﻿HYDROLOGY 
  OP 
  NEW 
  YORK 
  

  

  473 
  

  

  large 
  volume, 
  although 
  part 
  of 
  the 
  water 
  was 
  discharged 
  through 
  

   the 
  aqueduct 
  to 
  the 
  waste-weir 
  at 
  Mill 
  river, 
  fifteen 
  miles 
  below 
  

   Oroton 
  dam. 
  The 
  water 
  rose 
  in 
  Croton 
  lake 
  at 
  the 
  rate 
  of 
  four- 
  

   teen 
  inches 
  per 
  hour. 
  The 
  earthen 
  bank 
  remained 
  intact 
  until 
  the 
  

   water 
  nearly 
  reached 
  its 
  top, 
  when 
  it 
  flowed 
  between 
  the 
  frozen 
  

   and 
  unfrozen 
  earth, 
  twenty 
  inches 
  below 
  its 
  crest, 
  forming 
  a 
  

   breach. 
  The 
  large 
  amount 
  of 
  ice 
  in 
  the 
  river 
  demolished 
  the 
  pro- 
  

   tection 
  wall 
  and 
  the 
  whole 
  embankment 
  was 
  washed 
  away. 
  At 
  

   the 
  time 
  of 
  the 
  accident, 
  on 
  January 
  8, 
  the 
  water 
  flowed 
  over 
  the 
  

   weir 
  to 
  a 
  depth 
  of 
  15 
  feet. 
  

  

  Another 
  severe 
  flood 
  occurred 
  in 
  November, 
  1853, 
  while 
  in 
  

   April, 
  1854, 
  after 
  unprecedented 
  rains, 
  the 
  worst 
  freshet 
  was 
  

   experienced 
  which 
  has 
  yet 
  been 
  recorded. 
  The 
  depth 
  on 
  the 
  crest 
  

   of 
  the 
  Croton 
  dam 
  was 
  8.25 
  feet. 
  

  

  Floods 
  in 
  Fishkill 
  creek. 
  This 
  stream 
  is 
  subject 
  to 
  severe 
  floods, 
  

   although 
  there 
  is 
  not 
  a 
  great 
  deal 
  known 
  about 
  them. 
  The 
  follow- 
  

   ing 
  tabulation, 
  calculated 
  from 
  high-water 
  marks 
  observed 
  for 
  a 
  

   number 
  of 
  years 
  at 
  the 
  Groveville 
  dam, 
  embodies 
  practically 
  all 
  

   the 
  information. 
  The 
  dam 
  is 
  of 
  masonry 
  faced 
  with 
  plank, 
  with 
  a 
  

   straight 
  horizontal 
  crest, 
  4 
  feet 
  wide 
  and 
  134 
  feet 
  long. 
  The 
  dis- 
  

   charge 
  has 
  been 
  calculated 
  by 
  coefficients 
  derived 
  from 
  Cornell 
  

   University 
  experiment 
  No. 
  11. 
  

  

  

  Month 
  

  

  Depth 
  on 
  

   crest, 
  feet 
  

  

  Discharge 
  

  

  Year 
  

  

  Cubic 
  feet 
  

   per 
  second 
  

  

  Cubic 
  feet 
  

  

  per 
  second 
  

  

  per 
  square 
  

  

  niiJe 
  

  

  (1) 
  

  

  (2) 
  

  

  (3) 
  

  

  (4) 
  

  

  (5) 
  

  

  1882 
  

  

  September 
  24 
  

  

  6.3 
  

   5.0 
  

   4.5 
  

   6.3 
  

   4.0 
  

   4.0 
  

   6.9 
  

   5.0 
  

   4.3 
  

   5 
  . 
  5 
  

   5.0 
  

   4.0 
  

   6.7 
  

   4.5 
  

   6.7 
  

   9.5 
  

  

  7, 
  700 
  

   5,200 
  

   4,400 
  

   7.700 
  

   3,650 
  

   3. 
  650 
  

   8,800 
  

   5,200 
  

   4,000 
  

   6,100 
  

   5, 
  200 
  

   3,650 
  

   8,300 
  

   4,400 
  

   8, 
  300 
  

   13, 
  700 
  

  

  38.5 
  

  

  1888 
  

  

  March 
  22 
  

  

  26.0 
  

  

  1888 
  

  

  December 
  18 
  

  

  22.0 
  

  

  1891 
  

  

  January 
  12 
  

  

  38.5 
  

  

  1891 
  

  

  January 
  13 
  

  

  18.3 
  

  

  1891 
  

  

  January 
  22 
  ... 
  

  

  18.3 
  

  

  1891 
  

  

  January 
  23 
  

  

  44.0 
  

  

  1893 
  

  

  March 
  10 
  

  

  26.0 
  

  

  1893 
  

  

  March 
  11 
  

  

  20 
  

  

  1893 
  

  

  March 
  12 
  

  

  30.5 
  

  

  1893 
  

   1893 
  

  

  March 
  13 
  

  

  March 
  14 
  

  

  26.0 
  

   18.3 
  

  

  1896 
  

  

  February 
  7 
  

  

  41.5 
  

  

  1896 
  

  

  March 
  1 
  

  

  22.0 
  

  

  1896 
  

  

  March 
  20 
  

  

  41.5 
  

  

  1902 
  

  

  March 
  1 
  

  

  68.5 
  

  

  

  

  

  