Overview

SDS was appointed to design, supply and install a below-ground stormwater management system for Kestrel Park business park near Barnsley that would maintain current safe rates of surface stormwater dispersal.

Context

‘Kestrel Park’ is a new, high quality business park strategically located just off Junction 36 of the M1, approx. 5.7km south of Barnsley town centre. It is being developed in an area which sits inside the South Yorkshire Investment Zone and which has seen sustained development over the past decade. With a prominent roadside position fronting the Dearne Valley Parkway, this £12 million, 77,411 sq ft industrial development comprises seven warehouse, industrial and trade units with offices, built to a high specification and ranging in size from 3,010 to 21,535 sq ft. The units have been built to meet BREEAM ‘Very Good’ sustainability standards and incorporate multiple green features including solar panels, EV charging points, cycle parking, LED lighting and fully fitted offices/amenities, all within a secure landscaped site.

Objectives

To ensure the buildings and associated access, parking and service yard areas remain flood risk-free, despite the increase in impermeable areas, greater traffic volume and potential for heavier, climate change induced rainfall.

Requirements

To design and install a surface water management system which complies with the current versions of the ‘Design Manual for Road & Bridges’ (‘DMRB’), the ‘Specification for Highway Works’ (‘SHW’), and the Local Authority Design Guide & Specification.

SDS product features

An attenuation tank comprising a mix of 6m-long by 3.5, 2.8 and 1.2m-diameter Weholite HDPE pipes, bonded together by 21 joints, has been installed, extending to a total length in excess of 100m. The tank also features four Weholite manholes and an oversize Weholite chamber incorporating a Vortex flow control and HDPE penstock.

This sustainable drainage system has been adopted by the incumbent Water Company, Yorkshire Water.

Challenges overcome

Two statutorily designated nature conservation sites, along with five non-statutorily designated sites, lie within 2km of the new business park’s boundary; furthermore, the development falls within the Impact Risk Zone for Dearne Valley Wetlands Site of Special Scientific Interest (SSSI). In order to mitigate the risk of these sites’ contamination by pollutants contained within surface water runoff, a number of oil and grit separators have been installed upstream of the attenuation tank whilst a flow control device ensures that the rate of discharge from the tank does not exceed the pre-existing peak run-off rate.

In order to guard against the risk of leptospirosis, also known as Weil’s disease, the installation crew was required to wear protective clothing. Though rare in the UK, this infection is spread through contact with soil and freshwater such as from a river, canal or lake, that contains the urine of infected animals, most commonly rats, mice, cows, pigs and dogs.

Result

The SDS Weholite® attenuation system now provides reliable, policy-compliant surface water management for the Kestrel Park business park. Surface water from the 1.77 hectare site is discharged at a controlled rate of up to 15 litres per second, maintaining pre-development runoff levels. The system effectively attenuates 100-year +40% climate change rainfall events using a combination of underground storage and surface management, while the removal of overland flows significantly reduces flood risk to buildings, roads and parking areas. In addition, the system safeguards nearby ecological sites, including the Dearne Valley Wetlands SSSI, from pollution and contamination.

The successful installation demonstrates SDS’s ability to deliver high-performance, sustainable drainage solutions for complex commercial developments, combining resilience, environmental protection, and operational reliability in a single integrated system.

Comments

"The attenuation scheme has addressed Natural England’s prior concerns that, without appropriate mitigation, the development would damage or potentially even destroy, through water and air pollution, key features for which Dearne Valley Wetlands has been designated a Site of Special Scientific Interest."
– Jason Cartwright, Key Account Manager, SDS

"As always for our sustainable development projects, at Kestrel Park we’ve focused on strong environmental, social and governance credentials."
– Martyn Carnell, Managing Director, Carnell Management Services