﻿PLANS 
  FOR 
  EXTENDED 
  IRRIGATION. 
  313 
  

  

  per 
  second-foot 
  ; 
  in 
  Valencia, 
  above 
  200 
  acres 
  per 
  second-foot, 
  and 
  in 
  Elche, 
  where 
  

   ■water 
  is 
  very 
  scarce, 
  a 
  second-foot 
  is 
  made 
  to 
  do 
  duty 
  for 
  1,000 
  acres. 
  Of 
  course 
  such 
  

   crops 
  as 
  rice 
  require 
  much 
  more 
  water, 
  giving 
  a 
  very 
  low 
  duty. 
  

  

  Hon. 
  G. 
  P. 
  Marsh, 
  in 
  his 
  well-known 
  work, 
  "Man 
  and 
  Nature," 
  after 
  discussing 
  this 
  

   question 
  thoroughly, 
  comes 
  to 
  the 
  couclusion 
  that 
  200 
  acres 
  to 
  the 
  second-foot 
  is 
  a 
  safe 
  

   allowance. 
  The 
  United 
  States 
  commissioners, 
  referred 
  to 
  above, 
  who 
  made 
  an 
  exam- 
  

   ination 
  of 
  the 
  great 
  valley 
  of 
  California, 
  came 
  to 
  a 
  similar 
  conclusion. 
  Mr. 
  W. 
  H. 
  

   Hall, 
  State 
  engineer 
  of 
  California, 
  concludes 
  by 
  saying 
  that 
  this 
  duty, 
  at 
  least, 
  can 
  be 
  

   reached. 
  Indeed, 
  it 
  seems 
  to 
  be 
  a 
  generally 
  accepted 
  conclusion, 
  that, 
  with 
  the 
  aver- 
  

   age 
  of 
  crops 
  and 
  soils, 
  and 
  without 
  considering 
  the 
  rainfall, 
  the 
  duty 
  should 
  reach 
  200 
  

   acres 
  per 
  second-foot. 
  In 
  Utah, 
  the 
  practice 
  is, 
  as 
  was 
  above 
  stated, 
  but 
  80 
  to 
  100 
  

   acres. 
  In 
  Colorado 
  it 
  is 
  much 
  less, 
  probably 
  40 
  or 
  50 
  acres. 
  

  

  To 
  arrive 
  at 
  any 
  definite 
  knowledge 
  concerning 
  the 
  amount 
  of 
  arable 
  land 
  in 
  the 
  

   West, 
  it 
  will 
  be 
  necessary 
  in 
  the 
  cases 
  of 
  nearly 
  all 
  the 
  streams 
  to 
  institute 
  a 
  system 
  

   of 
  gaugings, 
  to 
  be 
  made 
  at 
  intervals 
  not 
  greater 
  than 
  once 
  a 
  week, 
  to 
  extend 
  through- 
  

   out 
  the 
  year 
  at 
  least. 
  The 
  simplest 
  way 
  to 
  carry 
  this 
  out 
  would 
  be 
  to 
  have 
  a 
  section 
  

   made 
  of 
  the 
  river 
  channel 
  at 
  the 
  point 
  selected 
  for 
  the 
  measurements, 
  the 
  section 
  to 
  

   extend 
  to 
  the 
  marks 
  of 
  the 
  highest 
  floods 
  on 
  the 
  banks. 
  A 
  gauge-rod, 
  suitably 
  placed, 
  

   and 
  read 
  at 
  the 
  designated 
  times, 
  with 
  measurements 
  of 
  current 
  velocity 
  at 
  the 
  periods 
  

   of 
  high, 
  medium, 
  and 
  low 
  water, 
  would 
  give 
  data 
  for 
  the 
  computation 
  of 
  the 
  capacity 
  

   of 
  the 
  stream. 
  Until 
  this 
  is 
  done, 
  we 
  can 
  have 
  but 
  very 
  loose 
  ideas 
  regarding 
  the 
  

   capacity 
  of 
  our 
  public 
  domain 
  for 
  supporting 
  human 
  life. 
  

  

  As 
  the 
  result 
  of 
  a 
  tolerably 
  careful 
  examination, 
  but 
  not 
  a 
  thorough 
  survey, 
  it 
  has 
  

   been 
  estimated 
  that, 
  without 
  the 
  use 
  of 
  reservoirs, 
  Colorado 
  contains 
  7,323 
  square 
  miles 
  

   of 
  irrigable 
  land, 
  or 
  7 
  per 
  cent, 
  of 
  the 
  area 
  of 
  the 
  State. 
  By 
  storing 
  the 
  surplus 
  water 
  

   from 
  the 
  spring 
  floods 
  this 
  area 
  can 
  be 
  increased 
  to 
  10 
  per 
  cent, 
  at 
  least. 
  

  

  Of 
  the 
  area 
  of 
  Utah, 
  Major 
  Powell 
  estimates 
  that 
  2.8 
  per 
  cent, 
  are 
  irrigable 
  without 
  

   reservoirs. 
  This 
  estimate 
  is 
  based 
  upon 
  an 
  assumed 
  duty 
  of 
  but 
  100 
  acres 
  per 
  second- 
  

   foot. 
  Believing 
  that 
  this 
  duty 
  is 
  but 
  one-half 
  of 
  what 
  can 
  be 
  reached, 
  we 
  are 
  inclined 
  

   to 
  increase 
  his 
  estimate 
  to 
  nearly 
  double 
  this 
  amount, 
  and 
  to 
  place 
  it 
  at 
  5 
  per 
  cent. 
  

   The 
  use 
  of 
  reservoirs 
  will 
  not 
  greatly 
  increase 
  this 
  amount, 
  as 
  most 
  of 
  the 
  available 
  

   land 
  can 
  be 
  served 
  by 
  the 
  streams 
  directly. 
  It 
  is 
  probable 
  that 
  not 
  more 
  than 
  6 
  per 
  

   cent, 
  can 
  be 
  irrigated 
  by 
  the 
  employment 
  of 
  reservoirs. 
  

  

  In 
  California 
  it 
  has 
  been 
  shown 
  by 
  survey 
  that 
  practically 
  all 
  of 
  the 
  great 
  valley 
  

   can 
  be 
  brought 
  under 
  irrigation. 
  Add 
  to 
  this 
  area 
  of 
  15,000 
  square 
  miles 
  the 
  numerous 
  

   valleys 
  of 
  the 
  Coast 
  Range, 
  and 
  of 
  the 
  San 
  Bernardino 
  Mountains, 
  and 
  the 
  total 
  arable 
  

   area 
  of 
  the 
  arid 
  portion 
  of 
  the 
  State 
  will 
  exceed 
  20,000 
  square 
  miles. 
  

  

  Judging 
  from 
  the 
  character 
  and 
  size 
  of 
  the 
  streams 
  and 
  the 
  surface 
  of 
  the 
  country, 
  

   about 
  5 
  per 
  cent, 
  of 
  the 
  area 
  of 
  New 
  Mexico 
  is 
  irrigable, 
  and 
  of 
  Arizona 
  about 
  the 
  

   same 
  proportion. 
  Wyoming, 
  fully 
  as 
  well 
  watered 
  as 
  Colorado, 
  and 
  having 
  an 
  im- 
  

   mense 
  area 
  of 
  plains, 
  should 
  have 
  as 
  great 
  an 
  area 
  of 
  irrigable 
  land 
  in 
  proportion 
  to 
  

   its 
  size. 
  

  

  Montana 
  has 
  probably 
  very 
  nearly 
  the 
  same 
  proportion, 
  though 
  the 
  great 
  stretch 
  of 
  

   arid 
  plains 
  in 
  its 
  eastern 
  half 
  would 
  reduce 
  it 
  somewhat. 
  A 
  safe 
  estimate 
  of 
  its 
  arable 
  

   area 
  would 
  be 
  8 
  per 
  cent. 
  Idaho 
  has 
  a 
  slightly 
  smaller 
  proportional 
  area 
  than 
  Montana, 
  

   but 
  greater 
  than 
  Utah. 
  Probably 
  7 
  per 
  cent, 
  is 
  a 
  safe 
  estimate. 
  Nevada 
  has 
  compar- 
  

   atively 
  little 
  water, 
  it 
  is 
  safe 
  to 
  say 
  not 
  more 
  than 
  enough 
  to 
  irrigate 
  3 
  per 
  cent, 
  of 
  its 
  

   area. 
  

  

  Of 
  Oregon, 
  east 
  of 
  the 
  Cascade 
  Range 
  and 
  south 
  of 
  the 
  Blue 
  Mountains, 
  which 
  is 
  

   the 
  portion 
  requiring 
  irrigation, 
  probably 
  6 
  per 
  cent, 
  can 
  be 
  watered. 
  It 
  is 
  claimed 
  

   that 
  irrigation 
  is 
  unnecessary 
  in 
  any 
  part 
  of 
  Washington 
  Territory. 
  Whether 
  this 
  be 
  

   true 
  or 
  not, 
  will 
  soon 
  be 
  determined. 
  We 
  are 
  inclined 
  to 
  doubt 
  whether 
  the 
  eastern 
  

   part 
  can 
  be 
  cultivated, 
  with 
  safety, 
  without 
  water 
  at 
  hand 
  to 
  supply 
  the 
  deficiencies 
  

   of 
  the 
  heavens. 
  

  

  Of 
  that 
  portion 
  of 
  Dakota 
  lying 
  within 
  the 
  arid 
  region, 
  probably 
  not 
  more 
  than 
  5 
  

  

  