IWGP

STATE OF NORTH CAROLINA DEPARTMENT OF
ENVIRONMENT AND NATURAL RESOURCES
DIVISION OF WATER QUALITY
STATE GENERAL PERMIT FOR IMPACTS TO ISOLATED AND
OTHER NON -404 JURISDICTIONAL WETLANDS AND WATERS
PERMIT NUMBER: IWGP100000
FOR PROJECTS IMPACTING LESS THAN OR EQUAL TO ONE (1) ACRE OF
ISOLATEDAND OTHER NON -404 WETLANDS, LESS THAN OR EQUAL TOTHREE
HUNDRED FEET (300) OF ISOLATEDSTREAMS AND /OR LESS THAN ONE -THIRD
ACRE (1/3) OFISOLATED SURFACE WATERS
In accordance with the provision of Article 21 of Chapter 143, General Statutes of North Carolina
as amended and other lawful standards and regulations, including 15A NCAC 02H .1300 and 15A
NCAC 02B .0200, promulgated and adopted by the North Carolina Environmental Management
Commission.
Permission is hereby granted to all owners or operators of activities which impact isolated and
other non -404 wetlands, isolated streams or other isolated waters in accordance with the
conditions set forth in this General Permit.
This General Permit shall become effective on March 19, 2012.
This General Permit shall expire at midnight on March 18, 2017 or unless otherwise rescinded or
until deemed appropriate by the Director of the NC Division of Water Quality (DWQ).
Charles Wakild, P.E., Director
Division of Water Quality
By the Authority of the
NC Environmental Management Commission

Mate General Permit No. IWGP100000
This General Permit is issued in conformity with the requirements of North Carolina Division of
Water Quality (DWQ) Regulations in 15A NCAC 02H .1300 for the discharge of fill material to
isolated and other non -404 wetlands and isolated waters of the State of North Carolina. This
Permit may be rescinded when deemed appropriate by the Director of DWQ after appropriate
public notice.
Public Notice requirement — A separate Public Notice and Individual Permit will be required for all
projects which propose to impact greater than 300 linear feet of isolated streams, greater than
one (1) acre of isolated and other non -404 wetlands, or greater than one -third (1/3) acre of other
isolated waters in accordance with 15A NCAC 02H .1303. For impacts equal to or below these
thresholds, this General Permit is applicable without additional Public Notice.
The State of North Carolina certifies that the specified category of activity will not violate
applicable portions of Sections 301, 302, 303, 306 and 307 of the Public Laws 92 -500 and 95 -217
if conducted in accordance with the conditions hereinafter set forth.
Activities meeting any one (1) of the following thresholds or circumstances require written
approval from the Division of Water Quality (the "Division "):
a) Any impacts to isolated streams involving excavation or dredging; or
b) Any stream relocation; or
c) Any impacts to isolated streams and /or buffers in the Neuse, Tar - Pamlico, or Catawba
River Basins or in the Randleman, Jordan or Goose Creek Watersheds (or any other
basin or watershed with Riparian Area Protection Rules [Buffer Rules] in effect at the
time of application) unless the activities are listed as "EXEMPT" from these rules or a
Buffer Authorization Certificate is issued through N.C. Division of Coastal Management
(DCM) delegation for "ALLOWABLE" activities; or
d) Total isolated stream impacts within the project boundaries equal to or greater than 150
linear feet of intermittent and /or perennial stream, including temporary and /or
permanent impacts; or
e) Temporary or permanent impacts equal to or greater than one -tenth (1/10) acre of
isolated and other non -404 wetlands or isolated lakes and ponds; or
f) Any impacts to isolated and other non -404 wetlands adjacent to waters designated as:
ORW, SA, WS -I, WS -II, or Trout, or isolated and other non -404 wetlands contiguous to
waters designated as a North Carolina or National Wild and Scenic River; or.
g) Any impacts to isolated and other non -404 wetlands classified in accordance with 15A
NCAC 02B .0101(e)(7) as Unique Wetlands (UWL); or
Any impact associated with a high density project (as defined in Item (A)(iv) of the 401
Stormwater Requirements) that is not subject to either a state stormwater program
(such as, but not limited to, Coastal Counties, HQW, ORW or state - implemented Phase
II NPDES) or a certified community's stormwater program; or
h) Any impact associated with a Notice of Violation or an enforcement action for
violation(s) of DWQ Wetland Rules (15A NCAC 02H .0500), Isolated Wetland Rules
(15A NCAC 02H .1300), DWQ Surface Water or Wetland Standards, or Riparian Buffer
Rules (15A NCAC 02B.0200).
In accordance with North Carolina General Statute 143- 215.3D(e), any application for an Isolated
Wetland General or Individual Permit must include the appropriate fee. If a project also requires a
CAMA Permit, one payment to both agencies shall be submitted. This payment shall be the
higher of the two fees.
Activities included in this General Permit that do not meet one of the thresholds listed
above do not require written approval from the Division of Water Quality as long as they
comply with the Conditions of Permit listed below. If any of these Conditions cannot be
met, then written approval from the Division is required.
Isolated Wetlands General Permit (IWGP100000) 2

State General Permit No. IWGPI00000
Conditions of Permit:
1. Totaling and Reporting of Impacts
Isolated Streams - impacts to isolated streams as determined by the Division of Water
Quality shall be measured as the length of the centerline of the normal flow channel.
Permanent and /or temporary stream impacts shall be enumerated on the entire project for all
impacts regardless of which 404 Nationwide Permits are used (if any). Stream relocations
and streambed and /or bank hardening are considered to be permanent stream impacts. Any
activity that results in a loss of use of stream functions including but not limited to filling,
relocating, flooding, excavation, dredging and complete shading shall be considered stream
impacts.
Impacts to streams shall include streams enclosed by bottomless culverts, bottomless arches
or other spanning structures unless the entire structure (including construction impacts)
spans the entire bed and both banks of the stream, is only used for a road, driveway or path
crossing, and is not mitered to follow the stream pattern. Impacts for dam footprints and
flooding will count toward the threshold for stream impacts, but flooding upstream of the dam
will not count towards mitigation requirements as long as no filling, excavation, relocation or
other modification of the existing stream dimension, pattern or profile occurs. Any filling,
excavation, relocation or other modification of the existing stream (other than flooding) must
re- establish the same dimensions, patterns and profiles of the existing channel (or those of a
stable reference reach if the existing channel is unstable)
Isolated Lakes and Ponds — Impacts to isolated waters other than streams and wetlands as
determined by the Division of Water Quality shall be measured as area. Permanent and /or
temporary water impacts shall be enumerated on the entire project for all impacts proposed
regardless of which 404 Nationwide Permits are used (if any). Any activity that results in a
loss of use of aquatic functions including but not limited to filling, draining, and dredging shall
be considered waters impacts.
Isolated and Other Non -404 Wetlands - Impacts to isolated and other non -404 wetlands as
determined by the Division of Water Quality shall be measured as area. Permanent and /or
temporary wetland impacts shall be enumerated on the entire project for all impacts. Any
activity that results in a loss of use of wetland functions including but not limited to filling,
excavating, draining, and flooding shall be considered wetland impacts. Impacts to wetlands
shall include activities that change the hydrology of a wetland.
2. No Impacts Beyond those Authorized in the Written Approval or Beyond the Threshold of Use
of this Permit
No waste, spoil, solids, or fill of any kind shall occur in isolated and other non -404 wetlands,
isolated waters, or isolated riparian areas beyond the footprint of the impacts depicted in the
Pre - Construction Notification, as authorized in the written approval from the Division, or
beyond the thresholds established for use of this Permit without written authorization,
including incidental impacts. All construction activities, including the design, installation,
operation, and maintenance of sediment and erosion control Best Management Practices,
shall be performed so that no violations of state water quality standards, statutes, or rules
occur. Approved plans and specifications for this project are incorporated by reference and
are enforceable parts of this permit.
Isolated Wetlands General Permit (IWGP100000)

State General Permit No. lWGP100000
3. Standard Erosion and Sediment Control Practices
Erosion and sediment control practices must be in full compliance with all specifications
governing the proper design, installation and operation and maintenance of such Best
Management Practices and if applicable, comply with the specific conditions and
requirements of the NPDES Construction Stormwater Permit issued to the site:
a. Design, installation, operation, and maintenance of the sediment and erosion control
measures must be such that they equal or exceed the requirements specified in the most
recent version of the North Carolina Sediment and Erosion Control Manual. The devices
shall be maintained on all construction sites, borrow sites, and waste pile (spoil) projects,
including contractor -owned or leased borrow pits associated with the project.
b. For borrow pit sites, the erosion and sediment control measures must be designed,
installed, operated, and maintained in accordance with the most recent version of the
North Carolina Surface Mining Manual.
c. Reclamation measures and implementation must comply with the reclamation in
accordance with the requirements of the Sedimentation Pollution Control Act and the
Mining Act of 1971.
d. Sufficient materials required for stabilization and /or repair of erosion control measures
and stormwater routing and treatment shall be on site at all times.
e. If the project occurs in waters or watersheds classified as Primary Nursery Areas (PNAs),
SA, WS -I, WS -II, High Quality (HQW), or Outstanding Resource (ORW) waters, then the
sedimentation and erosion control designs must comply with the requirements set forth
in 15A NCAC 04B .0124, Design Standards in Sensitive Watersheds.
4. No Sediment and Erosion Control Measures in Wetlands or Waters
Sediment and erosion control measures shall not be placed in wetlands or waters.
Exceptions to this condition require application submittal to and written approval by the
Division. If placement of sediment and erosion control devices in wetlands and waters is
unavoidable, then design and placement of temporary erosion control measures shall not be
conducted in a manner that may result in dis- equilibrium of wetlands, stream beds, or banks,
adjacent to or upstream and downstream of the above structures. All sediment and erosion
control devices shall be removed and the natural grade restored within two (2) months of the
date that the Division of Land Resources (DLR) or locally delegated program has released
the specific area within the project.
5. Construction Stormwater Permit NCGO10000
An NPDES Construction Stormwater Permit is required for construction projects that disturb
one (1) or more acres of land. This Permit allows stormwater to be discharged during land
disturbing construction activities as stipulated in the conditions of the permit. If your project
is covered by this permit, full compliance with permit conditions including the erosion &
sedimentation control plan, inspections and maintenance, self- monitoring, record keeping
and reporting requirements is required. A copy of the general permit (NCG010000),
inspection log sheets, and other information may be found at
ham: / /portal.ncdenr.org /web /wg /ws /su /npdessw#tab -w .
The North Carolina Department of Transportation (NCDOT) shall be required to be in full
compliance with the conditions related to construction activities within the most recent version
of their individual NPDES (NCS000250) stormwater permit.
Isolated Wetlands General Permit (IWGP100000) 4

State General Permit No. IWGP100000
6. Construction Moratoriums and Coordination
If activities must occur during periods of high biological activity (i.e. sea turtle nesting, fish
spawning, or bird nesting), then biological monitoring may be required at the request of other
s ;Mte cr federal agencies and coordinated with these activities
All moratoriums on construction activities established by the NC Wildlife Resources
Commission (WRC), US Fish and Wildlife Service (USFWS), NC Division of Marine Fisheries
(DMF), or National Marine Fisheries Service (NMFS) to lessen impacts on trout, anadromous
fish, larval /post - larval fishes and crustaceans, or other aquatic species of concern shall be
implemented. Exceptions to this condition require written approval by the resource agency
responsible for the given moratorium.
Work within the twenty -five (25) designated trout counties or identified state or federal
endangered or threatened species habitat shall be coordinated with the appropriate WRC,
USFWS, NMFS, and /or DMF personnel.
7. Work in the Dry
All work in or adjacent to stream waters shall be conducted so that the flowing stream does
not come in contact with the disturbed area. Approved best management practices from the
most current version of the NC Sediment and Erosion Control Manual, or the NC DOT
Construction and Maintenance Activities Manual, such as sandbags, rock berms, cofferdams,
and other diversion structures shall be used to minimize excavation in flowing water.
Exceptions to this condition require application submittal to and written approval by the
Division.
8. Riparian Area Protection (Buffer) Rules
Activities located in the protected riparian areas (whether jurisdictional wetlands or not),
within the Neuse, Tar - Pamlico, or Catawba River Basins or in the Randleman, Jordan, or
Goose Creek Watersheds (or any other basin or watershed with buffer rules) shall be limited
to "uses" identified within and constructed in accordance with 15A NCAC 02B .0233, .0259,
.0243, .0250, .0267 and .0605, and shall be located, designed, constructed, and maintained
to have minimal disturbance to protect water quality to the maximum extent practicable
through the use of best management practices. All buffer rule requirements, including diffuse
flow requirements, must be met.
9. If concrete is used during the construction, then all necessary measures shall be taken to
prevent direct contact between uncured or curing concrete and waters of the state. Water
that inadvertently contacts uncured concrete shall not be discharged to waters of the state
due to the potential for elevated pH and possible aquatic life/ fish kills.
10. Compensatory Mitigation
In accordance with 15A NCAC 02H .1305 (c) & (d), compensatory mitigation may be required
for losses of equal to or greater than 150 linear feet of streams (intermittent and perennial)
and /or equal to or greater than one (1) acre of total wetland impacts, including all impacts to
404 and non -404 wetlands (see examples in "Attachment B" at the end of this Permit). If
collective wetland impacts, including 404 and non -404 wetlands, are equal to or greater than
one (1) acre, compensatory mitigation is required. If the project requires a mitigation plan, but
is otherwise below the written approval thresholds described above, the applicant may
provide a courtesy copy of the Pre - Construction Notification along with a copy of the
mitigation plan. For linear, public transportation projects, impacts equal to or exceeding 150
linear feet per stream shall require mitigation.
Isolated Wetlands General Permit (IWGP100000)

State General Permit No. IWGP100000
Buffer mitigation may be required for any project with Buffer Rules in effect at the time of
application for buffer impacts resulting from activities classified as "Allowable with Mitigation"
within the "Table of Uses" section of the Buffer Rules or require a variance under the Buffer
Rules.
A determination of buffer, wetland and stream mitigation requirements shall be made for any
General Permit. Design and monitoring protocols shall follow the US Army Corps of
Engineers Wilmington District Stream Mitigation Guidelines (April 2003), or its subsequent
updates. Compensatory mitigation plans shall be submitted for written Division approval as
required in those protocols. The mitigation plan must be implemented and /or constructed
before any impacts occur on site. Alternatively, the Division will accept payment into an in-
lieu fee program or a mitigation bank. In these cases, proof of payment shall be provided to
the Division before any impacts occur on site.
11. Relocated stream designs should include the same dimensions, patterns, and profiles as the
existing channel (or a stable reference reach if the existing channel is unstable), to the
maximum extent practical. The new channel should be constructed in the dry and water shall
not be turned into the new channel until the banks are stabilized. Vegetation used for bank
stabilization shall be limited to native woody species, and should include establishment of a
30 -foot wide wooded and an adjacent 20 -foot wide vegetated buffer on both sides of the
relocated channel to the maximum extent practical. A transitional phase incorporating
appropriate erosion control matting materials and seedling establishment is allowable,
however matting that incorporates plastic mesh and /or plastic twine shall not be used in
wetlands, riparian buffers or floodplains as recommended by the North Carolina Sediment
and Erosion Control Manual. Rip -rap, A- Jacks, concrete, gabions or other hard structures
may be allowed if it is necessary to maintain the physical integrity of the stream; however, the
applicant must provide written justification and any calculations used to determine the extent
of rip -rap coverage. Please note that if the stream relocation is conducted as a stream
restoration as defined in the US Army Corps of Engineers Wilmington District, April 2003
Stream Mitigation Guidelines (or its subsequent updates), the restored length may be used
as compensatory mitigation for the impacts resulting from the relocation.
12. Stormwater Management Plan Requirements
All applications shall address stormwater management throughout the entire project area per
the 401 Stormwater Requirements, referenced herein as "Attachment A" at the end of this
Permit.
13. Bridge deck drains shall not discharge directly into the stream. Stormwater shall be directed
across the bridge and pre- treated through site- appropriate means (grassed swales, pre-
formed scour holes, vegetated buffers, etc.) before entering the stream. Please refer to the
most current version of Stormwater Best Management Practices. Exceptions to this condition
require written approval by the Division.
14. Placement of Culverts and Other Structures in Waters and Wetlands
Culverts required for this project shall be designed and installed in such a manner that the
original stream profiles are not altered and allow for aquatic life movement during low flows.
Existing stream dimensions (including the cross section dimensions, pattern, and longitudinal
profile) must be maintained above and below locations of each culvert.
Placement of culverts and other structures in waters and streams must be below the
elevation of the streambed by one foot for all culverts with a diameter greater than 48 inches,
and 20 percent of the culvert diameter for culverts having a diameter less than or equal to 48
inches, to allow low flow passage of water and aquatic life.
Isolated Wetlands General Permit (IWGP100000)

State General Permit No. IWGP100000
When topographic constraints indicate culvert slopes of greater than 5 %, culvert burial is not
required, provided that all alternative options for flattening the slope have been investigated
and aquatic life movement/ connectivity has been provided when possible (rock ladders,
crossvanes, etc). Notification to the Division including supporting documentation to include a
location map of the culvert, culvert profile drawings, and slope calculations shall be provided
to the Division 60 days prior to the installation of the culvert.
When bedrock is present in culvert locations, culvert burial is not required provided that there
is sufficient documentation of the presence of bedrock. Notification to the Division including
supporting documentation such as, but not limited to, a location map of the culvert,
geotechnical reports, photographs, etc shall be provided to the Division a minimum of 60
days prior to the installation of the culvert. If bedrock is discovered during construction, then
the Division shall be notified by phone or email within 24 hours of discovery.
If other site- specific topographic constraints preclude the ability to bury the culverts as
described above and /or it can be demonstrated that burying the culvert would result in
destabilization of the channel, then exceptions to this condition require application submittal
to, and written approval by, the Division of Water Quality, regardless of the total impacts to
streams or wetlands from the project.
Installation of culverts in wetlands must ensure continuity of water movement and be
designed to adequately accommodate high water or flood conditions. Additionally, when
roadways, causeways, or other fill projects are constructed across FEMA- designated
floodways or wetlands, openings such as culverts or bridges must be provided to maintain
the natural hydrology of the system as well as prevent constriction of the floodway that may
result in destabilization of streams or wetlands.
The establishment of native, woody vegetation and other soft stream bank stabilization
techniques must be used where practicable instead of riprap or other bank hardening
methods.
15. If this General Permit is used to access building sites, then all lots owned by the applicant
must be buildable without additional impacts to streams or wetlands. The applicant is
required to provide evidence that the lots are buildable without requiring additional impacts to
wetlands, waters, or buffers if required to do so in writing by the Division. For road
construction purposes, this Permit shall only be utilized from natural high ground to natural
high ground.
16. Deed notifications or similar mechanisms shall be placed on all retained jurisdictional
wetlands, waters, and protective buffers within the project boundaries in order to assure
compliance for future wetland, water, and buffer impact. These mechanisms shall be put in
place at the time of recording of the property or of individual lots whichever is appropriate. A
sample deed notification can be downloaded from the Division's web site at
http : //portal.ncdenr.org/ web /wg /swp /ws /401 /certsandpermits /apply /forms. The text of the
sample deed notification may be modified as appropriate to suit to a specific project.
Documentation of deed notifications shall be provided to the Division upon request.
17. If an environmental document is required under the National or State Environmental Policy
Act (NEPA or SEPA), then this General Certification is not valid until a Finding of No
Significant Impact (FONSI) or Record of Decision (ROD) is issued by the State
Clearinghouse.
18. In the twenty (20) coastal counties, the appropriate DWQ Regional Office must be contacted
to determine if Coastal Stormwater Regulations will be required.
Isolated Wetlands General Permit (IWGP100000)

State General Permit No. IWGP100000
19. This General Certification does not relieve the applicant of the responsibility to obtain all other
required Federal, State, or Local approvals.
20. The applicant/permittee and their authorized agents shall conduct all activities in a manner
consistent with State water quality standards (including any requirements resulting from
compliance with §303(d) of the Clean Water Act), and any other appropriate requirements of
State and Federal Law. If the Division determines that such standards or laws are not being
met, including failure to sustain a designated or achieved use, or that State or Federal law is
being violated, or that further conditions are necessary to assure compliance, then the
Division may reevaluate and modify this General Water Quality Certification.
21. When written authorization is required for use of this certification, upon completion of all
permitted impacts included within the approval and any subsequent modifications, the
applicant shall be required to return the certificate of completion attached to the approval.
One copy of the certificate shall be sent to the DWQ Central Office in Raleigh at 1650 Mail
Service Center, Raleigh, NC, 27699 -1650.
22. Additional site- specific conditions, including monitoring and /or modeling requirements, may
be added to the written approval letter for projects proposed under this Water Quality
Certification in order to ensure compliance with all applicable water quality and effluent
standards.
23. This certification grants permission to the director, an authorized representative of the
Director, or DENR staff, upon the presentation of proper credentials, to enter the property
during normal business hours.
This General Permit shall expire five (5) years from the date of issuance of the written letter from
the Division. The conditions in effect on the date of issuance of Certification for a specific project
shall remain in effect for the life of the project, regardless of the expiration date of this Permit.
Non - compliance with or violation of the conditions herein set forth by a specific project may result
in revocation of this General Certification for the project and may also result in criminal and /or civil
penalties.
The Director of the North Carolina Division of Water Quality may require submission of a formal
application for Individual Permit for any project in this category of activity if it is determined that
the project is likely to have a significant adverse effect upon water quality, including state or
federally listed endangered or threatened aquatic species, or degrade the waters so that existing
uses of the wetland or downstream waters are precluded.
Public hearings may be held for specific applications or group of applications prior to a
Certification decision if deemed in the public's best interest by the Director of the North Carolina
Division of Water Quality.
History Note: This Isolated Wetlands General Permit replaces the Isolated Wetlands General
Permit (IWGP100000) issued on October 31, 2008 and October 3, 2003. This General Permit is
rescinded five (5) years from the effective date or unless otherwise rescinded or until deemed
appropriate by the Director of the Division of Water Quality.
Isolated Wetlands General Permit (IWGP100000) 8

State General Permit No. IV1iGP100000
Attachment A: 401 Stormwater Requirements
The requirements listed below shall be implemented in order to comply with Condition 12 of this
General Permit. Por the North Carolina Department of Transportation, compliance with NCDOT's
Individual NPDES permit NCS000250 shall serve to satisfy the 401 and Isolated Wetland
Stormwater Requirements.'
A. Design and Implementation Requirements. All projects, regardless of project area,
amount of built -upon area or amount of jurisdictional impact, shall meet the following
stormwater design requirements:
Non - Erosive Discharge to Streams and Wetlands. Stormwater conveyances that
discharge to streams and wetlands must discharge at a non - erosive velocity prior to
entering the stream or wetland during the peak flow from the ten -year storm.
Vegetated Setbacks. A 30 -foot wide vegetated setback must be maintained adjacent to
streams, rivers and tidal waters in areas that are not subject to a state Riparian Area
Protection Rule or other more stringent vegetated setback requirements. The width of
the setback shall be measured horizontally from the normal pool elevation of impounded
structures, the top -of -bank of streams and rivers, and the mean high waterline of tidal
waters, perpendicular to shoreline. Vegetated setback and filters required by state rules
or local governments may be met concurrently with this requirement and may contain
coastal, isolated or 404 jurisdictional wetlands. Non - jurisdictional portions of the
vegetated setback may be cleared and graded, but must be planted with and maintained
in grass or other vegetative or plant material . 3
iii. Construction and Operation. The stormwater management plan must be constructed
and operational before any permanent building or other structure is occupied or utilized at
the site. The stormwater management plan, including drainage patterns, must be
maintained in perpetuity.4
iv. Coordination with Other Stormwater Programs. Projects that are subject to another
Division of Water Quality (DWQ) stormwater program, including (but not limited to) the 20
Coastal Counties, HQW, ORW or state - implemented Phase II NPDES, or a Certified
Community's stormwater management program, must be constructed and maintained in
compliance with the approved stormwater management plan . 5
Stormwater Design Requirements for Projects Not Covered Under Item (iv).
Projects that are not subject to another DWQ stormwater program or a Certified
Community's stormwater program shall meet all of the following requirements:
a. Low Density. A site is low density if all the following requirements are met:
The development has a built upon area of twenty -four percent (24 %) or less,
considering both current and future development. When determining the amount
of built upon area, coastal wetlands shall be included; however, ponds, lakes and
rivers as specified in North Carolina's Schedule of Classifications shall be
excluded. If a portion of project has a density greater than 24 %, the higher
density area must be located in an upland area and away from surface waters
and drainageways to the maximum extent practicable.s
2. All stormwater runoff from the built upon areas is transported primarily via
vegetated conveyances designed in accordance with the most recent version of
the NC DWQ Stormwater Best Management Practices Manual. Alternative
designs may be approved if the applicant can show that the design provides
Isolated Wetlands General Permit (IWGP100000) 9

State General Permit No. IWGPl 00000
equal or better water quality protection than the practices specified in the manual.
The project must not include a stormwater collection system (such as piped
conveyances) as defined in 15A NCAC 02B .0202(60).7
b. High Density. Projects that do not meet the Low Density requirements shall meet
the following requirements:
1. Stormwater runoff from the entire site must be treated by structural stormwater
controls (BMPs) that are designed to remove eighty -five percent (85 %) of the
average annual amount of Total Suspended Solids (TSS). Stormwater runoff
that drains directly to Nutrient Sensitive Waters (NSW) must also be treated to
remove thirty percent (30 %) of Total Nitrogen (TN) and Total Phosphorus (TP).8
2. All BMPs must be designed in accordance with the version of the NC DWQ
Stormwater Best Management Practices Manual that is in place on the date of
stormwater management plan submittal. Alternative designs may be approved if
the applicant can show that the design provides equal or better water quality
protection than the practices specified in the manual.9
3. DWQ may add specific stormwater management requirements on a case -by-
case basis in order to ensure that a proposed activity will not violate water quality
standards.10
4. DWQ may approve Low Impact Developments (LIDs) that meet the guidance set
forth in the Low Impact Development: A Guidebook for North Carolina. 11
5. Proposed new development undertaken by a local government solely as a public
road project shall follow the requirements of the NC DOT BMP Toolbox rather
than Items (1) -(4) above. 12
B. Submittal Requirements. The submittal requirements listed below apply only to projects
that require written authorization as indicated in the applicable General Certification as well
as projects that require an Isolated Wetlands Permit. Any required documentation shall
be sent to the Wetlands, Buffers and Stormwater Compliance and Permitting Unit at
1650 Mail Service Center, Raleigh, NC 27699 -1650.
Projects that are Subject to Another DWQ Stormwater Program: If the project is
subject to another DWQ stormwater program, such as the 20 Coastal Counties, HQW,
ORW or state - implemented Phase II NPDES, then the applicant shall submit a copy of
the stormwater approval letter before any impacts occur on site. 13
Projects that are Subject to a Certified Community's Stormwater Program. If the
project is subject to a certified local government's stormwater program, then the applicant
shall submit one set of approved stormwater management plan details and calculations
with documentation of the local government's approval before any impacts occur on site.5
iii. Projects Not Covered Under Items (i) or (ii). If the project is not subject to another
DWQ Stormwater Program or a Certified Community's stormwater program, then it shall
be reviewed and approved by the DWQ through the Water Quality Certification
authorization process.
a. Low Density. For low density projects, the applicant shall submit two copies of the
DWQ Low Density Supplement Form with all required items. 13
Isolated Wetlands General Permit (IWGP100000) 10

State General Permit No. IWGP100000
b. High Density. For high density projects, the applicant shall submit two copies of a
DWQ BMP Supplement Form and all required items at the specified scales for each
BMP that is proposed. 13
iv. Phasing. Stormwater management plans may be phased on a case- by-case basis, with
the submittal of a final stormwater management plan per Items (i) -(iii) above required for
the current phase and a conceptual stormwater management plan for the future phase(s).
The stormwater management plan for each future phase must be approved by the
appropriate entity before construction of that phase is commenced. The approved
stormwater management plan for each future phase must be constructed and operational
before any permanent building or other structure associated with that phase is
occupied. 4
v. Stormwater Management Plan Modifications. The stormwater management plan may
not be modified without prior written authorization from the entity that approved the plan.
If the project is within a Certified Community, then the applicant shall submit one set of
approved stormwater management plan details and calculations with documentation of
the local government's approval for record - keeping purposes. If the project is subject to
DWQ review, then the applicant shall submit two copies of the appropriate Supplement
Forms per Item (iii) above for any BMPs that have been modified for DWQ's review and
approval.15
1 The stormwater requirement for 401 applications is codified in 15A NCAC 02H .0506(b)(5) and
(c)(5).
2 Non erosive discharge rates are required in SL 2008 - 211 §2(b)(1). The 10 -year design storm
standard is codified in 15A NCAC 02H .1008(f)(2) and .1008(g)(1).
3 30 -foot vegetated setbacks are required in SL 2006 - 246 §9(d), SL 2008 - 211 §2(b), 15A NCAC
02H .1006(2)(c) and .1007(1)(a).
4 Construction and maintenance of the stormwater plan is necessary to satisfy 15A NCAC 02H
.0506(b)(5).
5 Conveys application procedure to streamline the permitting process and reduce any unnecessary
duplication in the review of stormwater management plans.
6 Low density built upon area thresholds are set in SL 2006 - 246 §9(c) and SL 2008 - 211 §2(b).
The requirement for low density development to use vegetated conveyances is codified in SL
2006 - 246 §9(c), SL 2008 - 211 §2(b), 15A NCAC 02H .1006(2)(b) and .1007(1)(a). The Stormwater
BMP Manual is also referenced in 15A NCAC 02B .0265(3)(a) and .0277(4)(e).
8 85% TSS removal is required in SL 2006 - 246 §9(d), SL 2008 - 211 §2(b), 15A NCAC 02H
.1006(2)(c), 15A NCAC 02H .1007(1)(a). The 30% TN and TP removal requirements for NSW
waters are set forth in 15A NCAC 02B .0232, 15A NCAC 02B .0257(a)(1), 15A NCAC 02B
.0265(3)(a) and 15A NCAC 02B.0277(4).
9 The Stormwater BMP Manual is also referenced in 15A NCAC 02B .0265(3)(a) and .0277(4)(e).
10 The requirement for DWQ to ensure that water quality standards are protected before issuing a
401 certification is codified in 15A NCAC 02H .0506.
11 The LID Toolbox is also referenced in 15A NCAC 02B .0277(4)(g).
12 The term "public road project" is defined in15A NCAC 02B .0265(3)(x).
13 Conveys application procedure to streamline the permitting process.
14 phased development is addressed as a "common plan of development" in 15A NCAC 02H
.1003(3).
15 Procedures for modifying stormwater plans are set forth in 15A NCAC 02H .1011.
Isolated Wetlands General Permit (IWGP100000) 11

State General Permit No. IWGP100000
Attachment B
Example 1: Wetland Impacts and Compensatory Mitigation
In this example, the applicant proposes to fill 0.95 acre of 404 wetlands and 0.40 acre of
Isolated wetlands. Since the Isolated impact is over the IWGP10000 threshold, written
concurrence is required for the Isolated fill, in addition to the 404 fill. The applicant should
note both impacts on the PCN and seek the Isolated General Permit AND the appropriate
General Certification. Compensatory mitigation is required since total wetland impacts
exceed one (1) acre.
Isolated Wetlands General Permit (IWGP100000) 12

State General Permit No. IWGP100000
Example 2: Wetland Impacts and Compensatory Mitigation
In this example, the applicant proposes to fill 0.95 acre of 404 wetlands and 0.08 acre of
Isolated wetlands. Since the Isolated impact is under the IWGP100000 threshold, written
concurrence is not required for the Isolated fill. However, this impact should be noted on
the PCN submitted for written concurrence on the 404 wetland fill. Compensatory
mitigation is required since total wetland impacts exceed one (1) acre.
Isolated Wetlands General Permit (IWGP100000) 13