2 Prevention of Street Floods 



formerly ; for, on the 15tli October, 1872, I carefully noted 

 the time, and found it to be 14 J minutes from the com- 

 mencement of a thunder-storm until the streets became 

 impassable. It will thus be seen that the danger to human 

 life and property is greatly increased by the suddenness of 

 the change from the dry street to the bed of a raging 

 torrent. 



The area drained by the channel on the east side of 

 Swanston-street, when I made my survey in 1864, was 

 250.2 acres ; but this area has been increased 27.5 acres, 

 by altering the open channel that then crossed Flinders- 

 street at its junction with Russell-street, so as to discharge 

 the storm-water at Swanston-street, instead of under the 

 Suburban Railway Station. This makes the total area 

 drained by Swanston-street 277-7 acres, the greater portion 

 of which is closely built upon, and otherwise having favour- 

 able rates of inclination upon its surface for the rapid 

 discharge of storm-water. It extends to Grattan-street on 

 the north ; to Brunswick-street, Fitzroy, on the east ; and to 

 Flinders and Swanston -streets on the south and west. Had 

 the main street channel in Swanston-street as rapid a fall 

 as those in portions of Collins and Bourke-streets east, 

 but little harm would be done ; but it has not, and so 

 between Little Bourke-street on the north and Collins-street 

 on the south, on the occurrence of any heavy fall of rain, 

 this channel nils and overflows the street, running down 

 Little Bourke-street, Great Bourke-street, Little Collins- 

 and Collins-streets, into Elizabeth -street, there to increase 

 the damage and danger of its already impassable torrent. 



Seeing then that the storm- water from the 277.7 acres 

 drained by Swanston-street is greatly in excess of what the 

 channels in that street can discharge without overflowing, 

 and that the floods there are a constant source of inconveni- 

 ence to the public and loss to the Corporation, it will the 

 more readily be understood how inadequate are the channels 

 in Elizabeth-street to carry off the drainage of no less than 

 497 acres, particularly when the water from that area is so 

 increased by the overflow from Swanston-street previously 

 alluded to. 



Referring to past observations I have made on this sub- 

 ject, I find that on the 11th February, 1857, a heavy and 

 almost continuous rain for a period of seventeen hours 

 enabled me to take notes of the discharge of surface water 

 at the junction of Elizabeth and Flinders-streets, and I 



