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Home My WebLink About20150316 Ver 1_More Info Received_20150504r May 1, 2015 Jennifer Burdette 401 /Buffer Coordinator DWR 401 and Buffer Permitting Unit 1617 Mail Service Center Raleigh, NC 27699 -1617 North Carolina Coastal Federation 'Yorking iaget er ar a r;eakhy Coast Re. DWR # 150316, Carteret County April 14, 2015 Request for Additional Information Cape Carteret Stormwater Ponds Retrofit Dear Ms Burdette, I D L LE FMMAY ® _`-- ----- --��I 4 2015 I Included below is the information requested pertaining to our application dated March 24, 2015, requesting a 401 certification to retrofit two existing stormwater ponds in Cape Carteret to reduce the amount of polluted stormwater runoff reaching the impaired Deer Creek and thereby, help to improve its water quality. 1. This Office believes that the upper pond does not need to be disturbed, as it has naturalized and the marsh and stream seem to be stable Please provide justification as to why this area needs to be graded and disturbed instead of lust enhancing the existing wetland and stream that has naturalized there (I 5A NCAC 02H 05060 & (g)) After having observed the upper pond for several years, it is our opinion that the current appearance of stability is not sustainable. The current conditions in the upper pond are being maintained by a failed riser structure that continues to worsen over time. This structure was installed to support the former pond and the drain valve failed and was removed Currently, flow is being restricted in this structure by the small opening and the levels in the lower pond Continued deterioration of this structure will change the hydrologic regime of the upper pond and cause instabilities that may lead to the transport of sediment downstream and the loss of wetland hydrology upstream. In addition, the restoration work in the lower pond will lower the water level downstream by several feet This will in turn allow free drainage of the upper pond and compound the potential effect on the hydrology there. As a result, it is our opinion that the current conditions are far from natural and cannot be maintained without the successful completion of this entire project. This project has been carefully designed to have both restored areas work as a system The completed upper wetland will allow the hydrology to be maintained and also provide greater potential for water quality improvement. The finished project will be a better, more sustainable wetland than what currently exists. We are confident that our experience with these types of projects will result in long -term benefits to Deer Creek Northeast Office NC Coastal Federation Headquarters and Central Office Southeast Office 128 Grenville Street 3609 N C 24 (Ocean) , Newport, NC 28570.252 393 8185 • www nccoast org 309 W Salisbury Street Manteo, NC 27954 ,� Wrightsville Beach, 28480 252 4731607 10 910 509 2838 DWR Request 2 This Office is concerned about the water hyacinth found in the lower pond There is no mention of what protocols will be used to eradicate this invasive species Please provide documentation pertaining to what will be done to prevent the spreading of this invasive species to other areas (NCAC 02H 0506 (b)) Thank you for your concern over the water hyacinth One of the goals of the project is the removal of the hyacinth and it is absolutely imperative that this project does not result in the spread of this species The plan for the lower pond is to restore the area into a brackish marsh. Water hyacinth cannot survive in a brackish environment. Although pieces of this plant regularly float downstream, there is no evidence of it living in Deer Creek. This supports the design and is one of the main reasons we have chosen the brackish marsh approach. We have spoken with Rob Emens at NC Aquatic Weed Control Program to develop a plan to prevent the unintentional spread of hyacinth According to Rob, water hyacinth is currently not regulated in NC, and as a result, it does not have specific requirements. Although hyacinth can spread in many ways, the breaking off of small sections of plant and regrowth is the primary mode of reproduction As a result, our plan is focused on preventing this type of movement. The proposed restoration will involve the removal of a few feet of silt from the pond bottom. This dredge material will include hyacinth plants The current plan is to let this material sit on the pond banks and dry. As hyacinth is an aquatic weed, this should be enough to damage or kill most of the living plant tissue The material will be well mixed with sand and other soil dredged from the site. It will be put into dump trucks and hauled to a small local farm to be used as a soil amendment /mulch This methodology has been used commonly in Florida and other places where hyacinth has been prolific. This specific farm does not have an advanced drainage system or network of ditches similar to larger commercial operations and will therefore, not come into contact with any bodies of water where it can grow and spread. Please do not hesitate to contact me should you have any additional questions or concerns regarding this project Sincerely, /Z " Todd Miller Executive Director North Carolina Coastal Federation cc. Jim Gregson — DWR Wilmington Regional Office — electronic copy Joanne Steenhuis — DWR Wilmington Regional Office — electronic copy Tyler Crumbley — USACE — electronic copy Northeast Office NC Coastal Federation Headquarters and Central Office Southeast Office 128 Grenville Street 3609 N C 24 (Ocean) • Newport, NC 28570.252 393 8185 • www nccoastorg 309 W Salisbury Street Manteo, NC 27954 n Wrightsville Beach, 28480 252 4731607 := 910 509 2838