New wildlife pond + stream pump and filter advice please

[stevekind]

Hi We have dug out our old wildlife pond that we created over 30 years ago, making a lot of novice errors at the time. I'm hoping to replace it with a much larger pond for which the hole is almost dug (just needs another foot or so in part of the deepest level to give a total depth of 2'6" to 3' ) The area is approx 5m x 2.5m (sorry for mixed units) which, if it were a rectangular tank 1 meter deep would hold around 12, 500 litres. - of course it will be less because of the shelved sides, but I have no idea how to work out the actual capacity, We already have a more than adequate sized liner.

This time, I want to incorporate a short stream and water fall - no more than 6 feet long and a foot wide and would like to ask advice on a suitable size of pump The lift from the surface of the pond to the head of the stream should be no more that a couple of feet maximum, and I would want a low to medium flow of water - certainly not foaming rapids .

My other question is, since this is a wildlife / ornamental pond and will definitely NOT have fish, do I need any sort of filter, and do I need a header tank - or could I just pump water up from the pond to discharge directly into the head of the stream. The photos above are of the old pond after we had stripped most of the vegetation away, and the hole so far. The shallowest level will be rounded off to give a pleasing shape when the pond is finished. Hopefully my help will be coming back to finish the job first week in January, so I would like to have all needed equipment sorted by then .

Thanks in advance for any advice people can give.

 

[addy1]

I would do a bog type filter, it will give the wildlife a shallow water full of plants area to live, also help keep the pond water in better shape.

 

[stevekind]

OK - I like the idea of a bog filter - but the instructions I found online suggested the pump should deliver water direct to the bottom of the filter. I want a stream, so I'm wondering if this would work. (see very rough diagram attached. The idea is that the pump would deliver pond water direct to the head of the stream, which would then discharge into a sump - between the sump and the pond proper would be a bog filter fed from the bottom via a perforated manifold fed from the bottom og the sump. The bog filter would overflow into the pond. Does that make sense?

 

[Tara]

I can't offer any advice on building a bog, but I think it would be a wonderful addition to a wildlife pond. I hope when it it done that you share some pictures of the wildlife that visit. Good luck with the build.

 

[addy1]

That would work, the main issue is the wall between the sump and the bog needs to be high enough that the water won't just flow over the wall but will be forced to work up through the bog filter. Water loves to take the easiest path.

 

[stevekind]

That would work, the main issue is the wall between the sump and the bog needs to be high enough that the water won't just flow over the wall but will be forced to work up through the bog filter. Water loves to take the easiest path.

Yes - the flow from the sump to the bog filter as I've drawn ir her would be at the bottom - and I've just realised the flaw - I don't see how I can achieve that without making holes in the liner. Of course I could glue pipe connectors on to the liner - but everything I'm reading is saying that is really problematic for the integrity of the liner.

 

[addy1]

Build the wall on the liner. You could have a pass through bog wall with some openings at the bottom of the wall also

 

[stevekind]

Build the wall on the liner. You could have a pass through bog wall with some openings at the bottom of the wall also

That sounds interesting what materials would you suggest? Could you point me at anywhere that tells how to make a pass through wall?

 

[addy1]

Here is a thread about bog building

https://www.gardenpondforum.com/threads/bog-building.6894/

A porous barrier wall is rocks stacked, so water flows through but the pea gravel is kept in the bog. You don't want to use fabric landscape material as a barrier ow it will get clogged up fast with dirt debris etc.

 

[stevekind]

Here is a thread about bog building

https://www.gardenpondforum.com/threads/bog-building.6894/

A porous barrier wall is rocks stacked, so water flows through but the pea gravel is kept in the bog. You don't want to use fabric landscape material as a barrier ow it will get clogged up fast with dirt debris etc.

Thanks for the link Addy - really useful article - a plan is coming together in my head ! Will ask further questions on your excellent thread when I have a minute

 

[addy1]

Ask away

 

[stevekind]

Hi Addy - I *think* I've cracked it. The complication arose because , as I said in my earlier post, I wanted a stream/waterfall as well as the bog filter. I know the simplest solution would have been to have the stream running from the bog overspill to the pond - unfortunately, the shape and position of the pond makes that impractical without a major re-design of that part of the garden. So, if the stream is to feed the bog i would need some sort of sump BEFORE the bog to feed the manifold under the gravel.

My latest idea is to make the bog in the shallow part of the pond using a single, continuous liner for pond and bog and building the porous, wall as you advised, laid on top of the liner. If I then put a small pre-formed pond (about 55 gallons capacity?) into the corner of the bog, with the lip *slightly* higher than the gravel, and set the stream to discharge into that. That small pond would be linked to the distribution manifold via a bottom drain . Gravity should then push the water through the manifold.

The only issue then would be flow rates - the small pond would need to be draining at approximately the same rate as it is being fed by the stream. It occurs to me though that it wouldn't matter too much if the small pool overflowed into the gravel slightly. The alternative would be to make a non-porous wall with a spillway - that should make the flow rates less critical. In that case, I could even raise the bog vet slightly in order to form a small waterfall into the main pond - though I wouldn't want to disturb the water in the main pond too much.

Hope you follow all that. What do you think?

 

[addy1]

Just saw this, typed up a answer in the bog thread.

https://www.gardenpondforum.com/threads/bog-building.6894/page-40