INDEPENDENT SCHOOLS
SPORTS PITC PRO ECT GETS TOP MARKS The prestigious Concord College in Shrewsbury now has two new sports pitches and a series of amenity grassed areas on what used to be 32 acres of agricultural land
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By Colin Hoskins Features editor
The Hydraway
The feasibility study involved topographical surveying, digital 3D land remodelling, the production of a ground investigation report (via specialist geotechnical consultants) and a detailed project cost analysis. The development was part of an expansion plan that incorporated new teaching and residential blocks, plus car parking, which meant that new foul and storm sewers needed to cross the meadow. Consequently, Turfdry’s managing director Melvyn Taylor took on the prime role in a client-led multi-disciplinary team comprising architects, landscape architects, planning consultants, a sewerage consultant, a building contractor and quantity surveyors. Importantly, this close co-operation between all parties also embraced the Institute of Groundsmanship’s Turf Advisory Service, which was engaged to undertake independent monitoring of the project. The design proposal provided all the required sports pitches, designed to suitable gradients, in a visually attractive and user-friendly layout. The proposed landform also addressed peakstorm flooding of residential properties on Hall Meadow’s western boundary: an existing problem caused by surface water run-off from
“This close co-operation between all parties also embraced the IOG’s Turf Advisory Service” 28 THE GROUNDSMAN April 2019
the agricultural land. The design was purposely engineered so that no soil needed to be brought onto or removed from site, to minimise impact on the local community. Having been appointed to undertake project construction, Turfdry commenced in spring 2016, following archaeological investigations. The extensive earthworks using GPS-controlled machinery involved over 25,000m3 of topsoil strip, more than 25,000m3 of subsoil ‘cut and fill’, as well as the creation of a large-capacity attenuation lagoon to manage water outflow from the site in a controlled way. The lagoon has a capacity of 2,160m3 (an Olympic swimming pool holds 2,500m3).
TACKLING DRAINAGE
The pitches were to be sited on “slowly permeable, seasonally wet, slightly acid but base-rich loamy and clayey soils” – a soil type that once saturated can remain like that for prolonged periods – so land drainage systems of varying intensity for different parts of the site were installed, with Turfdry’s proprietary Hydraway system being used. This differs significantly from traditional piped drainage and features an innovative high-performance fin drain with an extremely permeable clog-resistant membrane installed in narrow trenches, with the top of the membrane typically 250mm below ground. The fin drain also benefits from having a greater surface area than conventional plastic pipes, so larger quantities of water can be dispersed much more quickly. While the general amenity areas (to the west and south of the site) had drainage installed at 5m centres, the ‘open age’ football pitch/athletics track area had drainage at 2m centres, and the under 14s/15s pitch had Hydraway at 3m centres (which is the most commonly adopted spacing). Drainage work was followed by stone burying, sand spreading and amelioration, cultivation, lagoon hydro-seeding, seed-bed preparation