Marsh 3 and new life!

Common River Frog

Dig number 3 would be another shallow endeavour dedicated to increasing the marsh space. At 10m long and more than 2m wide, this would be the largest of the marshes for this project, at least for now. With only around 20cm of topsoil to move, the dig was fairly straight forward - taking Kai and I a little more than 3 days. For perspective, the volume of soil removed was around 4.4cubic metres, and given it was quite compact - was estimated to weigh around 7 tonnes, 1 wheelbarrow at a time...

With the hole dug quickly, we had one bit of trouble - we were short on grass clippings that I planned to use as a buffer between the bare earth and the plastic liner. So we needed another afternoon to cut the lawn and get the hole prepared first. In went the plastic liner, followed by some course sand and a few sods of earth to keep the plastic from blowing away. Rain wasn't predicted for a few days, so to speed up the filling process a little - we emptied around 1000 litres of water into the marsh from our JoJo tank.

Filling the marsh with marsh plants on the other hand was going to take a rather monumental effort. Based on the number of truck loads needed to fill the already completed second marsh, I was looking at the prospect of needing nearly 20 truck loads of plants! That wouldn't work, so instead I lined the border with marsh plants whilst filling the inner section with sods of grass and earth - the flufftails and crakes would need some muddy patches to hunt for earthworms and other invertebrates.

The grass either side of the marsh itself would be allowed to grow at will, providing more cover for birds, amphibians and insects. Indeed, within a week of the pond being filled and the first vegetation planted - we had our first dragonflies, numbers that would increase from a mere handful to well over 50 individuals at any one time (species ID to follow one day...). The previously 'devoid of life, nothing but lawn' property had now seen a sudden spike in the amphibian population too, increasing from just one species of toad when we moved in, to at least 6 species that I could readily identify, I'm sure there are one or two more that I am missing. 

1. Gray's Stream Frog
2. Common River Frog
3. Natal Spiny Reed Frog
4. Painted Reed Frog
5. Guttural Toad
6. Snoring Puddle Frog

Post Ed: Birds have started to make use of the pond in decent numbers, with Hadada Ibis bathing every day, Bronze and Red-backed Mannikins drinking and devouring the seeding grass, and even the skulking Burchell's Coucal snagging large insects on his way through the morass.

Basic layout  - with Marshes 1 & 2 in the background.

Border grass removed, to be used later to hold plastic liner down.

Final depth was a little over 20cm deep

Grass clippings for cushioning between earth and plastic liner.

Course river sand and grass sod for weigh.

Border lined with marsh plants.

Open water and marsh edge for dragonflies and amphibians.

Growth increasing quickly.

Painted Reed Frog calling loudly

Gray's Stream Frog (Clicking)

Natal Spiny Reed Frog

Marsh 2

Marsh 2 was always planned to be shallow and full of dense marsh vegetation. With similar dimensions to Marsh 1, this hole would add little in terms of water volume, but produce 6m² of good marsh habitat.

Long term, our plan is to entice Black Crake and perhaps even a young Red-chested Flufftail to take up residence. They both require similar habitats, patches of dense cover, water edge and foraging areas of mud or short vegetation. Whilst only a small patch to start with, this again would be the testing ground for the much larger ‘Marsh 3’ to come.

Digging commenced on a Sunday, removing the grass layer to expose a small volume of topsoil over the much deeper clay. With a target depth of only 20cm, digging didn’t take long – indeed, only a few hours of labour were required late on Monday afternoon to finish the job. Grass trimmings added, the plastic sheeting was laid a few minutes later. Some helpful evening rain even filled the marsh ahead of marsh plant collection.

Despite its small size, filling the pond with the requisite marsh plants, mud and other aquatic wildlife took 6 trips to various locations. To keep my impact down to a minimum, I collected material from degraded or heavily disturbed seeps and drainage ditches within the area during the late Autumn, before the growing season had started.

Post Ed – a few months after planting and the increased rainfall, light hours and temperatures have spurred on growth. The marsh is now exactly as intended with plentiful cover and an ever-increasing density of frogs, insects and other invertebrates.

Initial grass clearance - not much topsoil here!

Plastic lining went on quickly with a few logs to hold things in place

Even drizzle flowing from roof to marsh.

A day after lining and the mrsh was already full of water

First marsh plants added.

Multiple trips later, still not fully vegetated.

Two months later - the marsh was growing fast.

A heavy downpour showing the growth of Marsh 2 and the beginnings of pond 1 in the background.

Manufacturing a wetland

When I was about 14, I convinced my parents to let me run riot in their garden. I chopped out all the exotic rubbish, replanted with indigenous and even put in a small pond (made with a piece of orange roofing plastic that my old man found for me somewhere…). Since then, I’ve always wanted a grander dam or lake in my backyard, but never lived anywhere long enough to make it happen.

Fast forward around 25 years and I found myself buying a property with Meg. I looked at the backyard and saw my chance. Fairly flat ground with only a vegetable garden and a lot of lawn to conquer. In the days before COVID, I imagined hiring a backhoe and digging one ginormous pond to house Large-mouthed Bass in order that I could go fishing in my own backyard… So, we moved the veg patch and enclosed it, got rid of a rudimentary rockery and built a fine BBQ area in its place. All I had to do was get working on the lake.

By the time I finished sorting our all the other upgrades and renovations around the house, COVID had arrived and lockdown was in full swing. Not only was the backhoe idea out, so was the ginormous pond for fishing - an alternate outcome was required, one that was going to cost very little and surely involve a rather large amount of personal labour… Back to the old days it was then, self-dug holes and plastic liners would be the order of the day. Since long and wide liners cost a small fortune, I planned to use smaller sheets of plastic that are more routinely used in roofing to provide under tile waterproofing. At 250um thick, they should do the trick. My intentions had changed somewhat too, out with the big fishing pond and in with a number of shallower marshes for amphibians, crakes and flufftails.

One afternoon with 'lockdown beverages' in hand, Meg and I arranged a pile of soda bottles, plant pots and hockey sticks around the backyard to form a basis for the grand scheme. A few days later, we started laying the main water feeder pipe – a 50mm ldpe pipe connected to our JoJo overflow. Trenching and pipe laying done, a multitude of connections were fixed and laid, ready to fill all the ponds and marshes.

Phase one would be a small pond – something that would allow us to test form and function. Early on a Saturday morning, Kaily and I headed outside with spades, shovels and wheelbarrows. The first hole was scheduled to be 3 metres long, 1.7metres wide and around 40 centimetres deep. 5 hours and 36 wheelbarrow loads of dirt later, we had our first hole. To provide some protection, we tipped in a few piles of old cut grass and laid the plastic. In went some water from the JoJo to get things going, before the evenings predicted rain arrived and proved that our piping worked too. Now we needed some life, so we hit a nearby marsh for some reeds, before another downpour the following day filled the pond. In the space of a week, we had increased our water capacity by 2000 litres and breathed some new life into what was the sterile lawn. 

*Postscript. Marsh 1 would indeed be the practice run, for we could not keep the water oxygenated enough. We ended up filling the pond in with soil from Pond 1 to create a contiguous marsh. Successfully punctured the lining and had to re-dig it and re-line it…

Planning - with soda bottles and hockey sticks

Feeder pipe form the JoJo overflow 

Breaking ground

Almost done

Black liner with first water going in

Almost complete

There was a leak somewhere, but it was a case of digging it out again

Re-lined and filled