Art. I. — On the Prevention of Street Floods in the City 

 of Melbourne. 



By A. K. Smith, C.E., &c. &c. 



[Read 14th May, 1873.] 



I have been induced to bring this subject before the 

 Society, not because the suggestion has the merit of novelty, 

 as I have several times brought it under notice before, 

 but because the surroundings of the question have altered 

 so much, as to render the necessity of taking preventive 

 measures of greater importance than it was nineteen, or 

 even sixteen years ago, when I brought the subject under 

 the notice of the Philosophical Institute. 



At the date last-named, I find from a series of observa- 

 tions made at the time (1856-7), that it took an average of 

 32 J minutes, after the commencement of a heavy and con- 

 tinuous fall of rain, before the street-channels in Elizabeth 

 and Swanston-streets were filled to over-flowing, so as to 

 impede ordinary foot traffic ; the minimum time being 30 

 minutes on the 23rd September, 1856. 



At that date comparatively little foot pavement was laid, 

 or yards and rights-of-way pitched, so that a considerable 

 amount of the rain was absorbed before the remainder 

 found its way to the street-channels. Much of the ground 

 was then vacant, and further assisted for a time to retain 

 the storm-water from the streets. However, so far as the 

 sudden rise of street-floods is concerned, the Melbourne of 

 1873 is widely different from that of 1856. Since the latter 

 date large numbers of houses and stores have been erected 

 with iron or slate roofs ; most of them draining immediately 

 into the street-channels. Many miles of streets and roads 

 with hard and even surfaces have been formed, and 

 numerous yards, courts, and rights-of-way have been paved 

 and pitched, all in such a manner as to readiJy discharge 

 the storm-water falling upon them. 



I find, that in 1 872-3 the street-channels, after sudden 

 and heavy falls of rain, become so flooded as to impede 

 pedestrian traffic in less than half the time they did 



