Warren sheaf. [volume] (Warren, Marshall County, Minn.) 1880-current, 1910-03-31

! erson has been instrumental IN provid-
ing way, by which all government
| land within the area is to be assessed
the same as the settlers land, without
failed.
"Perhaps the most helpful thing
large an area, and bring it into one
comprehensive system, is the typo
graphic survey by the United States
geological survey made in 19O7-8 This
was splendid piece Of work, in OBJ
tanning ia which Mr.. Stevenson and the
Thief River Valley Improvement asso-
| citation. A. W. Clark, president, are de-
serving Of great credit.
line working out, Of the most eco
nomlc system properly to drain each
| quarter section has resulted in making
the map of this area look more like a
cross between checker board and
an efficient drainage system of this ex-
! tent must have each mile of each main
| and branch of carrying capacity to
! meet, the demands made upon it by the
territory whose storm water must pass
through it.. This carrying capacity in
blned effect of five distinct factors,
| some OF which the engineer has under
complete control, while others he can
| safely control only within small limits.
The slde-slopes of the ditch he will de-
sign to suit the soil conditions to
be met in the ditch and the agency to
be employed in making the excavations
the sleeper side-slopes. These can be
employed where clay or gravelly-clav
predominant, but with sand or gravel
the sleeper side-slope will result in cav
ing banks and speedy and serious
filling up of the ditch will follow.
Matter of Slope.
eff the ditch is to be dug with
teams, that is, with horses and small
scrapers,. the fatter side-slopes will be
employed. Floating dipper -dredge ma
chimes can work only on the sleeper
slde-slopes, while the dry land exca-
vators can work on any slope fixed by
the engineer, but can afford to dig the
sleeper slopes at least cost
lin fixing upon the proper side
slopes the designing engineer will also
give some, weight to the fact that the
sleeper slopes permit. at the same cost,
a deeper ditch which insures better op-
IPortunlty for sub-drainage to bordering
lands and enables wider territory to
ing lateral bitches.
1.-The second factor with which the
drainage engineer has much to do in
designing system which shall have
each section just large enough efficient
~ to 90 its work is what is called the
5coefficient of ropg hness. Oyer this he
has no control whatever. He must de-
termine what it is, however, in order
to fix upon the necessary size and
grade of the channel, all other features
OF the design having been determined
upon. Hydraulic tables show this CO.
efficient to have range of values diff
fering by 400 per cent, depending
Npnl fh1 IL y
surfaces in contact with the water and
ditch.
1.-The remaining three factors of
the five which together largely
determine, the DISCHARGE capacity of
the ditch and which govern in
tom width, the allowable depth Of
water in the ditch at flood stage and
the slope or fall per mile of the bot
tom of the ditch.
Makes Saving.
can example of what may some-
Times n be saved ~ by a diligent search for
case Of the final design of the lower
five miles Of the main ditch of system
No. IL. Here saving over a. previons
design of $1,000 was made without
a. 5:tn the discharge capacity of
| Cne d1Cch.
"Drainage once consisted of means
provided by each man injured by it to
not want it to some place where some me-
one else did not want it, concluded
Mr.. Hoag.- "The early laws on drain
age were built on the theory that wa
ter in excess was a common enemy
against which every man was justified
in protecting himself by all possible
|
progress could be made in drainage AZ
science. Until comparatively recent
years it remained a more or less crude
art, the laws governing the flow Of
water in open channels being but lit.