WSP00575

• File Number: 8141
• Description: Fryingpan-Arkansas Project
• State: CO
• Basin: Arkansas
• Water Division: 5
• Date: 1/1/3000
• Author: William Howland
• Title: Pueblo Reservoir Flood Control Operation
• Water Supply Pro - Doc Type: Report/Study

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To: U...S. Ar<:lY Corps d'~ ,"E;)gineers
U.S. Bureau of Reclamation

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SUQject: Pueblo Reservoir Flood Control Operation

From: William Howland

Gentlemen:

I am Willia~ Ho~land. I am here today as Sec=etary -treasurer
0= tC2 Buff~lQ Mutual Irrigation Co~par.y.and 'also ~3 SUperint~nd~nt
and eneral l-fanag~r of the i\iility Eut1J-31 Irrigation Compat1:l. both of
which u=e dituated in Colorado ~clo~ 20hn Martin Reservoir. F~= the
record. I a~ also a rne~ber of the Region VI Water Resourc~ Cauncil
and Vice-presid.ent of the F01.ir-S'::'ates Irrigation CO'.Jncil.

The Pueblo Res.ervoir Flood Contro.! Plan is. for the mOst part.
a well-constructed document. HoweYer~ I agree with other~ her~
today who find fault with the limitation to a 5.000 cfs' flow :\'t .the
Avondale gauge. I believe this is an arbitrory figure which could be
substantially increased without any serious consequences.

Ba:.Jic Data

l~ The Avondale gauge is 23~6 miles downstre~~ from Pueblo Dam.

2. The actual channel capacity at Avondale, acc~rdi~g to informvtion
in the .t-!aste.r Wat.er Control t.lanual, is 6.600 cf~;..

3. Only at some point ahov~ AYondal~, namely below the Pu~blo Flood-
W2Y a';1d ~ve~ E:<te':"ls:!..an, is t'ne c':lf3n?l21 cE:pac.i.r_y L:"{~l;.hl.:::.c-d to 5.0r,0 c.t::>.

4. ThB Chann~l capacity in~r~~ses do~nstream to L~ Junta (eg.,n~pesta-
8',200 c=s. ; La Jun ta -10. 200 cfs~) J

S. Two ~ajor tri~utarles, the Fount~in a~d the St. Chdrle~ Rivers,
~nter the Arkansas between pueblo Dn~ and Avond~le gauge.

6. The di$charge curve for Avond.J.le ga'.lge indic~te3 that an inct'8~\!ie
in ri'"./e= stage of only 0.9 ft.. would increase disch.arge frol;,! 5,(lOU
cis to 20.000 cfs.

7 The pea~ discharge f~e~lency c~rVe sho~g th~t prior to Pueblo
Re3e~voir the p~=cent of chance of exceeding 5,000 cis Was abov~
70% and that there was a 50/50 chance of exceeding 8,500 CfR. ~5
modifi~d by Pueblo Reservoir. 5,000 cfs will be exceeded only 42%
of the years nereafter and there is a 50/50 chance of exceeding
o~ly 4,000 cfs in anyone year.

Concll.15ions

1. Thi.:3 plan pzobably ,.;ill aot injure de:cre:ed water rights in
Colo~~dc if the flow ~t Ne?~3ta ~~c~ed5 7,000 cis.. Bowe~er, a~y
do'..;n~"''"!cd adju.:sti'llent affecting flo~s .....:'lich exceed the total of
c312 ing priori ti-es in Wat'ar Districts 14 and 17 will have ~n adv\:!r:':;"?
wffect on sto~a~e in John ~arti~ ReservoiL~

2. Tne river channel will flow 6,600 cis at Avoncale without over-
i'loW'.

3. Flooding which l:'light. occur fro:n an increase to betwe:en 5,000
,:'!:1d 10,00 cfs ~t Avond.:t.le '."ouId be mini,=,al ~~d would be li!'T'lit~d
'::~ T.;;;!.'j>~ lrl!'ld, gr.::tzing lar.d, il:"l.d. O~:l.y o.c:c;=tssionally, f~:-r.l 1 <l;'!.G..

4~ Zx~~nsion oi levee ~ork or channelization hel~~ Pu~blo Floon_
wo:Y ant'! above Avondale ~oJould allo",j' d~3Ch<lrges to exce~d 5000 c:f3
i ~l th is reach.

(continued next paga)