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CHAPTER SIX
Design for Environment
If there had been no primary valleys there would be no primary ridges and the main ridge would be the only shape in the landscape and stretch from creek to creek and the creeks would be its boundaries.
But the intrusion, so to speak, of primary valleys into this one massive main ridge shape, gave the land three shapes and assisted in making three land forms. The primary valleys provided higher gathering places for water and higher sites for storing it below the amphitheatre where the three shapes unite and where water continues its attack. This is the place where the landscape can be made stronger, the focal point for improvements to be carried forward--the Keypoint for landscape designs.
The objective of landscape design has been stated at the end of Chapter 4, (1) to control and to use for the benefit of the landscape the water which, in the natural landscapes and in the present landscapes of man, flows over the surface of the land to the water courses, and (2) to improve the pattern of behaviour of water which falls as rain on the ridge shapes of the land, for the benefit of the landscape. The second is accomplished by designs for techniques which operate within the new design for the landscape and is dealt with in Chapter 12, Water the Forest.
The first objective--the control and better use of water--is the basis of landscape design. It is simply the addition of two new water lines to the landscape design of Nature.
The first water line is for the better control of water, the second is for the improved use of water.
We start off on a farm: if the area of land to be designed has a boundary fence which encloses only a part of the main ridge and one primary valley and its adjacent primary ridges, the first new water line would be placed so as. to divert the run-off from rainfall on the higher land to a storage site at the Keyline of the primary valley. This is the highest site for water storage in the highest valley of the landscape.
The storage dam in the primary valley is equipped with an outlet pipe to release the water to the second new water line. It uses the stored water to irrigate the land. Added to this plan can be a lower storage from which water would be pumped up to the irrigation dam.
The first new water line is a diversion channel to control the run-off water from rainfall; the second new water line is an irrigation channel to water the land. The design is made to suit the improved use of water during heavy run-off periods which provide water beyond the absorption capacity of the (and and the limits of the storages, (Chapter 12, Water the Forest).
These two new water lines are different from the water lines of Nature's landscape design. Whereas the natural drainage lines and water-divide lines do not touch, the new water lines cross over the drainage line of the primary valley and the water-divide line of the primary ridge. They may go on to cross the land and join up several primary valley drainage lines and primary ridge divide lines. In the same manner they cross over the water-divide line of a main ridge and join up with the drainage line of a creek or stream. They may thus connect up two or many unit-regions.
Now a concept is introduced which years ago helped solve the author's problem of designs for the farmscape. Called THE KEYLINE SCALE OF PERMANENCE, it is an order for planning based on the relative permanence of the various items which together make up the completed landscape. In the next chapter the concept will be applied to the design of the town and the Cityscape.
This is the scale:
The first three of the eight factors of the scale of permanence--climate, land shape and water--are THE INSEPARABLE TRINITY OF LANDSCAPE DESIGN.
The first two factors, climate and land shape, are the more or less unalterable background of the landscape. Water, with its lines and its patterns of flow, is the first factor of the landscape design of Nature which we change.
The two new water lines added to the landscape have a fall down the land--the same way the creek falls--but their gradient is made less than that of the creek below. Therefore the further the two new lines are extended, the greater the height difference between them and the creek below, and progressively more land lies between the new water lines and the drainage line of the creek.
Water is thus retained at higher levels on the land. Before it may join the water courses to flow on to the sea, it must cross-over the surface or go through the soil of the landscape.
The new water lines for city as well as for farm, are permanent features of the designed landscape. All factors below them on the scale are made to fit in with these new but now permanent water lines.
The fourth factor, roads, fit in with the new water lines. A road follows alongside the diversion channel right through to the boundary. The diversion channel with its associated road, has now added a 'zone' to the land by dividing the main ridge and the higher parts of the primary ridges--the high catchment area--from the rest of the land. Another road follows along the crest line of the main ridge to service this zone. The sites for shelter trees (the fifth factor) and for buildings (the sixth factor) with their work areas are positioned in this first zone of the land.
A second zone is added by the line of the irrigation channel which likewise, with its service road, divides the region from end to end. The second zone is thus bounded by the diversion channel above, the irrigation channel below, and the boundary fence at opposite ends.
The land which contains the areas for irrigating thus lies in another zone--the third zone of the land. This zone has a lower boundary; a channel; which controls the final overflow of water when it is in excess of the capacity of the soil and the storages.
The land lying between the lower boundary of the irrigation land and the creek, is yet another zone, the fourth zone of the land.
The four zones, with their service roads are connected. The site for this road is along the divide-lines, or centre lines, of the one or two large primary ridges in each unit-region. A primary ridge usually has a more or less uniform slope from the main ridge through to the creek below.
The system of new water lines and their roads has not only added four zones to the regions of Nature's landscape design; it has divided those zones in either two or in three parts by the one or two roads which connect and go through them. This further division of the natural regions provides the basis for the complete subdivision of the farmscape, or the cityscape--the seventh factor of the scale.
The fifth factor on the scale of permanence is trees.
Trees are absolutely essential for the health, for the balance, for the efficiency and for the aggrandisement of all the special purpose landscapes of man. If, as is said, they are second only in place to the diatoms of the seas for the supply of atmospheric oxygen, then trees and millions more trees are essential for the total environment.
They must be planted or 'left' in the right places. A plant, or a tree in the wrong place is a weed.
In the farmscape some trees will be associated with the layout of the new water lines, the roads and the fencing of the new zones. They are planted--or left in the initial clearing of land--to shade the stock and to break the winds which dry out the land. They provide in their leaf fall the elements from deep-down for the balance of the soil. But in landscape design, trees have another and special province. The strip forests for the farm and the City Forest for town and city, protect the natural drainage lines and the seas from the waste products which may remain in the water that flows from the land.
The strip forests of the farmscape are located principally in the fourth zone of the land. All water which may flow overland from the three higher zones is directed automatically into them. The water is absorbed into the deep soil of the strip forests and is cleaned and reconstituted before it flows to the streams. (Chapter 11, "Soil and Trees").
All primary valleys or perhaps even most of them do not possess suitable sites for storing water at their Keylines; the shape of the valley must have economic and practical significance for the purpose. If three primary valleys of the series in the one main ridge system have good storage shapes, these three valleys govern the position of the diversion channel. Because main ridges have a general rise toward the top of the region, the primary valleys tend to have a progressively rising relationship. In the opposite direction--with the fall of the creek--it is a failing relationship. The heights of the Keylines of the selected primary valleys are determined so that the one diversion channel may fall to the first storage site and continue beyond it to connect up with the other two sites. In this way the overflow water from the highest storage dam follows the diversion channel to help fill the dams further on down. In like manner the second new water line--the irrigation channel--connects up from dam to dam. When there is more water to be stared and more sites needed for storing it, the diversion channel and the irrigation channel are repeated and connect up the new storages lower down in the primary valleys. Zones two and three are then repeated above zone four.
The countryside has not been divided along the natural water-divide lines or according to the unit-regions, the twin regions and the larger regions of Nature. Boundary lines of farms generally cut across natural unit-regions since so many have been determined with a straight-edge on paper. Landscape design is not simply a matter to be applied only within the boundaries of the regions of Nature's subdivisions of the land, but within boundary fences. For instance, the higher boundary of a farm may start on a main ridge and divide a unit-region by crossing over a creek and the main ridge on the other side, and may include the head and one half of the next unit-region. The property may already have a good boundary fence, many subdivision fences, a stock dam in each paddock, roads through the farm, a homestead, other buildings and work areas. Moreover it may have been over-cleared of timber with trees left only in the steep places or standing in the "back-paddock."
Of the development work which was put in over the course of many years, only the boundary fence may be correctly located. There is a good chance also that the homestead--the sixth factor of the scale--is well positioned since this is often decided by the womenfolk. Because they like to overlook the entrance to the farm and the work areas, the homestead--more often than not--is located on a main ridge or on the higher part of a primary ridge.
To redesign such a farm the same two new water lines dominate the plan but there are several considerations which may determined their location. For instance on this particular property the water to be controlled does not all fall as rain on the farm, since, as one boundary fence crosses a region, water from outside the farm flows in via a creek. This source of water may be greater than from rain failing on the farm itself.
Design starts with the control of the water of greatest landscape significance, This is invariably water of greatest quantity and lowest cost.
Firstly the entire property is examined to determine the water resources available, to pin-point the features of the landscape and to envisage and decide on the landscape design for the farm.
Secondly, the most advantageous place for a starting-off project is selected. The prime requirements are that it fit the landscape design and be of such significance that it will quickly enhance the overall production and value of the farm. It proceeds by progressively controlling all the water resources which have profitable significance.
While these principles of design are universal in their application, there will be only one way to design each landscape. Every special purpose landscape will be unique; there will be no other like it on the face of the earth.
The last of the eight factors of the scale of permanence is soil.
Natural soils were not always fertile but when soil was fertile it was the great storehouse of the renewing and renewable surpluses of Nature. In the fertile natural grasslands and nearby forests, all the life in the landscape lived on the surpluses of Nature which had been provided by time and the reactions of the air, the water, the rocks of the earth and the heat and the light of the sun. They have lived, bred and died for countless generations yet the surpluses of Nature remained intact. THIS IS THE BALANCE OF THE LANDSCAPE.
The history of mankind in his series of leaps and retreats type of conquest of the earth, is the story of his discovery and exploitations of the great surpluses of Nature held in the soil and in the earth.
A fertile natural soil may be deprived of its fertility surpluses in a few decades as the various races of man have ably demonstrated over thousands of years.
But there is another side to the story of soil, which will be dealt with in the Chapters "Soil Sense" and and "The Bastardisation of Agriculture". Impoverished soil can be made fertile again and soil which was originally low fertility, can be made deep and fertile--both in a short space of time.
The management of this design for the farmscape is concerned with the improvement of the fertility of the soil. Therefore it is concerned to see that all the wastes of the farm from plants and from the urine and the dung of animals is absorbed again into the soil where it rightfully belongs. It is concerned to see that water which leaves the farm does so by first being absorbed into the soil to improve it, so that, as a coincidental, nothing from the farm may pollute the common waters of the land and the seas. The management of the design for the cityscape and for all the special purpose landscapes of man is likewise concerned with these same matters.