Management of the Aire and Calder Washlands - performance evaluation and optimisation by numerical modelling

Abstract

On the upper reaches of the River Aire the natural floodplain has been embanked by successive generations of landowners. This has resulted in a complex system of washlands. New development within the floodplain has recently required the construction of formal controlled washlands to retain the balance of the existing flooding regime. Along the lower reaches of the Aire and of the Calder a number of controlled washlands have been constructed and formalised over the last 30 years by River Authorities. Considerable changes in operation and washland storage volumes has taken place over this period due to mining subsidence, opencast working and gravel extraction. The restoration of opencast sites has also created the opportunity for the provision of additional washland capacity in conjunction with improved recreational and environmental amenity. This paper reviews past and present practice in the management of these washlands and application of the numerical model to assist with the evaluation of performance. -from Authors