SUMP DRAINS OR SOAKAWAYS

Otago Daily Times, Issue 23221, 19 June 1937, Page 7

SUMP DRAINS OR SOAKAWAYS

UTILITY AND LIMITATIONS The great importance of good drainage is always stressed in any instructions concerning cultivation of the soil. Nevertheless, far too many small gardens in thickly-populated areas are waterlogged to a degree which causes partial failure of many kinds of plants and total loss of some. It is all very well to say that the means of improvement in such conditions lies in the adoption of a proper system of pipe drainage. Such means are within range of possibility where extensive areas are dealt with, but pipe draining involves necessity for a proper outlet for all the water collected by the pipes, and one garden-owner cannot discharge the surplus water on to another’s ground. In the majority of cases the only practicable course open to amateur gardeners is to make a sump drain or

soakaway, and, although such have their defects and limitations, there can be no doubt that the benefit derivable is such that the slight cost and, perhaps, arduous labour of construction, wil be amply repaid. HOW SOAKAWAYS OPERATE

The basic principle of forming a soakaway is to draw the water to a lower level than that at which it stands under the surface soil. One starts by selecting a position at the lower end of the garden, or, in the case of a hollow, at its centre. When digging out the soil one will discover at what level the water is hold, and the greater the volume of water present after a period of wet weather, the deeper must be the soakaway. Four or five feet is a reasonable depth, and the diameter of the excavation must be governed by the volume of water it is necessary to draw from the surrounding ground. Whatever the depth of the pit may be, the base should not be left trodden hard, but should be forked up and broken as much as possible. On this rough floor, bricks, stones, and any hard material that will not decay should be placed, taking care to allow no soil to fall into the crevices between the rubble.

COVERING-IN When the rough material reaches to about two feet from the normal ground level, the whole should be covered with slates or flat stones in order to prevent soil percolating into the interstices among the stones and bricks, and thus impeding the passage oi i water. ( In cases where ground is oadl.y • water-logged, it may be necessary to ] form more than one soakaway, and if i the soil is of light character and easily ' moved by passing water, it is a good i plan to use bottomless barrels as walls I for each pit filling these barrels with 1 rubble. The immediate effect of drain- i age sumps is that water from a considerable area around will run into i them, and thence gradually soak away j into the lower subsoil. By this means \ the level of standing water is dropped j greatly lo the benefit of Ihe earth ; above. ; There arc. as we have already re- i marked, limitations to the capabilities of soakaways of this nature. When < water comes in great volume. *he pits < naturally become quickly filled and ' as the seeping awa” from the base \ proceeds at a slower pace,than the in- ] flux, the pit soon overflows From that i time additional rainfall must result in ; raising the level of standing water. , Nevertheless, this condition will be ol ( shorter duration than in cases where c there are no drainage pits provided j and it is infinitely better that a flooded state should occur occasionally, and fpi t brief spells, than that the soil should , be continually saturated and kept in the condition known as waterlogged r Many lawns which are constantly j wet lose their finer grasses and de- j velop moss growth. If the precaution, is taken to provide a soakaway be- , neath or at the end of such a lawn, j the condition of the grass will be £ greatly improved. , In cases where heavy clay soil has *

to be dealt with, it is sometimes advisable to dig channels from all points of the compass toward the sump, filling each of these channels to a depth of a foot with loose stones, which, of course, must be buried below a spade’s depth, so that they shall not be disturbed during digging and planting operations. A considerable amount of water will pass into these channels and find its way to the sump. Where garden paths are properly constructed with a deen rubble foundation, they help solve the problem of drainage, and if there is a slight fall in the course of the path, it is an excellent plan to form a rubble pit at its lower end. We have known instances where much good has been done by planting around the sumps strong growing shrubs and reeds, which are capable of absorbin'* a great amount of moisture. These things, by continually taking up water, help to keep the pit clear and reedy to receive furthet supplies after the next rainfall. Where pits of this character have been ormecl and have proved unsatisfactory the cause usually is that they have become clogged with soil If this happens it is well worth while to open the pit clear out the mud. line the sides with slates or old sheets of corrugated iron, and repack with clean rubble LOW-LYING GARDENS

Many gardens we have known were originally low-lying in hollows, toward which water from surrounding ground at higher level constantly found its way. When experienced gardeners have taken such situations in hand they have adopted the course of cutting deep foundations for pathways and then building up the areas for planting with soil, raising the surface six inches, or even a foot, above path levels. This has the effect of creating a deeper root run above the saturated subsoil.

There are some cases where it proves profitable to dig a deep ditch across the lower end of the garden, keeping this constantly cleaned and running channels wilh rubble drainage toward the ditch. Of course, unless there is an outlet for water from such exca r ations, occasions will arise when pan of the garden may be flooded, but here, again, it is better that this should occur at infrequent intervals than that the water-logging trouble shall be ever present.

Owners of new gardens will do well to ascertain now before introducing (heir plants whether or not it is advisable to provide sump drains A simple method of doing this is to open a few holes a yard deep to see whether water drains into them.—A. .1. M. in Amateur Gardening.

"The other day 1 was in South Wales and 1 spoke there to the headmaster of a school in one of the most distressed areas” -aid Mr Oliver Stanley Minister of Education, in a recent speech. “He told mo that he had -00 children on his books, and that during term 80 were receiving free milk. His local authority conceived the idea jI trying to extend the milk supply scheme into the school holidays, and his school was selected as one of ‘he experimental places During the Hobdays there was not a sinele dav when he had more than 10 of those 80 children as anplieants for the milk, and yet not one of those children had more than half a mi'e to walk to school *o get the milk There was, therefore no question of economics or of difficulty of supnly there; it was a problem of individuality and psychology and taste which cannot, bo solved on the basis of economics.”