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<br />002157 <br /> <br />, 2.2.2 'Gol f Course Levee <br /> <br />Concern: <br /> <br />Erosion of the north bank levee opposi te the Alamosa <br />stream gaging station was noticed by the Division of Water <br />Resources District Engineer on June 8, 1985. Monitoring of the <br />, site continued to Monday, June 10, when the city crews' placed <br />-approximately 60 dump truck loads of rubble concrete and dirt <br />in an 'attempt to stabilize the bank. This work continued on <br />Tuesday; July 11, 1985, when a contractor was hired to complete <br />cthe job so city crews could fight the flood at other <br />locations. By evening, city crews had to be called back in. <br />The flood waters peaked on June 12 just after this problem area <br />was stabilized. The city is concerned that this is still a <br />weak point in the levee system. <br /> <br />Findings: <br /> <br />Inspection of the levee indicated that the side of the <br />levee facing the river had eroded for a depth of 10 feet over a <br />length _of 125 teet. Placement of riprap during high flows did <br />not result in a satisfactory configuration. The existing <br />temporary protection needs to be reconstructed to provide <br />permanent protection. Approximately 138 cubic yards of <br />emergency riprap and fill should,be removed and 277 cubic yards <br />of new~conpacted fill should be replaced in 6-inch lifts to a <br />slope of 3 to 1. Approximately 370 cubic yards of, riprap <br />should then be placed on the exposed slope for protection from <br />, ' <br />eros~on, : <br /> <br />The filling in of <br />experienced seepage during <br />water surface elevations in <br /> <br />areas in the golf course that <br />the flood would tend to increase <br />the Cottonwood subdivision, <br /> <br />i <br />'.i <br />r <br />':. <br />I <br /> <br />,Cost Estimates <br /> <br />To remove emergency riprap <br />To place compacted fill <br />To replace riprap <br />Engineering <br /> <br />Total <br /> <br />$ 276 <br />2,216 <br />14,800 <br />1,730 <br />$19,022 <br /> <br />Recorrnnendation: <br /> <br />I" <br />1:"1 <br />I <br /> <br />The city should reconstruct this damaged portion of the <br />levee before next spring's runoff. This work should qualify <br />tor state emergency funding since the levee provides protection <br />to a public facility (the municipal golf course). <br /> <br />69 <br />