land drains

[Paul Mellor]

We were out surveying some fishing lakes and came across some springs that we think feed the bottom lakes however one theory is that there are also land drains in an adjacent field. The only problem is that the adjacent land is quite steep ( it is ploughed and sown ) and I was wondering is there a rule of thumb as to how steep land has to be before its not worth land draining and secondly if it is drained how far apart do you put land drains,thanks

[stephen]

hi paul,
you dont mention what the history of the fishing lake is, is it old quarry workings, a purpose built or perhaps just a natural 'pit hole' ?
in my experience the fall of the ground has no bearing on installing drainage, as a rule of thumb modern drains in a new system are about 20mts apart. however to drain isolated wet areas a localised herringbone system would be used, with any old spacings!

stephen

[Paul Mellor]

The lakes have been dug out in a flattish area of a valley and coincidentially there are a number of adjacent springs feeding into the bottom lake which is very healthy,however the top lake is very murky and does not support any life at present this is soley fed from the existing stream. This stream feeds from an industrial estate some distance away and we think it is polluting the top lake. There are also orbs seen at night shooting along the lakes and a very strong energy field on the middle embankment of the dividing embankment wall between the two lakes.In the area that we think there are land drains we get a positive result with the rods ever 5 paces which seem very close for drainage but also to regular for a natural feature.All very interesting .

[simonwheeler]

I recently had cause to dowse (with rods) for field drains, soakaway pipes and natural water courses within a field. It wasn't always that easy to differentiate- and as some of the field drains were proven to be broken this only added to the confusion. I marked out everything I could - the lines of whatever I was detecting- with coloured cones and was able to make "educated guesses" about what ran where and then redowsed. I also asked using the pendulum. And, of course, used the Cameron Aurameter! The farmer then trenched in what he thought were key places. He obviously felt I was close enough after digging up bits of drain because he then asked me to dowse elsewhere in his field. I believe I was about 85-90% correct; the farmer was less generous, saying about 50-60%. I was closer with the locations than I was with the depths- which may be why he was not that impressed.
There was no obvious regular pattern to any of the drains and pipes I found- indeed, some took routes that seemed odd; some drains crossed over others; some pipes were empty. These things can be haphazard (emphasis on "hazard" perhaps!).
The field concerned is rolling and quite steep in places. It has two septic tanks in it and a soakaway pipe running across; there are old sewer pipes there too.

[stephen]

hi paul, it could well be that the stream feeding the lake is impure, a call to your council environmental officer should answer that one, unless its a more recent problem. the 5 pace land drains if they are still operating should be visible, or if broken when the lake was excavated theres often a dribble or more showing on the bank?

i was once called in to put right a leaking fishing lake, a dowse around the perimeter revealed 2 incoming land drains well under the water level, and the same 2 exiting at the other end of the lake in a pool dividing embankment. dowsing there showed a flow of water out of the lake, a poor effort by the previous contractor. the problem was soon rectified by digging down and sealing the old land drains.

simons post paints an all too familiar picture of trying to piece together generations of different drainage scheme's ((the old ones are works of art) along with obscure runs towards an ancient field ditch, long ago filled in and the hedges ripped out but there are still the odd clues to help you, so yes it is entirely possible to have close spacings between dowsed drains.

stephen

[griff]

The principle that subterranean waters follow precisely the same laws as those upon the surface generally holds good. Base flows, however , can be modified by geological, topographical and edaphic conditions in the area under survey. If, in a valley formed in a diluvial or alluvial deposit overlying a more retentive stratum, the two sides are the same height, the subterranean stream would be found in the middle of the alluvial area and pond base springs would be tapped by excavating a lake in such a site; and if one side be steeper than the other. base flows would be found nearer the steeper side; in both cases supposing that the upper stratum is equally permeable throughout, and that the depression of the lower stratum forms a more or less regular basin. Other factors can affect the yield of springs. These include the proximity of intersecting secondary valleys and the angle at which they meet or transverse the main valley.

Regards Griff.