﻿HYDROLOGY 
  OF 
  NEW 
  YORK 
  

  

  113 
  

  

  is 
  discharged 
  into 
  Cayuga 
  lake 
  without 
  affecting 
  Seneca 
  river 
  

   below 
  the 
  mouth 
  of 
  Clyde 
  river 
  at 
  all. 
  It 
  is 
  undoubtedly 
  due 
  to 
  this 
  

   fact 
  that 
  fall 
  floods 
  on 
  Oswego 
  river 
  are 
  almost 
  entirely 
  unknown. 
  

  

  The 
  evaporation 
  of 
  the 
  Oswego 
  river 
  catchment 
  area 
  is 
  exceed- 
  

   ingly 
  large 
  — 
  about 
  28 
  inches— 
  whence 
  it 
  results 
  that 
  the 
  runoff 
  

   from 
  a 
  mean 
  annual 
  rainfall 
  of 
  from 
  36 
  to 
  37 
  inches 
  does 
  not 
  

   exceed 
  about 
  9 
  or 
  10 
  inches. 
  1 
  

  

  Computation 
  of 
  annual 
  runoff. 
  No 
  general 
  rule 
  can 
  be 
  formu- 
  

   lated 
  for 
  computing 
  annual 
  runoff. 
  The 
  formulas 
  of 
  Mr 
  Vermeule 
  

   are 
  excellent 
  formulas 
  of 
  the 
  purely 
  empirical 
  class, 
  applying 
  

   fairly 
  well 
  to 
  many 
  streams 
  in 
  the 
  northeastern 
  part 
  of 
  the 
  United 
  

   States, 
  but 
  they 
  do 
  not 
  apply 
  at 
  all 
  to 
  streams 
  of 
  the 
  middle 
  west 
  

   and 
  far 
  west. 
  Nor 
  do 
  they 
  apply 
  to 
  some 
  streams 
  in 
  the 
  north- 
  

   eastern 
  section. 
  Nevertheless, 
  they 
  take 
  into 
  account 
  the 
  ground 
  

   water, 
  and 
  are 
  the 
  most 
  useful 
  formulas 
  thus 
  far 
  devised. 
  It 
  may 
  

   be 
  mentioned 
  that 
  Mr 
  Vermeule 
  specially 
  disclaims 
  any 
  inten- 
  

   tion 
  of 
  working 
  out 
  any 
  formulas 
  applying 
  outside 
  of 
  the 
  State 
  of 
  

   New 
  Jersey. 
  His 
  general 
  formula 
  is 
  in 
  the 
  nature 
  of 
  a 
  suggestion. 
  

  

  Discrepancies 
  in 
  computation 
  of 
  runoff. 
  In 
  computing 
  the 
  run- 
  

   off 
  of 
  various 
  streams 
  small 
  discrepancies 
  will 
  continually 
  appear, 
  

   and 
  when 
  such 
  do 
  n'ot 
  exceed 
  1 
  to 
  2 
  inches 
  they 
  are 
  outside 
  the 
  

   limit 
  of 
  discussion. 
  The 
  question 
  does 
  not 
  admit 
  of 
  such 
  minute- 
  

   ness 
  as 
  to 
  permit 
  the 
  discussion 
  of 
  small 
  differences, 
  although 
  a 
  

   difference 
  of 
  2 
  inches 
  on 
  several 
  thousand 
  square 
  miles 
  would 
  be 
  

   much 
  less 
  serious 
  than 
  on 
  the 
  usual 
  municipal 
  catchment 
  area 
  

   of 
  from 
  20 
  to 
  100 
  square 
  miles. 
  The 
  size 
  of 
  the 
  catchment 
  area 
  

   should, 
  therefore, 
  in 
  this 
  particular 
  be 
  taken 
  into 
  account. 
  

  

  Moreover, 
  the 
  runoff 
  of 
  streams 
  has 
  thus 
  far 
  been 
  almost 
  uni- 
  

   versally 
  over-estimated. 
  Only 
  a 
  few 
  were 
  really 
  down 
  to 
  the 
  actual 
  

   fact. 
  Probably 
  in 
  no 
  department 
  of 
  professional 
  work 
  are 
  there 
  

   more 
  things 
  to 
  be 
  taken 
  into 
  account 
  than 
  here. 
  

  

  Actual 
  gaging 
  s 
  preferable 
  to 
  general 
  studies. 
  While 
  on 
  the 
  gen- 
  

   eral 
  subject 
  of 
  the 
  computation 
  of 
  runoff 
  the 
  writer 
  may 
  repeat 
  

  

  lThe 
  preceding 
  chapter 
  has 
  been 
  abstracted 
  from 
  the 
  writer's 
  report 
  on 
  

   Special 
  Water 
  Supply 
  Investigation 
  to 
  the 
  Board 
  of 
  Engineers 
  on 
  Deep 
  

   Waterways. 
  

  

  