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HomeMy WebLinkAbout20020409 Ver 1_Mitigation Site Visit_20100518Alfh, NCDENR North Carolina Department of Environment and Natural Resources Division of Water Quality Beverly Eaves Perdue Coleen H. Sullins Governor Director May 18, 2010 Mr. Todd Tugwell U.S. Army Corps of Engineers Wilmington District 11405 Falls of Neuse Road Wake Forest, NC 27587 Re: NCEEP Closeout Site Visits - May 10-12, 2010 Dee Freeman Secretary Division of Water Quality (DWQ) 401 Oversight and Express Review Permitting Unit personnel have participated in site visits of NCEEP sites that are being proposed for closeout (e.g. released from further monitoring requirements). Tammy Hill of this Office visited sites on Monday, May 10, and Eric Kulz visited sites on Tuesday May 11 and Wednesday, May 12. Our comments on each site visited are provided below. May 10, 2010 Haw River Swamp - Phases I and II Rockingham County EEP Full-Delivery Site (Restoration Systems) DWQ #03-1133 The project was designed to become a riverine swamp forest - bottomland hardwood forest complex. Wetland hydrology indicators were observed throughout the site, including high wrack lines indicative of substantial flooding from the Haw River. Most of the soils were undeniably hydric, with those in the wettest areas exhibiting a sulfidic odor. A relatively small area of bright soils observed on the westernmost edge of the site may or may not have been included in the credit calculation. Drier areas of the site hosted extremely dense woody vegetation, especially red maple and green ash volunteers. Other desirable species (including multiple oak and elm species, river birch, tulip poplar) were observed in sufficient densities to ensure their long-term presence on the site, such that these areas appeared to be on a trajectory toward the targeted forested wetland system. Wetter areas which experienced long-term inundation and saturation hosted primarily herbaceous wetland plants, with sporadic tree presence. These marshy areas contained a diverse herbaceous assemblage (including milkweed and multiple Polygonum, 1650 Mail Service Center, Raleigh, North Carolina 27699-1650 Location: 2321 Crabtree Blvd., Suite 250, Raleigh, North Carolina 27604-2260 .e Phone: 919-733-17861 FAX: 919-733-68931 Customer Service: 1-877-623-6748 NOi ffiCar olina Internet hftp://h2o.enr.state.nc.us/ncwefiands An Equal Opportunity 1 Affirmative Acton Employer r Mr. Tugwell NCEEP Closeout site Visits - May 10-12, 2010 Page 2 of 6 5/18/10 arrowhead, rush, and sedge species). While the targeted tree density was not being met across these areas, DWQ believes that the hydrology and vegetation are appropriate for the landscape position and connectivity with surrounding waterways, and that the areas are working in combination with the densely forested zones to provide significant water quality benefits. In this case, we support closeout of the site with full riverine wetland credit. Open Springs Site Randolph County EEP Full-Delivery Site (EBX) DWQ #04-1511 The restored stream has demonstrated stability through many overbank flooding events. Only one small structure bypass was noted during the closeout site visit, and the adjacent bank appeared to be stable. Riffles and pools were present in appropriate locations; however, herbaceous vegetation was rooted in many of the riffles due to low water levels and low flow conditions. Overall buffer stem density was acceptable. Many of the planted trees (especially sycamore, river birch, locust, and some green ash) were tall and vigorous; however, others (especially elms and some green ash) had been stunted due to herbivory and appeared unlikely to succeed. The buffer was generally at least 50 feet wide. The easement boundary along the lower end of restoration reach 1 was unclear; as discussed in the field, EEP will resurvey the area in order to determine the exact buffer width. Two power line crossings were observed along restoration reach 1. As these areas will experience perpetual maintenance of vegetation, DWQ suggests that they receive only 50-75% of stream restoration credit, consistent with the closeout terms currently under consideration for the Ellerbe Creek site. DWQ supports closeout of the remainder of the project with full stream enhancement and restoration credit, and understands that EEP will communicate directly with DWQ regarding potential credit for riparian buffer restoration. May 11, 2010 Kentwood Park Wake County EEP Design-Bid-Build DWQ #02-0409 The Kentwood Park site streams appeared to generally be stable and no significant evidence of degradation was observed. This site has also been visited in 2007 and 2009, and minimal change to the channels was noted. The riparian zone of the main channel was generally in good condition, with the exception of the right bank of the upper 150-200 feet, where streamside areas were very compacted due to heavy foot traffic. The riparian zone along the tributary was narrow, but appeared to be in good condition, and trees were large and healthy, with the 1650 Mail Service Center, Raleigh, North Carolina 27699-1650 Location: 2321 Crabtree Blvd., Suite 250, Raleigh, North Carolina 27604-2260 One Phone: 919-733-17861 FAX: 919-733-68931 Customer Service: 1-877-623-6748 NorthCarolina Internet http://h2o.enr.state.nc.ustncwetlands An Equal Opportunity 1 Affirmative Action Employer Aaamally Mr. Tugwell NCEEP Closeout site Visits - May 10-12, 2010 Page 3 of 6 5/18/10 exception of the "playover" area near the confluence of the tributary with the main channel. The vegetation in this area is maintained to allow a sight line for the disc golf course. This site was instituted prior to the implementation of the 2003 Stream Mitigation Guidelines; therefore, no deduction of credit is warranted based on narrower than standard buffers (tributary). DWQ supports closeout of this site. DWQ concurs with some deduction of credit for the "playover" area and approx. 100 feet of channel located within a DOT right-of-way at the upper end of the project. Ellerbe Creek (Hillandale Golf Course) Durham County EEP Dcsign-Bid-Balld DWQ #03-0368 The site streams appeared to generally be stable and no significant evidence of degradation was observed. An area of streambank near the downstream end of the main channel had bare spots and showed some evidence of scour. The riparian zones of the main channel and tributary were generally in good condition and of variable width. This site was instituted prior to the implementation of the 2003 Stream Mitigation Guidelines; therefore, no deduction of credit is warranted based on narrower than standard buffers. Trees were tall and appeared to be healthy. Several playover areas are present where the trees are pruned to allow a line of site to the greens. Since these areas will not be allowed to develop into a mature forest, it was agreed that these areas would only generate 75% of the credit based on stream length. In addition, credit will also be deducted for the cart path bridges, as the stream does not have natural banks at these locations (concrete) and the stream bed is shaded. Riparian areas with a width of 50 feet or greater and not within a playover (maintained zone) are being proposed for Neuse riparian buffer credit. 16 separate areas were identified. EEP is revising the boundaries of some of these proposed buffer areas based on discussion at the site. A revised map showing the buffer credit areas and acreages is to be provided. DWQ concurs with some deduction of credit for the "playover" areas and areas associated with the cart path bridges. DWQ supports the closeout of this site. 1650 Mail Service Center, Raleigh, North Carolina 27699-1650 Location: 2321 Crabtree Blvd., Suite 250, Raleigh, North Carolina 27604-2260 Phone: 919-733-17861 FAX: 919-733-68931 Customer Service: 1-877-623-6748 NonrthCarolina Internet: http://h2o.enr.state.nc.us/ncwetiands An Equal Opportunity 1 Affirmative Action Employer Awmally Mr. Tugwell NCEEP Closeout site Visits - May 10-12, 2010 Page 4 of 6 5/18/10 Third Fork Creek (Forest Hills) Durham County EEP Design-Bid-Build DWQ #03-0299 The site streams appeared to generally be stable and no significant evidence of degradation was observed, although the lower reach appeared to be trending toward downcutting, based on the cross sections and longitudinal profile. Observations made during the site visit did not identify any significant visual indications that the stream is actively downcutting, and it was apparent based on the presence of sand and drift lines on the floodplain that the stream is experiencing overbank flooding. The riparian zone was fairly densely vegetated, ,vith good tree growth and diversity. The width C? 0 of wooded buffer is less than 50 feet and there is an outer herbaceous (grassed zone), per the restoration plan. This site was instituted prior to the implementation of the 2003 Stream Mitigation Guidelines; therefore, no deduction of credit is warranted based on narrower than standard buffers. Of greatest concern was the amount of invasive exotic species present. Historically, EEP has contracted for invasives control to address porcelainberry and Chinese hops. However, during the site visit, privet appears to have become established, and Japanese knotweed was observed in clumps at several locations on the site. These species, if left unchecked, can significantly alter a riparian system and result in reduced diversity. EEP indicated that several more treatments were planned. Overall, the site appears to be functioning well. DWQ supports closeout of this site after documentation is provided to the IRT that the treatment has been done. May 12, 2010 ' Reedy Branch Alamance County EEP Design-Bid-Build DWQ #02-1572 The Reedy Branch site stream restoration was constructed within a mature wooded corridor, and many large trees were preserved within the riparian zone. This site is performing quite well, likely in part due to the retention of the existing wooded buffer. The presence of substantial amounts of bedrock at this site has also probably contributed to the stream stability. While several structures were observed to have experienced some level of failure (piping), the stream 1650 Mail Service Center, Raleigh, North Carolina 27699-1650 Location: 2321 Crabtree Blvd., Suite 250, Raleigh, North Carolina 27604-2260 One Phone: 919-733-17861 FAX: 919-733-68931 Customer Service: 1-877-623-6748 NorthCarolina Internet: http://h2o.enr.state.nc.us/ncwetands // An Equal Opportunity 1 Affirmative Acton Employer Nahmall'y Mr. Tugwell NCEEP Closeout site Visits - May 10-12, 2010 Page 5 of 6 5/18/10 bed and banks appeared stable. Based on the presence of drift lines throughout the site, the stream appears to regularly access its floodplain. While several of the vegetation plots did not meet the success criteria for planted stems (260 stems per acre), the riparian zone consisted of a mixture of large mature trees, smaller planted stems, and numerous volunteers. It was discussed that the presence of scattered more open areas represents habitat heterogeneity, and was not necessarily a negative aspect of the project. Volunteers of 6-7 tree species were observed throughout the site, and the site appeared to be on a trajectory to develop a well- functioning stream and riparian zone. The only issue of concern was the damaged condition of the two cattle fords. The fences had been damaged by debris from high flows, and the fords were minimally functional. EEP is working with the landowner to develop an alternative design that will allow high flow to pass but still function. tc cxcilude cattle .vh--n the fords are in use. Overall, the site appears to be functioning well, and DWQ supports the closeout of this site after the fords have been repaired, and documentation is provided to the IRT regarding the redesigned fords. Benbow Park Guilford County EEP Design-Bid-Build DWQ #02-0888b The site stream appeared to generally be stable (remarkably so for an urban stream) and no significant evidence of degradation was observed. All structures appeared to be functioning as intended. The riparian zone was variable in condition. It appears that herbicide was applied to the undergrowth, and some indications of cutting were noted. The riparian zone along the remainder of the project was more dense and wider. However, EEP indicated that replanting was done to a small area near the playground this past winter, as it appeared existing planted stems were removed. In addition, several maintained (grassed) areas were observed associated with utility easements and to provide a view corridor to the basketball court. This site was instituted prior to the implementation of the 2003 Stream Mitigation Guidelines; therefore, no deduction of credit is warranted based on narrower than standard buffers. Credits were deducted based on the maintained areas. Some invasives were observed; the City of Greensboro is responsible for invasives treatment, and more treatments are planned for this site. 1650 Mail Service Center, Raleigh, North Carolina 27699-1650 Location: 2321 Crabtree Blvd., Suite 250, Raleigh, North Carolina 27604-2260 One Phone: 919-733-17861 FAX: 919-733-68931 Customer Service: 1-877-623-6748 NorthCarolina Internet http://h2o.enr.state.nc.us/ncwetands An Equal Opportunity1 Affirmative Action Employer )Vaturally Mr. Tugwell NCEEP Closeout site Visits - May 10-12, 2010 Page 6 of 6 5/18/10 While DWQ concurs with the closeout of this site, there are concerns related to the long-term viability of the buffers at this site (and other urban sites). According to information provided by EEP, there is some public dissatisfaction with this project. The IRT should make a point to revisit some of these urban sites 4-5 years after closeout to assess the ability of EEP and/or the site easement holder to provide long-term protection to these riparian areas. This re-evaluation can then be used to make future decisions about siting mitigation projects in public parks. Thank you for the opportunity to comment on this project. Please feel free to contact Eric Kulz or Tammy Hill at (919) 733-1786 if you have any questions regarding this project or our comments. 7 S' ly, 014"'? Ian McMillan, Acting Supervisor 401 Oversight and Express Review Program cc: File Copy (Eric Kulz) 1650 Mail Service Center, Raleigh, North Carolina 27699-1650 Location: 2321 Crabtree Blvd., Suite 250, Raleigh, North Carolina 27604-2260 One Phone: 919-733-17861 FAX: 919-733-68931 Customer Service: 1-877-623-6748 NorthCarolina Internet ortunity \ a usn Naturally An Equal Opportunity \ Affirmative tive Action Employer r