206 HIGHER RATES IN HIGH SERVICE DISTRICTS 



mated expense of the service. These rates are given in Chapter 

 IV, page 44, and are shown graphically in Fig. 15, page 61. 



It may be noted that Mr. Philander Betts, Engineer of the 

 Commission, was a member of the Committee on Rates of the 

 New England Water Works Association, and that Mr. Weston 

 E. Fuller, a partner of the author, had to do with the arrange- 

 ment, as engineer of one of the interested parties. 



Rates for Special Seasons 



Some water-works systems are subject to wide fluctuations 

 in the quantity of water that is available at different times, 

 and in the demand for it. There are periods when the water 

 required to meet the consumption is much harder to get than 

 at other times. Sometimes a great increase in population sup- 

 plied at certain seasons of the year causes a relative shortage, 

 as, for instance, at summer resorts. It may happen that the 

 capacity of a plant on the seashore must be arranged to meet 

 a rate of output that is only required for a few weeks in August. 

 During the remainder of the year the load factor is much below 

 normal. 



The periodical reduction in the capacity of sources at dry 

 times is often a limiting condition. Some months of the year 

 are drier than others, and many water-works systems, having 

 upland supplies, are capable of less output during the dry 

 season in late Summer and early Fall than at other times. 

 Then, again, some years are drier than others, and a system 

 that has sufficient water through nine years may fail with the 

 greater drought of the tenth. It often happens that expen- 

 sive additions to supply works are required to prevent a shortage 

 of water that is not to be anticipated oftener than once in 

 ten or even twenty years and then only for a few weeks. 



In both of these cases it would be logical to charge higher 

 rates per thousand gallons for water during those periods when 

 there is difficulty in maintaining the supply, and to provide 

 for which the capacity of the supply works must be larger 

 than would otherwise be needed. 



For summer resorts, the collection of* a higher rate per 



