Keyline Design as an organizing pattern for Permaculture Design, Part 2
P.A.Yeoman’s Scale of Permanence
Water for Life
Water is where we begin with design; as it is the greatest limiting factor for production, and it’s movement in the landscape depends entirely on the landform. Earthen constructs such as ponds, dams, swales, etc, are very permanent features in a landscape. Roads are too, and the well constructed roads & earthworks of ancient cultures can still be found functioning today, from the Romans to the Kogi.
The principle of designing water into Permaculture systems involve taking water over the longest path, over the most time, moving as slowly as possible with the most passive friction, affecting as many living things as possible. This is a fertile situation.
Here in Sweden where we have snow melt in the spring many landowners put a lot of resources into draining water off their land, as discussed in the previous article. Can you have too much water? It is possible in the very short term, but as a system this is somewhat doubtful. How to rapidly build soil and make use of the water is a good directive. Under utilized rainfall are the primary reason desertification is now spread across the larger half of the land surface of the planet today. Agriculture is the largest consumer of water, and in many parts of the world this is derived from mega- dam projects. Mega- dams have displaced over 80M people in the last 100 years, and the methane released from stagnating nutrient flows make large dams more atmospherically polluting than coal fired power stations (Methane is 22x more potent as a greenhouse gas than CO2) Here we do not have the problems of the brittle landscapes, but I see few farmscapes that are future proof regarding water. Pumps and other degenerative technologies are costly and need constant maintenance, so any chance to use gravity fed systems is high up on the design agenda.
We will deal with water at the farm resiliently via soil development including Keyline subsoiling & ripping, managing our grazing holistically, perennial strip plantings, ponds, dams, intelligent farm track positioning and appropriate technology
Soil is by far the cheapest and most effective place to conserve water, with more layers of stacked benefits than any other way you could store it. One particle of humus can hold on average four parts of water, and so we start to see the cost effective, production-increasing effects of building healthy soils, the basis of all our production, and indeed, of civilization itself. For every percentage increase in soil carbon we increase the soil water holding capacity by 144 000l per Ha.
For the sake of design consideration in this article I will share this; I have seen swales implemented in various countries where I personally think they are totally inappropriate and unnecessary. It strikes me that trends in popular Permaculture risk diverging from design planning and holistic decision-making. For example, when I consider the cost of subsoiling, (which allows water to slow, sink & possibly spread) combined with good grazing (which can rapidly develop deeper living soil that can hold the water) I have seen quite a few earthwork examples where I'm positive I could achieve the same outcomes with radically lower cost, with water in the soil where it is actually needed for production with no major risks. Holistic Management decision making is incredibly useful in the design process when weighing up which technology/ strategies, etc, will lead you optimally towards the holistic goals and resource base you are managing for.
Constructing dams and ponds is a big subject and depends on so many variables, both human and geophysical. Due diligence is vital in order not to risk breaking the bank/ limbs/ laws. There are some brief notes of some considerations at the end of this old article I wrote after a Dryland training last year. Important considerations for designing these systems include;
Maximum perceived rainfall events
Catchments/ Watershed analysis
Soil infiltration rates
Because of our climate & water needs, and the fact we have flowing streams with a height difference (allowing us to run a RAM pump) our ponds and dams are mainly for simple aquaculture for farm use, recreation and habitat. They are not particularly cost effective in this regard, ie, we don't need the water, but we want it. Having friends with old machinery can be a big help as in this case investing a lot of money in this work would perhaps not be a great financial decision for the farm. On another hand well designed earthworks will add value to a property, so could be viewed as a longer term investment with a lot of great benefits. If soil resources do not allow earthen dam construction one good alternative is Geo- synthetic clay liners (GCL) which is a layer of bentonite clay sandwiched between textiles that swells with water contact. It is necessary to cover this with topsoil which, incidentally, allows immediate planting and rapid repair from the disturbance. GCL works out at about 8 Eur/ m2 here, which is great. It self seals around overspill pipes and roots, which makes it very pleasing to work with.
Our roof catchments will collect firstly into Ferro Cement tanking to ensure a good quality pump- free drinking water supply, then overspill into water bodies. Planning overflows from each water body is crucial! Understanding levels and calculating for extreme weather possibilities is in order. Natural swimming pools are an awesome integration into a home setting water system, and could double up in water cleaning & production systems as well as all the other benefits ponds bring to an ecosystem. To have a good swimming lane it pays to make a conventional shaped cut and the whole thing is created with cleverly folded liner. The shallow edges are planted with sub marginal aquatic species amongst gravel or similar medium to make an attractive and clean finish. A simple suspended and submerged rope marks the edges for swimmers. A solar powered skimmer can keep the surface clear of leaves, etc. The main cost is digging and a liner if it’s needed.
Ferro Cement Tanks
There are different methods of constructing ferrocement water tanks, but the usual ratio of cement to dry sand is 1:3 by volume. The ratio of water to cement has an important effect on the final strength of the mortar. A ratio of about 0.4:1 to 0.5:1 (ratio of water:cement by weight) is ideal, which is equivalent to between 20 to 25 litres of water to each 50kg bag of cement. When we have built tanks in hotter climates/ weather, we have used wet blankets to slow the curing process. Plastic wrapping could be used too.
Building tanks without using formwork This method requires a stiff wire frame around which flexible mesh such as 'chicken wire' is wrapped. The first layer of mortar is applied by a mason working on one side of the tank, with an assistant on the other side holding a plastering float in the right place to allow the mortar to be compacted without it falling through the mesh.
Building tanks using temporary formwork Temporary formwork, made of wood, flat or corrugated sheets of steel, or coiled pipe is placed against one face of the tank during the application of the initial layers of mortar. The formwork is removed before plastering the inside of the tank.
Building tanks using permanent formwork Formwork, such as corrugated sheets, may be left in place permanently, plastered on both the inside and the outside.
As mentioned in the previous article, we do not have convenient higher storage sites for earthen dams for irrigation of perennial crops or livestock. However, we have surface flow from springs in the NW paddock that can be developed, and marginal areas that make suitable dam sites. These areas will be suitable for recreation, a small amount of aquatic production for farm needs and in places acting as heat sinks and reflective surfaces (particularly important for leveraging the microclimate in the kitchen gardens for example). We also have a lot of large rocks (extracted from the field by hand long ago) that will be semi- submerged in the waters edge to help heat the water too. Having microclimates within the water bodies, eg shallow and deep water allows more “stacking” of life within it. Any overspills with height drop (such as in our N paddock) can be conveniently spilled down rocky falls to eliminate erosion and oxygenate the water in the process.
Badly constructed roads are incredibly expensive to maintain, and another good example of how useful the SOP is for organizing the patterning of landscapes with a much longer-term holistic overview in mind. P.A. Yeoman’s wrote The City Forest (1971) describing how whole towns/ cities could be planned very efficiently with this process, it's well worth a read.
For a 45 second video of how a RAM pump works see this vidoe;
One of the beautiful aspects of this set up is that we can run a 25mm pipe along our fencing to the barn with quick access outlets (and taps on “downstream” side) every 15- 20m. This means with 100m of 25mm hose on a trolley reel we can connect up and have running fresh water supplied anywhere on the farm, no electricity or oil needed. This will suit our mobile grazing set up, as well as give us security for the large number of perennial tree and shrub crops we are establishing on the Keyline layout. Simple and effective.
Conventionally it takes a lot of power to pump water around piping, and pipes are best laid along or slightly off contour on along the centers of ridges. Laying pipe by access/ fencing makes everything functional, accessible and just plain sensible. If we wanted to bury the pipe we could adapt the Keyline plow to do this, but we are keeping it exposed for simplicity & adaptability- conveniently the lowest point in the whole line is right above the creek so with a simple valve we can drain the whole system.
The pump can be run into each side of winter and can supply drinking troughs well past the time they conventionally freeze. As long as the pump keeps running it’s fine. If it stops pipes will burst! A nice example of a RAM in winter action in -10c, the benefit of running water;
In the next section we'll look at the planting patterns, species choices and ground preparations for our diverse perennial cropping as well as consider buildings - retrofitting and adapting for resiliency...
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Richard Perkins is director of Integralpermanence & Ridgedale PERMACULTURE, a pioneering project in the heart of Scandinavia where we demonstrate & educate about Permaculture, Keyline Design and managing holistically. We hold regular PRI (Aus) & PC Assoc (UK) certified PDC trainings as well as awesome 10 Week Permaculture Internships with over 530hrs of curriculum based learning and 5 Certificate courses beginning April & Jul 2014
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