116 Transactions. 
For this purpose it will be necessary, in the absence of particular data, to 
assume that the Waipori river and Silverstream delivered their waters at the 
same rate as the Taieri, in proportion to area ; and for the general purpose of 
this investigation that will be enough. This would show a total outpour from 
these sources of 5,532,900 cubic feet per minute; and deducting from that 
amount 1,186,900 cubic feet, which could flow towards the sea, the amount of 
water which would be dammed back would be 4,548,000 cubic feet per 
minute, representing the rate of rise of the flood. But it has been ascertained 
that on this occasion 4,585,996,800 cubic feet were the total flood waters, so 
that dividing the one quantity by the other we would have a period of flood 
equal to seventeen and a half hours. Of course, this is to be regarded as 
simply a hypothetical statement which will represent only the average rise and 
length of time resulting from that, for it is very likely that the rise would be 
at this rate only for a few hours, which would consequently necessitate a more 
lengthened period to produce the same total accumulation from a smaller rate 
of increase. 
We have now to consider the amount of water which it would be desirable 
to prevent flowing upon the plain by the Taieri river, in order that the floods 
may not attain to such an extent as to overflow the banks. It has been found 
that the damage caused about the West Taieri has been the consequence of 
the small section of the river further down not being sufficient to carry off the 
whole waters as they arrived ; and it has been shown by Mr. Thomson that 
_ the smallest section has been able to pass down 1,173,744 cubic feet per 
minute ; but it might not be safe to charge it with even this quantity, so we 
will leave a considerable margin by taking it only to the extent of 900,000 
cubic feet, looking to store the remainder in the Upper Taieri lake, or upon 
some of the tributaries of the river, such as the Deep, the Sutton, and the Lee 
streams. It will be observed that this makes no provision for the waters of 
the Silverstream, or the Waipori river. The first of these could probably be 
stored in the lagoon near its junction with the main river, and which is 
evidently the natural flood moderator of that stream, or in some reservoir 
higher up ; while the large flow from the Waipori would be allowed to spread 
over that and ey shale lakes. The general result, then, may be arrived at 
thus :— 
At Feet per Min. 
The quantity poured down the Taieri A ne 900,000 
” » oo Wap o sap 730,000 
1,630,000 
Outflow to sea ee ie = + k 1T87000 
443,000 
