828 



PARKS 



The amount of water for swimming pools would depend upon the size of 

 the pool and the frequency with which the water is changed. 



Where a river, a large creek or a lake is used as a source of water 

 supply, the available quantity w 7 ill likely far exceed the demand. If a very 

 small stream is used it may be necessary to impound the water by dam- 

 ming the stream in order to secure a sufficient quantity at some selected 



point. Under such circumstances 

 it is often desirable to ascer- 

 tain the volume of the flow of 

 the stream. This is done by 

 choosing a part of the stream 

 which is of suitable length and 

 fairly uniform in depth and 

 breadth. The width and depth 

 are measured in feet. A small 

 piece of wood or cork is allowed 

 to float on the surface of the 

 water for a measured distance 



Paise concrete apound 

 casino" to under side of 

 screw flange 



. iron strep 



Flange to be tapped for 

 stud bolts to fit drilling 

 ,-fr^^rr _9" pump base 



Uey concrete pavement 

 at te8st>feeton6ll 

 sides of we U> sloping 

 away from pump. 



SECTION 



Concrete pavement 



and the time noted. This will 

 give the surface velocity, which 

 is calculated in feet per hour. 

 Four-fifths of the surface veloc- 

 ity equals the mean velocity of 

 the flow. The formula then is: 

 D X B X V X 6.23 = number of 

 gallons of water per hour in 

 which D= depth in feet; B = 

 width in feet; V = mean veloc- 

 ity in feet per hour; 6.23 = num- 

 ber of gallons in one cubic foot. 

 If a well or spring water is 

 used, it should be determined 

 that the supply is sufficient to 

 meet all demands. The yield of a well may be roughly measured by pumping 

 out all or a part of the water and noting the level to which the water has 

 fallen and allowing the well to refill to the original level or to a selected 

 point. The distance between the level to which the water was reduced 

 by pumping and the point to which it rose after pumping is calculated in 

 feet. The time in hours required for the well to refill is then noted. The 

 capacity of the well is computed as follows: 



= gallons per hour. 



PLAN 



PLATE No. 303 



DRIVEN WELL WITH CONCRETE PLATFORM TO 



SHUT OUT SURFACE WATER 

 (Pennsylvania Department of Health.) 



