The  crest  of  the  dams  will  be  held  16  feet  above  low  water;  this  with  a  view  of  re-
icing  the  slough  discharge  at  high-water  stages.  It  is  also  propof>ed  to  revet  the
3d  and  banks  on  the  river  line  of  the  dams  with  thin  brusfa^mattress,  ballasted  as
lowD  in  the  drawings,  and  extending  30  feet  above  and  30  feet  below.  The  dams
ill  be  braced  to  a  row  of  short  piles  placed  in  rear  of  the  line,  said  braces  to  be  of
inch  by  12  inch  timbers,  bolted  to  main  piles  and  held  to  brace  piles  at  the  surface
f  the  ground  by  bent  shackles,  as  shown  in  the  drawings.
This  mode  of  fastening  braces  has  been  executed  by  me  with  perfect  success  at
>aint  Helen's.  It  is  simple,  cheap,  and  effective.  Braces  will  be  laid  at  intervals  of
5  feet.
On  shore  the  piles  will  be  sank  as  posts,  and  careful  measures  will  be  taken  to
ecnre  the  ground  around  the  extremities  of  the  danls.  It  is  anticipated  that  these
lams  will  rapidly  fill  up  the  sloughs  just  below  them  to  above  low  water,  when  a
rrowth  of  grass,  willows,  and  cotton- wood  will  be  started  to  make  the  closure  perma-
lent.
At  Deer  Island  it  is  proposed  to  lay  up  from  material  immediately  at  hand  a  fascine
lam  well  tied  through  from  top  to  bottom  and  weighted  with  rock,  or  gravel  and
land  in  bags,  all  as  shown  in  the  diagrams  submitted.  Height  above  low  wator  to  be
5  feet.  This  slough  is  of  the  same  width  as  Burke's,  but  being  bare  at  low  water  will
not  require  a  dam  more  than  6  feet.
