SRA End of Year Report 2015-16: Monitoring silt build-up (yearly survey)

Background: Somerset Rivers Authority has been working to identify places where silt builds up – how silt builds up – and what type of silt it is – so that maintenance work can be better targeted and dredging activities optimised. Collecting data that better illustrates the relationship between fluvial and tidal deposition also helps the SRA and its partners to better understand the impact of other potential flood risk solutions (for example, in the upper catchment).

Problem: Lack of accurate up-to-date information about fluvial and tidal deposition of silt to guide effective dredging and river management.

Achieved: Six-monthly surveys have been carried out on 160 cross-sections of the Rivers Parrett and Tone. These show where silt is accumulating – and how much – or where it is being removed by dredging or erosion. Findings were used to target most effectively the recent maintenance dredging of the Parrett and they will be used again to further enhance more maintenance dredging this year. Regular monitoring should be continued, so that it can help to develop and improve the SRA’s – and its partners’ – understanding of natural processes.