﻿HYDROLOGY 
  OF 
  NEW 
  YORK 
  633 
  

  

  when 
  developed 
  up 
  to 
  a 
  storage 
  of 
  13.5 
  inches 
  on 
  the 
  catchment 
  

   area 
  — 
  at 
  $840,000. 
  This 
  was 
  for 
  a 
  water 
  storage 
  reservoir 
  

   purely, 
  and 
  did 
  not 
  include 
  clearing 
  and 
  stripping 
  of 
  margins 
  

   any 
  further 
  than 
  that 
  cutting 
  and 
  burning 
  of 
  standing 
  timber 
  

   was 
  provided 
  for. 
  Investigations 
  made 
  in 
  1896 
  indicated 
  more 
  

   expense 
  for 
  foundation 
  of 
  dam 
  at 
  Tumblehead 
  falls 
  than 
  

   assumed 
  in 
  1895. 
  Moreover, 
  for 
  a 
  storage 
  reservoir 
  for 
  regula- 
  

   tion 
  of 
  stream 
  flow 
  purely, 
  nothing 
  was 
  allowed 
  for 
  sanitary 
  

   protection 
  of 
  catchment 
  or 
  for 
  removal 
  of 
  buildings 
  along 
  or 
  

   near 
  new 
  margins. 
  

  

  The 
  estimates 
  herewith 
  submitted 
  take 
  into 
  account 
  all 
  these 
  

   several 
  items, 
  as 
  well 
  as 
  an 
  allowance 
  for 
  present 
  labor 
  condi- 
  

   tions 
  and 
  price 
  of 
  materials 
  in 
  the 
  State 
  of 
  New 
  York. 
  

  

  In 
  the 
  first 
  report 
  on 
  upper 
  Hudson 
  surveys 
  (1895) 
  the 
  writer 
  

   discussed 
  extensively 
  the 
  question 
  of 
  proper 
  hight 
  of 
  flow 
  line 
  

   for 
  upper 
  Hudson 
  reservoir 
  system, 
  reaching 
  the 
  conclusion 
  that 
  

   for 
  stream 
  regulation 
  13.5 
  inches 
  in 
  depth 
  on 
  the 
  catchment 
  area 
  

   was 
  the 
  approximate 
  figure. 
  This 
  is 
  about 
  as 
  large 
  a 
  storage 
  

   as 
  can 
  be 
  ponded 
  at 
  the 
  several 
  upper 
  Hudson 
  sites. 
  At 
  Tumble- 
  

   head 
  falls, 
  however, 
  there 
  is 
  apparently 
  no 
  reason 
  why 
  the 
  

   development 
  may 
  not 
  be 
  carried 
  higher, 
  and 
  the 
  present 
  study 
  

   for 
  a 
  pure-water 
  reservoir 
  has 
  accordingly 
  been 
  based 
  upon 
  a 
  

   development 
  of 
  storage 
  up 
  to 
  18 
  inches 
  in 
  depth 
  on 
  the 
  tributary 
  

   catchment 
  area 
  of 
  518 
  square 
  miles. 
  Such 
  development 
  gives 
  a 
  

   total 
  storage 
  of 
  21,662,000,000 
  cubic 
  feet 
  (162,248,380,000 
  gallons) 
  

   and 
  will 
  utilize, 
  during 
  a 
  series 
  of 
  years, 
  substantially 
  the 
  entire 
  

   flow 
  of 
  the 
  stream. 
  

  

  To 
  accomplish 
  this 
  result 
  the 
  uniform 
  outflow 
  from 
  the 
  reser- 
  

   voir 
  has 
  been 
  taken 
  at 
  500,000,000 
  gallons 
  in 
  twenty-four 
  hours; 
  

   or, 
  for 
  even 
  figures, 
  at 
  775 
  cubic 
  feet 
  per 
  second. 
  It 
  is 
  easy 
  to 
  

   furnish 
  this 
  quantity 
  from 
  a 
  single 
  reservoir, 
  although 
  it 
  is 
  

   necessary 
  to 
  fix 
  the 
  flow 
  line 
  higher 
  than 
  13.5 
  inches. 
  

  

  In 
  order 
  to 
  show 
  the 
  effect 
  of 
  drawing 
  775 
  cubic 
  feet 
  per 
  

   second 
  continuously 
  from 
  such 
  a 
  reservoir 
  in 
  Schroon 
  valley, 
  

   table 
  Xo. 
  87 
  has 
  been 
  prepared. 
  The 
  data 
  are 
  (1) 
  the 
  runoffs 
  of 
  

   Hudson 
  river 
  for 
  the 
  twelve 
  years 
  1888-1899, 
  inclusive; 
  and 
  (2) 
  

   evaporation 
  at 
  Rochester. 
  The 
  computation 
  has 
  been 
  made 
  by 
  

   years, 
  beginning 
  with 
  an 
  assumed 
  depth 
  of 
  4 
  inches 
  on 
  the 
  catch- 
  

   ment 
  area 
  in 
  reservoir 
  at 
  the 
  end 
  of 
  November 
  1887, 
  and 
  is 
  

  

  