Laserfiche WebLink
<br />1 <br />1 <br />Ir <br />1 <br />1 <br />1 <br />1 <br />I <br />~ <br />~ ,- <br />~ <br />~ <br />~ <br />~ <br />, <br />, <br />.. <br />, <br />, <br /> <br />IIr. Ilemu. <br />September 12, 1994 <br />Page 2 <br /> <br />IIr. Veiner .uggested that we include the analy.i. of an alternative in which the <br />water level. in the .outhwe.t corner of the .ite could be artificially manipulated. <br />The area would be dewatered in the .pring to optimi.e conditions for herbaceou. <br />plant growth and then flooded (by pwap) in the fall to create area. for feeding and <br />loafing. Thie alternative would include an adju.table elevation .tructure to <br />allow free exchange with the lIi.souri River, except during the late fall monthl. <br /> <br />Ve have prepared a Summary of the .Advantagel. and .Disadvantage.. for each of the <br />proposed alternative. currently Itudied to help evaluate and .elect the <br />iIlprovementl which b..t meet the goall and objectiv.. of tbh project. fbh <br />lummary il presented belowl <br /> <br />A. Flow-through Chute and Ixilting Backwater Area <br /> <br />Advantellel <br /> <br />o Creates large river fishery hebitat. <br /> <br />o A low elevation sill would help maintain the vater level in tbe <br />existing backwater area. <br /> <br />Dhedvantelles <br /> <br />o Does not create as much backwater area as Alternativel C end D. <br /> <br />o Sediment from the IIhsouri River could accl1llulate behind the sill <br />thereby .filling. the exilting backwater area. <br /> <br />o High cost alternative. <br /> <br />o No substantial increase in benefit to vaterfowl habitat. <br /> <br />B. Plow-through Chut. and Backwater Area with Alternate Vater Supply <br /> <br />Advantnes <br /> <br />o Creates large river fishery habitat. <br /> <br />o A low elevation sill would help uintain the vater level in the <br />exilting backwater area. <br /> <br />o Small increase of flushing of the exilting back.ater area. <br /> <br />o Diverting the alternative water supply could provide for som. uptake of <br />nitrogen, phosphorus, heavy aetals, etc. <br />