Hydrology and Earth System Sciences www.hydrol-earth-syst-sci.net 1027-5606 1607-7938 7 1 2003 10.5194/hess-7-75-2003 http://www.hydrol-earth-syst-sci.net/7/75/2003/ http://www.hydrol-earth-syst-sci.net/7/75/2003/hess-7-75-2003.html http://www.hydrol-earth-syst-sci.net/7/75/2003/hess-7-75-2003.pdf 75 85 0000-00-00 Hydrological impacts of floodplain restoration: a case study of the River Cherwell, UK M. C. Acreman R. Riddington D. J. Booker Centre for Ecology and Hydrology, Wallingford, OX10 8BB, UK Peter Brett Associates,Westcote Road, Reading, RG30 2DE, UK Email for corresponding author: man@ceh.ac.uk This paper investigates the impacts on floods of hypothetical changes to river channel geometry by construction or removal of embankments to prevent water spreading onto the floodplain at high flows. A numerical model is applied to the River Cherwell between Oxford and Banbury to simulate changes to flood hydrographs. Embanking the river increases the peak flows downstream by 50-150%. Restoring the river channel through the floodplain to pre-engineered dimensions reduces peak flow by around 10-15% and increases peak water levels within the floodplain by 0.5-1.6 m. These results suggest that floodplain rehabilitation, in terms of embankment removal or returning the channel to pre-engineered dimensions, can be a valuable part of the flood management strategy of a catchment. Both measures lead to increased inundation of the floodplain, which can be positive for ecological restoration.</p> <p style="line-height: 20px;"><b>Keywords: </b>floodplains, hydrological impacts, rehabilitation, flood frequency