ABSTRACT OF PROCEEDINGS. XV11. 



from being present, and he then spoke of the great neces- 

 sity for an adequate supply of water in a city such as 

 Sydney, and considered it was both safe and prudent to 

 adopt as high as a 4% rate of population increase. He 

 mentioned that the increase of manufacturing and the 

 extension of the sewerage schemes in all the outlying 

 suburbs of Sydney will largely increase the amount of water, 

 and it is a matter of experience that the demand per head 

 increases with the lapse of time, and the use of water 

 always induces its use more lavishly, even for objects which 

 are perfectly legitimate and which are not wasteful. The 

 proximity of our sea beaches, and the facilities for sea 

 bathing, no doubt to some extent, reduce our requirements. 

 He thought that the consumption rate of 63 gallons per 

 head, as proposed by Mr. Keele for the year 1937, was too 

 low, and that a rate of at least 80 gallons per head should 

 be allowed, the consumption in the city of New York for 

 the next 25 years being estimated at 150 gallons per head. 

 He referred to the absence of available knowledge in regard 

 to the topography, physical characteristics, contours, rain- 

 fall, the run-off of the catchment area, and the amount of 

 water the catchment area can contribute, and said that 

 the author has been obliged to adopt a run-off of 44%, but 

 in all probability the higher parts of the catchment area 

 will contribute a greater rainfall and greater rate of run-off 

 than the author mentions. Under the circumstances it is 

 impossible to make any estimate of the amount of water 

 the catchment area can contribute, and the forecast made 

 by the author must be to a very large extent guess-work, 

 although in all probability it is a most conservative esti- 

 mate that he has given us. The author bases his estimate 

 of the yield of the catchment area on a 44% run-off, which 

 compared with American catchments is very conservative. 

 The Oroton watershed in New York gives 48%; Sudbury 

 46*3%, National 47*3%, the Upper Hudson 57%, and the 



