From Tarp-Lined Swamp to Thriving Habitat: Reviving a School Wildlife Pond
The Challenge We Faced
We were recently contacted by a local school, Blessed St Dominic's, to renovate their wildlife pond. This isn't unusual for us at Pond Life Aquatics; we often help clients whose ponds were poorly installed or need an overhaul to function correctly.
However, the situation at Blessed St Dominic's was extreme. This wasn't just a poorly installed pond; it seemed built with no intention of ever supporting wildlife or even holding water properly. Dug harshly with a digger, its steep edges made planting impossible. Ton bags of sand and shingle had been dumped in – a failed attempt to compensate for the poor design. To make matters worse, the edges were wildly uneven, with nearly a foot difference between the highest and lowest points. Most egregiously, the "liner" was just a basic tarpaulin – something never designed for long-term water retention.
It painted a picture of builders cutting corners, perhaps taking advantage of a school budget just before the pandemic hit, knowing that by the time the flaws were discovered, they'd likely be long gone.
Our Vision: A Pond Fit for Purpose
It’s rare to encounter a pond that literally couldn't get any worse, but this was one of those times. Simply removing everything would have been an improvement!
Our vision was clear: create a vibrant, healthy pond that the children and teachers at Blessed St Dominic's could truly enjoy. We wanted to build a space that would boost biodiversity, offer a relaxing spot for students, and become a valuable outdoor classroom. At the very minimum, it needed to reliably hold water! So, we got to work.
Rolling Up Our Sleeves
We started by piercing the old tarpaulin a week before the main work began, allowing the little water it held to drain away.
Day one involved surveying the swampy mess. After a quick laugh with the headmistress about where on earth to begin, we got stuck in. First, we cleared out the dead plants and sludge mixed with gravel – this allowed us to salvage and wash the gravel for reuse later. Not the easiest start, but a necessary one.
Next came the back-breaking task: removing two tons of gravel dumped into the pond base, presumably to hide the shoddy workmanship below. No digger for this part – just pure manual labour. One digging, one lifting. Brutal.
Uncovering More Surprises
With the gravel finally out, we hoped the worst was over. Unfortunately not. We discovered the previous builders had used underlay, strangely paired with the useless tarpaulin. Less strange, perhaps, when we found two tons of sand dumped underneath it, presumably another attempt to shape their monstrosity. Inexplicably, this sand sat on top of yet another layer of underlay.
For a moment, we worried we'd find endless layers of sand and gravel. The only way to know was to start removing the sand and hope it was the last nasty surprise.
Perseverance Pays Off
Thankfully, after removing the first sections of sand, we confirmed it was the final layer. We pushed through, and the sand turned out to be a blessing in disguise. It gave us pliable material to properly shape and level the base of the new pond, allowing us to create significantly more depth, especially at the lower end.
The Transformation: Finishing Touches & Final Results
With the pond properly shaped and levelled, the final construction phase began. We laid down fresh, high-quality underlay, followed by the heavy-duty 100kg pond liner. Once positioned, we began filling, carefully adjusting levels as the water rose to maximise depth where possible.
With the pond holding water beautifully, we created a bog garden area along the nearest edge using large boulders, aquatic compost, and much of the washed gravel we'd excavated earlier. This area now hosts a diverse range of marginal plants – both flowering and evergreen. Over the years, species like Caltha (Marsh Marigold), Mimulus (Monkey Flower), and Ragged Robin should flourish, providing seasonal colour, while evergreens like Equisetum (Horsetail Rush) offer year-round structure.
The newly established shelves we created during the shaping process now house various potted aquatic plants like Iris, Scirpus (Bulrush), and Lythrum (Loosestrife). Each adds unique beauty and provides vital shelter for aquatic insects and amphibians. In the deeper base, we planted several varieties of water lilies, whose pads and flowers should grace the surface during the summer months.
We didn't forget the surroundings either, scattering wildflower seeds across the adjacent grassy areas. Over time, these should develop into mini-meadows, attracting bees, butterflies, and other beneficial insects.
A Pond for the Future
Ultimately, we're incredibly pleased with the final outcome at Blessed St Dominic's. This is a pond that will evolve and mature over the years, hopefully only getting better with time. It will serve as a fantastic resource for studying biodiversity while bringing natural beauty to a previously neglected area. As the pond establishes itself, we hope everyone at Blessed St Dominic's will be as proud of it as we are to have created it.
Harris Bard
Company Director
Pond Life Aquatics @ Finchley Nurseries
London
NW7 1AS