One of my geography teachers defined a river as a watercourse where the ground water is at the surface, this makes sense when considering seasonal dry valleys that one gets in chalkland. So I suppose one could argue that the only difference between a drainage tunnel and a a drainage canal is one is on the surface and the other not. Other than that they are the same thing and topography usually defines the difference.
From: Michael Haseler <[log in to unmask]>
To: John Wood <[log in to unmask]>
Sent: Thursday, 15 March 2012, 14:28
Subject: Re: [BRITARCH] Longest pre-industrial Drain
On 15/03/2012 11:24, John Wood wrote:
> Keith Hunt wrote:
> Does [or did] the Car Dyke really act as a drain?
> It seems to be slightly elevated.
>>> Indeed it is slightly elevated but that is not uncommon for such drainage dykes. The drainage of the surrounding land, as it dries out, sinks to a lower level of the drainage canal. The dark and peaty fenland area around the Wash has sunk quite alot. Water in the past was pumped using windmills from the lower drainage channels into the higher drainage canals as the land around the canals sunk.
thanks for that. My original question was about a drainage tunnel, which I was thinking had nothing to do with open drains on the fens. But in reality I presume it is all part of the agricultural improvements, and the drainage of peat & lochs in were part of the same movement that led to drainage of the fens.
For information, is there any point digging a drain ... I mean excavating a drain ... archaeologically investigating ... you know what I mean.
Particularly one on peat, where presumably the sediment is going to look like the surrounding soil.