LXXII. REVIEW OF WATER CONSERVATION IN N.S.W. 
that to the eastward of this line there is usually sufficient 
rainfall over the coastal strip, and such country cannot be 
said to be in urgent want of conservation works. At the 
present time, it may be said that the most pressing problem 
is the reclamation of the arid country to the west of the 
20-inch line of rainfall. 
There is no doubt that the area of irrigable land in the 
State is so large, that even if all the coastal rainfall were 
conserved and conveyed inland, it would be insufficient to 
reclaim one-tenth of it. Itis therefore important that 
none of the water resources of the State should be wasted, 
in other words, the water should be reserved for the most 
suitable soils, and be applied in the most economical fashion. 
It would be a foolish policy to carry out large works with- 
out complete information as to the quantities of water 
available. For example, if an engineer is ignorant of the 
minimum flow, he is almost certain to design works which 
carry more water than can be continuously afforded. The 
result of such a procedure would be that ina dry year, just 
when the water was in strongest demand, the supply would 
fail, this single failure would destroy all confidence in the 
scheme, and progress would be retarded for an indefinite 
number of years. On the other hand, if he is ignorant of 
the maximum flow, the design of weirs becomes indeter- 
minate, since they must be arranged to pass the highest 
floods without submerging the adjacent country to an 
extraordinary extent. 
The whole of the arid portion of this State lies within 
the watershed of the river Murray, but of course, it is by 
no means of uniform character. Its hydrography will 
therefore consist of a complete investigation,.of all the 
various quantities of water passing down the various rivers 
and creeks for all seasons and rainfalls. It is quite clear 
that there is no fixed connection between the amount of a 
