Whirlow playing fields show benefits of natural flood management in latest Limb Brook project

Work implementing a series of natural flood management measures in the Limb Brook Catchment to help protect Sheffield and the region against future flooding continues on new sites, this time regenerating a popular urban site at Whirlow Playing Fields to provide flood water storage and improve the area for wildlife.

The Limb Brook Nature Based solutions (NBs) Demonstrator project is a partnership between the Environment Agency, Sheffield City Council and Sheffield & Rotherham Wildlife Trust.

As part of the Upper Don Source to Sea programme, the works use a number of natural flood management methods used to help store and slow water flows, to reduce the risk of flooding at at-risk locations downstream in the Don, as well as supporting wildlife.

Features like the sports pitches on Whirlow Fields, are usually artificially drained with the rapid run-off of water passed to nearby watercourses (here, the Limb Brook, a tributary of the Sheaf, in turn a tributary of the River Don). In periods of high rainfall, this can add to existing high flows which can cause flooding downstream.

Nowadays proposals for new pitches are required to slow the flow – this project has sought to do this retrospectively by breaking into drainage systems and bringing the flow to the surface as streams – in effect, discovering new watercourses – and directing it into a series of six attenuation ponds (which hold and slowly release excess water) and swales (shallow, grassy channels which slow and direct the flow of water, essentially little streams).

This more natural drainage causes slower movement of rainwater once it hits the ground, as it moves through long vegetation and snakes around bends. In addition, the ponds act to temporarily hold off water during storm events. Bringing water to the surface and out of its pipes can create a new dynamic and biodiverse landscape. These features along with wildflower, meadow and hedge planting will also support a range of wildlife including birds, insects and amphibians, as well as creating resilience to the climate and ecological emergencies.

A local solution

Dr Kevin Spence from Sheffield Hallam University undertook engineering design of the flood storage reservoirs and attenuation ponds for various s