The first consideration is where to place the pond and given the steepness of our land (an average 40% incline) I don't have all that much choice. I could put it at the very bottom of our land where it is least steep. It would be easiest to construct there. However there are two arguments against that: 1. it would be at the far end from where the action is, i.e. in terms of permaculture zoning almost in zone 5. So maintenance would become a chore and it would gradually become part of the far and beyond. Secondly, permaculture teaches us to catch water, which is a source of energy, at the highest point possible within a landscape. On a steep slope that is on or just below the so-called keypoint, the point of a slope where it turns from convex to concave, or in other words at the point where the slope is at its steepest and begins to level out. (For more on keypoints and the keyline system as invented by PA Yeoman check out this link). Catching the water quite high up it can still be of use to things planted below if there is excess water.
So this where I decided to construct the pond as you can see on the map below:
The other reason for choosing this particular point is that it is the natural point at where the water tends to run down, therefore also being the area that had suffered the worst damage from the landslides of Christmas 2010. Since then the area has virtually not been touched and is therefore a pretty useless area as it is, so I may as well catch and slow the water where it comes down and make some use of the area again.
Now that we have determined the location of the pond we begin with the survey of the site. I have given an idea of the greater area above, now we need to look at the specifics of the proposed area. To start of with it was covered in brambles and bamboo spreading from the negligent neighbours site. I needed to clear this first to get a better picture of the topography and plant and animal life other than brambles and bamboo. This is what it looked like after the initial clearing of the worst shrubbery:
To the south of the proposed site, on the neighbours land, there is a gigantic lime tree of some25-30 metres height, blocking off much of the sunlight.
On the terrace below, so to the east of the site, there is an old pear tree, however it does not take too much light away, as it is positioned lower. Also it was damaged during the 2010 landslides. In fact there used to be a pear tree standing at the very spot where the pond is to go, but it was one of the victims of the floods and as it fell it also took a fair portion of the lower tree with it:
Just above the site is another pear tree, which now sits precariously on a brink, as the landslide took away the soil all the way up to the tree. This is a problem which needs to be addressed within the design. I need to somehow extend the soil, building a pathway on the lower side of the tree for access and to extend the soil beyond the tree, and I also need to think of netting below the tree, so that ripe pears and leaves do not fall into the pond.
Now we take a closer look at the site itself. The original terrace structure was destroyed by the landslides and the landscape lies around in a hapharzard way as it was formed by the water (we had some 500mm rain in one day back then. We were lucky to have been spared by the much more publicised floods of October 2011, which destroyed much of the Cinque Terre and other nearby towns). So next we'll do a PASTE survey: Plants, Animals, Structures, Tools, Events.
Plants: I have already mentioned the main trees and the bramble and bamboo. In addition there some lime tree saplings emerging, one just above the proposed site.
I don't mind that, as lime has multiple uses, the roots should stabilise the soil, the young leaves are edible, the flowers are bee attractants and have medicinal properties, young shoots are used in basketry, the wood is useful for carving things, so I'm all for it, as long as I don't let it grow to 30m plus... Furthermore, once I cleared the shrubs, there was little biodiversity. Species recorded were bracken, campion, sorrel, mugwort, a few undefined members of the asteracea family also know as DYC (Damn Yellow Composites, due to their difficulty to tell one from another) and quite a bit of pellitory-of-the-wall. A couple of wild vines also creep about the place as is ivy and bindweed.
The low biodiversity point to low soil fertility, in fact just looking at the soil will confirm that. The types of plants indicate a poor alkaline soil, particularly indicated by fern and sorrel. The soil analysis also confirms that. By placing some soil in a jar with water and shaking it you can make a simple soil test. Different soil types sink to the bottom at different rates. Sand will settle first, followed by silt and finally clay, giving hopefully 3 distinct layers in your jar. If the solution is alkaline it may take a long time for the clay to settle out and the water at the top to become clear, as in that case the clay particles will repel each other rather than clump together and sink to the ground. This point is going to become very important at a later stage, when we are talking about sealing the pond.
Animals: Animals that we have observed or have seen or heard evidence of on our land include: Mammals: mice and rats, cats from the neighbour, dogs, incl. our own, bats, foxes. Birds: small song birds, incl. sparrows, starlings, blackbirds, wrens, robins, birds of prey, bee-eaters (seasonally), seagulls, from the nearby sea (just overhead really), cucckoos, woodpeckers, owls, penguins...(oh no, no penguins...), jays and crows. All manner of waterfowl can be found a few km away in the river. Reptiles: grass snakes, slow worms, various lizzards and gheckos and a mating pair of T-Rex (or did I imagine that one...). Amphibians: I have seen the odd toad, but as there is no water as yet, not much in evidence yet. Insects: Bees, wasps, hornets, bumble bees, mosquitoes (did I mention those before?), all manner of flies, those big buzzy, bumbly black bugs which like to live inside bamboo sticks and eat nectar, centipedes, stag beetles, various noisy crickets and far more critters than I care to mention. Worth pointing out that I haven't encountered many earthworms on the actual site, another indicator of the poverty of this particular spot.
Structures: By structures we mean imovable (wo)man made features in the landscape. The only ones directly related to the pond site is the already mentioned water tap in easy reach and a few metres to the north of the site the terrace has been repaired and strengthened with a sloping wall of old car tyres.
Tools: Are really more movable structures with a specific function. There are none in the vicinity. I suppose the water tap should really be under tools rather than structures.
Events: These can be both social or natural events. As this currently is an unused part of the land, there are no social events happening here. As for natural events, as already pointed out, it is the area worst affected by the landslides. Also being in the shade for much of the time, especially in winter, frosts are likely to occur there. We do get through many winters without a significant frost, but this small area would be particularly frost sensitive, even when the top terraces stay above zero. In the event of a general frost, as seems to be happening more frequently in recent years, temperatures would be even lower here.
I have already mentioned a few of the limiting factors above: a lot of shade, danger of frost, encroaching weeds from neighbouring land, potential catastrophic rainfalls, poor soil fertility, alkaline soils, cats going for any introduced wildlife. Looking at resources, there is a woodland below from which building materials can be gathered. Also the local skips are a great source for material, the town of Arcola not being far away from the land. Another resource, and a welcome one too as my bones are starting to creak, are helpXers or any passing permaculturists (preferably young and fit ones!).
Sooooo, having done our observations and survey of the site we go to the analysis stage of the design process. As I am being my own client in this particular case it makes interviewing the client a tad monotonous: "Well Mr. V., what is it you would like us to do with your plot of derelict land?" - "As if you didn't know, and stop talking to myself!". So lets go straight to the column of
Needs and Wants:
Let's start with needs:
- Reducing mosquito population by introducing a greater biodiversity
- Prevention of further landslides by slowing the water
- Food source by introducing edible pond plants
- A tranquil place for meditation and fish watching
- A soft fruit garden below the pond
Considering all those points I have come up with a rough shape design (the final shape will depend on the contours of the land):
To create some lower banks at 30-45cm depth for some of the marginal plants, I'm intending to 'terrace' the inside with upturned glass bottles. Below the higher pear tree I am intending to build a walk way out of 4 old pallettes, 2 vertical and two horizontal on top. This space between them can be filled with stones and organic material to create access to the tree from all sides. During the summer when the pears ripen and in autumn when the leaves fall, a net can be suspended from the pallettes under the branches to prevent organic material from falling into the pond.
In addition a walkway must be maintained all around the pond for full access to all parts, as I am intending to grow edible crops inside the pond and as I also need to be able to get to the far end of the pond to cut back the neighbours jungle at regular intervals.
One more word about the soft fruit bed, I intend to raise the bed in a technique I invented, which I call the reverse hugelkultur. Rather than building a mound with old wood as with a traditional hugelkultur, I fill in a gap with wood topped by all manner of organic material making for a nice rich and deep soil. The wood for this can be gathered from the forest below.
I started digging some the last couple of days and whilst I haven't got the final layout this should give you an idea what it looks like at the moment as see from the pear tree above:
Now as for plants. This is my wish list in no particular order:
- Water hawthorn – aponogeton distachyos – Edible tubers, stems and flowers. Originates from South Africa. Planting depth: 45cm, but in its natural habitat goes dormant during dry summer months, so can stand lower water table.
- Golden Club – orontium aquaticum – Edible roots and seeds, but needs to be thoroughly cooked or dried. Planting depth 15-45cm
- Buttercup – ranunculus lingua – Not edible but good ground cover for pond edge, removing nitrates and suitable for clay.
- Bulrush – scirpus genus – Various species with edible roots
- Water Hyacinth – eichhornia crassipis – Edible carotene rich leaves and flower spikes, though tasteless. Cleanses waste water. Produces biomass, fibre, fertilizer and insecticide. Beneficial for fish. Very invasive though. Plant on pond edge in 15cm depth max.
- Water Fringe – nymphoides peltata – Flowers, leaves and seeds edible, especially interior of stems. Medicinal uses against headaches, burns, fevers, ulcers, snake bites & swellings. Prefers alkaline conditions in shallow water. Can be invasive in rich soils
- Common Fish Weed – lagarosiphon major – Submerged oxygenating plant
- Water Violet – hottonia palustris - Oxygenating, semi-submerged plant with attractive flowers, giving shelter to fish. Plant in up to 80 cm depth
- Sweet Flag - Acorus calamus – Edible roots leaves & stems. Roots as ginger, cinnamon and clove substitute. It has various medicinal qualities. Leaves are used in basketry, it is an insect repellent and a fibre for weaving can be made. Sunny position in shallow water or mud in alkaline conditions. It grows up to 1m tall
- Flowering Rush – butomus umbellatus – Edible roots and seeds. Very ornamental. Sunny position in up to 30cm depth.
- Watercress – nasturtium officinale - Doesn't need much of a description
- Fool’s Watercress – apium nodiflorum –A native plant growing abundantly around here and cleansing water, as well as being edible as described previously here
- White Water Lilly – nymphaea alba – Edible roots and leaves. Medicinal uses. Supplying shade. Plant in minimum 1.2m depth
- Arrow Head – sagittaria sagittifolia – Erba Saetta – Edible roots and leaves. Medicinal uses: anti-scorbutic and diuretic. Plant in 30-60cm depth in sunny position
- Water Chestnut – trapa natans – Castagna d’Aqua – Edible seed. Plant in up to 60cm depth
As far as livestock is concerned, Goldfish are pretty hardy, they eat vast amounts of mosquito larvae and they are easy to spot if you are just sitting by the pond-side contemplating. Might add a few more algae eaters or other native fish as well as snails and frogs of course. There should be plenty of shelter for all of them. No doubt dragon flies will also be attracted to the pond.
As for sealing the pond I am hoping to utilise the fact I mentioned earlier concerning the alkalinity of the soil. If possible I want to avoid using plastic liners. I want to try a technique that involves sowing clover on the base of the pond before filling it with water. As the clover begins to grow you kill it by drowning. This will then alter the water and soil towards a mild acidity. As a consequence the clay particles will not repel each other anymore,, enabling them to clump together and seal the ground and leaving clear, unclouded water. I have not tried this, but it should be an interesting experiment when we get to it.
Here is another couple of views of what it looks like at the moment. First as seen from the north towards the neighbours jungle:
Right! All I need now is a few able-bodied helpers. Any volunteers?