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<br />Description of Proposed Improvements: Sheet 9 <br /> <br />Estimated Cost of Proposed Improvements: <br /> <br />Sheet 9 (Reach B) <br /> <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br /> <br />The l02-inch storm sewer, sized to convey the lO-year storm, <br /> <br /> <br />extends from Zephyr Street to the east side of Wadsworth Blvd. <br /> <br /> <br />Beneath l2th Avenue and Wadsworth, the proposed pipe would <br /> <br /> <br />parallel an existing 58-inch x 9l-inch elliptical pipe. The <br /> <br /> <br />new pipe would be much lower than the existing pipe in order to <br /> <br /> <br />avoid utilities. It is proposed that the existing culvert be <br /> <br /> <br />used to convey surface flows in floods exceeding the 10-year <br /> <br /> <br />flow. This will insure that Wadsworth Blvd. will not be affected <br /> <br /> <br />by lOO-year flows in Dry Gulch. A surface channel is planned <br /> <br /> <br />between 12th and l3th Avenues to collect flow from the low <br /> <br /> <br />drainage area which lies between the streets. The large apart- <br /> <br /> <br />ment complex north of Station l44+00 will continue to lie within <br /> <br /> <br />the lOO-year floodplain, although the improvements will reduce <br />both the magnitude and frequency of flooding. <br /> <br />Item Description <br /> <br /> <br />CONSTRUCTION <br /> <br /> <br />102" Storm Sewer <br /> <br /> <br />Manholes <br /> <br /> <br />Inle ts <br /> <br /> <br />Inlet Pipe <br /> <br /> <br />Asphal t over Inlet Pipe <br /> <br /> <br />Curb and Gutter <br /> <br />102" Pipe Jacked under Railroad <br /> <br /> <br />Ey.cavation for Open Channel <br /> <br /> <br />Concrete Low Flow Channel <br /> <br /> <br />Maintenance Roadway <br /> <br />Outlet Headwall <br /> <br /> <br />Construction Sub-total <br />15% Engineering <br />10% Contingencies <br />Total Construction <br /> <br />LAND ACQUISITION <br />Right-of-way Acquisition <br /> <br />Downstream from Wadsworth Blvd. an open channel with a concrete <br /> <br /> <br />low flow channel and grassed sideslopes is proposed. The channel <br /> <br /> <br />would have drop structures which would reduce flow velocities in <br /> <br /> <br />a ten-year flow to below 7.5 feet per second. The lOO-year flood <br /> <br /> <br />would be contained within the channel right-of-way. The channel <br /> <br /> <br />provides the opportunity for construction of an attractive green- <br /> <br /> <br />belt or parkway, with the maintenance access roadway serving also <br /> <br /> <br />as a hiker-biker trail. <br /> <br />10% Contingencies <br />5% Legal <br />Total Land Acquisition <br /> <br />TOTAL COST <br /> <br />Quantity Unit Unit Price Cost <br />1,290 L.F. $ 320 $412,800 <br />2 Ea. 1,000 2,000 <br />9 Ea. 1,000 9,000 <br />270 L.F. 30 8,100 <br />60 L.F. 18 1,080 <br />75 L.F. 10 750 <br />240 L.F. 1,300 312,000 <br />5,280 C.Y. 3 15,840 <br />130 C.Y. 210 27,300 <br />720 L.F. 14 10,080 <br />1 L.S. 7,000 7,000 <br /> 805,950 <br /> 120,893 <br /> 80,595 <br /> $1,007,438 <br /> <br />3.9 <br /> <br />15,000 <br /> <br />58,500 <br /> <br />A <br /> <br />5,850 <br />2,925 <br />$ 67,275 <br /> <br />$1,074,713 <br />