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Drainage problem with old pond
Hello. We've recently moved house and I'm currently in the process of dismantling a raised pond that the previous occupants had. We want the extra space and have a little one.
I've drained it and removed the liners but there is still approximately one foot of muddy, murky brown water and sludge in the bottom that is refusing point blank to drain away.
I'm a total novice at all things garden but it appears the soil underneath is compacted clay. I've tried piercing the clay as much as possible in an effort to get the water to drain but without success.
The pump won't remove the last bit of water and without resorting to a bucket, does anyone have any suggestions on assisting the water to drain.
Thanks.
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If its not been very dry, I doubt it will drain away as probably as soon as you empty it, more water will seep in from surrounding area. You might have a high water table, which is not unusual in areas which have poor drainage which occurs on heavy soils like clay. You could also have a soil pan where the ground has been compacted over many years and the only way to cure that is to try and break it up. Pickaxes and lots of sweat and toil comes to mind. The fact that the pond was already raised says something. It may be that the previous owners tried to put in a pond in before at ground level only to come a cropper when they dug down deep so to get around it, put in a raised pond.
Hi Tim, thanks for replying.
I'm tempted to just go about filling the hole in anyway. It's only about one foot max of muddy water. I have plenty of stone and rocks for the hardcore then a decent top soil up to ground level. Do you think that would be an issue if I just filled it in with the water still there?
Andrew ,we filled in a pond recently (not a raised one) which had the same issue - couldn't pump the yuk out of the bottom. Not sure how big yours is, our was a pretty big and deep one. We just filled with gravel, hard core and then soil over the top, thinking we might have a drainage issue but couldn't really get around it without heavy machinery! We haven't been through a winter yet as we've only done it this spring, but so far so good - not noticeably soggier in that part.
Hi Geum. Thanks for the reply.
My main concern is that I am planning on putting either a slightly sunken (or might now have to be slightly raised!) area that I am going to line with a membrane, edge with some wood and fill with rubber bark to be a play area for the little one.
The last thing after I do all that is to find the area turns into a swimming pool come winter haha!
I might have to drain the last bit with bucket and then turn all the soil as best I can. Hoping it is just a top layer of clay and underneath is another type that may drain better.
Hi, I don't think there will be any issue with filling the bottom of the hole with hardcore, and it will make the ground above more free draining. The only issue could be that in very wet weather, you might find water seeping in from surrounding area where the draining isn't so good, so you will have a patch which always fills with water when it rains heavily and for a sustained period of time, like winter period. You could end up with a bit of a bog garden!! To be honest, there may be no way of knowing until you fill the hole in and see what happens. You should also be aware that after a period of time, the ground may sink as the soil and hardcore settle, so unless you want a dip in the garden (which again, may cause a puddle as it becomes a sump), be prepared to throw in some more top soil to bring it up to the same level as the rest of the garden.
I'm thinking if you plan to line it with a membrane and fill with rubber bark that it will simply fill up with water and because it will be lower then the surrounding area, it will become a huge puddle as the water collected in the membrane won't have anywhere to run to. I think you would be better raising it slightly above the level of the surrounding ground (even 6/12 inches will be enough) so you can allow water to drain out.