﻿HYDROLOGY 
  OF 
  NEW 
  YORK 
  

  

  203 
  

  

  In 
  all 
  of 
  the 
  foregoing 
  statements 
  as 
  to 
  minimum 
  runoff, 
  it 
  

   should 
  be 
  understood 
  that 
  the 
  actual 
  quantity 
  appearing 
  in 
  the 
  

   stream 
  as 
  runoff 
  from 
  a 
  given 
  precipitation 
  will 
  vary, 
  depending 
  

   on 
  whether 
  ground 
  water 
  is 
  high 
  or 
  low 
  at 
  the 
  beginning 
  of 
  the 
  

   period 
  considered. 
  All 
  such 
  statements, 
  therefore, 
  are 
  necessarily 
  

   approximate 
  — 
  they 
  may 
  have 
  a 
  plus 
  or 
  minus 
  variation 
  from 
  the 
  

   diagram 
  of 
  one 
  or 
  two 
  inches. 
  Possibly 
  the 
  maximum 
  variation 
  

   may 
  be 
  more 
  than 
  this. 
  

  

  RIVER 
  SYSTEMS 
  

  

  Classification 
  of 
  rivers. 
  The 
  rivers 
  of 
  the 
  State 
  may 
  be 
  classi- 
  

   fied 
  into 
  seven 
  general 
  systems, 
  whose 
  relative 
  position 
  is 
  shown 
  

   by 
  the 
  accompanying 
  map, 
  fig. 
  17. 
  These 
  are 
  : 
  

  

  Fig. 
  17 
  Map 
  of 
  rivers 
  of 
  New 
  York. 
  

  

  