The Bismarck tribune. [volume] (Bismarck, N.D.) 1916-current, 1927-12-09
Project to Cost
About @7, 900, OOO

&VVIIC 0UU 0OVSu OoAOS0 sssy - VS0soH
water supply 10 falling, lake arc
disappearing, the rivers 70 falling
of and large Giles will shortly face
water famine.
Would Save Much Land
1T woult VI at least 5000
acres annually Of the richest kind
Of farm ~oil along the banks Of the
river between tho dam and Sioux
City. Iowa, because Of reduced -
sion. Il would effect saving fill
tration plant operating costs for the
cities along the banks Of the river
between he dam and Sic"~ City by
reason Of the reduced silt content. It
would save In future bridpe pier costs
and incident lily It would practically
eliminate Il jams.
Because Of the relatively large
low water flos possible with this
regulation and . head of 1t EAST 80
feet, which IL below any assumed
storage, there should b. available ct
Ill times rouehly.80, 900 horsepower.
A much larger but more uncertain
quantity would b available during
the summer Ope.: tions.
1.-THE silt content Of til river ct
Bismarck Is shown In m accompany
ing schedule. The silt viii BE- de-
posted in slack water over . sec.
ton Of about so miles Of river bed ct
the upper end Of the lake due to the
fiuctuation Of the lake level. Theo-
retically il would require 800 years
to fill the lake with siltl. Actual
encroachme.,t DOWN tn river, how.
ever. could b stopped by . cable
way excavator.
1.-THE mar Of the Mississippi river
basin shows that II Missouri river
basin Il large p..rt Of It. The pro-
file ct the Missouri river indicates
that the floods which travel down
Il have no reason to sflatten out"
and diminish il intensity because Of
change Of .ade. This is further
shown BY the rate Of travel ,twsen
Gegiug station !or the yea: 1928.
The average flow is about six miles
per hour. It 10 assumed, therefore,
that 10000 cubic feet u second
taken Of Of the crest flow 1t Bis
marck in 1928 would have reduced
the crest flow at Kansas City by the
same amount. BY the same rsason-
ing it is believed tia II $4,000
cubic 1ost per second were .dded to
the stleeu: Ut Bismarck during the
low water flow It would contribute
that much to the stream MI the
way to the mouth. j
Safe Dam Il Possible
"In anticipation Of the claim that
may be made by laymen that no safe
dam can be built in the channel Of
the Missouri, j: might be well to ex-
plLin briefly features Of construe.
tien which viii obvis asly insure
safety.
Dams usually tail for one or both
Of two reasons: insufficient spill
way capacity or improper bond be.
tween the structure and the founda.
ton or sides Of the .amsite.
"For safe spillways, flood stud.
les are he basis Of design. These
great floods can be anticipated It
the proper attention il given to the
pertinent data and information no7
available.
"Fer safety Of emb1nkment the
concrete core wal: Is sureested. The
steal sheet piling below the wall
would Be shale or hard cla,' e
deemed advisable. The 3ncrste core
wall would have hollow ribs extend.
ing vertically and spaced every 100
feet along the wall. These would
b u6nholes or inspection wells,
open ct the top and connected ct the
bottom With 4 horizontal chamber
| Ii tho bottom Of the wall which In
turn would b connected TO and
open out intg the spillway.
eThese wells would serve IN inn
portant part in the construction.
Frequent openings on both upstream
and downstream sides would provide
m exit down the wells and out the
spjllwaX for the excess sluicing wa
TOR which brings the soil down from
the hills! AZ the embsnkmeut pro-
creased these holes would b tenn
porarily stopped. After completion
Of the elnbankment the holes on the
downstream side would N ma
fnently stopped but the holes on the
upstream side woulS permit 3requent
inspection Of she process Of consoli-
dation. Any tendency toward
"necking" or blowouts would BE- i'm.
m9diately detected. The only dam.
age possible would be the loss Of
s0ch material g could b carried
away BY ths flow through these
holes into the spillway until the
reservoir could Be emptied and the
neck discovered and gfoutod."