THE SYDNEY WATER SUPPLY. 225 



The tunnels connecting the reservoirs in the Catchment 

 Area could be carried on from time to time as they were 

 required, but those connecting the Cataract and Cordeaux ? 

 and the Avon should be commenced at once, so as to be 

 completed at the same time with the dams for those reser- 

 voirs, namely, in 1920 and 1924. I estimate that the total 

 cost of the 20^ miles of tunnel on the Catchment Area would 

 cost £1,075,727. 



The Woronora Scheme is of the greatest importance, as it 

 would, when completed, be capable of conveying the drain- 

 age from 85 square miles of new country in every way simi- 

 lar to the present Catchment Area of the Upper Nepean and 

 Cataract Rivers, into the existing canal. 



The rainfall over this area is quite equal to that over the 

 area above-named. The works will consist of a ten mile tun- 

 nel and two reservoirs, which, I estimate, could be con- 

 structed for £1,365,064. If the full benefit of these works 

 is to be secured in 1923, when it may, perhaps, be sorely 

 needed, they should be commenced not later than next year. 



In the statement in Appendix I now submit for your in- 

 spection, I have set out in their proper sequence, the costs 

 of the several works year after year for the next thirty 

 years, which would have to be incurred if the Sydney Water 

 Supply is to be placed upon a satisfactory and secure basis 

 after the year 1924. 



During the next seven years, from the present time, I 

 have endeavoured to show that there may not be a sufficient 

 reserve storage to meet a possible protracted dry period, 

 and it is therefore obvious that the only way to make the 

 position secure would be to commence the works earlier than 

 I have shown, which would mean that the Avon Dam and 

 the Woronora Tunnel should be commenced at once or other- 

 wise with the least possible delay. We have already lost 



O— July 4, 1917. 



