On Thu, 25 Sep 2014 16:50:57 +0100 (BST), "Dave Liquorice"
wrote:

On Thu, 25 Sep 2014 16:20:48 +0100, Tim w wrote:

A tidal lagoon in the Bristol Channel would fill with mud in a year.

Properly designed you use the outgoing tide to flush it clear every
so often. Just like they used to flush Bristols Floating Harbour
partly by tide and partly by letting more of the Rivers Frome and
Avon flow that way instead of along the New Cut.

As a complete aside we took the monthly boat trip operated by Bristol
ferry boats up and back the New Cut last month, interesting trip for
people who like going along unusual waterways.
Exeter Canal next month.

G.Harman