Pueblo chieftain., 1921-08-07
detention storage with either bank
protection or channel enlargement
Flood Control on Arknu.as River


protection or channel enlargement.
Flood Control on Arkansas River
Plan A.--A solution of the problem
by flood detention etorage alone would
involve the construction of one
o" more detention reservoirs Of suf-
ficient capacity to retard all waters IN
excess of the presen, enamel capacity
through Pueblo Based on measure
ments taken during the recent flood
by Messrs. II. d. .imsley and G. S
Price. State Hydrographere. II would
appear that the present channel and
lovee Vorke limit the safe flow to
about 25,000 second feet
In the portion of this report dealing
with drainage area end rainfall data,
1, has been ectimated that a total
volume of $4,000 acre feet would result
from an average rur-ofr OF liz in
ches from storm area of LAO square
miles. 1t is assumed that this run-off
would occur IN 20 hours. From Dia-
gram No. O. 1t will be noted that a le-
tcntion reservoir withoutlet capacity
of $4,000 second feet would require
troll a run-otf Of l-2 inches in 70
hours from the storm area of 1,74O
square miles
The Rock Canyon reservoir site, 10
Gated on the Arkansas River about 8
miles west of pueblo, is believed to be
a
tention reservoir The dam site is To-
Gated in Section 36 r 20 s, r. 6s w.
where tho river flows through a gorge
In sandstone formation, The depth OF
sandstone below river bottom ie known
to be very great and the formation Is
composed of good hard sandstone suit
sble in every way for the foundation
o! concrete CT masonary dam.
The reservoir basin extends about
miles up Tho Arkansas River and
spreads into Bcgss Creek, Rock Creek
and Peck Greek. The basin floor is
privately owned land which is partly
under cultivation and partly in
pasture. The Denver and Rio
Grande and Santa Fe Railroads are
located In the reservoir site, also the
upper end of the Bessemer Canal.
Utilization of this site would in
vclve the reconstruction OF these rail-
roads for probably S to 10 miles and
some changes in tho Bessemer Canal
unless Il was considered safe to leave
them in the reservoir. In this con-
necton 1t Is probable tha, a flood
detention storage reservoir with large
permanent outlets could be utilized for
partial control OF unusual floods with
out increasing the damage from such
floods TO the railroads or tho Besse-
mer Canal In their present locations
Ir other words these + tIiroads and the
Eessemer Canal are so located that
they are subiset to damage from large
foods the damage being principally
due to high Velocltiea in the river.
With a flood detention reservoir of
large outlet capacity all ordinary
floods would Isss the dam without,
storing water and only unusual floods
would submerge the railroads and the
bssdemer Canal by storing water in
'H" reservoir, The effect OF sub
mergency in comparatively quiet water
might cause less damage than the high
q - FN#E
careful consideration should be given
90 the possibility OF constructing a
flood detention reservoir al the Rock
canyon site Without moving the rail-
roads and ths Bessemer Canal. The
crtimatss for this report are. however,
based on the reconstrpction OF rail-
roads to locate them outside the reser-
NcG- The BcCsemer canal could be
lett in the reservoir in any case and no
cost has been Included IN the estimates
fol the removal OF this canal.
IN connection with the reconstruc-
ton OF railroadr. II is understood that
the Santa Fe Railroad Company has
under confederation the abandonment
OF It's line between pueblo and Canon
city. which n accomplished would ms-
trrtally affect the cost for railroad
reconstruction around sne reservoir.
The construction OF a dam at the
Rock Canyon site would probably be
viewed with some concern by laymeu
not familiar with engineering design
due 20 the location Immediately above
Pueblo. Tho favorable foundation
conditions would. however. insure alb
bolIte safety against failure of
properly designed dam In this con-
rcction Il might be stated that the
Reclamation Igfvice has constructed
reservoirs OF vastly greater storage
capacity Ia locations whore the loss OF
life and propc-,y damage from failure
OF dam would Re equally great
II has been thown above that de-
tention storage capacity Of sbou: no.
COO acre feet would be required TO con-
troll the assumed maximum flood IN
the Arkansas River TO flow OF $1,000
second feet through Pueblo. unfor-
tunately the available data indicates
that the Rock Canyon nite can not be
economically developed o this quantity
and there are probably no other sites
o. suitable location and sufficient
capacity TO control the floods II Is.
Therefore concluded that Plan A. Will
proha bly, not prove feasible although II
should he considered when fun data
g. available.
DiaErpm No : shows capacity
curve and Diagram No. cost curve
for the Rock Canyon reservoir site
from which the following costa arc
taken:
Ht Of dam Res eau. Est Cost.
i25 It. 10000 a. f,.....'s ,5oo.o 600
II will be noted that storage In tho
Rock Canyon reservoir site ia esu-
mated to cost about 1851 per acre
foot Storage on the tributaries II
available at ,li would probably cos: