86 HALIFAX WATER WORKS. JOHNSTON. 



the writer is of the opinion that an average of 50 per cent, 

 throughout the whole year is available as the run-off from the 

 Long Lake drainage area. Since 1889 the quantity running to 

 waste yearly over Long Lake waste weir has varied from 

 250,000,000 gallons to 2,173,000,000 gallons. The reservoir 

 has always been full during those years i'n either March, April 

 or May. 



To increase the available flow, it is necessary to store the 

 water in time of flood and thus equalize the distribution of the 

 rainfall. There are three low service reservoirs, Long Lake, 

 with waste-weir level at 206.00 feet, having a surface area of 

 423 acres, an available depth of 8.20 feet and a capacity of 

 871,522,000 gallons; Upper Chain Lake, with waste-weir at 

 same level and sluicb at 194.70, an area of 37 acres and a 

 capacity of 107,674,000 gallons; Lower Chain Lake, with 

 waste-weir at same level of 206.00 feet, main pipe at level of 

 192.24 feet, and an area of 42 acres and a capacity of 157,374,- 

 000 gallons ; giving a total available storage in the low service 

 reservoirs of 1,136,570,000 gallons sufficient TO supply the 

 .legitimate wants of a population of 50,000 for a period of 225 

 days, allowing 100 gallons per capita. But to show the enor- 

 mous draught on this system, in November of 1905 all but 

 60,000,000 gallons of this storage had been exhausted in sup- 

 plying 18,000 consumers between the 15th of Juno, when the 

 reservoirs were full, and the 15th of November, the rainfall 

 during this period amounting to 12.683 inches. The lowest 

 level to which Long Lake has been drawn down being 8 

 feat below waste-weir on the 14th November, 1905. At the 

 end of December, 1905, the level of Long Lake waste-weir 

 was raised one foot, which will increase the available storage 

 by 115,000,000 gallons. 



High Service Gathering Grounds and Storage Reservoir. 

 The water-shed of Spruce Hill Lakes amounts to 1,009 

 acres, including a water area of 218 acres in the lake and 6 



