Building a Small Stream leading into the Pond

One of things that really makes a difference to our pond is the waterfall, little stream and bog area which also acts as a natural veggy filter to help keep the pond water clean.

When we built the stream we wanted something of our own, not a prefabricated fiber-glass or plastic unit. We used PVC pond liner for ours, although some people fashion a waterfall out of pre-made fibre-glass units or concrete.

We wanted it to flow out of the urn, down 3 or 4 steps turning as it went, and then level out before it led, at a slower pace, into a bog area.

On this page I will tell you how to build a small stream for your pond, and the problems we came up against as we built ours. Although you will likely have some ideas of your own for your water features you will still need to consider several things.

Unfortunately I didn't take any photos at the construction stage - so I'll describe it as best I can.

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Waterfall When we built the pond we ended up with a few tons of clay soil from digging the main hole for the pond. We used this to form the rockery and waterfall. I dug the ground and built it up to form the steps for the waterfall area, and smoothed out the bottom (ours is fairly solid clayish soil which meant it stayed in the form I made it). One of the key things with the waterfall, was to make sure the pond liner had plenty of overlap with each consecutive section. If you can, try to do it in one piece. See notes on this later on. Be sure you measure and then add plenty extra when you are buying your liner. If you don't allow enough you will have wasted your money! We found it impractical to use one piece, because of the turn in the waterfall, and pushing the liner into the shape of the steps. Whatever you do, don't cut the PVC pond liner until you've got it positioned nicely and have done some testing by filling with water to see how it flows. And always leave plenty of overlap for making adjustments as it ages, in case you find certain areas settle and form overflows and leaks. Make sure you exagerrate your levels to give plenty of depth to each step and plenty of height at the sides. If you don't you will end up with it being too shallow by the time you have put stones and gravel into each step.

Water flows out of the Urn into the Waterfall

Also angle each step backward, so that it becomes deeper at the back compared to the front. This will help create a nice pooling effect on each step, and prevents gravel from being washed down the waterfall. Similarly make the vertical part of each step reach out further at the top than at the bottom to try and encourage the water to "fall" rather than just flowing downhill. This is probably the most difficult thing to achieve with a "liner" waterfall, particularly if you don't have much force of water flowing. One made out of concrete can be fashioned to create very sharp steps, and therefore a more convincing water "fall". Fibre-glass waterfall units can be obtained readily from aquatic stores and combined with pond liner to create a stream if you prefer. Oasis Traditional Waterfall - Stream These Traditional waterfalls have been made using the latest technology allowing for complex mouldings and finishes creating this stunning waterfall range. The amazing colouring on these waterfalls is a completely unique process to Atlantis and unlike many other waterfalls ranges they will not noticeably fade over the years! ¦ Size: Width 61cm x Length 116cm x Height 16cm ¦ Tough - lifetime guarantee. ¦ Made from premium polyurethane for durability. ¦ Blends in with many rock types and backgrounds. ¦ No fade away - U.V stabilised Colour Effect Click here for Waterfall products and prices at Bradshaws Direct Also: A variety of waterfalls, rockfalls, header pools, waterfall streams, reservoirs, cobblefalls, left/right curved falls. If you can, it is best to use EPDM or Butyl Pond Liner, which is a very durable rubber liner. EPDM is AQUATIC SAFE, it is a highly stable material that is formulated for safety when exposed to fish and plant life in a decorative pond. EPDM is HIGHLY FLEXIBLE, it stays flexible in temperatures from -40° Fahrenheit to 175° Fahrenheit making it easy to install year round. Unlike other pond liner materials, it does not contain plasticizers that could make it become brittle with age and cause cracks or splits in the material, threatening aquatic life. EPDM has DESIGN VERSATILITY, its flexibility provides more versatility in the pond design. Unlike preformed liners, it can be easily shaped to fit the unique contours of the pond dimensions, allowing a more creative design. EPDM is WEATHER RESISTANT, it has remarkable resistance to the harmful effects of ultraviolet radiation (UV), ozone and other environmental conditions. EPDM has HIGH ELONGATION, it has high expansion and contraction characteristics that enable it to conform to objects in the sub grade. Should earth movement occur, rocks and tree roots could be dislodged beneath the liner, but EPDM's high elongation will enable it to stretch over such objects. MINIMAL MAINTENANCE, it requires little or no regular maintenance once installed. However, if repair becomes necessary, it is easy to do without removing the liner from the pond with the EPDM repair patch. Butyl Liner 3.0m X 2.5m A Butyl Pond Liner is the strongest liner to use to line your garden pond. Made from top quality Swedish Butyl, a type of rubber, it stretches making it highly puncture resistant and easy to fit. ¦ Top quality - 0.75mm thick. ¦ Ideal for garden ponds with lots of shelves - it moulds easily to the pond contours. ¦ Guaranteed for a lifetime - when installed with either a Polyfibrelay or Permalay underlay. Click here for Butyl Liner products and prices at Bradshaws Direct Also: 25 Year Polyex liners 35 Year Polyex liners PVC liners You will probably want to put some heavy stones into the steps, because the liner has a tendency to unfold itself after you push it into the shape of each step. Pebbles work better on a waterfall than small gravel which tends to get washed away. Note the use of "gravel liner" to hide the black liner underneath. I think this gravel liner is quite important because you just can't put pebbles on the slopes and vertical surfaces of black liner to hide it (see further below for supplier). Another consideration as you construct your waterfall is to strategically place a few large decorative "stepping stones" at the sides. Bed them in very securely. As well as looking nice, these are for you to stand on whenever you are maintaining the waterfall area, e.g. planting, clearing blanket-weed, working on the top pool, etc. Top

Learning the Hard Way!

The first year was one of continuously ironing out the wrinkles:- adjusting the liner for the stream, searching for small (and sometimes large) leaks, and generally getting everything working nicely. The stream was initially done in 4 sections of liner from the waterfall to the pond. One thing we overlooked with this method was capillary action which caused water to backtrack into open ground in the stream section because I hadn't allowed enough overlap. Its amazing how such a minor thing can lose water so quickly, and when your water is metered by the local council, constantly filling up the pond with 50 or 100 gallons every couple of weeks can soon mount up the water-bill !

Large stones with pitted holes allow places for moss and plants to grow.
In spring birds love to steal the moss for their nests.

Eventually we ended up pulling out the entire stream and re-laying a single piece of pond liner. That did the trick. I would strongly recommend if you are considering building a stream that you make sure to have a single piece of pond liner, with plenty of overlap at the sides (its easy to hide too much extra under stones or plants, but you sure can't add it back on once you've cut if off!).

Although there are vinyl bonding adhesives which are supposed to be able to glue pond liner together, I would not trust them. Maybe its ok in the pond itself where there is little movement, but a stream is a living moving thing which settles, gets trodden on, expands, contracts and weathers in the sun, rain, snow and ice.

Keep the Water Flowing - Maintaining your Stream

Bear in mind that over time the stream will settle and the extra overlap at the edges will naturally get pulled inward and downward. For example in one or two places the millstone edging has settled (usually because people stand on it) and required lifting and building up again by shovelling some additional gravel or sand under the edge of the liner to raise the level again.

Also make sure you've got sufficient depth to your stream;

a) your kids will probably paddle and play in it
b) pets will like to drink from it (therefore step in it)
c) during the summer it will undoubtedly get blanket-weed build up in it

All these things will result in the stones or any channel that you have formed becoming levelled out or clogged up, which in turn will raise the level of water possibly sufficient enough to find grooves in your liner at the edges which then overflow into the surrounding ground. As mentioned above, even the smallest leak, over hours and days will result in substantial loss of water from your pond. Evaporation in the summer does not account for a drop of 2 inches over 3 or 4 days - it means you've got a leak!

The stream bubbles under the slate bridge

Once finished and bedded in, every couple of weeks examine your stream for little pebble dams that might be causing a raise in water-level, clean out too much blanket-weed (I think some blanket weed is nice, and helps achieve a natural look as it sways slowly in the current), and push the pebbles towards the sides again to create more depth for the water to flow in the middle of the channel.

Sunlight shimmers gold in the moving water

An example of blockages raising water-levels and forming leaks.

I took the photo above as it is a prime example of the kind of problem you can get. This was not instantly obvious where we were losing water, until we discovered the soil in the rockery behind was very soggy. So the clue when searching for a leak is to look for soggy ground! The pebbles had fallen from the waterfall section, and built up a little dam, sufficient for the water to rise to the top of the gravel liner, then along the upper edge, and then drawn by capillary action into the surrounding rockery soil.

Pampering Your Bottom

Another important thing with a stream when you are building it is to give it plenty of padding underneath the liner, with lots of sand and/or old blankets. Most people recommend sand, but I think some material such as blanket will stay in place (sand might get washed out by rain), and also I think it might help deter creatures such as voles or moles from tunnelling into your stream.

Never put sharp stones or objects in the stream. The temptation for kids and pets to mess about in the stream is too great.

You're not concerned about the kids or pets!

What I'm talking about is their weight will push any sharp objects through the liner, puncturing it, and you will never find where the leak is! You would have to re-lay a new stream liner again.

Also explain to your children that pond liner does not like sharp sticks, football boots, toys, etc!

You Gotta Do A Bridge

Another thing that I added was a bridge. Here it is in the form of a large chunk of slate laid across the stream. I've also seen some very nice miniature wooden bridges which I've been tempted with, but they can be quite expensive, and wifey thought that the size of our stream didn't warrant a large wooden structure, so we went for the slate instead.

Marsh buttercups, cress and reeds thrive in the bog area and help
create a natural veggy filter to keep your water clean and clear.

For some reason kids just love to cross the stream, so I prefer them to step on the bridge rather than in the stream where they might puncture the liner. It also helps us adults take a short cut when we are gardening the surrounding rockery and plant beds.

A very early photo of the bog area before it was established

Two Layers Are Better Than One - Stone Liner

One thing that helps in this area is to consider two layers and types of garden pond liner;

1) a good thick strong black pond liner at the bottom (preferably EPDM Pond Liner), this gives the main waterproof membrane,
2) gravel coated pvc liner from Oase Living Water

Basically its a very thick butyl or PVC plastic (black on the back, grayish/white on the front). It has very small gravel glued/melted into the plastic. Being stone/gravel, it gives a more natural look at the edge of the stream.

It's called Stone Liner from Oase which is a German company. Some garden centres stock it, but if you cannot find it easily here is a link to the Oase web site, with the section containing the Stone Liner.

It can be quite expensive though, so rather than laying it the complete width of the stream, I cut it into narrow strips about 18 inches wide and laid it just at the edges of the stream. So this gives a nice effect at the sides, while the black liner bottom will be covered with smooth pebbles and normal gravel.

Tip: When cutting the gravel liner, cut it from the back side with an old knife that you don't mind getting blunted by the little stones.

Close-up of the sides where the black liner is covered by the (expensive) gravel coated plastic.

Now you have double-protection to a certain degree from the bottom layer getting punctured. Finally, put a layer of fine gravel on the black bottom liner then also lay rounded pebbles in the bottom, or large flat stones, slate and anything else that helps achieve a natural look.

Let Nature Do Her Work

The main thing to remember that is to enjoy it and not rush the job. It takes a good year or two to get a rockery established and the stream looking good with plants growing over the edges, etc. As long as you get the basic shape and size right to start with, you will continually be making little adjustments forever after, moving a rock here or there, selecting the right plants, and so forth. This is where my wife's gift of green fingers makes it look lovely. It is definitely a passion that we now both enjoy and it gives us something fun to do together.

A year later and the bog area looks great.
Various baubles and low-voltage garden lights complete the setting.
It looks wonderful at night too with its underwater lights.

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More About Overlapping

Where the bog area runs into the pond, the normal level of the pond water would be a couple of inches below the lip of the bog area. The PVC liner of the main pond and the liner of the stream are seperate pieces, but there is plenty of overlap.

The liner of the main pond extends up and out to form the whole bog area as well, and then up the stream a little way (to prevent capillary action), while the middle pond liner section forming the waterfall and stream also goes right down through the whole bog area, and overlaps into the pond. I'm talking of about 5 or 6 feet of overlap, so that both pieces of liner form the bog area! This is shown in the following illustration. Likewise the top pool liner overlaps the first step of the waterfall section.

Its double-protection. You have to be sure that this area is able to contain its water with no leaks.

Again if you can actually do the complete pond and stream in one piece of liner that will guarantee no leaks. It depends on the length you want your stream to be, and also whether you have already built your pond as to whether you can do it with one piece.

All I'm saying is you absolutely MUST get this right at the start of your project, because you don't want to be messing about with it later on.

Making the Bog

Also when fashioning the bog area I dug it deeper than the step which actually leads into the pond. This was so that we could lay a sufficient depth of pond-soil for the bog plants to grow in, without the soil being washed into the pond by the flow of water. Do NOT use ordinary soil. Get proper pond soil which is a lot more loamier and heavy and sinks to the bottom and stays there.

The River Flows Into The Sea

At the threshold of the stream going into the pond I also have a large flat piece of slate sat atop of the liner, which the water flows over before entering the pond. This looks nicer than the black liner, its also more attractive than the gravel liner, and more importantly it helps to prevent soil being washed into the pond and the water picks up a little bit more speed as it flows over the slate before it enters the pond.

One problem we encountered at first and which requires a bit of messing about with is that the water prefers to flow under the slate, rather than over it! Putting gravel and soil at the bottom edge of the slate helps to block it, and over time it silts up with muck and seals naturally.

Another ponding friend suggested that I could have used a can of plastic foam (like the kind used to fill cavity walls) to create a barrier underneath before bedding the stone and this would have helped prevent this problem. If I ever have to uproot and re-lay this step, then I will most likely do as she suggested.

The large flat piece of slate creates a kind of dam, to prevent soil and silt being washed into the pond from the bog. Pebbles at the sides help narrow the entrance into the pond creating a slightly faster flow. The fish like to push their heads out of the water facing up the stream to see what morsels of food might be washed out of the marsh to them!

Plenty of Piping

To feed the water from the pump in the pond, up to the bio-filter and then the top pool, I use 25mm flexible hosing which runs beneath the millstone edging of the stream. This means the pipework is protected, yet it is simply a matter of lifting the edging if ever I need to replace it.

When you cut the pipe to fit your equipment at the top of the stream, for example to go into flow control valves or the pre-filter, make sure you leave plenty of extra.

When I initially was using the Hozelock Bio-Force UVC filter (before I got fed up with it blocking and requiring cleaning all the time and replaced it with my own homemade bio-filter), cleaning it required unclipping and removing the top, but of course because the flexible pipe was attached to it, this meant the plastic pipe was constantly being bent back and stressed.

Now you might think "Isn't that what flexible piping is supposed to do?". Well yes - but in the winter when the plastic is cold, and in time due to the constant bending, one day the piping cracks and you're suddenly pouring gallons of water all over the place. To fix it you have to cut the pipe back to a good point, but you can't do that if you've cut it too short in the first place!

So please bear this in mind if you are thinking of using a filter unit that involves the pipework constantly being flexed.

Conclusion

Well that's the stream! We hope this gives you a few ideas, and would love to hear from you about your project, or if you have any questions.

Lights placed strategically light up the waterfall at night.

It's well worth the effort. A stream and bog area attracts so much wildlife; we get frogs, dragonflies, water-boatmen. Also its a delight to see wagtails and blackbirds come to wash in the stream. On some occasions when heavy rain has raised the water level in the pond to overflowing, the smaller fish will swim up the stream to explore the bog !

The problem with sexy Frogs in the Pond !

I received an amusing tale from a reader which went like this:-

"Although my wife and I are keen on native flora and fauna we have a problem with frogs invading the fish pond. Recently it has been cleaned out with netting secured at the base and also over the top of the pond. Having recently restocked the pond she is extremely peeved that the little blighters are finding a way in. Whether or not they are to blame at the moment for the few dead fish she has found is open to doubt. We do know that during the mating season the frog will jump almost anything that moves and fish suffer as a consequence! Any ideas about how to keep them out and where can we ship them with out killing them off?"

My answer: We always have frogs at our pond, but not necessarily in it. You will see elsewhere in my website that the layout is such that we have a top pool and water urn which feeds a waterfall, stream and bog area. The frogs frequent these nice damp places where plants provide cool and shade without them having to use the pond. Therefore the upper areas of the pond provide the main habitat for the frogs.

I can't say that we've ever had a problem with oversexed frogs "jumping" the fish though! We get frogspawn in the pond each year, but not much survives because the fish eat it. Obviously enough do actually make it though because we always have plenty eager to jump out at my wife when she's gardening!

Of course frogs help to keep other garden pests like slugs and insects down, so rather than fighting nature, work with it by living your frogs their own damp/wet area to live in.

This chap has found a home in the rocks in our stream/bog section:-

Upon closer inspection it turns out there were 3 frogs chilling out!!

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