A Modern Approach to Keyline Design for your property Part I
(First Published in Town & Country Farmer Magazine in 1996)
by Darren J. Doherty
In the Autumn edition of Town and Country Farmer we gave you an introduction to the history and basics behind Keyline Design. In this Winter issue we will help you start to develop a Keyline design of your land that will go a long way to drought-proofing your property by utilising landscape patterns in ways you may not have thought possible. We have a lot to go through and so in the Spring edition we will show you how to bring all of the information together into a useful and useable plan.
Introduction
“There’s nothing more convincing than the accomplished fact!i”
This is a resounding truth that the late P.A. Yeomans wrote way back in 1958 in “The Challenge of Landscape”. Equally as resounding is that Keyline Design has not been used to its full potential in the Australian landscape. A diversion drain here and there, maybe a bit of contour plowing as well, but too often only as a last measure when the land is slipping away.
How quickly a good season or two(as now seems evident!) would appear to lull many into not using the better seasons that we have to create the conditions where we protect ourselves against the vagaries that the Australian climate throws us.
It’s now over 40 years since P.A. Yeomans released his epic The Keyline Plan. Since then the precepts of Keyline Design have lived on and developed into the most viable, practical and cost-effective method of whole farm design available to Australian agriculture.
P.A. Yeomans put forward the Keyline Design plan with the intention that it be easily understood by the average land-holder. With this, I hope that the following article will help you to be able to get a rudimentary plan done of your property.
Some of What I’ve Seen
How many people over the years have seen, heard or have been to Keyline Design properties, with most, including myself, coming away amazed at the sheer simplicity involved in the design.
In February 1994 I attended a 3-day Keyline Design course held in the Albury-Wodonga district run by Chiltern Permaculture and Agricultural Consultant Vries Gravestein and Albury sustainable agriculture machinery manufacturer and earthmover Alan Lehmann. We visited about 5 properties in various landscapes(both flat and undulating), with one in particular sticking in my mind.
It was owned by the McGaffin family, at Castle Creek, to the south east of Wodonga. Their story in the early 1980’s was fairly typical of the time. Their 640 acre undulating granitic grazing property was at the crossroads. Conventionally it was getting that way that it was too small and they had done all the improving they could. But the size was just not there. Having an interest in Keyline, the family decided upon a path of development that would require no more land, just the ability to bring more of it into sustainable production.
Seven dams and 180 acre feet of storage capacity later, the McGaffin family are now able to irrigate 60 acres of summer pasture and 80 acres of autumn pasture year in year out – drought or no drought. In dollars and cents their Keyline development meant an extra 50 cows and calves due to the irrigated pasture. At 1994 prices(certainly not 1996!!) that translated to an extra $15 000 to $20 000 per annum. To buy the amount of land needed to carry that extra stock, John McGaffin reckoned he would have to have had spent $250 000. The total cost of his project: $87 000(and tax deductable!!!). And the investment would have paid for itself in around 6 years!
John also employs Keyline pattern cultivation to great effect with a single tyne ripper – very encouraging for those who have only a small tractor and that kind of implement.
The McGaffins still farm a profitable and easily managed property, one which at the time of our visit John remarked, was often irrigated by his 11 year old daughter without any difficulty and on a fairly large scale. It is pertinent to view this property as a simple and achievable model for many others on both larger and smaller holdings. And could follow, as I do on many of my consultancies.
My personal belief and observation is that what most Keyline properties are missing by and large is the total use of all of the Keyline Design principles to their full extent and benefit. Taking things further where we integrate Contour Strip Forests and Tree Crops into this system could only create even greater advances in production.
Another related point that a farmer friend of mine from Minyip(in the Victorian Wimmera) told me recently, is that ever since farms became larger the farmer could no longer manage them as he once could.
” Once a bloke could control all the weeds on and around his block, now you’re that flat out trying to manage the place that you can’t do that anymore, and so now we’re experiencing more and more problems…”
Simply using one or part of the different applications involved in Keyline Design does not give the design system it fullest productive potential. Not looking at the myriad methods available to us(in addition to Keyline) really does not give our farms(or ourselves!!) the scope for Keyline to show its full potential.
As I mentioned in my last article, we have as a nation not picked up the ball when it comes to a wholesale policy of embracing any particular farm design concept. Keyline Design has for a long time represented Australia with a land design system that is viable, permanent and sustainable. Of course include some Permaculture Design Ethics and Principles and the latter day Whole Farm Planning precepts and you have something very productive indeed!!
I read with interest in the April edition of the Murray Basin Landcarer, that on a flatter landscape “Keyline contoured alleys in association with drainage and water storage systems” have been employed. This is quite notable as the potential integration of these two systems is one of the ways we can attain higher levels of sustainability.
The emphasis on the use and integration of trees has always been a feature of the Keyline Design System. Shelterbelts growing between diversion and irrigation drains/channels, (in the better Keyline properties) have been renown for their successful growth in country conventionally considered not suited to the species selected.
Prior to any Keyline Design development being undertaken you should consult any of the Keyline books and literature available to you(see the resources and referenced list at the end of this article). This will give a more technical and historical appraisal of this much written about agricultural method.
The Keypoint and Keyline
For the benefit of those who don’t have a copy of the Autumn 1996 issue of Town and Country Farmer (see the back issues section to get your copy), I will again explain how to find these on your property. If we were to look at a contour map then the Keypoint would be where the contours in a gully suddenly became closer, thus indicating a sleeper slope (see Figures 1 and 1a for a graphic illustration of where a Keypoint lies).
The Keypoint is essentially a point in a primary gully where the landshape changes from being concave to convex. It has also been described, in more undulating conditions as where, above which cultivation becomes difficult because of the slope’s steepening angle.
In supposedly flat conditions it has often been suggested to me that Keyline is not an appropriate method of whole farm design. I would suggest that this is not the case (of course!!). There is no such thing as a totally flat landscape. Water always runs somewhere in its endeavour to return to the oceans.
In the flatter landscape one has to look at the situation as being broader in scale, with often the sort of land-use being different altogether to that of more undulating areas, eg. with cropping sometimes more appropriate than grazing (although not in all cases), with perhaps less irrigation taking place.
In flatter country we have to be much more precise especially where we are intent on irrigation, hence the conventional use of lasering to effect an optimal spread of the water used. Using Keyline Design in these circumstances we still need to survey precise levels. There is however, a greater emphasis on using the existing landscape pattern as opposed to creating very straight and lineal landscapes. These are often created using methods that are at the expense of soil structure and of the soil itself(ever noticed how much dust laser grading raises??).
Getting Started
Now if you read the first article I wrote in the Autumn edition of Town and Country Farmer, I had a list of items required for designing your property using Keyline principles. For those who did not read it you will require a few tools for the job.
* an aerial photo
* some clear plastic overlay
* some overhead projector markers(both permanent and non-permanent)
* a Rotring T20F eraser
* a contour map of your property
* a scale ruler(s)
* an A4 graph paper page
* a calculator
* a copy of Water for Every Farm – The Yeomans Keyline Plan by P.A. Yeomans edited by Ken B. Yeomans(see resources/references)
How I put the Map together
A lot of people may have had difficulty getting the resources necessary to help them get a whole farm layout plan put together. To help you, the process I use whenever I start a design goes as follows:
Get a Parish plan(or Cadastral plans) of your property. These can be arranged through Local or State Conservation/Lands departments.
An aerial photo of your property can be attained through government bodies such as VicImage in Victoria and through Conservation/Lands departments in other states. Even if you do not follow this process through, these aerial photos are essential cost-effective tools, I think, for any land-holder. There is also some Whole Farm Planning courses where you can get substantial subsidies on the purchase of these plans, that make your costs very small.
It is worthwhile having the aerial photo laminated so that it is protected from the rigours of the planning process eg. Feature marking out in the field, coffee spills, etc.
Clear plastic overlay is quite expensive and is available from bigger stationery suppliers. An alternative is to(as I do!) get off-cuts from poster laminating shops. They can sometimes be a bit crinkly, but do not cost anything!! If either aren’t available then you can get away with using clearer tracing paper. Have enough so that you can have several layers of information available on separate sheets, without cluttering or cramming all of it onto one sheet.
For contour or topographical maps I use quite a few different sources. I am an avid map collector and have most of the maps I need stored here, but if I do need them I go to Information Victoria, for 1:25 000 series topographical maps. These high quality maps cover a great part of Australia and usually have 10metre elevation contour intervals.
In some cases 1:10 000 maps are also available with contour intervals of between 2 and 5 metres(which is obviously better). Other sources for topographical maps are local government offices, water authorities, and sometimes orienteering clubs.
Orthophoto maps or aerial photos with contours on them, which although expensive are excellent mediums for this kind of work. These are available again through the appropriate government departments.
Now you have these tools you need to create a map for your property at scale similar to your aerial photo. The easiest way to do this is to use an enlarging/reducing photocopier. First of all though, you will need to familiarise yourself with both the topographical map and aerial photo and find reference points that are marked on both. This should be fairly easy as most topographical maps are referenced from the very aerial photos that are available to the public.
Information such as fences, dams and buildings are the best reference points. Start by taking both of your maps to the photocopy shop. I would suggest that a least your boundary fence and/or house and dams will be marked on the contour map. Blow up your property on the photocopier until the features you have chosen(the house, fences etc.) until they are in the same relative position as those on the aerial photo. You do this by overlaying the photocopy onto the aerial photo until the feature match up. With your official boundary and title information you follow a similar process, only you use the fences and roads as features.
Now you have done this you will need to transfer your enlargements onto your plastic overlay. This is accomplished by firstly positioning and fixing(I use Blutac) the photocopies onto the aerial photo, so that everything matches up. Then you trace the contours, boundaries/fences, roads, etc. onto the overlay. Now take the photocopies away and you have the map you need to do a Keyline Design!!!
Another thing you should take into the photocopier’s is a piece of graph paper. Get them to do a direct copy onto a clear transparency. You will need this to calculate catchment areas etc.
As Ken Yeomans points out in Water for Every Farm – The Yeomans Keyline Plan,
“The design process often reveals unsuspected potential and dispels illusions. It is a satisfying experience.” This truth is on the way to being divulged.
Understanding and Using your Maps
Keyline Design is based around the use and recognition of the existing landscape to make productive and effective use of the soil and water resources available. It is essential that an understanding be reached as to how the landscape functions, so that we may design a system that makes the most of these rather fixed, yet improvable resources. One also has to understand both the maps we have prepared and others we need for the process of design.
I often think of the landscape as being something akin to the roof of a house. It is designed(created) by nature to have water removed in the quickest possible way back to the oceans. A house roof operates in a similar way. The main difference being that the efficiency with which water runs off is much less on the land. This factor is one we can use to our advantage. We can keep rain where it falls.
There are some base terms used in Keyline Design that describe simple landscape characteristics, or as Yeoman’s put it, Primary Landforms. (See Figure 2)
Main Ridge
Describes the elevated land that divides creek systems. It is the dominant land shape in the “Keyline classification to topography…”ii
Primary Valley
Are the valleys formed on a main ridge. These are the valleys that contain keypoints. Keylines run out towards the adjacent ridges BUT STAY WITHIN THE VALLEY
Primary Ridges
Are the areas in between each of the primary valleys, which again are part of the dominant main ridge. As on the main ridge, the primary ridges have a water divide line, a line where water will fall either one side or the other, rather like the ridge-capping on a roof.
Also you will need to understand how the contours of a map relate to the land’s shape they describe. Looking at Figure 3 you can see the different landforms, contours and descriptions arranged graphically.
The Next Step
To relate the Keyline landform classifications to your own land you will need to have both the map you’ve made and the larger, original topographical map that goes beyond your boundary.
You will first of all need to mark where the Main Ridges, Primary Ridges and Primary Valleys are on your land. Do this on the first overlay. Now you can start to see in a graphical way the pattern of water flows, and gather which are the areas that form the various catchments of each water-shed.
Sometimes you will find, particularly on flatter and smaller properties, that the catchment area of a water-shed begins on someone else’s land. This is the reason why you need to have your larger topographical map and the graph paper transparency at the ready.
On this same layer also mark what you believe are the Keypoints of each of the Primary Valleys and the water divide lines of the Primary Ridges. At this stage you will realise that a walk over the property will be needed to get particularly the Keypoints in the right spots.
It is also worth noting some advice that David Holmgren(of Permaculture fame) gives and that is, “the map is not the territory,” and so you will need to reference and view your map with this in mind.
You will also need to ascertain the scale at which your map is at. This is simply done by using two points on the map that between which you know the distance. Sometimes aerial photos can have some distortion for a variety of reasons, and so it is worthwhile determining the distances between these two points physically. Make sure that these two points are clearly visible on the photo
Given that you have measured this distance, you can now establish the maps’ scale (I will use metric being a child of the late 1960’s!!). Say the length of a fence on the ground is 200metres. On the aerial photo it is 150millimetres. The formula to follow is then:
SCALE =
200m x 1000
150mm
= 1333.333
= 1:1333
1cm = 13m
Now that you have done that you can have a go at marking out your catchments so that you can calculate their areas. Once done you will be able to determine the amount of water available to you. This is done as follows: Look at Figure 5 to see the catchment boundaries denoted using the contours.
Overlay the graph paper overlay(remembering first to work out the scale of it in relation to the plan you are working with. If the squares at the scale we worked out equal 13m every cm then each box is 169 square metres. On larger catchments you may need to aggregate the cm boxes into larger squares so that there maybe 10 x10 cm squares – which would equal 16900 square metres: 1.69 hectares. Count the squares within each of the catchments and total them. Say there are 15 larger squares; this will mean 25 3500 square metres or 25.35ha. of catchment. The following tablesiii will allow you to now estimate the amounts of run-off sourced within these catchments.
Table 1.1
Once you’ve worked out a figure then use the following tables (Tables 1 & 2) to generate the total average run-off figures for a whole or given catchment. An engineer would also ascertain this as part of their investigation.
Table 1 – RUNOFF FROM CATCHMENTSi
|
Runoff as a % of average annual rainfall (Y) |
|||||||
|
Average annual rainfall (R) (mm) |
Total annual evaporation (mm) |
Reliability (years out of 10) |
Shallow sand or loam soils (%) |
Sandy clays (%) |
Elastic clays (%) |
Clay pans, inelastic clays or shales (%) |
|
|
> 1100 |
8 |
10 to 15 |
10 to 15 |
15 to 20 |
15 to 25 |
||
|
9 |
6.5 to 10 |
6.5 to 10 |
10 to 13 |
10 to 16.5 |
|||
|
901 to 1100 |
8 |
10 to 12.5 |
10 to 15 |
12.5 to 20 |
15 to 20 |
||
|
9 |
6.5 to 8 |
6.5 to 10 |
8 to 13 |
10 to 13 |
|||
|
501 to 900 |
less than 1300 |
8 |
7.5 to 10 |
7.5 to 15 |
7.5 to 15 |
10 to 15 |
|
|
9 |
5 to 6.5 |
5 to 10 |
5 to 10 |
6.5 to 10 |
|||
|
1300 to 1800 |
8 |
5 to 7.5 |
5 to 12.5 |
5 to 10 |
10 to 15 |
||
|
9 |
3 to 5 |
3 to 8 |
3 to 6.5 |
6.5 to 10 |
|||
|
401 to 500 |
1300 to 1800 |
8 |
2.5 to 5 |
5 to 10 |
2.5 to 5 7 |
7.5 to 12.5 |
|
|
9 |
1.5 to 3 |
3 to 6.5 |
1.5 to 3 |
5 to 8 |
|||
|
250 to 400 |
<1800 |
8 |
0 to 2.5 |
0 to 5 |
0 to 2.5 |
2.5 to 7.5 |
|
|
9 |
0 to 1.5 |
0 to 3 |
0 to 1.5 |
1.5 to 5 |
|||
|
>1800 |
8 |
0 |
0 to 2.5 |
0 |
2.5 to 5 |
||
|
9 |
0 |
0 to 1.5 |
0 |
1.5 to 3 |
|||
Elastic clays when dry develop pronounced surface cracking, which reduces runoff.
Inelastic clays are identified, when dry, by a fine dust cover; this dust prevents seepage into the ground and so increases runoff.
For irrigation schemes a reliability of 8 years out of 10 is acceptable, for domestic and stock schemes the aim is 9 years.
Table 2 – ESTIMATED ANNUAL RUNOFF FORMULA
Catchment runoff = 100 x A x R x Y litres
where: A is the catchment area in hectares (ha)
R is the average annual rainfall in millimetres (mm)
Y is the runoff as a percentage of annual rainfall
eg.
A small catchment of 100 hectares is forested and the soil is sandy clay. It receives an average annual rainfall of 750 mm and has an annual evaporation of 1000 mm. What would the estimated yield be for an irrigation scheme?
A = 100 ha1
R = 750 mm
Y = 7.5 % (reliability of 8 in Table 2)
Therefore runoff = 100 x 100 x 750 x 7.5
= 56 250 000 litres
= 56.25 megalitres (Ml)
Table 1.2
Some Typical Yields From Catchments
Treatment Yield as a % of annual rainfall
Roaded catchments
400 mm – 5%
800 mm – 30%
1100 mm – 60%
Bitumen – 80%
Roads:
Gravel – 60%
bitumen or
concrete – 90%
Most Solid Roofs – 80%
Spread-bank tanks – 50% for rainfall in excess of 400mm
Examples:
(a) 1 ha of roaded catchment in a 400 mm annual rainfall area
(b) 2 ha of gravel road in a 750 mm annual rainfall region
(c) A house and shed of 200 sq.m with a rainfall of 1000 mm
Solutions:
(a) Roaded catchment
5/100 x 400/1000 x 10 000 = 200 cubic metres = 200 000 litres
(b) Gravel road:
60/100 x 750/1000 x 2 x 10 000 = 9000 cubic metres = 9 000 000 litres or 9 Ml
(c) House and Shed:
80/100 x 1000/1000 x 200 = 160 cubic metres = 160 000 litres
References
i Yeomans, P.A., 1958 The Challenge of Landscape, The Development and Practice of Keyline, Keyline Publishing Pty. Ltd., Sydney.
ii Yeomans P.A., K.B. Yeomans ed. 1993, Water For Every Farm – Yeomans Keyline Plan, Keyline Designs, Southport, Queensland.
iii Nelson, K.D., 1985, 1991reprinted, Design and Construction of Small Earth Dams, Inkata Press, Melbourne.
Yeomans P.A., 1971, The City Forest – The Keyline Plan for the Human Environment Revolution, Keyline Publishing Pty. Ltd., Sydney.
Yeomans P.A.,1968, Water for Every Farm – A practical irrigation plan for every Australian property, K.G. Murray Publishing Co. Pty. Ltd., Sydney.
Campbell, A., 1991, Planning for Sustainable Farming – The Potter Farmland Plan Story, Lothian Publishing Co. Pty. Ltd., Port Melbourne.
Mollison, B, 1985, Permaculture: A Designers Manual, Tagari Publications, Tyalgum, N.S.W.