CHAIRMAN’S ADDRESS. XLI. 
would be exhausted in 1°66 years. If the storage at Pros- 
pect be considered to be available only to gravitation level 
the total supply would last only 1°37 years; but we know 
by experience that Prospect reservoir should not be drawn 
upon toa greater extent than 3,000 million gallons, except 
under great emergency, this being 1,000 million gallons 
more than the Stuart Murray Commission considered safe, 
so that the permissible storage should not be regarded as 
being more than 24,000 million gallons, which would last only 
fifteen months. 
Although it is very unlikely that such a length of time 
as stated would occur without rain falling and making 
some addition to the storage, we do know, however, that 
during the droughts the percentage of the rain which finds 
its way into the river channels is exceedingly small, and 
gaugings have shown that periods of eight and nine 
months sometimes occur when only +s of the water which 
fell as rain was available for storage purposes. The figures 
showing the time the storage would last under the 
conditions stated are useful to enable us to realise what 
the situation would be after a year of exceedingly low 
rainfall, with the following five or six years much below 
the mean, the population rapidly increasing, and the daily 
loss from the reservoirs exceeding 50 million gallons per 
day. Hven with the strictest economy and large reduction 
in the consumption the situation would be very serious. It 
is obviously unnecessary for me to further enlarge upon the 
position of the city with reference to the water supply 
under such circumstances. 
Let us now take the other case, and assume that on the 
termination of the drought in 1907, the weather conditions 
will be similar to those experienced after the end of the 
drought in 1859. The diagram (2) of the Cordeaux River 
rainfall does not go back far enough to show the curve at 
