Missouri Valley times. [volume] (Missouri Valley, Iowa) 1874-1931, 1903-02-26

MtuuGSOH0
rne experience of many farmer.
during the past year, when the crop.
were completely destroyed as the,
were just maturing, showed that some
thing must be done for the protection
of these lands or they will be compelled
to abandon them.
While our state drainage laws do no.
seem TO favor prompt action and lm
mediate relief, yet persistent, perse
verlng effort on the part of those in
terested will III time be awarded
In the northwest corner of the
county q large area is frequently flood
ed by overflow from the Little Sl"n,
river aud its tributaries. This overflow
coming from Mon"na and other conn
ties north, the Little Sioux itself rarely
if ever OVERLOOKING its channel IN thi.
county.
This overflow can he prevented b,
building diKes and diiches IN MOn"ne
conntv-some dlking ofthe river may
he required in This county to insure
complete protection.
Nearly seventeen wears ago surveys
we're made and plans proposed for the
nrOtection of these lands against over
ll,w. and quite recantlv pati'i"ns havf
heen presented i'm hoth Harr,snn anf
Monona counties. AVID pnh'ic "plnt"r
spt ms To favor the drainage plan pro
posed i'm 1885.
have been informed that daring
the past summer tl',a "t ievs,s WA
rum from the SO.dier rlver ut the f""
OF the bluff; in u putt,WeSierly dlrtc
tion to- the Mlssonrl river. and If .hs
reported dltferpnc, nt ei-v ttl"n Ia.
tween tn. two p,lnts mentioned. tx
lists there would he no ditiirnltv IN pre-
ve;,tlng overflow of the stream nv
msk,nga channel of proper dimensions
on pracf'c,lly he the llna referred 10
The Il 'nd IN this vicinity last veal
was aggravated by the overflow from
the Soldier river.
II is eStim 4ted that an area nt 6I1!
square m'las on the bottom lands wa.
flood d last year. and thai the crops
growing thereon we're nearly tota
loss, amounting to S648 COO. which i
considered p very low estimate. A
system of drainage and protection
works for that distr'c4. 10 estimated II
coat not to exc aei 50 TO $3.50 per acre
dedncsing this cost from the loss h,
the 0pod OF last vear. and there Womb
he a halanceo of $4,000 to the credit ol
drainage.
The Boyer river, and other stream:
IN the county, perhaps need AZ mucf
attention as the streams north ant
west of this locality. by straighten
ing the channels of these streams ant
th- construction of d.kes they can be
restrained in proper limits
LIN the loo alton of drainage di'ches
IL IS regarded as the best practice tt
follow, so far az practicable, the lint
OF lOwrst elevation. But this CAT
rarely be done without making ditch
so crooked and increasing its length tt
sucN an extent as to seriously impair
ITS efficiency.
A location should he made on the
very besl line, regardless of persona
interests or local prejudice, and shoulc
be planned to accommodate as large
an area AS possible
The location and grading of roads
and road bitches is All important par
of drainage system which shOrld no.
be neglected or overlooked.
Where the slopes are steep and tine
m .terial of loose character, " wouIc
be better to avoid the shorter line anc
adopt a longer one that will reduce the
grade to such an extent as to prevent
securing the bottom or eroding the
sides A change in cross section vii
in many cases accomplish the sam'
purpose.
The cross-section of ditch-espec
tally when light slope only is avail
able should he such as TO present the
smallest FRACTIONAL! area to the move
.mant of the water. and the smoother
the slopes and bottom the better.
Mylimited experience leads meto be
.lieve that ordinarily the side slopes ~
a ditch should be vertical. or as nearly
vartic II, as the chracter of the materia
will permit, and that tho bottom. in
stead of being fiat, should he v shap
especially in silt hearing streams
When the sides are vertical, tnf
channel is not liable tn become Oh
atrncted nv growth of weeds or grass
as vegetation cannot flourish on
vartical slope.
In V shaped bottom the silt carried
in suspension naturally gravltates TO-
" ard the center where the flow ls con-
centrated and the channelclears itself
AS to the re, or cross-section OF
often, there is great variety OF opln-
ion especially among those who nave
not made the matter . special study.
Some writer's, who are considered
good authority, compute the cross-sec,
Itlon of a ditch upon a certain per cen
of rainfall over the drainage area
usually 80 to go per cent.
For several reasons this is not re-
liable basis to make estimates from.
A heavy down-pour may occur Wher
the drainage basin is already fully sat
urated, OF in this latitude. when TN
ground is solldly frozen, and IN either
case the run off would largely exceed
so to 60 per cent of the precipitation.
Again, the area may be covered, q
partially covered, with a heav
growth of timber, and under brush, o.
y large growth of grass and Vegetation
which would greatly retard the II DIV OF
water. If the larger part of the drain
age basin is land under cultivation
the conditions NAV be such that al
ordinary rainfall will be almost entire
" absorbed, leaving very little to rut
off. As I stated before. there are NJ
two localities where the conditions ant
surroundings are the same, and care.
full study should be- made of eac'
locality before deciding upon the siz'
n channel shall be.
The more recent method of compnt-
ing the siza of a channel is to take tn
aetna, gaugings of the overflow whe'
the streams are at maximum tioot
height for as long a series of years al
possible. AZ many nbseravtlons as pos
sihle, and under all the varying con
ditions