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~ flood:' control IIpaoe ba.1I ..a ,.,t. beeu oenll~uote4. - to dC"Tote ..11 the 1 oonlltl'1ctecl worn to the 1101. purpoae of flood oontrol. &II DO nt_plated by . ". exilltl"l; lnatrllCtlona, ... aId .._ to be 1noo~.i.t.n1uor1 th-publ1o,-inte.....t.-"l th-- -e---Congre8ll1'oniil aatliorbat'1on. and with the war proU"" It would ...... ..or. oonaletent and reuon..b1e, durlSl& the intera uutH rind olllllp1etion. aDd neDellsary. durll1g the war. to sO operate Caddoa ReaerYolr ... to attain ..s IWoh '":l &II feasible of eaoh of the dual benefits or flood oontrol and _ter cOlUIervation. ,-, In other word., durillg t;he WU'. haurlb and benefits auri; be weighed. llJ1d ohances N be taken. The probabHl ties of floods of various magnitudell. and the damage. that; W might result theretrOJll. Jlms'\; be b&l.anoed agains'\; the bene1'l'tB of "..tor oOllllerv..Uon. N ,.. 11. The greatest 1'lood of reoord. whloh oocurred in June 1921. had a orellt flow..t Caddo.. esti_ted lit 170,000 cfs. To control a flood or t.hat. intensity and duration requires a storage oapaoity of 270,000 A.F.. as designed. in ord..r to hold the flowlI in the downstrelUll channel to within 10.000 01'.... t.hat beillg the estimated bank-full and non-overflow oapaoity of the downstream channel. Benoe the oontrel at t.h.. 1921 1'lood ~ht be assUll\ed to r..quire all the preaently conatructed reservoir oapaoity. Rcll"....er. as disolosed by stre.... flow reoords now coverint a period cf about ,0 years, suoh a flood hall ooourred but once, ,\;he probability of it.a occurrenoe in 1943. or during the war. is extremely remote, and all other floods of reoord ....re of magnitudes considerebly less than the 1921 flood and hence, t.hey O&n be oo1Itrolled by ..-ller storage capaoit.ieli.. Detailed atudie. show that the 1921 flood oould ha"" been controlled to within 26,000 c1"a. by.a flood pool. capaoity of 170.000 A.F., and that such a flood pool oapaoity f'I111 oontrol all floods of reoord except the 1921 flood. inoluding the flood 01' April 19L2. to within 10.000 ofs.' - /JO,ocO 12. Should a flood OCOlU"' during the war, 01' the aagnitude of the 1921 . .flood. at a time when the space available for flood oontrol "&8 170.000 A.T. (ie. "" assuming the reJllaining constnicted spaoe "as filled with conserved watera at the ~ : tiJae of the IlSSUJI18d flood). the question i trVolTes weighing the benef1 ta or i' l regulation IIld conservation against the d&magell that. ll'.ight result 1"rcm a flow in A :l 0 the downstream ohannel 01" 26.000 c1"s. at ~ts crest. In this oonnection it should ~ .;, ~ be recalled, (1) that creat flows 01" 49.600 era. below Caddoa and of 40,000 cfa. ~ ~ ;!. at l.amar were enaountercd in April 19L2. with some moderate but no extensIve or '\.: t t1 critical damages to landa. property. irri[;ation facilities Dr crop produotion, -.:t ~ i,j (2) .that during the pro[;1"ess 01' construotion at Caddoa. several floods hs:n y ... ~ occurred in dOwnBtre"", tributaries. including one at l4mar and t.o at. Rolly. with :I 1 '" cren flaws in the main river in excess of .10.000 eta.. which thereafter diminished ,,~~_, with dist"noe downstre8Jlli and. (3) ~hat the lands.;.m property a~ong the down- '.i.... { stream channel are. and af'ter Caddoa u cC2r.pleted w~ll remain. subJect to the .'\ hazard. of floods ori!';inating in the 5.600 square-miles of drainage &rea tribut~ to the river section between C"ddoa and t.ha Statel1ne. .- 13. Consldering the improbability of occurrenoe of a flood during the wer of _gnitude of the 1921 flood, CDr.lparing the d8lllages t.hat might result rrd'm suoh a flood. should it occur, 8.lI controlled by a reservoir capacity of 170,000 A.F. ressrved for that purpose, end recalling that suoh a reBervoir. oapacity will control all other floods of record to within the non-overflow and -3-