Sedimentation of the River Exe?

All over the UK geographers study the effect of erosion and depositon by the sea on the landscape of the nation. We've all heard about the Holbeck Hall Hotel landslide, where the collapse of the cliff it stood on at Holderness caused the five star hotel to fall into the North Sea, as an example of the sea's erosional power, and of how depostition of sediment carried by long shore drift has caused spits to form and created the need for groynes and beach nourishment schemes in places like Barton on Sea and Bournemouth. However, a lesseer known and more recent worry to some South West geographers has been that of the effect of continued long shore drift at Dawlish Warren.

Already at Dawlish Warren there is a spit formed from long shore drift carrying sediment out across the Exe estuary, and this spit has extended out across the estuary over time, forming salt marshes and mud flat areas in behind it from where the river has been forced to deposit lots of its sediment load due to its new obstacle of the spit narrowing the mouth of the river. The current fear is that the growth of the spit is at such a rate that soon its growth, along with the resulting depostion behind it of sediment that the Exe carries, will soon cause depositon in such a volume that the Exe will get blocked eventually by a huge bar of sediment strecthing from Dawlish Warren to Exemouth, causing massive flooding and an overall heightening of the river's level.

This would cause flooding of settlements like Exminster and Topsham, along with a growth in the size of the mud flats, and a destruction by the flooding of the Exminster Marshes which are protected due to their biodiversity and scientific interest.