Bare. — On the Taieri Floods. 117 



So that the flood, under these conditions, would accumulate at the rate of 

 443,000 cubic feet per minute, which would spread over the areas of these two 

 lakes, and raise their surface about three feet nine inches in a twenty-four 

 hours flood. Even though there were such a rise, no serious damage would 

 result to the adjoining lands ; but in this calculation there are two elements, 

 which are taken at extreme figures, viz., the length of time, and the rate of 

 discharge by the Waipori, which is much in excess of tbat estimated by Mr. 

 Thomson, so that we may reasonably presume that even under such circum- 

 stances as those of the 1868 floods, the rise would be very much less than that 

 I have stated. 



Q^he quantity to be stored above Outram would evidently be the difference 

 between the largest flood delivery there in the 1868 floods, and the quantity 

 which I have already named as likely to get past the least capable section of 

 the river, between there and the East Taieri bridge, amounting to 3,200,000 

 cubic feet per minute. Now this would be derived from different districts, 

 the comparative areas of which are — 



Square Miles. 

 Above Taieri lake and Kyeburn ... ... ... 850 



Sutton, Deep, and Lee streams ... ... ... 480 



East of river between Lake and Outram ... ... 370 



1,700 

 But the configuration of the country to the east of the river is unfavourable 

 for storing a large quantity of water upon any of the tributary gullies, and the 

 basin of the Taieri lake is more favourable, so that we must calculate upon 

 having none upon the eastern portion, but store a correspondingly larger 

 amount upon the Taieri lake. Taking therefore three-fourths of the total for 

 that part, and the remaining fourth to be stored in small reservoirs upon the 

 Sutton, Deep, and Lee streams, the Taieri lake would require to have its outlet 

 so raised as to enable it to store as much as 3,002,400,000 cubic feet in 

 eighteen hours. Now the area of that lake and part of the Kyeburn valley 

 which would be affected so far up as the present ford on the Dunedin road is 

 about 91,846,260 square feet, so that the increase of depth would amount to 

 thirty-four feet. This additional depth would be required over the whole area 

 named ; but owing to the fall of the valleys, this could not be got on an 

 average without raising the dam to a height above the bank at the bridge, 

 and thus requiring a considerable extension in length. Probably a more 

 economical method might be by a smaller dam at that part, and other two at 

 the outlets from the lake proper, by which means suflicient storage might 

 possibly be obtained for the waters of floods less than that of February, 

 1868, and also sufficient to reduce a similar one to safe limits, for if they 



