Building big ponds in the Caribbean. Part 3

With a virgin piece of ground in which to dig a giant pond and being able to be there on site right from the start, I knew we could get it right. But life, the world, Sod's law and everything just dont let thingsThe site was levelled before the pond excavation proper started. happen too smoothly. The Landscape Architect, the cool and worldly wise Kevin Talma from Barbados, wanted to see more room being made for the landscaping and planting, thereby shrinking in the edges of the pond just a fraction. However the pond was a sort of bone or dumbell shape and shrinking the dimensions of the middle made the central thin bit little more than a canal. No, less than that, just a wide ditch. This instigated some secondary thoughts that entailed making this area into a shallow reed bed area through which the water would have to pass on it way down to the river. It would also mean that the dumbell ends could be treated as separate ponds. This was no problem since I foresaw both sections needing their own filtration systems.

First things first. A water level had to be established. This would be a foot or 300mm below the Pond 1 level since there was a distance of about 30metres from 1 to 2 and Pond 1 had to flow into Pond 2 when it rained. It seemed that a stream with a gentle fall of 1:100 was what we had to try to work with. It couldn't be more because we still needed a fall from Pond 2 to the outflow to the river. This would also be 1:100, on the very limit of the fall required to make water flow effectively. A 1:80 minimum is preferable.

Once the shape of the pond was mapped out on the ground the lads in the big slews were determined to 'go down' and get shifting some debris, egged on by the truck drivers contracted to shift it off site because they were being paid by the load. But a level area was the first and foremost task. When we had a level edge, we could then see what we were doing - level, depth and profile-wise.

Constant supervision of the slew drivers was essential to ensure the kept to the right level.: As soon as the 'level men' turned their backs, things would go askew.
Once the site was level, the interior of the pond was dug. The outside marginal shelf with its 'v' trench profile would be dug out later. This was easier said than done. The water that seemed to magically collect on site was making the ground very sticky, and then futher along to the narrow bit, the soil seemed to give way to layers of hardcore, rubble and a mass of iron and reed bar debris. The project slowed to an almost terminal crawl as each scoop of the bucket seemed to trawl up another vast octopus of reed bar tentacles and concrete that ripped apart the pond profile as it emerged. Because of the dire condition of the ground and the lack of subtle skill from the slew drivers, this would have to be all sorted out by hand later. The soggy bottom to the pond smelled of rotting vegetation, which made it imperative that the there should be a fall in the base of the pond so that any trapped gases under the liner would move up and out from under the liner. There would also have to be a hard base put down there if only to support the liner. Using the hard granular volcanic clay on site would be ideal since this would allow gas to travel through it whilst still providing a hard pan that allowed work to be finished on the pond.

It wasn't until several days later whilst talking to one of the older security guards who had been on site since 'day one' of the project and had also played down there in his youth, itCleaning out the excavation with the machine. You can begin to see beginnings of the marginal shelf profile.: The details would have to be sorted out by hand. emerged that an old house had stood where the narrow part of the pond was that had just been knocked down and buried, and that a swamp had been where the soft and soggy bit was. This had been partly filled with some of the debris of the house. It seemed that south side of whole valley drained to this point before draining out to the sea or the river. No wonder there was that distinctive boggy smell. When you come across an area like this, it very difficult to change what has occurred by a natural formation of the land and geology around. If it creates a problem with the positioning of your water garden, you just have to work with it and either compromise or make provision for it always being there. This is why one of the primary rules for siting water gardens is NOT to build it in low lying soggy, boggy parts of the garden.

The 'hard stuff', as we came to call the hard volcanically baked clay, in the base of the pond, would allow a natural flow under ground away for the site, but more importantly the whole pond system was going to be the collection and drainage of the valley out to the river, taking a lot of water overground that would otherwise make its way through soggy swampy ground. When the rainy seasons come in St Vincent, they are not too much of a hassle because it is so warm and although it may rain so hard it is painful to be out in it, it vary rarely rains for more than a couple of hours. The big BUT is: but what happens to all the water? You can get what is equivalent to a months rain in the UK in just two hours, so all the roads have 18inch deep channels That's as clean as you could get it by machine and still bits of stone and concrete and reedbar lie everywhere.running down the side of them and most gardens are constructed to shed excess water without runoff down to the sea. The soil is open and sandy and sucks it up. Here in Buccament Bay, there is likely to be more rain than you get anywhere else on the island because the prevailing winds blow rain filled clouds from the top of the island's volcanoe straight down the valley to the Bay. We were building this pond in the dry season, which was meant to last
more or less from January to April, but it still managed to rain
virtually every day. This is the last thing you want when you are
splicing liners together.

Once all the machine excavation had been complete, it was thanks to 'Little Rasta', 'Bequie' and 'Garry' who persistently plodded round and round day after day until all the levels and the profiles were right, that the sides were smooth and all rocks and reedbar where removed and cut out. The 'hard stuff' went in and was vibrated into place andLooking up through the narrow part of the pond, now to be a reed bed area.: Where the machine is digging is where the swamp was. then in went the protective terram.

The liners went in the last day I was there and I left the lads competantly splicing up the joints as i rushed to get my plane off the island. I was sorry to go, but I had originally been commissioned to stay 5 days, but when it became obvious they would need my help for longer, it was nearly month before I could leave. The last liner to go in whilst I was there was another 50foot by 100ft. I thought that it would have to be cut in half because the dimensions of that part of the pond were only a little over 50 by 50 even with the tape draped through the excavation. In fact I congratulated myself on the good luck to choose that liner because it fitted just right with all but a couple of metres to spare. The convolutions of the reed bed areas that were great inundations into the smooth contour of the pond, used up countless square feet, in this case, over two 'Little Rasta' (left) and 'Garry', and another willing helper who did mostly 'watch', finishing off the levels and cleaning out: With their hard work for days on end, the pond inched its way to completion.thirds on top of the estimated size of liner. I remembered I had almost come unstuck with this irritating fact of pond building before. Ah well, you live and relearn again and again. This time there was no problem.

The real problems were yet to come. I had seen them on the horizon so to speak, and they were possibilities related to other problems I had 'flagged' up in the very early stage of consultation, but little did I know they would come in such a storm. Intriguing eh? Not for me... More to come!

Another view of the lads showing the levels they have created. The 'level man' is in the distance.

Bequie, DJ, poet, philosopher and carpenter. He would take over being incharge when Levi was otherwise occupied.: There are few nicer nor more humble men on the planet.

The first strip of terram goes down for liner protection.

Pond 2 was lined in 2 halves. Here the south end of the pond was lined first.

Viewed from the south end when all the liner was in place. Now for the edging.: This was the last view i had of the pond before I left.