Critical Days Ahead for Plans to Dredge the Bude Canal

Cornwall Council has been developing a dredging programme for the canal in response to community and stakeholder demand for some time, and coming days will see a turning point for the proposals if the scheme is successful in its funding bid to the South West Regional Flood and Coastal Committee: South West Regional Flood and Coastal Committee (RFCC) - GOV.UK (www.gov.uk)

The canal receives high levels of silt input, particularly during times of flood, when the canal is opened to act a pressure value reliving the Lower Neet of flood waters. The catchments of the Start and Neet, which terminate in the canal, are flashy, changing rapidly at times of high rainfall, during which overland flow and energetic rivers have the power to erode exposed surface soil and river banks, bringing particles along in suspension until energy disperses across the wider reach of the canal and therefore settle out of the water column, building up on the bed of the canal.

Due to constraints around protected sites, invasive non-native zebra mussels and lack of available space canal-side, the de-silting operation is complex and brings with it a significant price-tag, but with the benefit of being highly effective and environmentally friendly. In the lower reaches the proposal is to deploy a Cornish developed and patented cutter-head technology, which encapsulates sediment in housed apparatus within which the invasive zebra mussel can die-off before onward transport to a suitable receptor site. This technology, delivered by a Cornish firm, has had no evidence of dredging operations recorded just 3 meters from the dredging point in lab and real-world trials.

The planned dredging programme aims to reinstate the desired depths for a navigable channel throughout the lower reaches, from the harbour to Rodd's lock. prior works will also excavate silt at Whalesborough so that the source of silt supply is reduced. Doing this will safeguard the canal for current users and future generations, a ambition that is in the spotlight following the temporary closure of the canal this year.

The dredging proposal also has relevance to climate change impacts, with an increase in periods of drought increasingly likely in the future. A silted-up canal will carry a shallower depth of water and therefore dry more rapidly posing an increased a risk of aquatic habitat loss as a result. With a full-scale fish rescue being only narrowly avoided this year, we can see this as evidence that steps, including dredging, should be taken now to avoid similar, or worse, events.

If you would like to find out more about our dredging proposals, please see the presentations in our documents bar.