THE NORTH SYDNEY AND DOUBLE BAY SEWERAGE 



SCHEMES. 



By J. Davis, M. Inst. O.E. 



[Read before the Engineering Section of the Royal Society of N. S. 

 Wales, June 21st, 1899.] 



THE NORTH SYDNEY SEWERAGE SYSTEM. 



In the year 1882, the sanitary condition of what was then known 

 as North Shore, comprising the old Boroughs of St. Leonards, 

 East St. Leonards, and Victoria, had become so defective that 

 the Minister for Public Works authorised the preparation of a 

 sewerage scheme, and accordingly the late Mr. W. C. Bennett, 

 M. Inst. C.E., who was Engineer-in-Chief for Sewerage at the 

 time, instructed Mr. Bowyer-Smijth, M. Inst. C.E., to deal with 

 the question comprehensively. 



The area under consideration being hilly, sloping to the shores 

 of Long Bay (Middle Harbour) on the North, and Sydney 

 Harbour on the South, has ideal facilities for drainage by 

 gravitation to one or the other of its tidal frontages. 



Mr. Bowyer-Smijth recommended that provision should be 

 made for collecting and conveying the sewage by gravitation 

 through the hill between Sydney Harbour and Willoughby Bay, 

 to disposal works at the latter place. The total area provided for 

 in the proposal was 350 acres, the length of sewers contemplated 

 9 \ miles. It was suggested that the sewage should be precipitated 

 and filtered before being discharged into the waters of Middle 

 Harbour, and it was estimated the works would cost =£60,000. 



The surroundings of North Sydney are such that a sufficient 

 area of suitable land, within any reasonable distance, could not 

 be found for broad irrigation, and it was therefore decided that 

 no more satisfactory method could be adopted than precipitation 

 and intermittent filtration. 



