With changes in planning rules and the prospects of climate change the management of drainage from sports pitches is becoming an issue for the sports pitch construction industry. In particular, the treatment of sports surfaces as impermeable areas and the tight discharge consents granted by local authorities in planning often require costly attenuation systems that can amount to a significant proportion of a project's budget.
Many in the land drainage and pitch construction industry, have for years insisted that the engineers have got it all wrong when it comes to calculating the volume of water discharged from a pitch drainage system whether it be natural or synthetic grass. Pitch builders or their clients are often required to undertake costly studies to demonstrate the discharge volumes and the SUDS scheme required to satisfy discharge consents.
The major problem currently, is that the available software used to compute these designs, whilst excellent for impermeable areas such as road & housing development schemes, fall short of the mark when dealing with grass areas due to the rationale method used.
Some years ago, in an attempt to find out how much water came out of the drain when rain fell on a grass pitch, Agripower invested Â£ 7000 in equipment to monitor some natural pitches built at Harrow School. Unfortunately, due to an unsuitable method of monitoring, this initial attempt failed. However, following the construction of pitches at Merchant Taylors' School, the scheme was shifted to this site and a new concept of monitoring employed which is beginning to produce some very interesting results that show the discharge volume is far less than the volume that falls on the pitches.
A chance reading of the STRI monthly newsletter last year, revealed an article on a project being run by Dr Paul Fleming, Dr Matthew Frost and PhD researcher Murray Simpson at Loughborough University which was looking at the same area in synthetic pitches and is being funded by support from Institute of Groundsmanship and Sport England with additional advisory roles played by the STRI and SAPCA. This led to a very fruitful meeting swapping knowledge, some additional synthetic monitoring sites for Loughborough and sharing of information.A new monitoring site is shortly to be set up covering two rugby pitches in Bicester which are nearing completion. It is hoped that within a couple of years, sufficient suitable data will be available to initiate a radical rethink for the design of pitch drainage attenuation schemes.