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Articles 1 - 7 of 7
Full-Text Articles in Physical Sciences and Mathematics
Water Supplies : Dams And Roaded Catchments, W J. Burdass, T. R. Negus, A. L. Prout, I. A. F. Laing
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
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
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
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
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
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
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.