﻿HYDROLOGY 
  OF 
  NEW 
  YORK 
  129 
  

  

  time 
  the 
  net 
  runoff 
  did 
  not 
  exceed 
  under 
  the 
  assumed 
  conditions 
  

   7.09 
  inches. 
  The 
  average 
  runoff 
  for 
  20 
  months 
  was 
  0.354 
  inch 
  and 
  

   for 
  7 
  months 
  0.116 
  inch. 
  

  

  On 
  Genesee 
  river 
  there 
  have 
  been 
  two 
  low-water 
  periods 
  during 
  

   the 
  time 
  covered 
  by 
  the 
  gagings. 
  The 
  first 
  was 
  from 
  June, 
  1894, 
  

   to 
  February, 
  1896, 
  a 
  period 
  of 
  21 
  months, 
  during 
  which 
  time 
  there 
  

   was 
  a 
  gross 
  runoff 
  of 
  13.02 
  inches. 
  Evaporation 
  has 
  been 
  com- 
  

   puted 
  for 
  a 
  proposed 
  reservoir 
  of 
  12.4 
  square 
  miles 
  water- 
  surface 
  

   area, 
  with 
  allowance 
  for 
  actual 
  hight 
  of 
  water 
  during 
  the 
  differ- 
  

   ent 
  months. 
  On 
  this 
  basis 
  and 
  with 
  a 
  small 
  allowance 
  for 
  per- 
  

   colation, 
  leakage, 
  etc. 
  the 
  total 
  evaporation 
  loss 
  for 
  the 
  21 
  months 
  

   becomes 
  0.65 
  inch, 
  leaving 
  a 
  net 
  runoff 
  of 
  12.37 
  inches. 
  The 
  aver- 
  

   age 
  runoff 
  for 
  21 
  months 
  was 
  0.59 
  inch, 
  or, 
  if 
  we 
  assume 
  1.43 
  

   inches 
  left 
  in 
  reservoir 
  at 
  end 
  of 
  period, 
  the 
  average 
  allowable 
  

   runoff 
  becomes 
  0.52 
  inch. 
  For 
  10 
  months, 
  with 
  some 
  allowance, 
  

   the 
  average 
  runoff 
  is 
  0.30 
  inch 
  and 
  for 
  7 
  months 
  0.10 
  inch. 
  

  

  The 
  second 
  period 
  was 
  from 
  June, 
  1896, 
  to 
  December, 
  1897, 
  a 
  

   period 
  of 
  19 
  months, 
  during 
  which 
  time 
  the 
  net 
  runoff 
  was 
  13.24 
  

   inches. 
  The 
  average 
  runoff 
  for 
  19 
  months, 
  with 
  1.24 
  inches 
  left 
  

   in 
  reservoir 
  at 
  end 
  of 
  the 
  period, 
  was 
  0.63 
  inch; 
  for 
  8 
  months, 
  0.31 
  

   inch, 
  and 
  for 
  6 
  months, 
  0.17 
  inch. 
  These 
  figures, 
  without 
  being 
  

   exhaustive, 
  show 
  that 
  the 
  Genesee 
  river 
  is 
  a 
  somewhat 
  better 
  

   water 
  yielder 
  than 
  the 
  Muskingum 
  river. 
  The 
  relation 
  of 
  the 
  

   rainfalls 
  is 
  shown 
  in 
  the 
  tables. 
  

  

  A 
  large 
  number 
  of 
  other 
  interesting 
  and 
  valuable 
  tabulations 
  

   could 
  be 
  drawn 
  from 
  these 
  data, 
  specially 
  those 
  relating 
  to 
  

   storage. 
  In 
  any 
  case, 
  enough 
  has 
  been 
  said 
  to 
  sustain 
  the 
  state- 
  

   ment 
  that 
  streams 
  vary, 
  not 
  only 
  as 
  regards 
  their 
  total 
  capability 
  

   of 
  yielding 
  water, 
  but 
  as 
  regards 
  their 
  distribution. 
  In 
  order 
  to 
  

   develop 
  a 
  stream 
  to 
  its 
  maximum 
  capacity 
  for 
  either 
  water 
  power 
  

   or 
  municipal 
  purposes, 
  it 
  is 
  absolutely 
  indispensable 
  to 
  have 
  a 
  

   series 
  of 
  carefully 
  prepared 
  gagings. 
  Lacking 
  these, 
  there 
  should 
  

   be 
  gathered 
  as 
  long 
  a 
  rainfall 
  record 
  as 
  possible, 
  from 
  which, 
  by 
  

   comparison, 
  the 
  approximate 
  runoff 
  of 
  the 
  stream 
  may 
  be 
  com- 
  

   puted. 
  A 
  carefully 
  taken 
  series 
  of 
  gagings 
  is, 
  however, 
  in 
  every 
  

   way 
  preferable. 
  

  

  