Abstract
This paper presents an analysis of the difference to residual sediment transport pathways and bed level changes forced by the installation of four tidal stream turbine arrays in the Pentland Firth. Two areas are considered in detail: the Sandy Riddle, a large banner bank and a sandbank in the Inner Sound close to the Meygen development. No noticeable differences are found for the Sandy Riddle at the modelled level of extraction, residual pathways are the same and the difference in bed level change between the two scenarios is at most 3% of the total modelled change. Greater differences are noted for the Inner Sound case, but uncertainties in sediment coverage and mesh effects in this area mean confidence is lower in these results.