SEWAGE FLOW AND WATER SUPPLY. 223 



the whole of the water used for household purposes to reach the 

 sewers. 



November has a slightly greater rainfall than October, and 

 there is a small decrease in the water consumption, and a return 

 of the sewer discharge to the July figure. This docs not alter 

 the fact that approximately sixteen million gallons were used 

 during the month that did not have any visible effect on the 

 sewage flow compared with that during the month of minimum 

 consumption. The total above the July consumption is fifty-one 

 million gallons. 



Deceml)er has a rainfall of 5.50 inches. It is promptly shown 

 by a drop in the water consumed of eight million gallons. The 

 discharge of sewage is only increased by one million gallons. 

 This still leaves seven million gallons that can only be accounted 

 for by the watering of gardens. This brings the total above the 

 July consumption rate to fifty-eight million gallons. 



January has rather a deficient rainfall, it being only 

 3.30 inches. The water consumption is seventy-eight million 

 gallons. com])ared with seventy-one million gallons for December. 

 The sewage flow is still only about half a million gallons above 

 that of Jidy. 



The dift'erence between the water consumed in January 

 and the water consumption for July compared on the basis of 

 flow of sewage, is fourteen and a half million gallons. This 

 would bring the total water used since July that did not show 

 any efl^ect on the quantity of sewage up to seventy-two and a half 

 million gallons. 



February has a good rainfall, it being 5.70 inches. On this 

 account the drop in the water consumption amounts to twelve 

 million gallons for the mnoth. The water consumed is three 

 million gallons above, and the discharge of sewage three million 

 gallons below, that of July. There is probably no diminution of 

 the household consumption, the difl:'ercnce in the flow of sewage 

 being due to the usual garden irrigation, by utilising the water 

 that has been used in the house. 



The quantity of water over and above that actually neces- 

 sary for domestic and trade consumption, as shown by the July 

 figures, now reaches the total of seventy-five million gallons. 

 There is no doubt that more water is actually used during the 

 summer months for baths, etc., but there are no means of esti- 

 mating the quantity. 



In the four months ending December, 1912, fifty-eight 

 million gallons were supplied in excess of that shown by the 

 sewer discharge, on the basis of the Jidy figures, and in one 

 month — October — the excess was seventeen million gallons. 

 From this it can be seen that a pumping plant is* reqtiired for 

 supplying this excess, which would be idle during six months 

 of the year. 



A study of the diagram shows that, if the whole town was 

 reticulated by sewers, and all the water consumed in July reached 

 the sewer, the maximum flow of sewage would be only one and 



