Physical Sciences and Mathematics Commons^™

Unconventional Energy, Fall/Winter 2015, Issue 31

Sustain Magazine

No abstract provided.

Water Supplies : Dams And Roaded Catchments, W J. Burdass, T. R. Negus, A. L. Prout, I. A. F. Laing

Journal of the Department of Agriculture, Western Australia, Series 4

Western Australia's Upper and Lower Great Southern statistical areas include most of the broad-scale agricultural land south of a line from Perth to Hyden. Much of the area is well-developed and carries 13.4 million sheep, 203 00 cattle and 95 000 pigs, almost half the State's livestock.

There are few natural rivers and lakes to water livestock in summer and much of the bore water is salty. On-farm waterr conservation, therefore, consits mainly of excavated earth tanks (dams) which are filled by surface runoff or shallow seepage. In the drier areas and in the sandplain roaded catchments have neen built …

Dam Site Selection In The North-Eastern Wheatbelt, J L. Frith

Journal of the Department of Agriculture, Western Australia, Series 4

Western Australia's wheatbelt farm dams are dug three to eight metres deep and are generally sited in soils which either are inherently impermeable or can be made so during construction.

In the eastern and north-eastern wheatbelt, however, only a small proportion of the soils meets these criteria. Dam site selection in these areas therefore depends on a good knowledge ofwhich soils aresuitable and on our being able to locate them efficiently by using surface indications such as surface soil, natural vegetation or topographic features.

Northern Wheatbelt Water Supply Study, I A F Laing, R. M. Pridham

Journal of the Department of Agriculture, Western Australia, Series 4

Department of Agriculture surveys have shown that many farms in Western australia's northern wheatbelt have inadequate water supplies. More than 80 per cent of all farms in that area depend soley on groundwater for watering livestock, a much higher percentage than for most other farming areas. Because groundwater salinities have increased in recent years, concern is held for the long-term future of this recource.

In contrast to more southern agricultural areas, farm dams in the northern wheatbelt are relatively uncommon. Only 30 per cent of the existing dams in the northern wheatbelt constitute effective water supplies. More than half of …

Improved Catchments For Farm Dams, I A F Laing

Journal of the Department of Agriculture, Western Australia, Series 4

The amounts and frequency of runoff from unimproved farmland catchments in Western Australia's cereal and sheep districts are notoriously variable and unreliable. As a result many farmers have constructed improved catchments to ensure better reliability of farm dams for livestock and homestead water supplies.

Improved catchments which are used extensively on these farms are all of the compacted or bare-earth type. These include roaded catchments, flat batter dams and, to a lesser extent, scraped catchments. This article mainly discusses roaded catchments, the most common of the improved catchment types on farms.

Sandplain Hardpan : A Different Dam Construction Material, A F. Mccrea

Journal of the Department of Agriculture, Western Australia, Series 4

Before 1980, the Department of Agriculture did not believe that suitable farm dam materials could be found in light land soils. However Beacon earthmoving contractor, V> J> Pavlinovich, has demonstrated that where suitable cemented subsoils or 'hardpan' existed, a succcessful dam site could be found.

This material should not be confused with compaction or traffic hardpans ehich are dense layers of soil found near the surface. Traffic hardpans result from compaction of soil materials with the passage of vehicles and farm machinery. Rather, the hardpan referred to here is a natural subsoil layer that has been cemented by silica and …

Drought Proofing The Farm : Case Studies, J L. Frith

Journal of the Department of Agriculture, Western Australia, Series 4

For many years, Western Australia's north-eastern wheatbelthas suffered chronic shortages of water for stock and domestic use. The area's averageannual rainfall is generally low - less than 300 millimetres - and droughts in the 1970s caused futher problems. manydams in the area leak or have inadequate catchmentsand groundwater is scarce ormofmpoor quality.

In March 982, the Western Australian Government provided $100 000 for the Department of agriculture to demonstrate the potential of establishing permanent, drought-proof water supplies on farms in the north-eastern wheatbelt. The methods were to use exixting techniques to build dams and catchments. In a year of low …

Chemical Sealing Of Earth Dams, R G. Pepper

Journal of the Department of Agriculture, Western Australia, Series 4

Leakage is not a major cause of failure of farm dams in the Western Australian wheatbelt, but it is a problem in some districts where it can limit stock carrying capacity. Leaking dams are especially common in the West midlands, the north-eastern wheatbelt and the 'jarrah-belt' which extends from Bindoon, southward to Manjimup and Mt Barker (see map and Table 1).

Some dams which leaked when first built have sealed themselves over the years. Others have been successfully sealed using sodium tripolyphosphate.

Test Sites For Farm Dams, Department Of Agriculture, Western Australia

Journal of the Department of Agriculture, Western Australia, Series 4

A short article outlining procedures for testing potential dam sites.

Farm Dams In The Wheatbelt, I A F Laing

Journal of the Department of Agriculture, Western Australia, Series 4

Of the estimated 76 000 farm dams in the wheatbelt, about 8 per cent either leak or are salt affected. The remaining 70 000 dams are capable of holding water for livestock use and can be regarded as sercicable dams.

A great many of the serviceable dams are unreliable water supplies due to the combined effects of lack of runoff from catchments, shallow depth of storage and small size of storage in relation to expected demand from livestock and evaporation loss.

Design Standards For Farm Surface Water Supplies, J L. Frith

Journal of the Department of Agriculture, Western Australia, Series 4

Design is usually concerned with getting adequate return from limited recources. Farm dams which dry up represent dam failure. Less seriously, so too do dams which, although not drying out, never fill; they waste a recource.

A Logical Approach To Wheatbelt Water Supply, Stanley Thomas Smith

Journal of the Department of Agriculture, Western Australia, Series 4

My particular task in this seminar (paper) has been to enunciate a logical approach to water recource utilisation in the wheatbelt, based on the points made by the speakers.

Sealing Farm Dams, I A F Laing, R. G. Pepper

Journal of the Department of Agriculture, Western Australia, Series 4

Research over the past 10 years has shown that it is technically possible to seal many leaking farm dams. In some situations a cheap chemical treatment is effective but in most cases it is cheaper to construct a replacement dam.

This article reviews the situation in western Australia and outlines some of the methods used for sealing dams.

Farm Dams In High Rainfall Areas, G C. Brown

Journal of the Department of Agriculture, Western Australia, Series 4

WATER storage is essential on most south-west farms to ensure adequate irrigation supplies in the dry summers. Government irrigation water supply schemes are limited and most farmers must supply their own water storage.

Reducing Evaporation From Farm Dams : A Progress Report December 1969, I A F Laing

Journal of the Department of Agriculture, Western Australia, Series 4

IN most seasons in the Western Australian Wheatbelt evaporation reduction techniques rate a low priority due to either the expense or the relative inefficiency of the techniques.

It is generally agreed that a similar investment in deepening or enlarging existing dams, or making new dams larger from the outset, is likely to be more profitable.

Water Conservation : The Storage Life Of Farm Dams, D J. Carder

Journal of the Department of Agriculture, Western Australia, Series 4

HOW MANY stock can a dam of a certain size and depth be expected to carry and how long will the supply last?

What size of dam is needed in case the winter rains fail? How many stock can a dam support and still provide a drought supply?

Water Storage Has Not Kept Pace With Stock Numbers : South Stirling Survey Finding, A L. Prout

Journal of the Department of Agriculture, Western Australia, Series 4

RESULTS of a survey on water storage capacity in the South Stirlings area indicate that farm water storage has not kept pace with increased clearing and stock numbers.

This has resulted in many farmers requesting advice on water conservation projects following two consecutive years of low rainfall runoff.

West Midlands Development : Water Supplies In The West Midlands, I A F Laing

Journal of the Department of Agriculture, Western Australia, Series 4

IF it is practical and economic to develop both surface and underground supplies, the aim on each farm should be to provide half the farm water requirement from dams, and the other half from bores.

How To Measure The Capacity Of Farm Dams, G Gauntlett

Journal of the Department of Agriculture, Western Australia, Series 4

AT some time or another nearly every farmer needs to be able to measure the capacity of an ordinary farm dam of the "excavated earth tank" type and many requests are made for a method of calculating this volume.

This article describes how this can be done.

Planning New Farm Dams : Excavated Earth Tanks, J E. Watson, J. C. Grasby

Journal of the Department of Agriculture, Western Australia, Series 4

A GOOD farm dam is a valuable asset, and well worth its cost, but there are many aspects to consider when a new dam is required. Careful planning with adequate testing and checking will help to get the best value for money and reduce the chance of costly failures.

This article discusses these aspects in relation to the excavated earth tank type of dam.

Farm Dams In The Wheatbelt, J E. Watson

Journal of the Department of Agriculture, Western Australia, Series 4

MANY new farm dams are sunk each year in the wheatbelt and much money is spent on them.

With continued development of new land, and increasing stock carrying capacity of older land under legume pastures, the need for more water supplies will continue for a long time.

Water Conservation On The Farm, John W. Lewis

Journal of the Department of Agriculture, Western Australia, Series 4

SMALL scale conservation of water for agricultural use is becoming increasingly important throughout Australia.

As land development intensifies, it is natural that farmers turn to more dams and earthen tanks for stock water and irrigation.

Adequate water is essential to supply the carrying capacities made possible by improved pastures, and where greater quantities of water can be stored, fodder crops, pastures, orchards and vegetables can be irrigated.

Overcoming Stock Watering Problems In The Kimberleys, B Swan

Journal of the Department of Agriculture, Western Australia, Series 4

ONE of the ever-present problems of the pastoral areas is that of providing: watering-points in reasonably close proximity to the grazing areas.

All too frequently, the country on the river frontages and that in the vicinity of the water-holes becomes eaten out and although there may be ample feed on other portions of the run, it is too far distant from the available water to be effectively utilised.

Contour Banks For Filling Dams, B A'B Marsh

Journal of the Department of Agriculture, Western Australia, Series 4

A LTHOUGH contour banks have been used in this State for many years to lead water into earth tanks or "dams," it is only comparatively recently that the idea has become really popular.

Thanks to the publicity given to this matter during the last three years many farmers now know that dams may be filled by contour banks, but because they do not know the finer points of the method, they are apt to mislead themselves into thinking that their territory is unsuitable for putting it into practice.