L. A. BY WADE. <i." LXxV, 
the natural conditions. It is certain that the Murray 
watershed now responds to rainfall much more freely than 
it formerly did, and no doubt this effect has been produced 
by the puddling of the surface by the trampling of stock. 
Also, tracks to watering places become smali tributaries 
during rainfall. With regard to the extensive ring-barking 
which has been indulged in by all the pastoralists, it is more 
difficult to trace cause and efiect. There does not appear 
to be any evidence to shew that the destruction of forests 
causes a diminution of the rainfall, but there is no doubt 
that the presence of bush causes a catchment to run off 
during a longer period, thus increasing the low flow in the 
rivers. Trees and bush also prevent erosion of the soil, 
and this is a most important point, some large storages 
have already been spoilt by the quantities of silt carried 
into them. The importance of shade trees, both for man 
and beast, has not yet been recognized in the country, and 
forest conservation is ina most backward state. The most 
profitable policy would be to arrange that the conservation 
of water and trees should go hand in hand. 
The last few dry years have conclusively proved that 
before any large diversions can be made from our rivers, it 
will be necessary to construct large storage reservoirs to 
supplement the flow in bad seasons. As may be supposed, 
the opportunities for storage are different on each river. 
When the river flows continuously throughout the year, 
the fluctuations can be controlled by a capacious storage 
at the head. This would usually be made by building a 
high dam across the stream, preferably at a point where 
the channel runs through a narrow gorge. When the 
location permits of the water being led out by a cutting 
and brought to the surface of the country by gravitation, 
the problem of irrigation at once becomes easy and 
profitable. 
