Laserfiche WebLink
North Fork, Gunnison River Ecosystem Restoration <br />Appendix B: Engineering Appendix ~ March 2005 <br />Site Design: The objective at this site is to restore a proper riverine ecosystem [o a heavily <br />impacted reach of the river. <br />Scale 1: Meanders would be restored to the first 4,400 lineaz feet of [he site from the <br />south property line upstream through the two instream gravel pits. In addition to the channel <br />realignment approximately 7 acres of tloodplain grading and revegetation will be necessary to <br />rehabilitate the in-stream grave[ pits. Bank stabilization in this area will consist of 20 j-hooks and <br />up to 2,000 bundles of willows. <br />The V andiford Ditch will be reconstructed with a permanent concrete headgate and low-head <br />rock diversion structure to limit annual bulldozing and improve diversion efficiencies. [n <br />addition, the diversion will be designed to allow for 5sh passage past the structure. The initial 4' <br />drop from the diversion strucmre will be broken up by two drop/pool rack s[rucmres to enhance <br />fish habitat and stabilize the channel. <br />The existing pond created by [he off-stream pit will be connected to the river by a backwater <br />channel for additional habitat enhancement. Six addition j-hooks will be constructed between the <br />existing channel and the off-stream pond between stations 252+50 and 257+50 to prevent future <br />channel avulsion and enhance habitat. <br />An addition 1,550 linear feet of channel realignment will begin at station 278+00 to add sinuosity <br />to the channel and reduce gradient. The new channel will be stabilized with 9 additional j-hooks <br />and another 1,000 bundles of willows. <br />Scale 2: The primary impacts ar this site lie between the south boundary and the north <br />end of the existing gravel mining area at the off-stream pond site. Therefore, stage 2 will <br />concentrate it's efforts in these areas. The new channel layout in this area has been changed from <br />it's initial proposal in stage 1 to a slightly different alignment which better utilizes the existing <br />channel and preserves more of [he existing vegetation. This new alignment will also allow for less <br />placement of topsoil and better efficiency in the placement of upland trees and shrubs. <br />The Vandiford Ditch reconstruction and the inclusion of a backwater channel [o the pond will <br />remain the same. The same amount ofj-hooks and boulder clusters will be used in [his area <br />The most prominent change between stage I and stage 2 will be the elimination of the 1,550 <br />linear feet of channel realignment, bank stabilization, and revegetation a[ the northern end of [he <br />site adjacent to Si[e No. 4 near station 278+00. Additional funding from other non-federal sources <br />has been identified to construct this portion of the project. <br />Access and Staging Areas: Existing public access currently extends from County Road J75 <br />through [he Tri-County Gravel Company offices and into Delta County District 3 Road Bam. <br />Access easements will be obtained from Mc Curry to continue on from the existing public access <br />approximately %: mile to the river and then north along the river on an existing private road. <br />Heavy equipment can access the site form a series of points along the access road. <br />There will be 3 staging aeeas. The first one is located near the south property line in [he - ~ ~ ' , <br />floodplain adjacent [o the south in-stream pit. The second one is located adjacent to the north in- -. <br />stream pit and the third is located along the southern portion of the pond area. They are all a <br />minimum of %. acre on level ground and are contained within the permanent project limits. <br />B-33 <br />