robert Bray Associates and the London Wildlife Trust have been commissioned to design an extensive SuDS scheme to solve current drainage and erosion problems affecting several footpaths. Many people are attracted to Holland Park to experience the tranquility and abundance of wildlife already present within the park. The SuDS design therefore had to consist of subtle and predominately soft SuDS interventions which blend in with the natural setting of the park and provide a mosaic of new habitat types.
Place Making
Working closely with the London Wildlife Trust and the Parks department, the SuD scheme was carefully designed to complement the historic park setting whilst also providing a more varied and biodiverse landscape. The majority of interventions will be soft landscaped features and where hard-edged features are needed natural materials have been selected. Channels, lined micropools and basins have been placed close to the main footpaths for visitors to enjoy the journey of water and supported wildlife. The gradients of the site provide many opportunities for raised berms and low walls to hold some permanent water, playful cascades and steps within features and varying water depths to create a biodiverse SuDS landscape. Several contemplative and tranquil spaces have been designed to allow park visitors to sit close to the water’s edge and enjoy open views into newly created woodland glades and pools within inaccessible parts of the woodland to further support a unique park experience. A new low wall along the bottom of the D Garden forms the edge of a larger SuDS basin to protect the surrounding neighbourhood from flooding and will create an inviting entrance into this popular London Park.
How it works
The site was split into several catchment areas:
Footpaths
The two main sloping paths and linking paths will be resurfaced with bespoke resin-bonded gravel to provide a more robust surface. Granite sett cross channels at regular intervals will direct surface runoff into micropools, which overflow via swales into shallow basins which are designed to store 1 in 2 year flows. The basins overflow into wet woodland areas, which can store up to the 1 in 10 year return event, where water either infiltrates into the ground or slowly passes through the woodland into the existing ditch or the basin within the D-Garden.
D-Garden:
The basin within the D Garden is designed to store 1 in 10 year flows from the western main footpath and one linking footpath.
Car Park:
Granite sett channels direct flows from hard surfaces into retrofitted basins within exiting planters and the adjacent green space designed to store the 1 in 2 year event, which overflow back onto the road.
Key Data
Location : West London, borough of Kensington and Chelsea
Return Period Attenuated : 1 in 10 + 30%
Techniques used : Channels, swales, micropools, basins, wet woodland areas
Discharge Destination : Sewer
Discharge Flow Rate : Greenfield Runoff Rate
Client : Royal Borough of Kensington and Chelsea
