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HomeMy WebLinkAbout20151021 Ver 1_B-4792 - Bridge No 4 - NW 14 Permit Application - Polk County_20151112 (2) Carpenter,Kristi From:Davis, Mark S Sent:Thursday, November 12, 2015 9:57 AM To:Chambers, Marla J; 'Lori Beckwith (Loretta.A.Beckwith@usace.army.mil)' Cc:Deyton, Joshua B; Hill, Mark E; Chapman, Amy; Carpenter,Kristi; Barnett, Kevin; McHenry, David G Subject:FW: B-4792 - Bridge No. 4 - NW 14 Permit Application - Polk County Attachments:B4792_Polk Bridge No. 4_404 REVISED Culvert Avoid and Min.pdf; Upstream.JPG; Upstream Bridge face.JPG; Upstream Boulders.JPG; Downstream Bridge face.JPG; Madison County Bridge to Culvert.pdf Follow Up Flag:Follow up Flag Status:Flagged Marla and Lori, See the email below and the attached information regarding the culvert avoidance and minimization form for the subject project. The project was reviewed by Stephen Morgan of our Hydraulics Unit and it appears the former form was incorrect. This project has been in the works since 2008 and been passed around to several DOT units before it finally found its way to the Division 14 Bridge Management Unit. There have been at least two or three consulting firms working on this project since inception, which probably led to the incorrect culvert avoidance and minimization form. The Department does not believe a bridge is warranted at this site. If you have any further questions, please advise. Thanks, Mark Mark S. Davis Environmental Supervisor NC Department of Transportation/Division 14 828 586 2141 office 282 508 9670 mobile markdavis@ncdot.gov 253 Webster Road Sylva, NC 28779 Email correspondence to and from this address is subject to the North Carolina Public Records Law and may be disclosed to third parties. From: Morgan, Stephen R Sent: Tuesday, November 10, 2015 5:56 PM To: Davis, Mark S 1 Cc: Djernes, Roger E Subject: RE: B-4792 - Bridge No. 4 - NW 14 Permit Application - Polk County Mark, The Culvert Avoidance and Minimization Form should be revised as attached. My response to WRC comments are below. Thanks, Stephen Please note the corrections to the Culvert Avoidance and Minimization form. The low flow velocities were taken from higher storm events and therefore were incorrect. Also, the stream width is variable and boulder-rich, creating many natural bifurcations throughout this reach. The channel width, form and slope are not significantly altered by the design. While the culvert is a double barrel culvert, we fully anticipate it to function very much the same as the existing two span bridge. The culvert geometry, slope and bed material will approximate those of the existing bridge, thus providing similar passage for terrestrial wildlife as well as aquatic species. The culvert will be sufficiently buried and the stream is sufficiently stable with bed armoring to alleviate any concerns of head-cutting or culvert perching. In the sketch below, note how the culvert width and bridge width are very similar: Also note how the stream width as shown by the JS lines vary in the above depiction. They are much wider upstream than downstream. Because these lines represent the limits of jurisdictional waters they include several sections of varying stream widths and bifurcated flows due to boulder depositions- see attached pictures. 2 We would anticipate any woody debris capture to behave similarly or better than the existing bridge, which has a much wider center bridge bent. The existing bridge does not appear to capture appreciable amounts of woody debris. Similarly any mid-channel deposition would be similar to the existing bridge. No mid-channel deposition was present downstream of the site. Also included are pictures from a reference project that replaced a two span bridge with a double barrel culvert on a trout stream in Madison County. The drainage area was 6 square miles for that site versus 2 square miles for this site. The culvert was buried with baffles and sills to retain bedload. We fully anticipate any of the concerns raised by WRC to be mitigated appropriately. We fully expect the net result to be a stream crossing that will provide terrestrial and aquatic passage while providing the long-term operational and economic benefits of a culvert structure. Stephen Morgan, PE Project Manager, Design Support Hydraulics Unit NCDOT 919 707 6739 office 919 961 0887 mobile smorgan@ncdot.gov 1590 Mail Service Center Raleigh NC 27699-1590 1020 Birch Ridge Dr Raleigh NC 27610 Email correspondence to and from this address is subject to the North Carolina Public Records Law and may be disclosed to third parties. _____________________________________________________________ From: Davis, Mark S Sent: Thursday, October 29, 2015 8:56 AM To: Morgan, Stephen R; Djernes, Roger E Subject: FW: B-4792 - Bridge No. 4 - NW 14 Permit Application - Polk County Stephen, Please response to the comments below. Roger, 3 We have the same concerns for Bridge No. 107 in Graham County as we discussed yesterday. Thanks for your help, Mark From: Chambers, Marla J Sent: Wednesday, October 28, 2015 3:56 PM To: Beckwith, Loretta A SAW Cc: Davis, Mark S; Chapman, Amy; Barnett, Kevin Subject: RE: B-4792 - Bridge No. 4 - NW 14 Permit Application - Polk County I have significant concerns regarding the design of this bridge replacement project involving a trout stream. Our scoping comments from 2009 are attached; this project is number 17 in the project specific comments section (page 6). It appears that the proposed design will convert this bridge crossing, just upstream of the confluence with the Pacolet River, to a 2-barreled box culvert on a 4% slope that apparently splits the flow of this reported 20’ wide stream into two 11’ wide barrels. As the Bridge to Culvert Avoidance and Minimization form indicates, this will increase the existing low flow velocity of 5.9 fps to 8.9 fps. I found the following in the Technical Supplement 14N – Fish Passage and Screening Design (Part 654 National Engineering Handbook, 2007): For adult salmonid passage through a culvert, NOAA Fisheries Service (2000) recommends average calculated velocities of 6.0 feet per second for distances of less than 60 feet, 4.0 feet per second for distances between 100 and 200 feet, and 2.0 feet per second for distances greater than 300 feet. You can access the handbook at http://directives.sc.egov.usda.gov/17824.wba. Standard recommendations in our scoping letters indicate that a continuum of water depth and channel width without substantial modifications of velocity should be provided. Concerns with splitting the stream flow have been voiced before and included altering the natural flows, potentially decreasing velocities upstream and forming mid-channel bars or stream aggradation and increasing velocities at the outlet, potentially creating scour and perching the culvert. Woody debris is more likely to get caught up at the inlet, causing maintenance issues and potentially exacerbating the effects of the altered flow. The project also appears to narrow and reduce the opening for flood flows at this crossing and provides no flood plain access; which seems important at a location in very close proximity to a river. The ability of fish and other aquatic species to access tributaries for spawning and refuge is vital and the current design of this crossing may block passage due to slope, velocities, and altered flow regimes. Stream corridors often serve as travel corridors for wildlife. Crossing designs that allow wildlife passage are also important concerns that should be considered for this project to increase safety for the traveling public and animals, alike, and to reduce the negative effects of habitat fragmentation. As indicated in our scoping comments, Wild Rainbow Trout occur in the project area, as well as rare fish and crayfish species. The Rainbow Trout moratorium from January 1 to April 15 and Design Standards in Sensitive Watersheds should apply to any bridge replacement project at this location. We believe replacing this bridge with another spanning structure is the most appropriate for this location, setting, and existing fish and wildlife resources. I recommend further investigation into an appropriate design for this crossing. I can participate in a site visit, if desired. If a formal letter is needed, let me know. Thank you, Marla Marla Chambers // NCDOT Coordinator 4 Habitat Conservation Program NC Wildlife Resources Commission c/o NCDOT 206 Charter Street Albemarle, North Carolina 28001 office: 704-982-9181 mobile: 704-984-1070 Marla.chambers@ncwildlife.org ncwildlife.org From: Davis, Mark S Sent: Tuesday, September 29, 2015 10:19 AM To: Beckwith, Loretta A SAW; Chapman, Amy; Carpenter,Kristi; Barnett, Kevin; Jason Mays (Jason_Mays@fws.gov); Chambers, Marla J; DeWit, Benjamin J Cc: Deyton, Joshua B; Hill, Mark E Subject: B-4792 - Bridge No. 4 - NW 14 Permit Application - Polk County Ladies and Gentlemen, Attached for your review and comment is the subject permit application. If you have any questions, please advise. Thanks, Mark Mark S. Davis Division 14 Environmental Supervisor 253 Webster Rd. Sylva, NC 28779 828-586-2141 email: markdavis@ncdot.gov Email correspondence to and from this sender is subject to the N.C. 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