Spectacular effects at the stunning 2017 Serpentine Pavilion in London’s Kensington Gardens have a below ground water management solution right at its heart, provided by sustainable drainage market-leader SDS.

Spectacular effects at the stunning 2017 Serpentine Pavilion in London’s Kensington Gardens have a below ground water management solution right at its heart, provided by sustainable drainage market-leader SDS.

A dramatic rainwater cascade from the Pavilion’s arching tree-like roof canopy is a central feature of this year’s design by the award-winning Burkina Faso architect Diébédo Francis Kéré, which opened to the public on 23 June.

During peak summer storms, rainwater is designed to run off the Pavilion’s expansive roof into an open central courtyard, so an underground attenuation solution using GEOlight® geocellular storage from SDS was designed by the engineering project team from AECOM.

AECOM has provided technical advisory services for the Serpentine Pavilion project for the past five years. Principal Engineer, Michael Orr explains:

“This is the first time in recent years that a positive drainage design has been required for the Pavilion, as this time rainwater is part of the architectural concept and is featured by being directed into the centre of the structure.”

The roof canopy is supported by a central steel framework and covered with a transparent twin-wall polycarbonate skin. With the roof pitch varying between 5° and 9°, the rainwater is conveyed quickly through a funnel before dropping into the centre of the courtyard.

Underground storage

The water cascades down from the roof onto a publicly-accessible, elliptical-shaped 21m2 area of 130mm-deep cream-coloured granular stone, before being conveyed to the GEOlight® storage tank beneath. 

The underground storage is designed to hold back up to 6,000 litres of water, sufficient to protect against a 1 in 100 year rainfall event. Water is then gravity-fed slowly away via two surface water pipes to an existing soakaway.

In view of the clay ground conditions, it was necessary to design a central attenuation tank to capture rainwater and take it away from the foundations, allowing it to infiltrate slowly into the park’s existing soakaway system.

SDS Sales and Marketing Director Richard Averley commented:

 “As is so often the case, it’s the engineering behind the scenes which has enabled a sustainable drainage concept to be realised.”