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<br />
<br />Purgatoire No, 2 site, al'proxiinately6 miles belew Higbee, Colo.;
<br />and the 1. S. site at the Highland (Carman) Dam, approximately 29
<br />D;liles belew Higbee: It' was feund that for tho l,'urpese ef providing
<br />a supplementary water supply for Arkansas RIver,: the Mammoth,
<br />site, although an excellent one, would control insufficient watershed.
<br />Since the inflow downstream from the Mammoth D&ro site constitutes
<br />the major portion of the nnused water discharged from the basin;, the'
<br />project would not be feasible. The Purgatoire No.2 'site, appears,
<br />to be more feasible than the 1. S. site, , ", , ' ,
<br />, 63. The Purgatoire No. 2 site was originally surveyed in 1999
<br />with a view to providing water 'storage for the development efthe
<br />land lying south of the present irrigation area in ArkllDsas :Basin.
<br />In 1924, the State Engineering Department 'of Colorado made, a
<br />detailed survey of the site and proposed a dam 113 feet high "bove
<br />, the stream bed, which would provide a capacity of 123,999 aere,feet.
<br />The "398" studies eondncted under the direction of .the Corps of
<br />Enginecrs, United States Army, and pulllished in HOljse Dee,unent
<br />No. 398, Seventy,fourth Congress, first session, considered a dam 118
<br />.feet iit height with a capacity of 145,990. acre,feet at the Purgatoire
<br />, No.2 site to give a supplementary supply of 48,599 acre,feet.
<br />64. The "398" studICS have indicated, and,the present studies con"
<br />f\rm, that the benefits to be gained, in the lower, Purgatoire River:,
<br />Basin from the development of supplementary water supply akt!).e,
<br />Mammoth, 1. S., er Purgatoire No.2 sites, are negligible l1J1d'that'
<br />developments at 'these sites would have value only in the Arka.nsas
<br />River 13asin. " ' , '
<br />65. 'Oha""nel rectification,' levees, and bank stabilization fpr.,fir!Q!f, 'c.Oj!!-
<br />trol.-Chanuel rectification, levees, and bank stabilizatien have boen
<br />considered, alone and in combination, for the protection of the rural
<br />portions of the area and also, along streams tributary to Purgatoire
<br />River. Owing t<:> the length of the valley and the distribution ef the
<br />damagcs, works ef this nature weuld be very extensive and thcir cost
<br />would exceed the benefits to be obtained. ' In the construction of
<br />levecs 01' rcctifying the channel in the narrOW flood plain, it would be
<br />neccssary to utilize some lands on which damages occur. The aver,
<br />age annual preventable flood damages to crops and improvements are
<br />about $21 pCI' mile of channel in the flood plain. Channel rectifica-
<br />tion, levces, and bank stabilization in, the rural areas are not economio-
<br />aliy justified at this time, nor does any otlter type' of works for' the
<br />gencral preventi<:>n of overflow or bank recession appear to be war,
<br />ranted at present in the agricultul'nll1reas or along tributl1l'y streams.
<br />66, Water power and municipalsuprly.-The erratic stream flow of,
<br />Purgatoire River and demand for al available water for other pur-
<br />poses Jlreeludes the development of hydroelectric power in this area.
<br />There is no need for further municipal water supply in the basin as
<br />existing reservoirs meet the present needs. The existing storage
<br />capacity for water supply exerts no significant regulatory effect on
<br />stream flow:
<br />67, Sopris Reservoir forilood control and irrigation,-A dual,purpose
<br />flood control and irrigation rcservoir at the Sopris sitc has been con,
<br />sidered as a plan for providiug flood protection in Purgatoire Valley.
<br />In ordc\' not to induce a sense of false secmity in people in the flood
<br />plain, it was considered that thc structure should provide flood protec"
<br />tion equal to 'that of the maximum flood of record (September 1904)
<br />if economically justified. '
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