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

erson has been instrumental IN provid-
ing a way, by which all government
land within the area is to be assessed
the same as the settlers land, without
which the whole plan would have
"Perhaps the most helpful thing
done to make it possible to treat SO
comprehensive system, is the typo
graphic survey by the United States
geological survey made in 1908. This
was a splendid piece of work, in OBJ
tanning which Mr.. Stevenson and the
Thief River Valley Improvement asso-
cation, A; W. Clark, president, are de-
serving of great credit.
The 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 a checker board and a
crazy,,quilt than a drainage system. But
an efficient drainage system of this ex-
tent ten p must nave each mile of each main
and branch of a carrying capacity to
meet the demands made upon it by the
territory whose storm water must pass
through it. This carrying capacity in
every ditch is the result of the com
bined effect of five distinct factors,
some OF which the engineer has under
complete control, while others he can
-.
The 81 de-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
Greatest economy will be secured with
the sleeper side-slopes. These can be
employed where clay or gravelly-clay
predominate,. but with sand or gravel
the sleeper side-slope will result in cav
ing banks and a 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 en- Floating ,dipper- dredge ma
side-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 some4 weight to the fact that the
deeper ditch which insures better op'
portunlty. for sub-drainage to bordering
lands and enables a wider territory to
be properly drained through intercept
| ing lateral bitches.
1.-The second factor with which the
drainage engineer has much to do in
designing a system which shall -. have
ly to do its work is what IS called the
coeficient of roughness. Over 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
largely upon the nature Of the ditch
surfaces in contact with the water and
slightly effected by the grade of the
1.-THE remaining three factors of
the five which together r. largely
the ditch 'n and SS whieS G aGTeqa e
it's economic design, are the bot
tom width, the allowable depth Of
water in the ditch at food stage and
the slope or fall per mile of the bot
tom of the ditch.
Makes Saving.
IAN example of what may some
times be saved by diligent search for
the most efficient design, occurs in the
case of the final design of the lower
five miles Of the main ditch Of system
! No. IL. Here saving over a. previous
design of $1,000 was made without
diminishing the discharge capacity of
the ditch.
"Drainage once consisted of means
provided by each man injured by it to
conduct water away from where he did
not want it to some place where some
one else did not want it, concluded
MI. Hoag., 1.-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
means. Under these conditions no
progress could be made in drainage as
science. Until comparatively recent
years it remained more or less crude
art the laws governing the flow Of
water in open channels being but lit.
| tie known.'