Laserfiche WebLink
<br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br /> <br />, <br />IJ <br />I <br />Ii <br />Ii <br />I <br />I <br />I <br />I <br />I <br />I <br />1- <br /> <br />PART I I <br />NARRATIVE REPORT: <br />DESCRIPT1VE AND DESIGN INFORMATION <br /> <br />A. Description of project Site. <br />The Town of Lake City is located in a valley formed by the Lake Fork <br />of the Gunison, on a relatively flat terrace (ancient flood plain) with steep <br />mounta in s lopes r i sing on either side. Henson C reek emerges fran a steep <br />walled canyon on the west side of Town and joins the Lake Fork of the <br />Gunnison approximately 1700 feet downstream. (see map, p. 111-4). <br />Within the project site, Henson Creek flows in a well defined <br />trapezoidal shaped channel, approximately 50 feet wide with stream banks <br />4 to 5 feet high on either side. Water depth during normal flows is 1 to 2 <br />feet deep. Stream gradient is about 1.2%. The channel substrate consists <br />primari ly of stream deposited cobbles; there are very few large boulders <br />or flood debris in the channels. Vegetation along the bank consists <br />primari Iy of occasional scattered trees and brush. <br />Average annual flow on Henson Creek is 107 cfs. The 100 year flood <br />has been calculated at 2300 cfs and the 500 year flood has been calculated <br />at 3300 t.f s. <br />The north bank is partially protected by a levee. The condition of <br />this levee is as follows (stations start at bridge): <br />Location Information <br /> <br />o + 00 to 3 + 50 <br /> <br />Levee is in poor condition with <br />sub- standard freeboard and top <br />width. <br />No ex i st ing levee. <br />Critical channel section with <br />marginal conveyance. <br />Downstream limits of Corps of <br />Engineers emergency works. <br />Ex isting levee system. <br /> <br />3 + 50 to 5 + 00 <br /> <br />5 + 00 <br /> <br />6 + 00 to 7 + 00 <br /> <br />7 + 00 to 1 0 + 00 <br /> <br />11-1 <br />