Upgrade of existing car park to incorporate Sustainable Drainage principle at National Trust site, Hebden Bridge. Works completed Spring 2020
Design and implementation
Our old car park at Clough Hole was in need of an upgrade and was contributing to the very “flashy” response of one of the watercourses we look after. As part of a West Yorkshire Combined Authority funded Natural Flood Management project we upgraded the car park to incorporate Sustainable Drainage and Natural Flood Management principles whilst doubling the car park’s capacity.
The sustainable drainage system involves a permeable surface of gravel filled geogrid to new parking bays which allow the surface water to drain quickly from the surface and prevent surface water scouring. The water is collected in new perforated land drains across the centre and periphery of the site which discharges to a combination of stone filled
and PVC crate soakaways which have the capacity to hold a significant volume of water in peak rain periods and discharge this water gradually to the adjacent watercourse.
The outlet to the watercourse has a concrete headwall to prevent embankment scouring.
There is a native hedge through the centre of the car park to sub-divide the space and create a more attractive environment for visitors. This has the added benefit of allowing surface water run-off from the car park area to discharge into the topsoiled strip for the hedge and be collected by the perforated PVC land drain beneath.
Benefits and constraints
Meeting drainage requirements to satisfy local authority planning department meant that the detailed drainage design went through several iterations. We worked with an experienced Landscape Architect from start to finish which made the process much smoother.
Further opportunities
We’ve got two more car parks, one day it would be great to upgrade them to SuDS designs too!
Costs
£160,000 including track upgrades
Who?
Funded by West Yorkshire Combined Authority as part of a larger Natural Flood Management project. Project Managed by National Trust and Westwood Landscapes. Constructed by Midgley and Palmer Civil Engineering Ltd.
Contact email: rosie.holdsworth@nationaltrust.org.uk