Pueblo chieftain., 1921-09-25

| Below Is printed IN 1uH a letter re-
ceived by the Local Society of En-
gineers from a relative to River i'm
tex-State Engineer relative to River i'm
Iprovement The letter shows plainly
that Mr.. Greene whom many of US
know has not forgotten his home city.
September Q, 1921.
To The Pueblo Society of Engineers.
| Pueblo, Colo.
| Gentlemen:
| In connection with flood problem
work in the Arkansas Valley and cspe-
cially thru and adjacent to Pueblo, l.
take pleasure in submitting the follow
| ing observations:
| %. The evident demand is for chan
nels highly improved in depths, widths,
lgrades, section forms, alignmentS and
Innings (as mosonry. concrete or claD
| lresuting in radically increased dis
charge capacities for both the Arkan-
sas and the Fountain in and adjacent
to Pueblo; all so adjusted as to cimin-
ate, or largely eliminate, deposits in
| the channels-cspccially within the
city limits.
| t2) Separate channels for the con-
lveyance of flood waters are often de-
sirablc. This desirability is particu-
larly noticeabl in connection with the
run-o offs in flood times of the Arka nsas
and Fountain at Pueblo. The water
surfaces of each stream would have
been radically lower through the city
lhad each had separate highly i'm
proved channel for n few miles cast
ward from IA poi.:t above their present
junction.
The call then from this Viewpoint
| and TO me it seems "A most pressing
call,-is for two channels to the east
ward thru the city; the moro northcrly
thereof carrying the Fountain waters
and n part of the Arkansas waters in
| flood timeS, and the more southorly
carrying the balance of tho Arkansas
waters.
This plan calls for an overflow dam
to effect the delivery of "A part OF the
Arkansas waters to the northerly chan
mel allotted to the Fountain waters.
Tho proper adjustment of the pro-
PORTIONS of the total flood OF both
streams which should be allotted to
each of these channels is an interest
ing problem. At present | think that
about two-thirds of tie excess of the
extreme flow of tho Arkansas over the
extreme flow of the Fountain In re-
cent great run-offs should go to the
chaniel allotted to the Fountain.
| t3) Other things being the same, II
Is tho fall given the surface of the wa
;. ter In a channel which determines Its
dischar" =. the greater the fall of the
water surface the greater the dis
charge. By having two channels from
Isomc roint cast OF tbut not far to the
east OF Santa Fc avenue. the water
surface fall in tho channel thru the
l "
lv increased. so tha' channel OF less
width than otherwise necessary may
thcro he used.
| 90 The discharge OF channel in
crcascs about fifteen per cent with
each increase Of ten per cent in depth
OF water carried, The increase In dis
charge which accompanies n ten pcr
cent Increase In chsnnci breadth IL a
little more than ten per cent. but much
loss than fifteen per cent
Tho call then. from this Wow point
is for very deep channel thru tho
deeper II is tho narrower II may be
made with safety.
t5) The carriage and disposal of tho
matter carried In suspension and roll
cd down tho bottom Of tho channel In
flood times is matter of prime I'M
lportancc.
The call In this connection Is sub
channels. Tho aub-channclS feature of
the problem is study in itself. II
would seem that thru the main portion
OF tho city where tho more important
bridges arc that the suh-chanrcls
should hc parallel. while to tho cas-, OF
Santa Fc avenue where the channels
will he much broader the demand seems
to be for n successive series OF shallow
lsuh-channcis covering toward n main
sub channel holding except on curves.
about the center Of each Of the main
channels.
6) The channel allotted to carry tho
Fountain waters and a part OF the
Arkansas waters will also have to he
deep below the present bottom thereof.
at and below thcmouth OF the Fountain
The deepening OF the channel for two
or three miles above seems to require
a maxonry drop at the head thereof.
until such time ~ the Improvement tx
projected further west.
GDSomr five miles imoro or lcssl he
low tho city tho two proposed parallel
l-or nearly parailcl-chanucis may be
brought together again, They Will have
grade than does tho Arkbn'as thru and
wee; of tho main portion Of the city
and they ought 10 have less grade.
because this rushing business which n
desirable thru tho main portion OF tho
city. and is encouraged by having tho
two channels described. cannot hc kept
up indefinitely.
OF course tho stream channels above
and below tho main portion of the city
should be greatly widcncd and tho
suh-chanucis provided with proper
Innings. but tho rid. slorc- above and
below this main portion may he main.
talned hy occasional masonry or con
crete forms making side slopes steep.
ar than otherwise necessary.
II careful calculations disclose that
after having divided tho water, of the
Arkansas and tho Fountain between
tho two proposed channels to tho cast.
ward or S,fits Fc avenue and af,rr
improving tho channel thru tho main
portion of tho city tn tho highest dc.
grcc. there is stili demand f,r q
| al Eg.sa lF, g,HN ~