406 
On  River  Conservancy , 
necessity  ; that  without  an  outfall,  their  works  of  under-drainage 
and  improvement  would  be  rendered  abortive  ; that  whether  the 
water  from  their  drains  soaks  into  the  ground  or  passes  away 
along  the  ditches  and  watercourses,  its  ultimate  destination  is 
the  river,  the  great  highway  for  the  water  ; the  further,  there- 
fore, the  lands  are  removed  from  the  outfall,  the  greater  the 
length  their  rainfall  will  have  to  travel  over,  and  the  greater 
their  mileage  rate.  The  further  land  is  removed  from  the  out- 
fall the  more  river  it  requires.  A field  lying  near  the  sea  may 
get  rid  of  its  rainfall  by  a passage  through  a water-way  to  be 
measured  by  chains,  whereas  another  plot  of  land  near  the 
source  only  returns  its  rainfall  to  the  sea  after  a passage  of 
many  miles.  Acre  for  acre  the  rainfall  may  be  the  same,  and 
an  acre  at  the  source  of  a river  may  discharge  the  same  quantity 
as  a corresponding  area  at  the  outfall,  yet  the  duty  required  for 
the  removal  of  the  former  is  so  much  greater  as  its  distance  is 
from  the  point  of  discharge. 
The  proprietors  of  the  lower  lands,  who  have  in  many  cases, 
at  great  cost  to  themselves,  improved  the  outfalls  of  their  rivers, 
and  so  facilitated  the  discharge  from  lands  lying  above  them, 
further  contend  that  it  would  be  unfair,  in  assessing  the  rates  to 
pay  for  improving  a portion  of  the  river  lying  above  that  on 
which  their  works  are  situate,  not  to  give  any  credit  for  the 
amount  already  expended,  which  otherwise  would  have  required 
to  be  done. 
To  meet  these  various  demands,  the  Bills  brought  in  bv  the 
Government  divide  the  watershed  into  high  lands,  medium 
lands,  and  flood  lands.  The  former  being  taxed  only  to  one-tenth 
the  amount  of  the  latter,  and  the  proportion  of  taxation  of  the 
two  latter  to  be  determined  by  the  Government  Department 
entrusted  with  the  carrying  out  of  the  Act,  after  local  inquiry 
by  their  Inspector  sent  down  to  settle  the  details  for  each  river. 
Works  for  tee  Improvement  of  Rivers. 
While  it  is  impossible  to  lay  down  any  general  scheme  for 
the  improvement  of  all  rivers  alike,  there  are  certain  general 
principles  that  should  always  be  kept  in  view. 
These  may  be  stated  as  follows : — 
That  the  improvement  of  a river  should  be  progressive  from 
its  outfall  to  its  source. 
That  it  should  be  of  sufficient  capacity  to  carry  off  the 
rainfall  of  the  district  without  flooding  the  lands  through  which 
it  passes. 
That  the  flow  of  the  upland  water  should  be  equalised  as 
much  as  possible  throughout  the  year. 
