﻿454. 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  From 
  these 
  figures 
  we 
  learn 
  that 
  an 
  estimate 
  of 
  33 
  per 
  cent 
  of 
  

   void 
  space 
  in 
  the 
  soils 
  of 
  the 
  flats 
  would 
  be 
  very 
  conservative. 
  

   The 
  mean 
  low-water 
  surface 
  of 
  the 
  river 
  channel 
  is 
  mostly 
  from 
  

   15 
  to 
  20 
  feet 
  below 
  the 
  surface 
  of 
  the 
  flats. 
  We 
  will 
  also 
  assume 
  

   that 
  the 
  water 
  runs 
  out 
  of 
  the 
  upper 
  5 
  or 
  6 
  feet 
  quickly, 
  but 
  that 
  

   it 
  is 
  retained 
  and 
  delivered 
  slowly 
  from 
  the 
  balance. 
  We 
  have 
  

   then 
  33 
  per 
  cent 
  of 
  say 
  12.0 
  feet 
  or 
  4.0 
  feet 
  in 
  depth 
  over 
  80 
  square 
  

   miles 
  as 
  the 
  probable 
  available 
  groundwater 
  storage 
  of 
  the 
  flats. 
  

   For 
  80 
  square 
  miles 
  this 
  amounts 
  to 
  (80x640x43,560x4)= 
  

   8,921,088,000 
  cubic 
  feet. 
  If 
  there 
  were 
  any 
  way 
  to 
  control 
  this 
  

   ground-water 
  storage 
  of 
  the 
  flats 
  it 
  would 
  by 
  itself 
  furnish 
  an 
  

   outflow 
  of 
  800 
  cubic 
  feet 
  per 
  second 
  for 
  four 
  months, 
  or 
  130 
  days. 
  

  

  During 
  June 
  and 
  July, 
  1893, 
  the 
  rainfall 
  was 
  used 
  up 
  by 
  the 
  

   demands 
  of 
  growing 
  vegetation, 
  and 
  the 
  flow 
  of 
  the 
  stream 
  was 
  

   that 
  due 
  to 
  stored 
  ground 
  water 
  only, 
  except 
  possibly 
  a 
  very 
  

   slight 
  effect 
  from 
  the 
  rainfall 
  on 
  June 
  6. 
  By 
  July 
  24, 
  what 
  may 
  

   be 
  termed 
  the 
  high 
  level 
  rapid 
  runoff 
  ground 
  water 
  of 
  the 
  flats 
  

   was 
  entirely 
  exhausted, 
  and 
  from 
  that 
  time 
  on 
  the 
  flow 
  was 
  

   merely 
  due 
  to 
  the 
  deeper 
  seated 
  ground 
  water 
  of 
  the 
  whole 
  area, 
  

   assisted, 
  however, 
  by 
  the 
  relatively 
  more 
  rapid 
  delivery 
  of 
  the 
  

   flats. 
  It 
  may 
  be 
  remarked 
  that 
  the 
  surface 
  storage 
  of 
  the 
  lakes 
  

   of 
  the 
  lower-river 
  .system 
  is 
  usually 
  about 
  exhausted 
  by 
  July 
  24. 
  

  

  However, 
  it 
  should 
  not 
  be 
  overlooked 
  that 
  in 
  a 
  long 
  continued 
  

   drought 
  the 
  storage 
  of 
  these 
  flats 
  becomes 
  exhausted, 
  and 
  when 
  

   this 
  occurs 
  there 
  will 
  be 
  very 
  low 
  water 
  at 
  Rochester 
  until 
  this 
  

   storage 
  is 
  renewed 
  by 
  copious 
  rainfall. 
  

  

  As 
  to 
  the 
  propriety 
  of 
  including 
  in 
  this 
  discussion 
  the 
  area 
  of 
  

   the 
  Canaseraga 
  flats 
  it 
  may 
  be 
  mentioned 
  that 
  high 
  water 
  is 
  

   stated 
  by 
  the 
  inhabitants 
  to 
  only 
  occur 
  there 
  when 
  the 
  Genesee 
  

   is 
  full 
  to 
  overflowing 
  and 
  is 
  therefore 
  mostly 
  the 
  result 
  of 
  back- 
  

   water 
  from 
  the 
  Genesee. 
  The 
  catchment 
  area 
  of 
  the 
  Canaseraga 
  

   creek 
  is 
  259 
  square 
  miles, 
  and 
  although 
  the 
  creek 
  channel 
  has 
  

   for 
  several 
  miles 
  only 
  slight 
  declivity, 
  it 
  probably 
  has 
  capacity 
  

   enough 
  to 
  discharge 
  the 
  ordinary 
  flood-flows, 
  provided 
  the 
  Genesee 
  

   were 
  kept 
  within 
  its 
  banks. 
  

  

  The 
  value 
  of 
  a 
  reservoir 
  on 
  Genesee 
  river 
  in 
  mitigating 
  floods. 
  

   The 
  question 
  will 
  arise 
  in 
  storage 
  projects 
  as 
  to 
  the 
  value 
  of 
  a 
  

   reservoir 
  in 
  mitigating 
  flood-flows. 
  As 
  this 
  matter 
  has 
  been 
  

  

  