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<br />AlterndtiveNo.1 <br /> <br />Tnis alternative >Ii I 1 involve clea~ing and ~nlarge"'ent of the Lower <br /> <br />Cactus Valley Ditch from Ninth Street to ~ sp1ll locat ion at the City Park <br />Drainage. The capac1ty of the enlarged ditch would be suffic1ent to carry <br />floOd flows from Seventh Street Basin and normal 1rr1gat1o~ flows (50 cfs). <br />Some dike work would also be necessary at County Road 231 on First Street <br />~asin similar to item 4 1n Alternative No.1. Regular m~intenance would be <br />1mportant with th1s dlternative. There would be no improvements to West <br />Basin, Sixteenth Street Basin, or East Basin. <br />The following tables show structural measures, estimated construction <br />costs, and benefits for each of tMe ~bove alternatives. <br /> <br />STRUCTURAL MEASURES <br /> <br />Work Item Unit AH 1 Alt2 Alt ) Alt4 <br />Concrete Drop InletStr Number , , 1 1 <br />Concrete Ditch Un1 ~g Feet 3850 _u 4870 no <br />Pipeline Feet 2400 3430 n_ --- <br />Ditch Cleaning ~ Enl~rg. Feet 1380 1380 1380 6250 <br />Earth Dike C"_ 'd_ 11,700 12,200 u- no <br /> <br />COMPARISON OF ALTERNATIVES 1/ <br /> <br />Alternative Cost <br />C <br /> <br />Alt n <br /> <br />Alt#2 <br /> <br />An,3 <br /> <br />Alt ~4 <br /> <br />om arlson <br />Construction Cost , 962,000 , 783,900 I 613.800 I 209,900 <br />land Rights Cost 227,200 167,200 99.000 99,000 <br />Eng. ~ Adm. Asst. 298,200 243.000 190.300 65,000 <br />Total Inst. Cost n:-41l7~O"O $r;19<f;um I 903,100 , 373,900 <br />Annual Alternative <br />Cost and Effects " Altj4 <br />Comparison Alt ~1 Alt*2 A1< <br />Annualiled Cost \ 154,700 , 124,300 1 94,100 \ 39,500 <br />Annualized Benefits 13.500 9,400 11.200 7,100 <br />Net Annualized I -141.200 1 _114.900 , - 82,'100 , - 32.400 <br />~enef1 ts <br /> <br />1/ Price base September 1986, D1scounted and annualized dt 8 7/8% <br />for 25 years. <br /> <br />25 <br /> <br />RECOMMENDATIONS <br /> <br />The follow1n~ recommendations are included for consideration in reducing <br />potential flood damages. <br /> <br />'- <br /> <br />Loca I units of government shou I d 1mp 1 ement ~ flood P 1 a i n management <br /> <br />,- <br /> <br />or flood hazard mitigat10n plan. <br />Existing restrictions that contribute to overbank floodi,g should be <br />corrected where possible dnd when possible. <br />Structural alternat1ves studied herein dO not appear to be economically <br />feasible projectS. This is primarily because of the expected shallow <br />depth of flow w1tMin the flOOd plain. Steep slopes through town <br />generally disperse flOOd waters except in a few locations. The most cost <br />effective alternative studied is Alternative No. 4 discussed unde r <br /> <br />3_ <br /> <br />"Structural Flood Control Measures". This set of treatment measures <br /> <br />Should be considered in more detail. <br /> <br />4. OwTlers and occupants of buildings and other property w1thin or <br />adjacent to the delineated flood boundary should consider flOOd <br /> <br />insurance. <br /> <br />5. <br /> <br />Public i~format10n and education programs on flood hazards should be <br /> <br />made available to the public. <br />6. Ndti~e habitat along the main channels Should be maintained to <br />preserve channel st~bi 1 ity dnd provide w1ld life habitat. <br /> <br />-26- <br />