Designing our new wildlife pond

Back in June I shared the first stage of my project to build a wildlife pond in our new garden.  We hoped to have our pond up and running this summer, but due to the cost of buying the liner, plants, and other equipment, plus the sheer monumental task of shifting so much concrete and the need to repeatedly dig up reappearing bamboo suckers, it has taken us longer to get everything in place.  We’ve been thinking about and working on the pond for ages!

Before we dismantled the old pond, we created two temporary ponds to provide refuge for any wildlife displaced by the removal of our old water feature.  One was an old plastic basin that we dug a hole for in an area of long grass, and our other temporary pond was a little larger in size.  This small, circular pond may or may not end up being temporary….we’ve not decided yet!

My husband has worked his socks off digging out the old pond and creating the shape for our new pond.  I must emphasise that all the physical aspects of the removal of the old pond and installation of our new pond are entirely down to my husband and our lovely friends Ian, John, and Martin, who all worked incredibly hard helping remove the old concrete pond.  I’ve been working on the design of our pond and my husband has been working on all the physical aspects of our new pond’s construction.

What was wrong with our old pond?

The old pond that my team dug out and removed this summer was constructed from concrete and pond liner with steep sides, a considerable amount of brick edging, and a few fake stones.  The pond itself was full of overgrown reeds and a humongous water lily that had outgrown its space and needed three people to lift out!  This pond was a death trap for any visiting wildlife due to its lack of any slope or beach area; due to the steep sides of the old pond it would be impossible for a hedgehog to get out of the pond once it entered the water.  The closely cut lawn that surrounded the pond was a savage environment for small froglets and toadlets to cross.  I dread to think how many poor froglets, toadlets, and other creatures were brutally shredded by the lawn mower that cut the grass around the edge of the old pond every week for so many years.

Removing the old fish pond and catching fish!

Once all the concrete was broken up and removed and we had lifted the plants, we then spent a considerable amount of time using our net to check for pond life.  After not finding anything at all in the water for ages, we were taken aback when we pulled out first one and then two large-sized, muddy-brown coloured goldfish!  Fish predate on amphibians.  Since we’re creating a wildlife pond for newts, frogs, toads, dragonflies, damselflies, and wildlife and not a fish pond we gave the fish to one of our lovely neighbours in the village who already had a fish pond in their garden.  Fish are happiest in a fish pond designed for fish, and wildlife are happiest in a wildlife pond designed for nature.

Removing the old pond liner and checking for wildlife

Before we removed the pond liner we spent a considerable amount of time with our net swooping around in the water looking for wildlife to rescue.  There wasn’t much pond life, so we cut the liner and let the majority of the water drain away overnight.  The next day there was just a few inches of muddy water remaining in the bottom of the pond.  We went through it all with a sieve and net to ensure no wildlife was left.  In total we found around 20 smooth and palmate newts during all the stages of removing the old fish pond, but not much else.  There were a handful of beetle and dragonfly larvae, but very few relative to the substantial size of the pond.  Spending so much energy going through the water with a net and a sieve really demonstrated how wildlife-unfriendly the old fish pond was.  In comparison, if we dipped our net into our old wildlife pond (at our old house) at any time of year we would always find vast numbers of dragonfly and damselfly larvae – that pond was teeming with life.

With no other wildlife found, the pond liner was punctured again to let the rest of the water drain out of the pond.  We were then able to remove the liner completely and see the hole that would be the basis for our new wildlife pond.

Wildlife pond layout and design

It’s the shape and size of the old fish pond combined with my desire to create a water feature that will attract a wide range of wildlife that are my influences for my design of our new wildlife pond.

Once the old pond liner was removed I could clearly see what I was working with and I was finally able to start designing the final layout of the pond.  I’ve essentially kept the old fish pond, which now is deepest section of our new wildlife pond and extends down to around 70cm (2.3ft) deep.  To ensure that our new pond was a wildlife friendly space, I needed to remove the steep sides of the old pond and replace them with a shallow slope with the least gradient possible – this meant extending the diameter of the pond considerably to accommodate the extra space needed to create the slope.  I also wanted to have some moving water and open water.  Luckily, my garden is on a very slight gradient, meaning that it’s possible to install a pump to push water up to the top of a short stream which runs down into the pond.  Creating a healthy ecosystem is the priority for me when designing my wildlife pond, so I wanted to include a bog filter (more on this later).  Here’s the plan I came up with below.

This is a side view of the plan, showing the main pond and bog filter pond as a cutaway.

Features I’ve incorporated into my design for our new wildlife pond

I’ve designed my pond for wildlife. These are some of the features of my new wildlife pond:

• A very shallow beach area with a gradual slope to the edge of the water, making it easy for wildlife to access (and exit) the pond.
• All around the pond there are gently sloping sides which aren’t too steep or vertical and make it easy for wildlife to get in and out.
• Two shelved areas to allow us to grow marginal plants around the edge of the pond at different depths.
• Three bog beds which will be lined with punctured pond liner and back-filled with soil to provide wetter growing areas for moisture-loving plants and marginals.
• A stream approximately 6 metres long, which will have moving water.
• A waterfall to help with the oxygenation of the water.
• The aquatic plants I’ve chosen will offer food, shelter, and other opportunities for wildlife.
• Planting around the pond will provide cover for wildlife visiting the pond.

Installing a bog filter

A problem with many garden ponds is trying to find a way to keep the water crystal clear.  A good solution to this is to create a bog filter.  The idea behind a bog filter is very similar to a reed-bed filter; you create a small pond with approximately 10-20% of the surface area of the main pond, line it, and then feed it with water driven by a pump in the main pond.  The water comes in through a manifold at the the bottom of the pond.  The small pond is then back-filled with 8-10mm gravel to a depth of about  30-35cm (12-14 inches).  The water flows out of the manifold, up through the gravel and then overflows up from the bog filter and makes its way back to the pond, in this case via the stream.  Any debris and detritus from the pond is filtered out by the gravel.  The aquatic plants are planted directly into the gravel (not in pots) and as they grow, they absorb the nutrients from the decaying matter trapped in the gravel filter, breaking it down until it eventually disappears.

Shaping the pond, digging the stream, and installing a bog filter

The next step was to start digging out and shaping the pond – creating the beach area and digging out the stream and the hole for the bog filter.  My husband has used a spade and a pick-axe to create the shape for our wildlife pond.  The WOLF-Garten Straight Spade that I reviewed back in 2019 is still going strong and is definitely a spade that I would recommend.  The WOLF-Garten Straight Spade is designed for sandy soils – the soil we had in our old garden.  We have compacted clay soil in our new garden but this spade has worked very well indeed.

Ensuring our wildlife pond is level

One of the crucial steps as the pond began to take shape was to ensure the edges of the pond were level.  There would be nothing worse than spending all the effort and expense of digging a pond, putting in the liner, filling it up, and then finding that one side of the pond is a couple of inches lower than the other, leaving an area of unsightly pond liner on show.  Worse still, this could leave the pond leaking out of the lower side whenever it’s close to being full.

With a small pond it’s possible to check the levels with a spirit level and a line, but it becomes more challenging to ensure the levels are correct on larger ponds with these tools.  My new pond measures about 7-8m (23-26ft) across at its widest point.  I used a 360-degree laser level to check the heights of all the edges of the pond.  This tool was very useful, and made it easier to ensure that the pond levels were correct all around the pond.  It also meant I could see the exact waterline of the shallow beach area.

Installing bog beds for moisture-loving plants

The last step was to dig out the holes for the bog beds at the edge of the pond.  I decided to have three bog garden beds.  These beds were all dug out to a depth of about 50cm (20 inches).  The pond liner was carried over the pond edge and down into the bog bed and the beds were filled with the soil that had been excavated when building our wildlife pond.  I am looking forward to planting moisture-loving bog plants in the bog beds around our wildlife pond.

In my next article I’ll write about the equipment I’m using in my wildlife pond, and I’ll explain how everything works and update you on our progress with our new wildlife pond.  To see every article I’ve written about my new wildlife pond, please click here.

For gardening advice for October, please click here.

For more articles about ponds, please click here.

For more articles about wildlife gardening, please click here.

To see all the articles about my old wildlife pond, please click here.

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