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Home My WebLink About20120285 Ver 1_Meeting Minutes_20110715Oji�o NORTH CAROLINA Turnpike Authority MEETING SUMMARY Date July 15 2011 10 00 AM Location Various (see below) Project STIP U 3321 Gaston E W Connector — STP 1213(6) Attendees Liz Hair — USACE Marella Buncick — USFWS Polly Lespinasse — NCDWQ Michael Gloden — Atkins Phillip Rogers — HNTB Purpose Visit Linwood Springs Golf Course mitigation site and review existing conditions and proposed hydraulic design at three proposed culvert locations as requested by agencies at the June 9 2011 Concurrence Point (CP) 4B meeting [Note at the CP 4B meeting agencies also requested to visit Stream S297 however during the field visit it was agreed not to visit this site ] Summary Linwood Springs Golf Course Site Visit NCDOT recently purchased the Linwood Springs Golf Course in Gastonia to use as a mitigation site for this project and /or others in the area The site visit at Linwood Springs Golf Course began with a review of mapping depicting the jurisdictional delineation and a discussion of the various resources on the site The delineation previously performed for the Garden Parkway did not include resources located within the limits of the golf course and Atkins staff has subsequently mapped all site features Atkins staff is also preparing a conceptual mitigation plan which includes an assessment of existing conditions and the proposed restoration concept Under existing conditions surface water on the site is contained within numerous ponds (water hazards) that drain to Crowders Creek through vegetated ditches and an underground drainage network Crowder s Creek was observed by the group from the southern most golf cart crossings where it was noted that streambank vegetation is disturbed and maintained Crowder s Creek shows evidence of dredging and straightening as well as manipulation to stream banks including artificial levees constructed to keep flood waters within the channel and away from the fairways Priority 2 restoration is proposed for Crowders Creek From the bridge crossing over Crowders Creek it was also observed that an unnamed tributary to Crowders Creek that enters the site from the west (S59) is routed through a series of ponds and then a linear vegetated ditch A combination of Priority 1 and 2 restoration is proposed for the unnamed tributary The remaining tributaries that enter the site from the northeast were not reviewed during the site visit in the interest of reviewing the culvert crossings requested by agencies at the June 2011 Concurrence Field Visit - 07/15/11 Page 2of3 Point 4B meeting. A second site visit with the USACE and NCDWQ is planned to review the delineation and discuss the restoration concept in more detail. Site #1 Stream S296 (Sheet 10): A 2 -cell 7x6 foot reinforced concrete box culvert (RCBC) is proposed to convey cross drainage associated with Stream S296. The culvert length is 395 feet with an approximate slope of 0.76 percent. The alternate box will include a concrete sill and a floodplain bench. Class I riprap will be placed on stream banks as specified on the outlet channel improvement details. Stream S296 has an average width of 6 feet and an average depth of 2 -4 inches. At the CP 4B meeting, agencies noted that the alignment of the culvert inlet at the end of a meander may be of concern. The group discussed potential realignment. If the inlet was realigned, it would likely impact approximately 60 linear feet more of S296. If the fill slope was steepened so the culvert inlet was farther downstream, the steeper slope may be difficult to stabilize. The currently proposed fill slope is at 2:1. A steeper slope may require rock plating. Another challenge will be getting the water from the lateral ditches to the culvert, particularly if the culvert is realigned. During the field visit, severe stream bank erosion was observed approximately 50' upstream of the proposed RCBC inlet. USFWS expressed concern about drainage that is being ditched to the inlet of the proposed RCBC. USFWS and NCDWQ stated that they preferred reducing the skew of the proposed RCBC, considering the existing upstream erosion and stream meander. They also inquired about the possibility of shortening the proposed RCBC. Mr. Rogers stated that the current design is utilizing 2:1 fill slopes; therefore, in order to steepen these proposed slopes, rock plating would have to be utilized. NCTA/HNTB will investigate changing the skew of the proposed RCBC. Stream S296 Looking East Stream S296 Looking North near Proposed Inlet Field Visit - 07/15/11 Stream S296 Looking West Page 3 of 3 • Site #2 Stream S300 (Sheet 30): A 2 -cell 6x6 foot box culvert is proposed for the crossing of Stream S300 associated with the proposed Tucker Road service road located to the southwest of the NC 273 (Southpoint Road interchange). The culvert would be approximately 166 feet long with an approximate 1.2 percent slope. Stream S300 has an average width of 3 -5 feet. NCDWQ expressed some concern over the width of the existing stream channel relative to the proposed RCBC cell width of 6 feet. However, after viewing the existing stream no further revisions were requested and no further action is required. Site #3 Stream S312M317 (Sheet 41): At this location, there is a proposed service road (connecting Garrison Road to Dixie River Road) crossing of Stream S312A (Beaverdam Creek) downstream of the mainline crossing of Beaverdam Creek. There is the main channel of the creek and an adjacent wetland (W317) with an enclosed intermittent stream (Stream S318A) on the west side of the creek's floodplain. A 2 -cell 10x5 foot box culvert is proposed for Stream S312A and a 2 -cell 10x4 foot box culvert is proposed for Wetland W317 and Stream S318A. These are sized to meet FEMA requirements. The fill slopes are 2:1 and it would not be practicable to steepen them in this location to reduce the culvert lengths. At the CP 4B meeting on June 9, 2011, USFWS asked if the roadway could be shifted slightly south to an area where Wetland W317 is narrower. It was also noted that this site was discussed at the Concurrence Point 2A meetings held March 4, 2008 and April 8, 2008. The site is referred to as crossing KD29 in the meeting minutes. At the CP2A meeting, the USACE noted that the wetland W317 near crossing KD29 was highly silted. Sediment was observed throughout the streams and wetlands in this area. At that time, the attendees agreed a culvert was the appropriate hydraulic structure. During the field visit, both the wetland and stream sites were reviewed. The group observed that the proposed RCBC cell width is consistent with the existing stream width for S312. NCDWQ and USACE that the current proposed roadway alignment is satisfactory, since it appears that a shift in the alignment to minimize wetland impact would likely increase stream impacts. Stream S312A Looking South Field Visit - 07/15/11 Stream S312A Looking North