HYDROLOGY OF NEW YORK 



689 



of water pumped was equivalent to a depth of 1.44 inches on the 

 catchment, or 3.82 per cent of the total rainfall. In 189$ the 

 total rainfall was 38.82 inches. The amount of water pumped 

 during that year would cover the catchment to a depth of 11 

 inches, this being over 28 per cent of the total rainfall. The 

 average yield as obtained by pumping was 0.81 cubic foot per 

 second per square mile of catchment. 



Table No. SS — Total anttoal rainfall, per cext utilized, and average 



YIELD PER SQUARE MILE OF CATCHMENT OF BROOKLYN WATERWORKS 



YEAR 



(1) 



1860 . . . 



1861 . . . 



1862 . . . 



1863 . . . 



1864 . . . 



1865 . . . 



1866 . . . 



1867 . . . 



1868 . . . 



1869 . . . 

 1870 

 1871 .'. . 

 1872 

 1873 . . . 

 1874 

 1875 

 1876 

 1877 

 1878 



Rainfall 



in 

 inches 



(2) 



37.65 

 4r,. 65 

 38.02 

 32 . 76 

 32.00 

 46.14 

 51 .68 

 54.61 

 38.58 

 43.13 

 39.35 

 51 .26 

 39.75 

 47.99 

 4."). 83 

 40.00 

 41.77 

 40.18 

 48.66 



Per 

 cent 

 utilized 



(3) 



Cubic- 

 feet per ! 

 second i 

 per i 

 : square 

 mile 



3.82 

 3 . 02 

 5.73 

 8.39 



10.53 

 8.39 

 8.88 

 9.39 



1 7 . 20 



i ; ao 



19.82 

 15.78 

 23.47 

 20.88 

 21.40 

 20.SVI 

 27.08 

 30.29 

 25.15 



(4) 



0.11 

 0.13 

 0.16 

 0.20 

 0.25 

 0.28 

 0.34 

 . 38 

 0.40 

 0.55 

 0.57 

 0.60 

 0.67 

 0.74 

 0.73 

 0.81 

 0.83 

 0.90 

 0.00 



YEAR 



(1) 



1879 

 1880 

 i 1881 

 | 1882 

 i 1883 

 I 1884 

 1885 

 1886 

 1887 

 1888 

 1889 

 1890 

 1891 

 1892 

 1893 

 1894 

 1895 

 1896 



Cubic 



Rainfall Per f ^ lf 

 in cent ™™™ 



inches | utilized gq F e a r re 



mile 



(2) 



(3) 



39.61 

 40.76 

 39 . 53 

 39.83 

 37.22 

 45.39 

 36 85 

 51 .38 

 45 . 66 

 48.45 

 56.54 

 52 . 15 

 39.18 

 37 . 75 

 39.62 

 36.88 

 35 . 64 

 38 . ^2 



33.40 

 30.23 

 29.42 

 30.73 

 33.05 

 27.80 

 37.94 

 28 32 

 32 . 59 

 33.19 

 29.54 

 33.90 

 44 82 

 24 . 53 

 26.27 

 26.33 

 28.98 

 28.31 



(4) 



0.97 

 0.90 

 0.86 

 0.90 

 0.91 

 0.93 



03 

 07 

 .10 

 ,18 

 .23 

 .30 

 1 20 

 0.68 

 0.7T 

 0.72 

 0.76 

 0.81 



Generally the Brooklyn Water Works have not been so designed 

 as to furnish records of the quantity drawn from these several 

 different sources. There are also no records of the hights of the 

 ground water at different points in the catchment area. If such 

 were to be kept for a series of years, the records of the Brooklyn 

 Water Works would possess a value uot easily estimated. They 

 would give a far more positive indication of the amount of water 

 that can be drawn from such sandy areas than can now be gained 

 from them. A few T tests, however, of some of the driven-w 7 ell 

 plants have been made in the last few years. The Greater New 

 York W T ater Supply Commission of 1903 has measured the hight 



