20130030 Ver 1_Staff Comments_20130315

Lucas, Annette
From: Lucas, Annette
Sent: Friday, March 15, 2013 1:33 PM
To: Smith, Cherri L
Subject: 13 -0030 Bass Lake Outfall Greenway — DIFFUSE FLOW CONDITION
Attachments: 13 -0030 Bass Lake Outfall Greenway — DIFFUSE FLOW CONDITION.docx
Cherri,
Please issue with this condition.
Have a great weekend!
Thanks,
Annette
Annette M. Lucas, PE
Environmental Engineer
NCDENR I DWQ ( Wetlands and Stormwater Branch
1650 Mail Service Center, Raleigh, NC 27699 -1650 (Mail)
512 N. Salisbury St, Raleigh, NC 27604 1 9th Floor (Location & Parcels)
Phone: [phone] Fax: [phone] Email: Annette. Lucas(uncdenr.gov
Website: http:/ /portal.ncdenr.org/web /wq /swp /ws /401
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13 -0030 Bass Lake Outfall Greenway — DIFFUSE FLOW CONDITION
AML comments
March 15, 2013
1. Diffuse Flow Condition
All new stormwater conveyances constructed to drain the greenway discharge to existing swales
in a manner that does not result in erosion to the receiving swales or stream. The portions of
the greenway that are not drained by stormwater conveyances shall allow runoff to sheet flow
into adjacent riparian buffers. No additional stormwater will be collected or concentrated by
the proposed project. If this is not possible, then it may be necessary to provide an engineered
level spreader or stormwater practice to remove nitrogen and phosphorus prior to discharge. If
deemed necessary, these practices will require additional approval from the DWQ.