Glorious mud

The Central Dredging Association is holding a seminar on December 10th, called Disposal Of Dredged Material On Land.

No, really, this is probably more interesting than it sounds, for waterways lovers at least.

The issue of dredging canals exercises our minds all the time, and not just canal boaters.  Anglers, too, worry about water depth and quality as well as the professional and volunteer canal restoration teams.  And so do the waterways engineers and hydrologists who must maintain not just the channels but the reservoirs too.  The deeper the channel, the less pressure on the water supply.

I thought about this particularly in the recent Caldon Canal breach, where the photos showed an empty canal that looked half the depth it would have been when it was build 230-odd years ago. 

But digging out the silt is only half the problem, and perhaps a quarter of the cost.  Getting rid of it is a bigger headache.  

There's not only the issue of creating unwanted mounds, but of considering pollution from centuries of industrial chemicals in the silt, and transporting it where it'll do the least damage.   Indeed, this can sometimes form half the cost of a new marina.

The most important parts for canaloholics will be probably be 'Classification of British Waterways’ dredged material' by Paul Beckwith of BW, and 'Disposal of dredged material from inland waterways on land' by  James Maclean of Land & Water Services.  The latter company seems to dominate dredging and excavation on Britain's canals.

For me, dredging is like proctology - it's a vital subject that I'm hugely glad someone else is specialising it.  And if it's not a problem pressing on your mind (and your backside) you might well fall asleep very quickly at this seminar.

However, with the right hands on keyboard and camera, the subject would make for an interesting article.  Perhaps a whole series of articles.  Even if you went into it in-depth, as it were.

Comments

[iain smith]

the mud defiantly seems as deep as the puddle lining going on the stratification and the bank just looks like piled up earth unlike the other side on the slight bend that appears to be reinforced. This seems a little strang as the bank that burst seems to be the more vulnerable part.

[iain smith]

The holiday association that our chalets are in has been protected and extended using unwanted materials mainly earth but also i believe building rubble and got payed for allowing it to be dumped.That was many years ago now and you would not guess from the berm now.

[Halfie]

Andrew, last month we passed a dredging operation on the Llangollen Canal just east of Ellesmere Tunnel. Here the dredgings appeared to be simply placed on polythene sheeting on the towpath. Original blog post and photos here:

http://jhalfie.blogspot.com/2009/11/dredging-pumpout-cassette-or-portaloo.html